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kernel_samsung_a34x-permissive/drivers/iio/adc/stm32-adc.c

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Import A346BXXU1AWB9 kernel source Android 13
2024-04-28 06:49:01 -07:00
// SPDX-License-Identifier: GPL-2.0
/*
* This file is part of STM32 ADC driver
*
* Copyright (C) 2016, STMicroelectronics - All Rights Reserved
* Author: Fabrice Gasnier <fabrice.gasnier@st.com>.
*/
#include <linux/clk.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/iio/iio.h>
#include <linux/iio/buffer.h>
#include <linux/iio/timer/stm32-lptim-trigger.h>
#include <linux/iio/timer/stm32-timer-trigger.h>
#include <linux/iio/trigger.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include "stm32-adc-core.h"
/* Number of linear calibration shadow registers / LINCALRDYW control bits */
#define STM32H7_LINCALFACT_NUM 6
/* BOOST bit must be set on STM32H7 when ADC clock is above 20MHz */
#define STM32H7_BOOST_CLKRATE 20000000UL
#define STM32_ADC_CH_MAX 20 /* max number of channels */
#define STM32_ADC_CH_SZ 10 /* max channel name size */
#define STM32_ADC_MAX_SQ 16 /* SQ1..SQ16 */
#define STM32_ADC_MAX_SMP 7 /* SMPx range is [0..7] */
#define STM32_ADC_TIMEOUT_US 100000
#define STM32_ADC_TIMEOUT (msecs_to_jiffies(STM32_ADC_TIMEOUT_US / 1000))
#define STM32_DMA_BUFFER_SIZE PAGE_SIZE
/* External trigger enable */
enum stm32_adc_exten {
STM32_EXTEN_SWTRIG,
STM32_EXTEN_HWTRIG_RISING_EDGE,
STM32_EXTEN_HWTRIG_FALLING_EDGE,
STM32_EXTEN_HWTRIG_BOTH_EDGES,
};
/* extsel - trigger mux selection value */
enum stm32_adc_extsel {
STM32_EXT0,
STM32_EXT1,
STM32_EXT2,
STM32_EXT3,
STM32_EXT4,
STM32_EXT5,
STM32_EXT6,
STM32_EXT7,
STM32_EXT8,
STM32_EXT9,
STM32_EXT10,
STM32_EXT11,
STM32_EXT12,
STM32_EXT13,
STM32_EXT14,
STM32_EXT15,
STM32_EXT16,
STM32_EXT17,
STM32_EXT18,
STM32_EXT19,
STM32_EXT20,
};
/**
* struct stm32_adc_trig_info - ADC trigger info
* @name: name of the trigger, corresponding to its source
* @extsel: trigger selection
*/
struct stm32_adc_trig_info {
const char *name;
enum stm32_adc_extsel extsel;
};
/**
* struct stm32_adc_calib - optional adc calibration data
* @calfact_s: Calibration offset for single ended channels
* @calfact_d: Calibration offset in differential
* @lincalfact: Linearity calibration factor
*/
struct stm32_adc_calib {
u32 calfact_s;
u32 calfact_d;
u32 lincalfact[STM32H7_LINCALFACT_NUM];
};
/**
* stm32_adc_regs - stm32 ADC misc registers & bitfield desc
* @reg: register offset
* @mask: bitfield mask
* @shift: left shift
*/
struct stm32_adc_regs {
int reg;
int mask;
int shift;
};
/**
* stm32_adc_regspec - stm32 registers definition, compatible dependent data
* @dr: data register offset
* @ier_eoc: interrupt enable register & eocie bitfield
* @isr_eoc: interrupt status register & eoc bitfield
* @sqr: reference to sequence registers array
* @exten: trigger control register & bitfield
* @extsel: trigger selection register & bitfield
* @res: resolution selection register & bitfield
* @smpr: smpr1 & smpr2 registers offset array
* @smp_bits: smpr1 & smpr2 index and bitfields
*/
struct stm32_adc_regspec {
const u32 dr;
const struct stm32_adc_regs ier_eoc;
const struct stm32_adc_regs isr_eoc;
const struct stm32_adc_regs *sqr;
const struct stm32_adc_regs exten;
const struct stm32_adc_regs extsel;
const struct stm32_adc_regs res;
const u32 smpr[2];
const struct stm32_adc_regs *smp_bits;
};
struct stm32_adc;
/**
* stm32_adc_cfg - stm32 compatible configuration data
* @regs: registers descriptions
* @adc_info: per instance input channels definitions
* @trigs: external trigger sources
* @clk_required: clock is required
* @has_vregready: vregready status flag presence
* @selfcalib: optional routine for self-calibration
* @prepare: optional prepare routine (power-up, enable)
* @start_conv: routine to start conversions
* @stop_conv: routine to stop conversions
* @unprepare: optional unprepare routine (disable, power-down)
* @smp_cycles: programmable sampling time (ADC clock cycles)
*/
struct stm32_adc_cfg {
const struct stm32_adc_regspec *regs;
const struct stm32_adc_info *adc_info;
struct stm32_adc_trig_info *trigs;
bool clk_required;
bool has_vregready;
int (*selfcalib)(struct stm32_adc *);
int (*prepare)(struct stm32_adc *);
void (*start_conv)(struct stm32_adc *, bool dma);
void (*stop_conv)(struct stm32_adc *);
void (*unprepare)(struct stm32_adc *);
const unsigned int *smp_cycles;
};
/**
* struct stm32_adc - private data of each ADC IIO instance
* @common: reference to ADC block common data
* @offset: ADC instance register offset in ADC block
* @cfg: compatible configuration data
* @completion: end of single conversion completion
* @buffer: data buffer
* @clk: clock for this adc instance
* @irq: interrupt for this adc instance
* @lock: spinlock
* @bufi: data buffer index
* @num_conv: expected number of scan conversions
* @res: data resolution (e.g. RES bitfield value)
* @trigger_polarity: external trigger polarity (e.g. exten)
* @dma_chan: dma channel
* @rx_buf: dma rx buffer cpu address
* @rx_dma_buf: dma rx buffer bus address
* @rx_buf_sz: dma rx buffer size
* @difsel bitmask to set single-ended/differential channel
* @pcsel bitmask to preselect channels on some devices
* @smpr_val: sampling time settings (e.g. smpr1 / smpr2)
* @cal: optional calibration data on some devices
* @chan_name: channel name array
*/
struct stm32_adc {
struct stm32_adc_common *common;
u32 offset;
const struct stm32_adc_cfg *cfg;
struct completion completion;
u16 buffer[STM32_ADC_MAX_SQ];
struct clk *clk;
int irq;
spinlock_t lock; /* interrupt lock */
unsigned int bufi;
unsigned int num_conv;
u32 res;
u32 trigger_polarity;
struct dma_chan *dma_chan;
u8 *rx_buf;
dma_addr_t rx_dma_buf;
unsigned int rx_buf_sz;
u32 difsel;
u32 pcsel;
u32 smpr_val[2];
struct stm32_adc_calib cal;
char chan_name[STM32_ADC_CH_MAX][STM32_ADC_CH_SZ];
