/* * Simple synchronous userspace interface to SPI devices * * Copyright (C) 2006 SWAPP * Andrea Paterniani * Copyright (C) 2007 David Brownell (simplification, cleanup) * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ /* * Modified by ST Microelectronics. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define ST21NFCD_MTK 1 // #define WITH_SPI_CLK_MNGT 1 #ifdef ST21NFCD_MTK #include #endif // ST21NFCD_MTK #include "st21nfc/st21nfc.h" // #ifdef ST21NFCD_MTK /* * Define WITH_SPI_CLK_MNGT for integrations * where the SPI clock needs to be enabled on request */ // #define WITH_SPI_CLK_MNGT 1 // #ifdef WITH_SPI_CLK_MNGT // extern void mt_spi_enable_master_clk(struct spi_device *spidev); // extern void mt_spi_disable_master_clk(struct spi_device *spidev); // #endif // WITH_SPI_CLK_MNGT // #endif //ST21NFCD_MTK /* * This supports access to SPI devices using normal userspace I/O calls. * Note that while traditional UNIX/POSIX I/O semantics are half duplex, * and often mask message boundaries, full SPI support requires full duplex * transfers. There are several kinds of internal message boundaries to * handle chipselect management and other protocol options. * * SPI has a character major number assigned. We allocate minor numbers * dynamically using a bitmask. You must use hotplug tools, such as udev * (or mdev with busybox) to create and destroy the /dev/st54spi device * nodes, since there is no fixed association of minor numbers with any * particular SPI bus or device. */ //#define SPIDEV_MAJOR 0 /* dynamic */ static int spidev_major; #define N_SPI_MINORS 1 /* ... up to 256 */ static DECLARE_BITMAP(minors, N_SPI_MINORS); #define ST54SPI_IOC_RD_POWER _IOR(SPI_IOC_MAGIC, 99, __u32) #define ST54SPI_IOC_WR_POWER _IOW(SPI_IOC_MAGIC, 99, __u32) /* Bit masks for spi_device.mode management. Note that incorrect * settings for some settings can cause *lots* of trouble for other * devices on a shared bus: * * - CS_HIGH ... this device will be active when it shouldn't be * - 3WIRE ... when active, it won't behave as it should * - NO_CS ... there will be no explicit message boundaries; this * is completely incompatible with the shared bus model * - READY ... transfers may proceed when they shouldn't. * * REVISIT should changing those flags be privileged? */ #define SPI_MODE_MASK \ (SPI_CPHA | SPI_CPOL | SPI_CS_HIGH | \ SPI_LSB_FIRST | SPI_3WIRE | SPI_LOOP | \ SPI_NO_CS | SPI_READY | SPI_TX_DUAL | \ SPI_TX_QUAD | SPI_RX_DUAL | SPI_RX_QUAD) struct st54spi_data { dev_t devt; spinlock_t spi_lock; struct spi_device *spi; struct spi_device *spi_reset; struct list_head device_entry; /* TX/RX buffers are NULL unless this device is open (users > 0) */ struct mutex buf_lock; unsigned int users; u8 *tx_buffer; u8 *rx_buffer; u32 speed_hz; /* GPIO for SE_POWER_REQ / SE_nRESET */ int power_or_nreset_gpio_mode; int power_or_nreset_gpio; int nfcc_needs_poweron; int sehal_needs_poweron; int se_is_poweron; struct pinctrl *pctrl; struct pinctrl_state *pctrl_mode_spi, *pctrl_mode_idle; }; #define POWER_MODE_NONE -1 #define POWER_MODE_ST54H 0 #define POWER_MODE_ST54J 1 static LIST_HEAD(device_list); static DEFINE_MUTEX(device_list_lock); static unsigned int bufsiz = 4096; module_param(bufsiz, uint, 0444); MODULE_PARM_DESC(bufsiz, "data bytes in biggest supported SPI message"); static bool debug_enabled = true; #define VERBOSE 1 /*-------------------------------------------------------------------------*/ static ssize_t st54spi_sync( struct st54spi_data *st54spi, struct spi_message *message) { DECLARE_COMPLETION_ONSTACK(done); int status; struct