};
struct stm32_adc_diff_channel {
u32 vinp;
u32 vinn;
};
/**
* struct stm32_adc_info - stm32 ADC, per instance config data
* @max_channels: Number of channels
* @resolutions: available resolutions
* @num_res: number of available resolutions
*/
struct stm32_adc_info {
int max_channels;
const unsigned int *resolutions;
const unsigned int num_res;
};
static const unsigned int stm32f4_adc_resolutions[] = {
/* sorted values so the index matches RES[1:0] in STM32F4_ADC_CR1 */
12, 10, 8, 6,
};
/* stm32f4 can have up to 16 channels */
static const struct stm32_adc_info stm32f4_adc_info = {
.max_channels = 16,
.resolutions = stm32f4_adc_resolutions,
.num_res = ARRAY_SIZE(stm32f4_adc_resolutions),
};
static const unsigned int stm32h7_adc_resolutions[] = {
/* sorted values so the index matches RES[2:0] in STM32H7_ADC_CFGR */
16, 14, 12, 10, 8,
};
/* stm32h7 can have up to 20 channels */
static const struct stm32_adc_info stm32h7_adc_info = {
.max_channels = STM32_ADC_CH_MAX,
.resolutions = stm32h7_adc_resolutions,
.num_res = ARRAY_SIZE(stm32h7_adc_resolutions),
};
/**
* stm32f4_sq - describe regular sequence registers
* - L: sequence len (register & bit field)
* - SQ1..SQ16: sequence entries (register & bit field)
*/
static const struct stm32_adc_regs stm32f4_sq[STM32_ADC_MAX_SQ + 1] = {
/* L: len bit field description to be kept as first element */
{ STM32F4_ADC_SQR1, GENMASK(23, 20), 20 },
/* SQ1..SQ16 registers & bit fields (reg, mask, shift) */
{ STM32F4_ADC_SQR3, GENMASK(4, 0), 0 },
{ STM32F4_ADC_SQR3, GENMASK(9, 5), 5 },
{ STM32F4_ADC_SQR3, GENMASK(14, 10), 10 },
{ STM32F4_ADC_SQR3, GENMASK(19, 15), 15 },
{ STM32F4_ADC_SQR3, GENMASK(24, 20), 20 },
{ STM32F4_ADC_SQR3, GENMASK(29, 25), 25 },
{ STM32F4_ADC_SQR2, GENMASK(4, 0), 0 },
{ STM32F4_ADC_SQR2, GENMASK(9, 5), 5 },
{ STM32F4_ADC_SQR2, GENMASK(14, 10), 10 },
{ STM32F4_ADC_SQR2, GENMASK(19, 15), 15 },
{ STM32F4_ADC_SQR2, GENMASK(24, 20), 20 },
{ STM32F4_ADC_SQR2, GENMASK(29, 25), 25 },
{ STM32F4_ADC_SQR1, GENMASK(4, 0), 0 },
{ STM32F4_ADC_SQR1, GENMASK(9, 5), 5 },
{ STM32F4_ADC_SQR1, GENMASK(14, 10), 10 },
{ STM32F4_ADC_SQR1, GENMASK(19, 15), 15 },
};
/* STM32F4 external trigger sources for all instances */
static struct stm32_adc_trig_info stm32f4_adc_trigs[] = {
{ TIM1_CH1, STM32_EXT0 },
{ TIM1_CH2, STM32_EXT1 },
{ TIM1_CH3, STM32_EXT2 },
{ TIM2_CH2, STM32_EXT3 },
{ TIM2_CH3, STM32_EXT4 },
{ TIM2_CH4, STM32_EXT5 },
{ TIM2_TRGO, STM32_EXT6 },
{ TIM3_CH1, STM32_EXT7 },
{ TIM3_TRGO, STM32_EXT8 },
{ TIM4_CH4, STM32_EXT9 },
{ TIM5_CH1, STM32_EXT10 },
{ TIM5_CH2, STM32_EXT11 },
{ TIM5_CH3, STM32_EXT12 },
{ TIM8_CH1, STM32_EXT13 },
{ TIM8_TRGO, STM32_EXT14 },
{}, /* sentinel */
};
/**
* stm32f4_smp_bits[] - describe sampling time register index & bit fields
* Sorted so it can be indexed by channel number.
*/
static const struct stm32_adc_regs stm32f4_smp_bits[] = {
/* STM32F4_ADC_SMPR2: smpr[] index, mask, shift for SMP0 to SMP9 */
{ 1, GENMASK(2, 0), 0 },
{ 1, GENMASK(5, 3), 3 },
{ 1, GENMASK(8, 6), 6 },
{ 1, GENMASK(11, 9), 9 },
{ 1, GENMASK(14, 12), 12 },
{ 1, GENMASK(17, 15), 15 },
{ 1, GENMASK(20, 18), 18 },
{ 1, GENMASK(23, 21), 21 },
{ 1, GENMASK(26, 24), 24 },
{ 1, GENMASK(29, 27), 27 },
/* STM32F4_ADC_SMPR1, smpr[] index, mask, shift for SMP10 to SMP18 */
{ 0, GENMASK(2, 0), 0 },
{ 0, GENMASK(5, 3), 3 },
{ 0, GENMASK(8, 6), 6 },
{ 0, GENMASK(11, 9), 9 },
{ 0, GENMASK(14, 12), 12 },
{ 0, GENMASK(17, 15), 15 },
{ 0, GENMASK(20, 18), 18 },
{ 0, GENMASK(23, 21), 21 },
{ 0, GENMASK(26, 24), 24 },
};
/* STM32F4 programmable sampling time (ADC clock cycles) */
static const unsigned int stm32f4_adc_smp_cycles[STM32_ADC_MAX_SMP + 1] = {
3, 15, 28, 56, 84, 112, 144, 480,
};
static const struct stm32_adc_regspec stm32f4_adc_regspec = {
.dr = STM32F4_ADC_DR,
.ier_eoc = { STM32F4_ADC_CR1, STM32F4_EOCIE },
.isr_eoc = { STM32F4_ADC_SR, STM32F4_EOC },
.sqr = stm32f4_sq,
.exten = { STM32F4_ADC_CR2, STM32F4_EXTEN_MASK, STM32F4_EXTEN_SHIFT },
.extsel = { STM32F4_ADC_CR2, STM32F4_EXTSEL_MASK,
STM32F4_EXTSEL_SHIFT },
.res = { STM32F4_ADC_CR1, STM32F4_RES_MASK, STM32F4_RES_SHIFT },
.smpr = { STM32F4_ADC_SMPR1, STM32F4_ADC_SMPR2 },
.smp_bits = stm32f4_smp_bits,
};
static const struct stm32_adc_regs stm32h7_sq[STM32_ADC_MAX_SQ + 1] = {
/* L: len bit field description to be kept as first element */
{ STM32H7_ADC_SQR1, GENMASK(3, 0), 0 },
/* SQ1..SQ16 registers & bit fields (reg, mask, shift) */
{ STM32H7_ADC_SQR1, GENMASK(10, 6), 6 },
{ STM32H7_ADC_SQR1, GENMASK(16, 12), 12 },
{ STM32H7_ADC_SQR1, GENMASK(22, 18), 18 },
{ STM32H7_ADC_SQR1, GENMASK(28, 24), 24 },
{ STM32H7_ADC_SQR2, GENMASK(4, 0), 0 },
{ STM32H7_ADC_SQR2, GENMASK(10, 6), 6 },
{ STM32H7_ADC_SQR2, GENMASK(16, 12), 12 },
{ STM32H7_ADC_SQR2, GENMASK(22, 18), 18 },
{ STM32H7_ADC_SQR2, GENMASK(28, 24), 24 },
{ STM32H7_ADC_SQR3, GENMASK(4, 0), 0 },
{ STM32H7_ADC_SQR3, GENMASK(10, 6), 6 },
{ STM32H7_ADC_SQR3, GENMASK(16, 12), 12 },
{ STM32H7_ADC_SQR3, GENMASK(22, 18), 18 },
{ STM32H7_ADC_SQR3, GENMASK(28, 24), 24 },
{ STM32H7_ADC_SQR4, GENMASK(4, 0), 0 },
{ STM32H7_ADC_SQR4, GENMASK(10, 6), 6 },
};
/* STM32H7 external trigger sources for all instances */
static struct stm32_adc_trig_info stm32h7_adc_trigs[] = {
{ TIM1_CH1, STM32_EXT0 },
{ TIM1_CH2, STM32_EXT1 },
{ TIM1_CH3, STM32_EXT2 },
{ TIM2_CH2, STM32_EXT3 },
{ TIM3_TRGO, STM32_EXT4 },
{ TIM4_CH4, STM32_EXT5 },
{ TIM8_TRGO, STM32_EXT7 },
{ TIM8_TRGO2, STM32_EXT8 },
{ TIM1_TRGO, STM32_EXT9 },
{ TIM1_TRGO2, STM32_EXT10 },
{ TIM2_TRGO, STM32_EXT11 },
{ TIM4_TRGO, STM32_EXT12 },
{ TIM6_TRGO, STM32_EXT13 },
{ TIM15_TRGO, STM32_EXT14 },
{ TIM3_CH4, STM32_EXT15 },
{ LPTIM1_OUT, STM32_EXT18 },
{ LPTIM2_OUT, STM32_EXT19 },
{ LPTIM3_OUT, STM32_EXT20 },
{},
};
/**
* stm32h7_smp_bits - describe sampling time register index & bit fields
* Sorted so it can be indexed by channel number.
*/
static const struct stm32_adc_regs stm32h7_smp_bits[] = {
/* STM32H7_ADC_SMPR1, smpr[] index, mask, shift for SMP0 to SMP9 */
{ 0, GENMASK(2, 0), 0 },
{ 0, GENMASK(5, 3), 3 },
{ 0, GENMASK(8, 6), 6 },
{ 0, GENMASK(11, 9), 9 },
{ 0, GENMASK(14, 12), 12 },
{ 0, GENMASK(17, 15), 15 },
{ 0, GENMASK(20, 18), 18 },
{ 0, GENMASK(23, 21), 21 },
{ 0, GENMASK(26, 24), 24 },
{ 0, GENMASK(29, 27), 27 },
/* STM32H7_ADC_SMPR2, smpr[] index, mask, shift for SMP10 to SMP19 */
{ 1, GENMASK(2, 0), 0 },
{ 1, GENMASK(5, 3), 3 },
{ 1, GENMASK(8, 6), 6 },
{ 1, GENMASK(11, 9), 9 },
{ 1, GENMASK(14, 12), 12 },
{ 1, GENMASK(17, 15), 15 },
{ 1, GENMASK(20, 18), 18 },
{ 1, GENMASK(23, 21), 21 },
{ 1, GENMASK(26, 24), 24 },
{ 1, GENMASK(29, 27), 27 },
};
/* STM32H7 programmable sampling time (ADC clock cycles, rounded down) */
static const unsigned int stm32h7_adc_smp_cycles[STM32_ADC_MAX_SMP + 1] = {
1, 2, 8, 16, 32, 64, 387, 810,
};
static const struct stm32_adc_regspec stm32h7_adc_regspec = {
.dr = STM32H7_ADC_DR,
.ier_eoc = { STM32H7_ADC_IER, STM32H7_EOCIE },
.isr_eoc = { STM32H7_ADC_ISR, STM32H7_EOC },
.sqr = stm32h7_sq,
.exten = { STM32H7_ADC_CFGR, STM32H7_EXTEN_MASK, STM32H7_EXTEN_SHIFT },
.extsel = { STM32H7_ADC_CFGR, STM32H7_EXTSEL_MASK,
STM32H7_EXTSEL_SHIFT },
.res = { STM32H7_ADC_CFGR, STM32H7_RES_MASK, STM32H7_RES_SHIFT },
.smpr = { STM32H7_ADC_SMPR1, STM32H7_ADC_SMPR2 },
.smp_bits = stm32h7_smp_bits,
};
/**
* STM32 ADC registers access routines
* @adc: stm32 adc instance
* @reg: reg offset in adc instance
*
* Note: All instances share same base, with 0x0, 0x100 or 0x200 offset resp.
* for adc1, adc2 and adc3.
*/
static u32 stm32_adc_readl(struct stm32_adc *adc, u32 reg)
{
return readl_relaxed(adc->common->base + adc->offset + reg);
}
#define stm32_adc_readl_addr(addr) stm32_adc_readl(adc, addr)
#define stm32_adc_readl_poll_timeout(reg, val, cond, sleep_us, timeout_us) \
readx_poll_timeout(stm32_adc_readl_addr, reg, val, \
cond, sleep_us, timeout_us)
static u16 stm32_adc_readw(struct stm32_adc *adc, u32 reg)
{
return readw_relaxed(adc->common->base + adc->offset + reg);
}
static void stm32_adc_writel(struct stm32_adc *adc, u32 reg, u32 val)
{
writel_relaxed(val, adc->common->base + adc->offset + reg);
}
static void stm32_adc_set_bits(struct stm32_adc *adc, u32 reg, u32 bits)
{
unsigned long flags;
spin_lock_irqsave(&adc->lock, flags);
stm32_adc_writel(adc, reg, stm32_adc_readl(adc, reg) | bits);
spin_unlock_irqrestore(&adc->lock, flags);
}
static void stm32_adc_clr_bits(struct stm32_adc *adc, u32 reg, u32 bits)
{
unsigned long flags;
spin_lock_irqsave(&adc->lock, flags);
stm32_adc_writel(adc, reg, stm32_adc_readl(adc, reg) & ~bits);
spin_unlock_irqrestore(&adc->lock, flags);
}
/**
* stm32_adc_conv_irq_enable() - Enable end of conversion interrupt
* @adc: stm32 adc instance
*/
static void stm32_adc_conv_irq_enable(struct stm32_adc *adc)
{
stm32_adc_set_bits(adc, adc->cfg->regs->ier_eoc.reg,
adc->cfg->regs->ier_eoc.mask);
};
/**
* stm32_adc_conv_irq_disable() - Disable end of conversion interrupt
* @adc: stm32 adc instance
*/
static void stm32_adc_conv_irq_disable(struct stm32_adc *adc)
{
stm32_adc_clr_bits(adc, adc->cfg->regs->ier_eoc.reg,
adc->cfg->regs->ier_eoc.mask);
}
static void stm32_adc_set_res(struct stm32_adc *adc)
{
const struct stm32_adc_regs *res = &adc->cfg->regs->res;
u32 val;
val = stm32_adc_readl(adc, res->reg);
val = (val & ~res->mask) | (adc->res << res->shift);
stm32_adc_writel(adc, res->reg, val);
}
/**
* stm32f4_adc_start_conv() - Start conversions for regular channels.
* @adc: stm32 adc instance
* @dma: use dma to transfer conversion result
*
* Start conversions for regular channels.
* Also take care of normal or DMA mode. Circular DMA may be used for regular
* conversions, in IIO buffer modes. Otherwise, use ADC interrupt with direct
* DR read instead (e.g. read_raw, or triggered buffer mode without DMA).
*/
static void stm32f4_adc_start_conv(struct stm32_adc *adc, bool dma)
{
stm32_adc_set_bits(adc, STM32F4_ADC_CR1, STM32F4_SCAN);
if (dma)
stm32_adc_set_bits(adc, STM32F4_ADC_CR2,
STM32F4_DMA | STM32F4_DDS);
stm32_adc_set_bits(adc, STM32F4_ADC_CR2, STM32F4_EOCS | STM32F4_ADON);
/* Wait for Power-up time (tSTAB from datasheet) */
usleep_range(2, 3);
/* Software start ? (e.g. trigger detection disabled ?) */
if (!(stm32_adc_readl(adc, STM32F4_ADC_CR2) & STM32F4_EXTEN_MASK))
stm32_adc_set_bits(adc, STM32F4_ADC_CR2, STM32F4_SWSTART);
}
static void stm32f4_adc_stop_conv(struct stm32_adc *adc)
{
stm32_adc_clr_bits(adc, STM32F4_ADC_CR2, STM32F4_EXTEN_MASK);
stm32_adc_clr_bits(adc, STM32F4_ADC_SR, STM32F4_STRT);
stm32_adc_clr_bits(adc, STM32F4_ADC_CR1, STM32F4_SCAN);
stm32_adc_clr_bits(adc, STM32F4_ADC_CR2,
STM32F4_ADON | STM32F4_DMA | STM32F4_DDS);
}
static void stm32h7_adc_start_conv(struct stm32_adc *adc, bool dma)
{
enum stm32h7_adc_dmngt dmngt;
unsigned long flags;
u32 val;
if (dma)
dmngt = STM32H7_DMNGT_DMA_CIRC;
else
dmngt = STM32H7_DMNGT_DR_ONLY;
spin_lock_irqsave(&adc->lock, flags);
val = stm32_adc_readl(adc, STM32H7_ADC_CFGR);
val = (val & ~STM32H7_DMNGT_MASK) | (dmngt << STM32H7_DMNGT_SHIFT);
stm32_adc_writel(adc, STM32H7_ADC_CFGR, val);
spin_unlock_irqrestore(&adc->lock, flags);
stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADSTART);
}
static void stm32h7_adc_stop_conv(struct stm32_adc *adc)
{
struct iio_dev *indio_dev = iio_priv_to_dev(adc);
int ret;
u32 val;
stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADSTP);
ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val,
!(val & (STM32H7_ADSTART)),
100, STM32_ADC_TIMEOUT_US);
if (ret)
dev_warn(&indio_dev->dev, "stop failed\n");
stm32_adc_clr_bits(adc, STM32H7_ADC_CFGR, STM32H7_DMNGT_MASK);
}
static int stm32h7_adc_exit_pwr_down(struct stm32_adc *adc)
{
struct iio_dev *indio_dev = iio_priv_to_dev(adc);
int ret;
u32 val;
/* Exit deep power down, then enable ADC voltage regulator */
stm32_adc_clr_bits(adc, STM32H7_ADC_CR, STM32H7_DEEPPWD);
stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADVREGEN);
if (adc->common->rate > STM32H7_BOOST_CLKRATE)
stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_BOOST);
/* Wait for startup time */
if (!adc->cfg->has_vregready) {
usleep_range(10, 20);
return 0;
}
ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_ISR, val,
val & STM32MP1_VREGREADY, 100,
STM32_ADC_TIMEOUT_US);
if (ret) {
stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_DEEPPWD);
dev_err(&indio_dev->dev, "Failed to exit power down\n");
}
return ret;
}
static void stm32h7_adc_enter_pwr_down(struct stm32_adc *adc)
{
stm32_adc_clr_bits(adc, STM32H7_ADC_CR, STM32H7_BOOST);