spi_device *spi; spin_lock_irq(&st54spi->spi_lock); spi = st54spi->spi; spin_unlock_irq(&st54spi->spi_lock); if (spi == NULL) status = -ESHUTDOWN; else status = spi_sync(spi, message); if (status == 0) status = message->actual_length; return status; } static inline ssize_t st54spi_sync_write( struct st54spi_data *st54spi, size_t len) { struct spi_transfer t = { .tx_buf = st54spi->tx_buffer, .len = len, .speed_hz = st54spi->speed_hz, }; struct spi_message m; spi_message_init(&m); spi_message_add_tail(&t, &m); return st54spi_sync(st54spi, &m); } static inline ssize_t st54spi_sync_read( struct st54spi_data *st54spi, size_t len) { struct spi_transfer t = { .rx_buf = st54spi->rx_buffer, .len = len, .speed_hz = st54spi->speed_hz, }; struct spi_message m; spi_message_init(&m); spi_message_add_tail(&t, &m); return st54spi_sync(st54spi, &m); } /*-------------------------------------------------------------------------*/ /* Read-only message with current device setup */ static ssize_t st54spi_read( struct file *filp, char __user *buf, size_t count, loff_t *f_pos) { struct st54spi_data *st54spi; ssize_t status = 0; /* chipselect only toggles at start or end of operation */ if (count > bufsiz) return -EMSGSIZE; st54spi = filp->private_data; if (debug_enabled) dev_info(&st54spi->spi->dev, "st54spi Read: %d bytes\n", count); mutex_lock(&st54spi->buf_lock); status = st54spi_sync_read(st54spi, count); if (status > 0) { unsigned long missing; missing = copy_to_user(buf, st54spi->rx_buffer, status); if (missing == status) status = -EFAULT; else status = status - missing; } mutex_unlock(&st54spi->buf_lock); if (debug_enabled) dev_info(&st54spi->spi->dev, "st54spi Read: status: %d\n", status); return status; } /* Write-only message with current device setup */ static ssize_t st54spi_write( struct file *filp, const char __user *buf, size_t count, loff_t *f_pos) { struct st54spi_data *st54spi; ssize_t status = 0; unsigned long missing; /* chipselect only toggles at start or end of operation */ if (count > bufsiz) return -EMSGSIZE; st54spi = filp->private_data; if (debug_enabled) dev_info(&st54spi->spi->dev, "st54spi Write: %d bytes\n", count); mutex_lock(&st54spi->buf_lock); missing = copy_from_user(st54spi->tx_buffer, buf, count); if (missing == 0) status = st54spi_sync_write(st54spi, count); else status = -EFAULT; mutex_unlock(&st54spi->buf_lock); if (debug_enabled) dev_info(&st54spi->spi->dev, "st54spi Write: status: %d\n", status); return status; } static int st54spi_message( struct st54spi_data *st54spi, struct spi_ioc_transfer *u_xfers, unsigned int n_xfers) { struct spi_message msg; struct spi_transfer *k_xfers; struct spi_transfer *k_tmp; struct spi_ioc_transfer *u_tmp; unsigned int n, total, tx_total, rx_total; u8 *tx_buf, *rx_buf; int status = -EFAULT; spi_message_init(&msg); k_xfers = kcalloc(n_xfers, sizeof(*k_tmp), GFP_KERNEL); if (k_xfers == NULL) return -ENOMEM; /* Construct spi_message, copying any tx data to bounce buffer. * We walk the array of user-provided transfers, using each one * to initialize a kernel version of the same transfer. */ tx_buf = st54spi->tx_buffer; rx_buf = st54spi->rx_buffer; total = 0; tx_total = 0; rx_total = 0; for (n = n_xfers, k_tmp = k_xfers, u_tmp = u_xfers; n; n--, k_tmp++, u_tmp++) { k_tmp->len = u_tmp->len; total += k_tmp->len; /* Since the function returns the total length of transfers * on success, restrict the total to positive int values to * avoid the return value looking like an error. Also check * each transfer length to avoid arithmetic overflow. */ if (total > INT_MAX || k_tmp->len > INT_MAX) { status = -EMSGSIZE; goto done; } if (u_tmp->rx_buf) { /* this transfer needs space in RX bounce buffer */ rx_total += k_tmp->len; if (rx_total > bufsiz) { status = -EMSGSIZE; goto done; } k_tmp->rx_buf = rx_buf; if (!access_ok(VERIFY_WRITE, (u8 __user *)(uintptr_t)u_tmp->rx_buf, u_tmp->len)) goto done; rx_buf += k_tmp->len; } if (u_tmp->tx_buf) { /* this transfer needs space in TX bounce buffer */ tx_total += k_tmp->len; if (tx_total > bufsiz) { status = -EMSGSIZE; goto done; } k_tmp->tx_buf = tx_buf; if (copy_from_user(tx_buf, (const u8 __user *)(uintptr_t)u_tmp->tx_buf, u_tmp->len)) goto done; tx_buf += k_tmp->len; } k_tmp->cs_change = !!u_tmp->cs_change; k_tmp->tx_nbits = u_tmp->tx_nbits; k_tmp->rx_nbits = u_tmp->rx_nbits; k_tmp->bits_per_word = u_tmp->bits_per_word; k_tmp->delay_usecs = u_tmp->delay_usecs; k_tmp->speed_hz = u_tmp->speed_hz; if (!k_tmp->speed_hz) k_tmp->speed_hz = st54spi->speed_hz; #ifdef VERBOSE dev_dbg(&st54spi->spi->dev, " xfer len %u %s%s%s%dbits %u usec %uHz\n", u_tmp->len, u_tmp->rx_buf ? "rx " : "", u_tmp->tx_buf ? "tx " : "", u_tmp->cs_change ? "cs " : "", u_tmp->bits_per_word ?: st54spi->spi->bits_per_word, u_tmp->delay_usecs, u_tmp->speed_hz ?: st54spi->spi->max_speed_hz); #endif spi_message_add_tail(k_tmp, &msg); } status = st54spi_sync(st54spi, &msg); if (status < 0) goto done; /* copy any rx data out of bounce buffer */ rx_buf = st54spi->rx_buffer; for (n = n_xfers, u_tmp = u_xfers; n; n--, u_tmp++) { if (u_tmp->rx_buf) { if (__copy_to_user( (u8 __user *)(uintptr_t)u_tmp->rx_buf, rx_buf, u_tmp->len)) { status = -EFAULT; goto done; } rx_buf += u_tmp->len; } } status = total; done: kfree(k_xfers); return status; } static struct spi_ioc_transfer *st54spi_get_ioc_message( unsigned int cmd, struct spi_ioc_transfer __user *u_ioc, unsigned int *n_ioc) { struct spi_ioc_transfer *ioc; u32 tmp; /* Check type, command number and direction */ if (_IOC_TYPE(cmd) != SPI_IOC_MAGIC || _IOC_NR(cmd) != _IOC_NR(SPI_IOC_MESSAGE(0)) || _IOC_DIR(cmd) != _IOC_WRITE) return ERR_PTR(-ENOTTY); tmp = _IOC_SIZE(cmd); if ((tmp % sizeof(struct spi_ioc_transfer)) != 0) return ERR_PTR(-EINVAL); *n_ioc = tmp / sizeof(struct spi_ioc_transfer); if (*n_ioc == 0) return NULL; /* copy into scratch area */ ioc = kmalloc(tmp, GFP_KERNEL); if (!ioc) return ERR_PTR(-ENOMEM); if (__copy_from_user(ioc, u_ioc, tmp)) { kfree(ioc); return ERR_PTR(-EFAULT); } return ioc; } static void st54spi_power_off(struct st54spi_data *st54spi) { int ret; if (debug_enabled) dev_info(&st54spi->spi->dev, "%s\n", __func__); // Set NSS pin as highZ (ST54H and ST54J). // Change NSS polarity to have NSS low. ret = pinctrl_select_state(st54spi->pctrl, st54spi->pctrl_mode_idle); if (ret < 0) { dev_info(&st54spi->spi->dev, "%s : change NSS management to High Z failed!\n", __func__); } // Set SE_PWR_REQ / SE_nRESET to low if (st54spi->power_or_nreset_gpio) gpio_set_value(st54spi->power_or_nreset_gpio, 0); // if ST54H block access to SPI in case this is done during a CLF reset if (st54spi->power_or_nreset_gpio_mode == POWER_MODE_ST54H) { // disallow access to SPI r/w if (st54spi->spi) { spin_lock_irq(&st54spi->spi_lock); st54spi->spi_reset = st54spi->spi; st54spi->spi = NULL; spin_unlock_irq(&st54spi->spi_lock); } // Give time to the CLF to detect falling SE_PWR_REQ // and pull down the line before continue. usleep_range(2000, 4500); } #ifdef WITH_SPI_CLK_MNGT // no need for the SPI clock to be enabled. dev_info(&st54spi->spi->dev, "%s : disabling PMU clock of SPI subsystem\n", __func__); mt_spi_disable_master_clk(st54spi->spi); #endif // WITH_SPI_CLK_MNGT st54spi->se_is_poweron = 0; } static void st54spi_power_on(struct st54spi_data *st54spi) { int ret; if (debug_enabled) dev_info(&st54spi->spi->dev, "%s\n", __func__); #ifdef WITH_SPI_CLK_MNGT // the SPI clock needs to be enabled. dev_info(&st54spi->spi->dev, "%s : enabling PMU clock of SPI subsystem\n", __func__); mt_spi_enable_master_clk(st54spi->spi); #endif // WITH_SPI_CLK_MNGT // set SE_PWR_REQ / SE_nRESET to high and wait for CLF + eSE reaction if (st54spi->power_or_nreset_gpio) { gpio_set_value(st54spi->power_or_nreset_gpio, 1); usleep_range(1000, 1500); } // Set NSS pin for the SPI function. ret = pinctrl_select_state(st54spi->pctrl, st54spi->pctrl_mode_spi); if (ret < 0) { dev_info(&st54spi->spi->dev, "%s : change NSS management to SPI failed!\n", __func__); } usleep_range(4000, 5000); if (st54spi->power_or_nreset_gpio_mode == POWER_MODE_ST54H) { // re-allow SPI xfers if (st54spi->spi_reset) { spin_lock_irq(&st54spi->spi_lock); st54spi->spi = st54spi->spi_reset; st54spi->spi_reset = NULL; spin_unlock_irq(&st54spi->spi_lock); } } st54spi->se_is_poweron = 1; } static void st54spi_power_set(struct st54spi_data *st54spi, int val) { if (!st54spi) return; if (debug_enabled) dev_info(&st54spi->spi->dev, "st54spi sehal pwr_req: %d\n", val); if (val) { st54spi->sehal_needs_poweron = 1; if (st54spi->se_is_poweron == 0) st54spi_power_on(st54spi); } else { st54spi->sehal_needs_poweron = 0; if ((st54spi->se_is_poweron == 1) && (st54spi->nfcc_needs_poweron == 0)) // we don t need power anymore st54spi_power_off(st54spi); } } static int st54spi_power_get(struct st54spi_data *st54spi) { if (st54spi->power_or_nreset_gpio) return gpio_get_value(st54spi->power_or_nreset_gpio); return 0; } static long st54spi_ioctl( struct file *filp, unsigned int cmd, unsigned long arg) { int err = 0; int retval = 0; struct st54spi_data *st54spi; struct spi_device *spi; u32 tmp; unsigned int n_ioc; struct spi_ioc_transfer *ioc; /* Check type and command number */ if (_IOC_TYPE(cmd) != SPI_IOC_MAGIC) return -ENOTTY; /* Check access direction once here; don't repeat below. * IOC_DIR is from the user perspective, while access_ok is * from the kernel perspective; so they look reversed. */ if (_IOC_DIR(cmd) & _IOC_READ) err = !access_ok(VERIFY_WRITE, (void __user *)arg, _IOC_SIZE(cmd)); if (err == 0 && _IOC_DIR(cmd) & _IOC_WRITE) err = !access_ok(VERIFY_READ, (void __user *)arg, _IOC_SIZE(cmd)); if (err) return -EFAULT; /* guard against device removal before, or while, * we issue this ioctl. */ st54spi = filp->private_data; spin_lock_irq(&st54spi->spi_lock); spi = spi_dev_get(st54spi->spi); spin_unlock_irq(&st54spi->spi_lock); if (debug_enabled) dev_info(&st54spi->spi->dev, "st54spi ioctl cmd %d\n", cmd); if (spi == NULL) return -ESHUTDOWN; /* use the buffer lock here for triple duty: * - prevent I/O (from us) so calling spi_setup() is safe; * - prevent concurrent SPI_IOC_WR_* from morphing * data fields while SPI_IOC_RD_* reads them; * - SPI_IOC_MESSAGE needs the buffer locked "normally". */ mutex_lock(&st54spi->buf_lock); switch (cmd) { /* read requests */ case SPI_IOC_RD_MODE: retval = __put_user( spi->mode & SPI_MODE_MASK, (__u8 __user *)arg); break; case SPI_IOC_RD_MODE32: retval = __put_user( spi->mode & SPI_MODE_MASK, (__u32 __user *)arg); break; case SPI_IOC_RD_LSB_FIRST: retval = __put_user( (spi->mode & SPI_LSB_FIRST) ? 