/* Setting DEEPPWD disables ADC vreg and clears ADVREGEN */
stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_DEEPPWD);
}
static int stm32h7_adc_enable(struct stm32_adc *adc)
{
struct iio_dev *indio_dev = iio_priv_to_dev(adc);
int ret;
u32 val;
stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADEN);
/* Poll for ADRDY to be set (after adc startup time) */
ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_ISR, val,
val & STM32H7_ADRDY,
100, STM32_ADC_TIMEOUT_US);
if (ret) {
stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADDIS);
dev_err(&indio_dev->dev, "Failed to enable ADC\n");
} else {
/* Clear ADRDY by writing one */
stm32_adc_set_bits(adc, STM32H7_ADC_ISR, STM32H7_ADRDY);
}
return ret;
}
static void stm32h7_adc_disable(struct stm32_adc *adc)
{
struct iio_dev *indio_dev = iio_priv_to_dev(adc);
int ret;
u32 val;
/* Disable ADC and wait until it's effectively disabled */
stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADDIS);
ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val,
!(val & STM32H7_ADEN), 100,
STM32_ADC_TIMEOUT_US);
if (ret)
dev_warn(&indio_dev->dev, "Failed to disable\n");
}
/**
* stm32h7_adc_read_selfcalib() - read calibration shadow regs, save result
* @adc: stm32 adc instance
*/
static int stm32h7_adc_read_selfcalib(struct stm32_adc *adc)
{
struct iio_dev *indio_dev = iio_priv_to_dev(adc);
int i, ret;
u32 lincalrdyw_mask, val;
/* Enable adc so LINCALRDYW1..6 bits are writable */
ret = stm32h7_adc_enable(adc);
if (ret)
return ret;
/* Read linearity calibration */
lincalrdyw_mask = STM32H7_LINCALRDYW6;
for (i = STM32H7_LINCALFACT_NUM - 1; i >= 0; i--) {
/* Clear STM32H7_LINCALRDYW[6..1]: transfer calib to CALFACT2 */
stm32_adc_clr_bits(adc, STM32H7_ADC_CR, lincalrdyw_mask);
/* Poll: wait calib data to be ready in CALFACT2 register */
ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val,
!(val & lincalrdyw_mask),
100, STM32_ADC_TIMEOUT_US);
if (ret) {
dev_err(&indio_dev->dev, "Failed to read calfact\n");
goto disable;
}
val = stm32_adc_readl(adc, STM32H7_ADC_CALFACT2);
adc->cal.lincalfact[i] = (val & STM32H7_LINCALFACT_MASK);
adc->cal.lincalfact[i] >>= STM32H7_LINCALFACT_SHIFT;
lincalrdyw_mask >>= 1;
}
/* Read offset calibration */
val = stm32_adc_readl(adc, STM32H7_ADC_CALFACT);
adc->cal.calfact_s = (val & STM32H7_CALFACT_S_MASK);
adc->cal.calfact_s >>= STM32H7_CALFACT_S_SHIFT;
adc->cal.calfact_d = (val & STM32H7_CALFACT_D_MASK);
adc->cal.calfact_d >>= STM32H7_CALFACT_D_SHIFT;
disable:
stm32h7_adc_disable(adc);
return ret;
}
/**
* stm32h7_adc_restore_selfcalib() - Restore saved self-calibration result
* @adc: stm32 adc instance
* Note: ADC must be enabled, with no on-going conversions.
*/
static int stm32h7_adc_restore_selfcalib(struct stm32_adc *adc)
{
struct iio_dev *indio_dev = iio_priv_to_dev(adc);
int i, ret;
u32 lincalrdyw_mask, val;
val = (adc->cal.calfact_s << STM32H7_CALFACT_S_SHIFT) |
(adc->cal.calfact_d << STM32H7_CALFACT_D_SHIFT);
stm32_adc_writel(adc, STM32H7_ADC_CALFACT, val);
lincalrdyw_mask = STM32H7_LINCALRDYW6;
for (i = STM32H7_LINCALFACT_NUM - 1; i >= 0; i--) {
/*
* Write saved calibration data to shadow registers:
* Write CALFACT2, and set LINCALRDYW[6..1] bit to trigger
* data write. Then poll to wait for complete transfer.
*/
val = adc->cal.lincalfact[i] << STM32H7_LINCALFACT_SHIFT;
stm32_adc_writel(adc, STM32H7_ADC_CALFACT2, val);
stm32_adc_set_bits(adc, STM32H7_ADC_CR, lincalrdyw_mask);
ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val,
val & lincalrdyw_mask,
100, STM32_ADC_TIMEOUT_US);
if (ret) {
dev_err(&indio_dev->dev, "Failed to write calfact\n");
return ret;
}
/*
* Read back calibration data, has two effects:
* - It ensures bits LINCALRDYW[6..1] are kept cleared
* for next time calibration needs to be restored.
* - BTW, bit clear triggers a read, then check data has been
* correctly written.
*/
stm32_adc_clr_bits(adc, STM32H7_ADC_CR, lincalrdyw_mask);
ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val,
!(val & lincalrdyw_mask),
100, STM32_ADC_TIMEOUT_US);
if (ret) {
dev_err(&indio_dev->dev, "Failed to read calfact\n");
return ret;
}
val = stm32_adc_readl(adc, STM32H7_ADC_CALFACT2);
if (val != adc->cal.lincalfact[i] << STM32H7_LINCALFACT_SHIFT) {
dev_err(&indio_dev->dev, "calfact not consistent\n");
return -EIO;
}
lincalrdyw_mask >>= 1;
}
return 0;
}
/**
* Fixed timeout value for ADC calibration.
* worst cases:
* - low clock frequency
* - maximum prescalers
* Calibration requires:
* - 131,072 ADC clock cycle for the linear calibration
* - 20 ADC clock cycle for the offset calibration
*
* Set to 100ms for now
*/
#define STM32H7_ADC_CALIB_TIMEOUT_US 100000
/**
* stm32h7_adc_selfcalib() - Procedure to calibrate ADC (from power down)
* @adc: stm32 adc instance
* Exit from power down, calibrate ADC, then return to power down.
*/
static int stm32h7_adc_selfcalib(struct stm32_adc *adc)
{
struct iio_dev *indio_dev = iio_priv_to_dev(adc);
int ret;
u32 val;
ret = stm32h7_adc_exit_pwr_down(adc);
if (ret)
return ret;
/*
* Select calibration mode:
* - Offset calibration for single ended inputs
* - No linearity calibration (do it later, before reading it)
*/
stm32_adc_clr_bits(adc, STM32H7_ADC_CR, STM32H7_ADCALDIF);
stm32_adc_clr_bits(adc, STM32H7_ADC_CR, STM32H7_ADCALLIN);
/* Start calibration, then wait for completion */
stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADCAL);
ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val,
!(val & STM32H7_ADCAL), 100,
STM32H7_ADC_CALIB_TIMEOUT_US);
if (ret) {
dev_err(&indio_dev->dev, "calibration failed\n");
goto pwr_dwn;
}
/*
* Select calibration mode, then start calibration:
* - Offset calibration for differential input
* - Linearity calibration (needs to be done only once for single/diff)
* will run simultaneously with offset calibration.
*/
stm32_adc_set_bits(adc, STM32H7_ADC_CR,
STM32H7_ADCALDIF | STM32H7_ADCALLIN);
stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADCAL);
ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val,
!(val & STM32H7_ADCAL), 100,
STM32H7_ADC_CALIB_TIMEOUT_US);
if (ret) {
dev_err(&indio_dev->dev, "calibration failed\n");
goto pwr_dwn;
}
stm32_adc_clr_bits(adc, STM32H7_ADC_CR,
STM32H7_ADCALDIF | STM32H7_ADCALLIN);
/* Read calibration result for future reference */
ret = stm32h7_adc_read_selfcalib(adc);
pwr_dwn:
stm32h7_adc_enter_pwr_down(adc);
return ret;
}
/**
* stm32h7_adc_prepare() - Leave power down mode to enable ADC.
* @adc: stm32 adc instance
* Leave power down mode.
* Configure channels as single ended or differential before enabling ADC.
* Enable ADC.
* Restore calibration data.
* Pre-select channels that may be used in PCSEL (required by input MUX / IO):
* - Only one input is selected for single ended (e.g. 'vinp')
* - Two inputs are selected for differential channels (e.g. 'vinp' & 'vinn')
*/
static int stm32h7_adc_prepare(struct stm32_adc *adc)
{
int ret;
ret = stm32h7_adc_exit_pwr_down(adc);
if (ret)
return ret;
stm32_adc_writel(adc, STM32H7_ADC_DIFSEL, adc->difsel);
ret = stm32h7_adc_enable(adc);
if (ret)
goto pwr_dwn;
ret = stm32h7_adc_restore_selfcalib(adc);
if (ret)
goto disable;
stm32_adc_writel(adc, STM32H7_ADC_PCSEL, adc->pcsel);
return 0;
disable:
stm32h7_adc_disable(adc);
pwr_dwn:
stm32h7_adc_enter_pwr_down(adc);
return ret;
}
static void stm32h7_adc_unprepare(struct stm32_adc *adc)
{
stm32h7_adc_disable(adc);
stm32h7_adc_enter_pwr_down(adc);
}
/**
* stm32_adc_conf_scan_seq() - Build regular channels scan sequence
* @indio_dev: IIO device
* @scan_mask: channels to be converted
*
* Conversion sequence :
* Apply sampling time settings for all channels.
* Configure ADC scan sequence based on selected channels in scan_mask.
* Add channels to SQR registers, from scan_mask LSB to MSB, then
* program sequence len.
*/
static int stm32_adc_conf_scan_seq(struct iio_dev *indio_dev,
const unsigned long *scan_mask)
{
struct stm32_adc *adc = iio_priv(indio_dev);
const struct stm32_adc_regs *sqr = adc->cfg->regs->sqr;
const struct iio_chan_spec *chan;
u32 val, bit;
int i = 0;
/* Apply sampling time settings */
stm32_adc_writel(adc, adc->cfg->regs->smpr[0], adc->smpr_val[0]);
stm32_adc_writel(adc, adc->cfg->regs->smpr[1], adc->smpr_val[1]);
for_each_set_bit(bit, scan_mask, indio_dev->masklength) {
chan = indio_dev->channels + bit;
/*
* Assign one channel per SQ entry in regular
* sequence, starting with SQ1.
*/
i++;
if (i > STM32_ADC_MAX_SQ)
return -EINVAL;
dev_dbg(&indio_dev->dev, "%s chan %d to SQ%d\n",
__func__, chan->channel, i);
val = stm32_adc_readl(adc, sqr[i].reg);
val &= ~sqr[i].mask;
val |= chan->channel << sqr[i].shift;
stm32_adc_writel(adc, sqr[i].reg, val);
}
if (!i)
return -EINVAL;
/* Sequence len */
val = stm32_adc_readl(adc, sqr[0].reg);
val &= ~sqr[0].mask;
val |= ((i - 1) << sqr[0].shift);
stm32_adc_writel(adc, sqr[0].reg, val);
return 0;
}
/**
* stm32_adc_get_trig_extsel() - Get external trigger selection
* @trig: trigger
*
* Returns trigger extsel value, if trig matches, -EINVAL otherwise.
*/
static int stm32_adc_get_trig_extsel(struct iio_dev *indio_dev,
struct iio_trigger *trig)
{
struct stm32_adc *adc = iio_priv(indio_dev);
int i;
/* lookup triggers registered by stm32 timer trigger driver */
for (i = 0; adc->cfg->trigs[i].name; i++) {
/**
* Checking both stm32 timer trigger type and trig name
* should be safe against arbitrary trigger names.
*/
if ((is_stm32_timer_trigger(trig) ||
is_stm32_lptim_trigger(trig)) &&
!strcmp(adc->cfg->trigs[i].name, trig->name)) {
return adc->cfg->trigs[i].extsel;
}
}
return -EINVAL;
}
/**
* stm32_adc_set_trig() - Set a regular trigger
* @indio_dev: IIO device
* @trig: IIO trigger
*
* Set trigger source/polarity (e.g. SW, or HW with polarity) :
* - if HW trigger disabled (e.g. trig == NULL, conversion launched by sw)
* - if HW trigger enabled, set source & polarity
*/
static int stm32_adc_set_trig(struct iio_dev *indio_dev,
struct iio_trigger *trig)
{
struct stm32_adc *adc = iio_priv(indio_dev);
u32 val, extsel = 0, exten = STM32_EXTEN_SWTRIG;
unsigned long flags;
int ret;
if (trig) {
ret = stm32_adc_get_trig_extsel(indio_dev, trig);
if (ret < 0)
return ret;
/* set trigger source and polarity (default to rising edge) */
extsel = ret;
exten = adc->trigger_polarity + STM32_EXTEN_HWTRIG_RISING_EDGE;
}
spin_lock_irqsave(&adc->lock, flags);
val = stm32_adc_readl(adc, adc->cfg->regs->exten.reg);
val &= ~(adc->cfg->regs->exten.mask | adc->cfg->regs->extsel.mask);
val |= exten << adc->cfg->regs->exten.shift;
val |= extsel << adc->cfg->regs->extsel.shift;
stm32_adc_writel(adc, adc->cfg->regs->exten.reg, val);
spin_unlock_irqrestore(&adc->lock, flags);
return 0;
}
static int stm32_adc_set_trig_pol(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan,
unsigned int type)
{
struct stm32_adc *adc = iio_priv(indio_dev);
adc->trigger_polarity = type;
return 0;
}
static int stm32_adc_get_trig_pol(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan)
{
struct stm32_adc *adc = iio_priv(indio_dev);
return adc->trigger_polarity;
}
static const char * const stm32_trig_pol_items[] = {
"rising-edge", "falling-edge", "both-edges",
};
static const struct iio_enum stm32_adc_trig_pol = {
.items = stm32_trig_pol_items,
.num_items = ARRAY_SIZE(stm32_trig_pol_items),
.get = stm32_adc_get_trig_pol,
.set = stm32_adc_set_trig_pol,
};
/**
* stm32_adc_single_conv() - Performs a single conversion
* @indio_dev: IIO device
* @chan: IIO channel
* @res: conversion result
*
* The function performs a single conversion on a given channel:
* - Apply sampling time settings
* - Program sequencer with one channel (e.g. in SQ1 with len = 1)
* - Use SW trigger
* - Start conversion, then wait for interrupt completion.
*/
static int stm32_adc_single_conv(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan,
int *res)
{
struct stm32_adc *adc = iio_priv(indio_dev);
const struct stm32_adc_regspec *regs = adc->cfg->regs;
long timeout;
u32 val;
int ret;
reinit_completion(&adc->completion);
adc->bufi = 0;
if (adc->cfg->prepare) {
ret = adc->cfg->prepare(adc);
if (ret)
return ret;
}
/* Apply sampling time settings */
stm32_adc_writel(adc, regs->smpr[0], adc->smpr_val[0]);
stm32_adc_writel(adc, regs->smpr[1], adc->smpr_val[1]);
/* Program chan number in regular sequence (SQ1) */
val = stm32_adc_readl(adc, regs->sqr[1].reg);
val &= ~regs->sqr[1].mask;
val |= chan->channel << regs->sqr[1].shift;
stm32_adc_writel(adc, regs->sqr[1].reg, val);
/* Set regular sequence len (0 for 1 conversion) */
stm32_adc_clr_bits(adc, regs->sqr[0].reg, regs->sqr[0].mask);
/* Trigger detection disabled (conversion can be launched in SW) */
stm32_adc_clr_bits(adc, regs->exten.reg, regs->exten.mask);
stm32_adc_conv_irq_enable(adc);
adc->cfg->start_conv(adc, false);
timeout = wait_for_completion_interruptible_timeout(
&adc->completion, STM32_ADC_TIMEOUT);
if (timeout == 0) {
ret = -ETIMEDOUT;
} else if (timeout < 0) {
ret = timeout;
} else {
*res = adc->buffer[0];
ret = IIO_VAL_INT;
}
adc->cfg->stop_conv(adc);
stm32_adc_conv_irq_disable(adc);
if (adc->cfg->unprepare)
adc->cfg->unprepare(adc);
return ret;
}
static int stm32_adc_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct stm32_adc *adc = iio_priv(indio_dev);
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
ret = iio_device_claim_direct_mode(indio_dev);
if (ret)
return ret;
if (chan->type == IIO_VOLTAGE)
ret = stm32_adc_single_conv(indio_dev, chan, val);
else
ret = -EINVAL;
iio_device_release_direct_mode(indio_dev);
return ret;
case IIO_CHAN_INFO_SCALE:
if (chan->differential) {
*val = adc->common->vref_mv * 2;
*val2 = chan->scan_type.realbits;
} else {
*val = adc->common->vref_mv;
*val2 = chan->scan_type.realbits;
}
return IIO_VAL_FRACTIONAL_LOG2;
case IIO_CHAN_INFO_OFFSET:
if (chan->differential)
/* ADC_full_scale / 2 */
*val = -((1 << chan->scan_type.realbits) / 2);
else
*val = 0;
return IIO_VAL_INT;
default:
return -EINVAL;
}
}
static irqreturn_t stm32_adc_isr(int irq, void *data)
{
struct stm32_adc *adc = data;
struct iio_dev *indio_dev = iio_priv_to_dev(adc);
const struct stm32_adc_regspec *regs = adc->cfg->regs;
u32 status = stm32_adc_readl(adc, regs->isr_eoc.reg);
if (status & regs->isr_eoc.mask) {
/* Reading DR also clears EOC status flag */
adc->buffer[adc->bufi] = stm32_adc_readw(adc, regs->dr);
if (iio_buffer_enabled(indio_dev)) {
adc->bufi++;
if (adc->bufi >= adc->num_conv) {
stm32_adc_conv_irq_disable(adc);
iio_trigger_poll(indio_dev->trig);
}
} else {
complete(&adc->completion);
}
return IRQ_HANDLED;
}
return IRQ_NONE;
}
/**
* stm32_adc_validate_trigger() - validate trigger for stm32 adc
* @indio_dev: IIO device
* @trig: new trigger
*
* Returns: 0 if trig matches one of the triggers registered by stm32 adc
* driver, -EINVAL otherwise.