1 : 0, (__u8 __user *)arg); break; case SPI_IOC_RD_BITS_PER_WORD: retval = __put_user( spi->bits_per_word, (__u8 __user *)arg); break; case SPI_IOC_RD_MAX_SPEED_HZ: retval = __put_user( st54spi->speed_hz, (__u32 __user *)arg); break; case ST54SPI_IOC_RD_POWER: retval = __put_user( st54spi_power_get(st54spi), (__u32 __user *)arg); break; /* write requests */ case SPI_IOC_WR_MODE: case SPI_IOC_WR_MODE32: if (cmd == SPI_IOC_WR_MODE) retval = __get_user(tmp, (u8 __user *)arg); else retval = __get_user(tmp, (u32 __user *)arg); if (retval == 0) { u32 save = spi->mode; if (tmp & ~SPI_MODE_MASK) { retval = -EINVAL; break; } tmp |= spi->mode & ~SPI_MODE_MASK; spi->mode = (u16)tmp; retval = spi_setup(spi); if (retval < 0) spi->mode = save; else dev_dbg(&spi->dev, "spi mode %x\n", tmp); } break; case SPI_IOC_WR_LSB_FIRST: retval = __get_user(tmp, (__u8 __user *)arg); if (retval == 0) { u32 save = spi->mode; if (tmp) spi->mode |= SPI_LSB_FIRST; else spi->mode &= ~SPI_LSB_FIRST; retval = spi_setup(spi); if (retval < 0) spi->mode = save; else dev_dbg(&spi->dev, "%csb first\n", tmp ? 'l' : 'm'); } break; case SPI_IOC_WR_BITS_PER_WORD: retval = __get_user(tmp, (__u8 __user *)arg); if (retval == 0) { u8 save = spi->bits_per_word; spi->bits_per_word = tmp; retval = spi_setup(spi); if (retval < 0) spi->bits_per_word = save; else dev_dbg(&spi->dev, "%d bits per word\n", tmp); } break; case SPI_IOC_WR_MAX_SPEED_HZ: retval = __get_user(tmp, (__u32 __user *)arg); if (retval == 0) { u32 save = spi->max_speed_hz; spi->max_speed_hz = tmp; retval = spi_setup(spi); if (retval >= 0) st54spi->speed_hz = tmp; else dev_dbg(&spi->dev, "%d Hz (max)\n", tmp); spi->max_speed_hz = save; } break; case ST54SPI_IOC_WR_POWER: retval = __get_user(tmp, (__u32 __user *)arg); if (retval == 0) { st54spi_power_set(st54spi, tmp ? 1 : 0); dev_dbg(&spi->dev, "SE_POWER_REQ/SE_NRESET set: %d\n", tmp); } break; default: /* segmented and/or full-duplex I/O request */ /* Check message and copy into scratch area */ ioc = st54spi_get_ioc_message( cmd, (struct spi_ioc_transfer __user *)arg, &n_ioc); if (IS_ERR(ioc)) { retval = PTR_ERR(ioc); break; } if (!ioc) break; /* n_ioc is also 0 */ /* translate to spi_message, execute */ retval = st54spi_message(st54spi, ioc, n_ioc); kfree(ioc); break; } mutex_unlock(&st54spi->buf_lock); spi_dev_put(spi); if (debug_enabled) dev_info(&spi->dev, "st54spi ioctl retval %d\n", retval); return retval; } #ifdef CONFIG_COMPAT static long st54spi_compat_ioc_message( struct file *filp, unsigned int cmd, unsigned long arg) { struct spi_ioc_transfer __user *u_ioc; int retval = 0; struct st54spi_data *st54spi; struct spi_device *spi; unsigned int n_ioc, n; struct spi_ioc_transfer *ioc; u_ioc = (struct spi_ioc_transfer __user *)compat_ptr(arg); if (!access_ok(VERIFY_READ, u_ioc, _IOC_SIZE(cmd))) return -EFAULT; /* guard against device removal before, or while, * we issue this ioctl. */ st54spi = filp->private_data; spin_lock_irq(&st54spi->spi_lock); spi = spi_dev_get(st54spi->spi); spin_unlock_irq(&st54spi->spi_lock); if (debug_enabled) dev_info(&st54spi->spi->dev, "st54spi compat_ioctl cmd %d\n", cmd); if (spi == NULL) return -ESHUTDOWN; /* SPI_IOC_MESSAGE needs the buffer locked "normally" */ mutex_lock(&st54spi->buf_lock); /* Check message and copy into scratch area */ ioc = st54spi_get_ioc_message(cmd, u_ioc, &n_ioc); if (IS_ERR(ioc)) { retval = PTR_ERR(ioc); goto done; } if (!ioc) goto done; /* n_ioc is also 0 */ /* Convert buffer pointers */ for (n = 0; n < n_ioc; n++) { ioc[n].rx_buf = (uintptr_t)compat_ptr(ioc[n].rx_buf); ioc[n].tx_buf = (uintptr_t)compat_ptr(ioc[n].tx_buf); } /* translate to spi_message, execute */ retval = st54spi_message(st54spi, ioc, n_ioc); kfree(ioc); done: mutex_unlock(&st54spi->buf_lock); spi_dev_put(spi); if (debug_enabled) dev_info(&st54spi->spi->dev, "st54spi compat_ioctl retval %d\n", retval); return retval; } static long st54spi_compat_ioctl( struct file *filp, unsigned int cmd, unsigned long arg) { if (_IOC_TYPE(cmd) == SPI_IOC_MAGIC && _IOC_NR(cmd) == _IOC_NR(SPI_IOC_MESSAGE(0)) && _IOC_DIR(cmd) == _IOC_WRITE) return st54spi_compat_ioc_message(filp, cmd, arg); return st54spi_ioctl(filp, cmd, (unsigned long)compat_ptr(arg)); } #else #define st54spi_compat_ioctl NULL #endif /* CONFIG_COMPAT */ static int st54spi_open(struct inode *inode, struct file *filp) { struct st54spi_data *st54spi; int status = -ENXIO; mutex_lock(&device_list_lock); list_for_each_entry(st54spi, &device_list, device_entry) { if (st54spi->devt == inode->i_rdev) { status = 0; break; } } if (status) { dev_dbg(&st54spi->spi->dev, "st54spi: nothing for minor %d\n", iminor(inode)); goto err_find_dev; } // Authorize only 1 process to open the device. if (st54spi->users > 0) { dev_info(&st54spi->spi->dev, "%d: already open\n"); mutex_unlock(&device_list_lock); return -EBUSY; } if (debug_enabled) dev_info(&st54spi->spi->dev, "st54spi: open\n"); if (!st54spi->tx_buffer) { st54spi->tx_buffer = kmalloc(bufsiz, GFP_KERNEL); if (!st54spi->tx_buffer) { // dev_dbg(&st54spi->spi->dev, "open/ENOMEM\n"); status = -ENOMEM; goto err_find_dev; } } if (!st54spi->rx_buffer) { st54spi->rx_buffer = kmalloc(bufsiz, GFP_KERNEL); if (!st54spi->rx_buffer) { // dev_dbg(&st54spi->spi->dev, "open/ENOMEM\n"); status = -ENOMEM; goto err_alloc_rx_buf; } } st54spi->users++; filp->private_data = st54spi; nonseekable_open(inode, filp); mutex_unlock(&device_list_lock); if (debug_enabled) dev_info(&st54spi->spi->dev, "st54spi: open - force power on\n"); st54spi_power_set(st54spi, 1); return 0; err_alloc_rx_buf: kfree(st54spi->tx_buffer); st54spi->tx_buffer = NULL; err_find_dev: mutex_unlock(&device_list_lock); return status; } static int st54spi_release(struct inode *inode, struct file *filp) { struct st54spi_data *st54spi; mutex_lock(&device_list_lock); st54spi = filp->private_data; filp->private_data = NULL; if (debug_enabled) dev_info(&st54spi->spi->dev, "st54spi: release\n"); /* last close? */ st54spi->users--; if (!st54spi->users) { int dofree; if (debug_enabled) dev_info(&st54spi->spi->dev, "st54spi: release - may allow power off\n"); st54spi_power_set(st54spi, 0); kfree(st54spi->tx_buffer); st54spi->tx_buffer = NULL; kfree(st54spi->rx_buffer); st54spi->rx_buffer = NULL; spin_lock_irq(&st54spi->spi_lock); if (st54spi->spi) st54spi->speed_hz = st54spi->spi->max_speed_hz; /* ... after we unbound from the underlying device? */ dofree = ((st54spi->spi == NULL) && (st54spi->spi_reset == NULL)); spin_unlock_irq(&st54spi->spi_lock); if (dofree) kfree(st54spi); } mutex_unlock(&device_list_lock); return 0; } static const struct file_operations st54spi_fops = { .owner = THIS_MODULE, /* REVISIT switch to aio primitives, so that userspace * gets more complete API coverage. It'll simplify things * too, except for the locking. */ .write = st54spi_write, .read = st54spi_read, .unlocked_ioctl = st54spi_ioctl, .compat_ioctl = st54spi_compat_ioctl, .open = st54spi_open, .release = st54spi_release, .llseek = no_llseek, }; /*-------------------------------------------------------------------------*/ /* The main reason to have this class is to make mdev/udev create the * /dev/st54spi character device nodes exposing our userspace API. * It also simplifies memory management. */ static struct class *st54spi_class; static const struct of_device_id st54spi_dt_ids[] = { {.compatible = "st,st54spi"}, {}, }; MODULE_DEVICE_TABLE(of, st54spi_dt_ids); #ifdef