*/
static int stm32_adc_validate_trigger(struct iio_dev *indio_dev,
struct iio_trigger *trig)
{
return stm32_adc_get_trig_extsel(indio_dev, trig) < 0 ? -EINVAL : 0;
}
static int stm32_adc_set_watermark(struct iio_dev *indio_dev, unsigned int val)
{
struct stm32_adc *adc = iio_priv(indio_dev);
unsigned int watermark = STM32_DMA_BUFFER_SIZE / 2;
unsigned int rx_buf_sz = STM32_DMA_BUFFER_SIZE;
/*
* dma cyclic transfers are used, buffer is split into two periods.
* There should be :
* - always one buffer (period) dma is working on
* - one buffer (period) driver can push with iio_trigger_poll().
*/
watermark = min(watermark, val * (unsigned)(sizeof(u16)));
adc->rx_buf_sz = min(rx_buf_sz, watermark * 2 * adc->num_conv);
return 0;
}
static int stm32_adc_update_scan_mode(struct iio_dev *indio_dev,
const unsigned long *scan_mask)
{
struct stm32_adc *adc = iio_priv(indio_dev);
int ret;
adc->num_conv = bitmap_weight(scan_mask, indio_dev->masklength);
ret = stm32_adc_conf_scan_seq(indio_dev, scan_mask);
if (ret)
return ret;
return 0;
}
static int stm32_adc_of_xlate(struct iio_dev *indio_dev,
const struct of_phandle_args *iiospec)
{
int i;
for (i = 0; i < indio_dev->num_channels; i++)
if (indio_dev->channels[i].channel == iiospec->args[0])
return i;
return -EINVAL;
}
/**
* stm32_adc_debugfs_reg_access - read or write register value
*
* To read a value from an ADC register:
* echo [ADC reg offset] > direct_reg_access
* cat direct_reg_access
*
* To write a value in a ADC register:
* echo [ADC_reg_offset] [value] > direct_reg_access
*/
static int stm32_adc_debugfs_reg_access(struct iio_dev *indio_dev,
unsigned reg, unsigned writeval,
unsigned *readval)
{
struct stm32_adc *adc = iio_priv(indio_dev);
if (!readval)
stm32_adc_writel(adc, reg, writeval);
else
*readval = stm32_adc_readl(adc, reg);
return 0;
}
static const struct iio_info stm32_adc_iio_info = {
.read_raw = stm32_adc_read_raw,
.validate_trigger = stm32_adc_validate_trigger,
.hwfifo_set_watermark = stm32_adc_set_watermark,
.update_scan_mode = stm32_adc_update_scan_mode,
.debugfs_reg_access = stm32_adc_debugfs_reg_access,
.of_xlate = stm32_adc_of_xlate,
};
static unsigned int stm32_adc_dma_residue(struct stm32_adc *adc)
{
struct dma_tx_state state;
enum dma_status status;
status = dmaengine_tx_status(adc->dma_chan,
adc->dma_chan->cookie,
&state);
if (status == DMA_IN_PROGRESS) {
/* Residue is size in bytes from end of buffer */
unsigned int i = adc->rx_buf_sz - state.residue;
unsigned int size;
/* Return available bytes */
if (i >= adc->bufi)
size = i - adc->bufi;
else
size = adc->rx_buf_sz + i - adc->bufi;
return size;
}
return 0;
}
static void stm32_adc_dma_buffer_done(void *data)
{
struct iio_dev *indio_dev = data;
struct stm32_adc *adc = iio_priv(indio_dev);
int residue = stm32_adc_dma_residue(adc);
/*
* In DMA mode the trigger services of IIO are not used
* (e.g. no call to iio_trigger_poll).
* Calling irq handler associated to the hardware trigger is not
* relevant as the conversions have already been done. Data
* transfers are performed directly in DMA callback instead.
* This implementation avoids to call trigger irq handler that
* may sleep, in an atomic context (DMA irq handler context).
*/
dev_dbg(&indio_dev->dev, "%s bufi=%d\n", __func__, adc->bufi);
while (residue >= indio_dev->scan_bytes) {
u16 *buffer = (u16 *)&adc->rx_buf[adc->bufi];
iio_push_to_buffers(indio_dev, buffer);
residue -= indio_dev->scan_bytes;
adc->bufi += indio_dev->scan_bytes;
if (adc->bufi >= adc->rx_buf_sz)
adc->bufi = 0;
}
}
static int stm32_adc_dma_start(struct iio_dev *indio_dev)
{
struct stm32_adc *adc = iio_priv(indio_dev);
struct dma_async_tx_descriptor *desc;
dma_cookie_t cookie;
int ret;
if (!adc->dma_chan)
return 0;
dev_dbg(&indio_dev->dev, "%s size=%d watermark=%d\n", __func__,
adc->rx_buf_sz, adc->rx_buf_sz / 2);
/* Prepare a DMA cyclic transaction */
desc = dmaengine_prep_dma_cyclic(adc->dma_chan,
adc->rx_dma_buf,
adc->rx_buf_sz, adc->rx_buf_sz / 2,
DMA_DEV_TO_MEM,
DMA_PREP_INTERRUPT);
if (!desc)
return -EBUSY;
desc->callback = stm32_adc_dma_buffer_done;
desc->callback_param = indio_dev;
cookie = dmaengine_submit(desc);
ret = dma_submit_error(cookie);
if (ret) {
dmaengine_terminate_sync(adc->dma_chan);
return ret;
}
/* Issue pending DMA requests */
dma_async_issue_pending(adc->dma_chan);
return 0;
}
static int stm32_adc_buffer_postenable(struct iio_dev *indio_dev)
{
struct stm32_adc *adc = iio_priv(indio_dev);
int ret;
if (adc->cfg->prepare) {
ret = adc->cfg->prepare(adc);
if (ret)
return ret;
}
ret = stm32_adc_set_trig(indio_dev, indio_dev->trig);
if (ret) {
dev_err(&indio_dev->dev, "Can't set trigger\n");
goto err_unprepare;
}
ret = stm32_adc_dma_start(indio_dev);
if (ret) {
dev_err(&indio_dev->dev, "Can't start dma\n");
goto err_clr_trig;
}
ret = iio_triggered_buffer_postenable(indio_dev);
if (ret < 0)
goto err_stop_dma;
/* Reset adc buffer index */
adc->bufi = 0;
if (!adc->dma_chan)
stm32_adc_conv_irq_enable(adc);
adc->cfg->start_conv(adc, !!adc->dma_chan);
return 0;
err_stop_dma:
if (adc->dma_chan)
dmaengine_terminate_all(adc->dma_chan);
err_clr_trig:
stm32_adc_set_trig(indio_dev, NULL);
err_unprepare:
if (adc->cfg->unprepare)
adc->cfg->unprepare(adc);
return ret;
}
static int stm32_adc_buffer_predisable(struct iio_dev *indio_dev)
{
struct stm32_adc *adc = iio_priv(indio_dev);
int ret;
adc->cfg->stop_conv(adc);
if (!adc->dma_chan)
stm32_adc_conv_irq_disable(adc);
ret = iio_triggered_buffer_predisable(indio_dev);
if (ret < 0)
dev_err(&indio_dev->dev, "predisable failed\n");
if (adc->dma_chan)
dmaengine_terminate_sync(adc->dma_chan);
if (stm32_adc_set_trig(indio_dev, NULL))
dev_err(&indio_dev->dev, "Can't clear trigger\n");
if (adc->cfg->unprepare)
adc->cfg->unprepare(adc);
return ret;
}
static const struct iio_buffer_setup_ops stm32_adc_buffer_setup_ops = {
.postenable = &stm32_adc_buffer_postenable,
.predisable = &stm32_adc_buffer_predisable,
};
static irqreturn_t stm32_adc_trigger_handler(int irq, void *p)
{
struct iio_poll_func *pf = p;
struct iio_dev *indio_dev = pf->indio_dev;
struct stm32_adc *adc = iio_priv(indio_dev);
dev_dbg(&indio_dev->dev, "%s bufi=%d\n", __func__, adc->bufi);
if (!adc->dma_chan) {
/* reset buffer index */
adc->bufi = 0;
iio_push_to_buffers_with_timestamp(indio_dev, adc->buffer,
pf->timestamp);
} else {
int residue = stm32_adc_dma_residue(adc);
while (residue >= indio_dev->scan_bytes) {
u16 *buffer = (u16 *)&adc->rx_buf[adc->bufi];
iio_push_to_buffers_with_timestamp(indio_dev, buffer,
pf->timestamp);
residue -= indio_dev->scan_bytes;
adc->bufi += indio_dev->scan_bytes;
if (adc->bufi >= adc->rx_buf_sz)
adc->bufi = 0;
}
}
iio_trigger_notify_done(indio_dev->trig);
/* re-enable eoc irq */
if (!adc->dma_chan)
stm32_adc_conv_irq_enable(adc);
return IRQ_HANDLED;
}
static const struct iio_chan_spec_ext_info stm32_adc_ext_info[] = {
IIO_ENUM("trigger_polarity", IIO_SHARED_BY_ALL, &stm32_adc_trig_pol),
{
.name = "trigger_polarity_available",
.shared = IIO_SHARED_BY_ALL,
.read = iio_enum_available_read,
.private = (uintptr_t)&stm32_adc_trig_pol,
},
{},
};
static int stm32_adc_of_get_resolution(struct iio_dev *indio_dev)
{
struct device_node *node = indio_dev->dev.of_node;
struct stm32_adc *adc = iio_priv(indio_dev);
unsigned int i;
u32 res;
if (of_property_read_u32(node, "assigned-resolution-bits", &res))
res = adc->cfg->adc_info->resolutions[0];
for (i = 0; i < adc->cfg->adc_info->num_res; i++)
if (res == adc->cfg->adc_info->resolutions[i])
break;
if (i >= adc->cfg->adc_info->num_res) {
dev_err(&indio_dev->dev, "Bad resolution: %u bits\n", res);
return -EINVAL;
}
dev_dbg(&indio_dev->dev, "Using %u bits resolution\n", res);
adc->res = i;
return 0;
}
static void stm32_adc_smpr_init(struct stm32_adc *adc, int channel, u32 smp_ns)
{
const struct stm32_adc_regs *smpr = &adc->cfg->regs->smp_bits[channel];
u32 period_ns, shift = smpr->shift, mask = smpr->mask;
unsigned int smp, r = smpr->reg;
/* Determine sampling time (ADC clock cycles) */
period_ns = NSEC_PER_SEC / adc->common->rate;
for (smp = 0; smp <= STM32_ADC_MAX_SMP; smp++)
if ((period_ns * adc->cfg->smp_cycles[smp]) >= smp_ns)
break;
if (smp > STM32_ADC_MAX_SMP)
smp = STM32_ADC_MAX_SMP;
/* pre-build sampling time registers (e.g. smpr1, smpr2) */
adc->smpr_val[r] = (adc->smpr_val[r] & ~mask) | (smp << shift);
}
static void stm32_adc_chan_init_one(struct iio_dev *indio_dev,
struct iio_chan_spec *chan, u32 vinp,
u32 vinn, int scan_index, bool differential)
{
struct stm32_adc *adc = iio_priv(indio_dev);
char *name = adc->chan_name[vinp];
chan->type = IIO_VOLTAGE;
chan->channel = vinp;
if (differential) {
chan->differential = 1;
chan->channel2 = vinn;
snprintf(name, STM32_ADC_CH_SZ, "in%d-in%d", vinp, vinn);
} else {
snprintf(name, STM32_ADC_CH_SZ, "in%d", vinp);
}
chan->datasheet_name = name;
chan->scan_index = scan_index;
chan->indexed = 1;
chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |
BIT(IIO_CHAN_INFO_OFFSET);
chan->scan_type.sign = 'u';
chan->scan_type.realbits = adc->cfg->adc_info->resolutions[adc->res];
chan->scan_type.storagebits = 16;
chan->ext_info = stm32_adc_ext_info;
/* pre-build selected channels mask */
adc->pcsel |= BIT(chan->channel);
if (differential) {
/* pre-build diff channels mask */
adc->difsel |= BIT(chan->channel);
/* Also add negative input to pre-selected channels */
adc->pcsel |= BIT(chan->channel2);
}
}
static int stm32_adc_chan_of_init(struct iio_dev *indio_dev)
{
struct device_node *node = indio_dev->dev.of_node;
struct stm32_adc *adc = iio_priv(indio_dev);
const struct stm32_adc_info *adc_info = adc->cfg->adc_info;
struct stm32_adc_diff_channel diff[STM32_ADC_CH_MAX];
struct property *prop;
const __be32 *cur;
struct iio_chan_spec *channels;
int scan_index = 0, num_channels = 0, num_diff = 0, ret, i;
u32 val, smp = 0;
ret = of_property_count_u32_elems(node, "st,adc-channels");
if (ret > adc_info->max_channels) {
dev_err(&indio_dev->dev, "Bad st,adc-channels?\n");
return -EINVAL;
} else if (ret > 0) {
num_channels += ret;
}
ret = of_property_count_elems_of_size(node, "st,adc-diff-channels",
sizeof(*diff));
if (ret > adc_info->max_channels) {
dev_err(&indio_dev->dev, "Bad st,adc-diff-channels?\n");
return -EINVAL;
} else if (ret > 0) {
int size = ret * sizeof(*diff) / sizeof(u32);
num_diff = ret;
num_channels += ret;
ret = of_property_read_u32_array(node, "st,adc-diff-channels",
(u32 *)diff, size);
if (ret)
return ret;
}
if (!num_channels) {
dev_err(&indio_dev->dev, "No channels configured\n");
return -ENODATA;
}
/* Optional sample time is provided either for each, or all channels */
ret = of_property_count_u32_elems(node, "st,min-sample-time-nsecs");
if (ret > 1 && ret != num_channels) {
dev_err(&indio_dev->dev, "Invalid st,min-sample-time-nsecs\n");
return -EINVAL;
}
channels = devm_kcalloc(&indio_dev->dev, num_channels,
sizeof(struct iio_chan_spec), GFP_KERNEL);
if (!channels)
return -ENOMEM;
of_property_for_each_u32(node, "st,adc-channels", prop, cur, val) {
if (val >= adc_info->max_channels) {
dev_err(&indio_dev->dev, "Invalid channel %d\n", val);
return -EINVAL;
}
/* Channel can't be configured both as single-ended & diff */
for (i = 0; i < num_diff; i++) {
if (val == diff[i].vinp) {
dev_err(&indio_dev->dev,
"channel %d miss-configured\n", val);
return -EINVAL;
}
}
stm32_adc_chan_init_one(indio_dev, &channels[scan_index], val,
0, scan_index, false);
scan_index++;
}
for (i = 0; i < num_diff; i++) {
if (diff[i].vinp >= adc_info->max_channels ||
diff[i].vinn >= adc_info->max_channels) {
dev_err(&indio_dev->dev, "Invalid channel in%d-in%d\n",
diff[i].vinp, diff[i].vinn);
return -EINVAL;
}
stm32_adc_chan_init_one(indio_dev, &channels[scan_index],
diff[i].vinp, diff[i].vinn, scan_index,
true);
scan_index++;
}
for (i = 0; i < scan_index; i++) {
/*
* Using of_property_read_u32_index(), smp value will only be
* modified if valid u32 value can be decoded. This allows to
* get either no value, 1 shared value for all indexes, or one
* value per channel.