CONFIG_ACPI /* Dummy SPI devices not to be used in production systems */ #define SPIDEV_ACPI_DUMMY 1 static const struct acpi_device_id st54spi_acpi_ids[] = { /* * The ACPI SPT000* devices are only meant for development and * testing. Systems used in production should have a proper ACPI * description of the connected peripheral and they should also use * a proper driver instead of poking directly to the SPI bus. */ {"SPT0001", SPIDEV_ACPI_DUMMY}, {"SPT0002", SPIDEV_ACPI_DUMMY}, {"SPT0003", SPIDEV_ACPI_DUMMY}, {}, }; MODULE_DEVICE_TABLE(acpi, st54spi_acpi_ids); static void st54spi_probe_acpi(struct spi_device *spi) { const struct acpi_device_id *id; if (!has_acpi_companion(&spi->dev)) return; id = acpi_match_device(st54spi_acpi_ids, &spi->dev); if (WARN_ON(!id)) return; } #else static inline void st54spi_probe_acpi(struct spi_device *spi) {} #endif /*-------------------------------------------------------------------------*/ static int st54spi_parse_dt(struct device *dev, struct st54spi_data *pdata) { int r = 0; struct device_node *np = dev->of_node; np = of_find_compatible_node(NULL, NULL, "st,st54spi"); if (np) { const char *power_mode; #if (!defined(CONFIG_MTK_GPIO) || defined(CONFIG_MTK_GPIOLIB_STAND)) r = of_get_named_gpio(np, "gpio-power_nreset-std", 0); if (r < 0) dev_info(dev, "%s: get ST54 failed (%d)", __FILE__, r); else pdata->power_or_nreset_gpio = r; r = 0; #else of_property_read_u32_array( np, "gpio-power_nreset", &(pdata->power_or_nreset_gpio), 1); #endif // Read power mode. power_mode = of_get_property(np, "power_mode", NULL); if (!power_mode) { dev_info(dev, "%s: Default power mode: ST54H\n", __FILE__); pdata->power_or_nreset_gpio_mode = POWER_MODE_ST54H; } else if (!strcmp(power_mode, "ST54J")) { dev_info(dev, "%s: Power mode: ST54J\n", __FILE__); pdata->power_or_nreset_gpio_mode = POWER_MODE_ST54J; } else if (!strcmp(power_mode, "ST54H")) { dev_info(dev, "%s: Power mode: ST54H\n", __FILE__); pdata->power_or_nreset_gpio_mode = POWER_MODE_ST54H; } else if (!strcmp(power_mode, "none")) { dev_info(dev, "%s: Power mode: none\n", __FILE__); pdata->power_or_nreset_gpio_mode = POWER_MODE_NONE; } else { dev_info(dev, "%s: Power mode unknown: %s\n", __FILE__, power_mode); return -1; } } else { dev_info(dev, "%s : get num err.\n", __func__); return -1; } // We need to use pinmux to control NSS pdata->pctrl = devm_pinctrl_get(dev); if (IS_ERR(pdata->pctrl)) { dev_info(dev, "%s: Unable to allocate pinctrl: %d\n", __FILE__, PTR_ERR(pdata->pctrl)); return -1; } pdata->pctrl_mode_spi = pinctrl_lookup_state(pdata->pctrl, "pinctrl_state_mode_spi"); if (IS_ERR(pdata->pctrl_mode_spi)) { dev_info(dev, "%s: Unable to find pinctrl_state_mode_spi: %d\n", __FILE__, PTR_ERR(pdata->pctrl_mode_spi)); return -1; } pdata->pctrl_mode_idle = pinctrl_lookup_state(pdata->pctrl, "pinctrl_state_mode_idle"); if (IS_ERR(pdata->pctrl_mode_idle)) { dev_info(dev, "%s: Unable to find pinctrl_state_mode_idle: %d\n", __FILE__, PTR_ERR(pdata->pctrl_mode_idle)); return -1; } dev_info(dev, "[dsc]%s : pinctrl initialized\n", __func__); dev_info(dev, "[dsc]%s : get power_or_nreset_gpio[%d]\n", __func__, pdata->power_or_nreset_gpio); return r; } #ifndef MODULE static void st54spi_st21nfc_cb(int dir, void *data) { struct st54spi_data *st54spi = (struct st54spi_data *)data; if (!st54spi) return; dev_info(&st54spi->spi->dev, "%s : dir %d data %p\n", __func__, dir, st54spi); switch (dir) { case ST54SPI_CB_RESET_START: if (st54spi->se_is_poweron) st54spi_power_off(st54spi); break; case ST54SPI_CB_RESET_END: // wait for the