*/
of_property_read_u32_index(node, "st,min-sample-time-nsecs",
i, &smp);
/* Prepare sampling time settings */
stm32_adc_smpr_init(adc, channels[i].channel, smp);
}
indio_dev->num_channels = scan_index;
indio_dev->channels = channels;
return 0;
}
static int stm32_adc_dma_request(struct device *dev, struct iio_dev *indio_dev)
{
struct stm32_adc *adc = iio_priv(indio_dev);
struct dma_slave_config config;
int ret;
adc->dma_chan = dma_request_chan(dev, "rx");
if (IS_ERR(adc->dma_chan)) {
ret = PTR_ERR(adc->dma_chan);
if (ret != -ENODEV) {
if (ret != -EPROBE_DEFER)
dev_err(dev,
"DMA channel request failed with %d\n",
ret);
return ret;
}
/* DMA is optional: fall back to IRQ mode */
adc->dma_chan = NULL;
return 0;
}
adc->rx_buf = dma_alloc_coherent(adc->dma_chan->device->dev,
STM32_DMA_BUFFER_SIZE,
&adc->rx_dma_buf, GFP_KERNEL);
if (!adc->rx_buf) {
ret = -ENOMEM;
goto err_release;
}
/* Configure DMA channel to read data register */
memset(&config, 0, sizeof(config));
config.src_addr = (dma_addr_t)adc->common->phys_base;
config.src_addr += adc->offset + adc->cfg->regs->dr;
config.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
ret = dmaengine_slave_config(adc->dma_chan, &config);
if (ret)
goto err_free;
return 0;
err_free:
dma_free_coherent(adc->dma_chan->device->dev, STM32_DMA_BUFFER_SIZE,
adc->rx_buf, adc->rx_dma_buf);
err_release:
dma_release_channel(adc->dma_chan);
return ret;
}
static int stm32_adc_probe(struct platform_device *pdev)
{
struct iio_dev *indio_dev;
struct device *dev = &pdev->dev;
irqreturn_t (*handler)(int irq, void *p) = NULL;
struct stm32_adc *adc;
int ret;
if (!pdev->dev.of_node)
return -ENODEV;
indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc));
if (!indio_dev)
return -ENOMEM;
adc = iio_priv(indio_dev);
adc->common = dev_get_drvdata(pdev->dev.parent);
spin_lock_init(&adc->lock);
init_completion(&adc->completion);
adc->cfg = (const struct stm32_adc_cfg *)
of_match_device(dev->driver->of_match_table, dev)->data;
indio_dev->name = dev_name(&pdev->dev);
indio_dev->dev.parent = &pdev->dev;
indio_dev->dev.of_node = pdev->dev.of_node;
indio_dev->info = &stm32_adc_iio_info;
indio_dev->modes = INDIO_DIRECT_MODE | INDIO_HARDWARE_TRIGGERED;
platform_set_drvdata(pdev, adc);
ret = of_property_read_u32(pdev->dev.of_node, "reg", &adc->offset);
if (ret != 0) {
dev_err(&pdev->dev, "missing reg property\n");
return -EINVAL;
}
adc->irq = platform_get_irq(pdev, 0);
if (adc->irq < 0) {
dev_err(&pdev->dev, "failed to get irq\n");
return adc->irq;
}
ret = devm_request_irq(&pdev->dev, adc->irq, stm32_adc_isr,
0, pdev->name, adc);
if (ret) {
dev_err(&pdev->dev, "failed to request IRQ\n");
return ret;
}
adc->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(adc->clk)) {
ret = PTR_ERR(adc->clk);
if (ret == -ENOENT && !adc->cfg->clk_required) {
adc->clk = NULL;
} else {
dev_err(&pdev->dev, "Can't get clock\n");
return ret;
}
}
if (adc->clk) {
ret = clk_prepare_enable(adc->clk);
if (ret < 0) {
dev_err(&pdev->dev, "clk enable failed\n");
return ret;
}
}
ret = stm32_adc_of_get_resolution(indio_dev);
if (ret < 0)
goto err_clk_disable;
stm32_adc_set_res(adc);
if (adc->cfg->selfcalib) {
ret = adc->cfg->selfcalib(adc);
if (ret)
goto err_clk_disable;
}
ret = stm32_adc_chan_of_init(indio_dev);
if (ret < 0)
goto err_clk_disable;
ret = stm32_adc_dma_request(dev, indio_dev);
if (ret < 0)
goto err_clk_disable;
if (!adc->dma_chan)
handler = &stm32_adc_trigger_handler;
ret = iio_triggered_buffer_setup(indio_dev,
&iio_pollfunc_store_time, handler,
&stm32_adc_buffer_setup_ops);
if (ret) {
dev_err(&pdev->dev, "buffer setup failed\n");
goto err_dma_disable;
}
ret = iio_device_register(indio_dev);
if (ret) {
dev_err(&pdev->dev, "iio dev register failed\n");
goto err_buffer_cleanup;
}
return 0;
err_buffer_cleanup:
iio_triggered_buffer_cleanup(indio_dev);
err_dma_disable:
if (adc->dma_chan) {
dma_free_coherent(adc->dma_chan->device->dev,
STM32_DMA_BUFFER_SIZE,
adc->rx_buf, adc->rx_dma_buf);
dma_release_channel(adc->dma_chan);
}
err_clk_disable:
if (adc->clk)
clk_disable_unprepare(adc->clk);
return ret;
}
static int stm32_adc_remove(struct platform_device *pdev)
{
struct stm32_adc *adc = platform_get_drvdata(pdev);
struct iio_dev *indio_dev = iio_priv_to_dev(adc);
iio_device_unregister(indio_dev);
iio_triggered_buffer_cleanup(indio_dev);
if (adc->dma_chan) {
dma_free_coherent(adc->dma_chan->device->dev,
STM32_DMA_BUFFER_SIZE,
adc->rx_buf, adc->rx_dma_buf);
dma_release_channel(adc->dma_chan);
}
if (adc->clk)
clk_disable_unprepare(adc->clk);
return 0;
}
static const struct stm32_adc_cfg stm32f4_adc_cfg = {
.regs = &stm32f4_adc_regspec,
.adc_info = &stm32f4_adc_info,
.trigs = stm32f4_adc_trigs,
.clk_required = true,
.start_conv = stm32f4_adc_start_conv,
.stop_conv = stm32f4_adc_stop_conv,
.smp_cycles = stm32f4_adc_smp_cycles,
};
static const struct stm32_adc_cfg stm32h7_adc_cfg = {
.regs = &stm32h7_adc_regspec,
.adc_info = &stm32h7_adc_info,
.trigs = stm32h7_adc_trigs,
.selfcalib = stm32h7_adc_selfcalib,
.start_conv = stm32h7_adc_start_conv,
.stop_conv = stm32h7_adc_stop_conv,
.prepare = stm32h7_adc_prepare,
.unprepare = stm32h7_adc_unprepare,
.smp_cycles = stm32h7_adc_smp_cycles,
};
static const struct stm32_adc_cfg stm32mp1_adc_cfg = {
.regs = &stm32h7_adc_regspec,
.adc_info = &stm32h7_adc_info,
.trigs = stm32h7_adc_trigs,
.has_vregready = true,
.selfcalib = stm32h7_adc_selfcalib,
.start_conv = stm32h7_adc_start_conv,
.stop_conv = stm32h7_adc_stop_conv,
.prepare = stm32h7_adc_prepare,
.unprepare = stm32h7_adc_unprepare,
.smp_cycles = stm32h7_adc_smp_cycles,
};
static const struct of_device_id stm32_adc_of_match[] = {
{ .compatible = "st,stm32f4-adc", .data = (void *)&stm32f4_adc_cfg },
{ .compatible = "st,stm32h7-adc", .data = (void *)&stm32h7_adc_cfg },
{ .compatible = "st,stm32mp1-adc", .data = (void *)&stm32mp1_adc_cfg },
{},
};
MODULE_DEVICE_TABLE(of, stm32_adc_of_match);
static struct platform_driver stm32_adc_driver = {
.probe = stm32_adc_probe,
.remove = stm32_adc_remove,
.driver = {
.name = "stm32-adc",
.of_match_table = stm32_adc_of_match,
},
};
module_platform_driver(stm32_adc_driver);
MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>");
MODULE_DESCRIPTION("STMicroelectronics STM32 ADC IIO driver");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:stm32-adc");
Reference in a new issue Copy permalink