CLF to boot once nRESET is released usleep_range(4000, 8000); st54spi_power_on(st54spi); break; case ST54SPI_CB_ESE_USED: st54spi->nfcc_needs_poweron = 1; if (st54spi->se_is_poweron == 0) st54spi_power_on(st54spi); break; case ST54SPI_CB_ESE_NOT_USED: st54spi->nfcc_needs_poweron = 0; if ((st54spi->se_is_poweron == 1) && (st54spi->sehal_needs_poweron == 0)) // we don t need power anymore st54spi_power_off(st54spi); break; } } #endif // !MODULE /* Change CS_TIME for ST54 */ #ifdef ST21NFCD_MTK // Unit is 1/109.2 us. static struct mtk_chip_config st54spi_chip_info = { .cs_setuptime = 2184, // 20 us }; #endif static int st54spi_probe(struct spi_device *spi) { struct st54spi_data *st54spi; int status, ret; unsigned long minor; #ifdef ST21NFCD_MTK struct mtk_chip_config *chip_config = spi->controller_data; #endif /* * st54spi should never be referenced in DT without a specific * compatible string, it is a Linux implementation thing * rather than a description of the hardware. */ st54spi_probe_acpi(spi); /* Allocate driver data */ st54spi = kzalloc(sizeof(*st54spi), GFP_KERNEL); if (!st54spi) return -ENOMEM; /* Initialize the driver data */ st54spi->spi = spi; spin_lock_init(&st54spi->spi_lock); mutex_init(&st54spi->buf_lock); INIT_LIST_HEAD(&st54spi->device_entry); /* If we can allocate a minor number, hook up this device. * Reusing minors is fine so long as udev or mdev is working. */ mutex_lock(&device_list_lock); minor = find_first_zero_bit(minors, N_SPI_MINORS); if (minor < N_SPI_MINORS) { struct device *dev; st54spi->devt = MKDEV(spidev_major, minor); dev = device_create(st54spi_class, &spi->dev, st54spi->devt, // spidev, "spidev%d.%d", // spi->master->bus_num, spi->chip_select); st54spi, "st54spi"); status = PTR_ERR_OR_ZERO(dev); } else { dev_dbg(&spi->dev, "no minor number available!\n"); status = -ENODEV; } if (status == 0) { set_bit(minor, minors); list_add(&st54spi->device_entry, &device_list); } mutex_unlock(&device_list_lock); st54spi->speed_hz = spi->max_speed_hz; dev_dbg(&spi->dev, "st54spi->speed_hz=%d\n", st54spi->speed_hz); // { // /* fixed SPI clock speed: 109200000 */ // int period = DIV_ROUND_UP(109200000, st54spi->speed_hz); // st54spi_chip_info.cs_idletime = period; // st54spi_chip_info.cs_holdtime = period; // } #ifdef ST21NFCD_MTK // set timings for ST54 if (chip_config == NULL) { spi->controller_data = (void *)&st54spi_chip_info; dev_dbg(&spi->dev, "Replaced chip_info!\n"); } else { chip_config->cs_setuptime = st54spi_chip_info.cs_setuptime; chip_config->cs_idletime = st54spi_chip_info.cs_idletime; chip_config->cs_holdtime = st54spi_chip_info.cs_holdtime; dev_dbg(&spi->dev, "Added into chip_info!\n"); } #else dev_info(&spi->dev, "%s : TSU_NSS configuration be implemented!\n", __func__); // platform-specific method to configure the delay beween NSS slave // selection and the start of data transfer (clk). // If no specific method required, you can comment above line. #endif if (status == 0) spi_set_drvdata(spi, st54spi); else kfree(st54spi); (void)st54spi_parse_dt(&spi->dev, st54spi); if (st54spi->power_or_nreset_gpio != 0) { int default_value = 0; ret = gpio_request(st54spi->power_or_nreset_gpio, #if (!defined(CONFIG_MTK_GPIO) || defined(CONFIG_MTK_GPIOLIB_STAND)) "gpio-power_nreset-std" #else "gpio-power_nreset" #endif ); if (ret) dev_info(&spi->dev, "%s : power request failed (%d)\n", __FILE__, ret); dev_info(&spi->dev, "%s : power/nreset GPIO = %d\n", __func__, st54spi->power_or_nreset_gpio); ret = gpio_direction_output(st54spi->power_or_nreset_gpio, default_value); if (ret) dev_info(&spi->dev, "%s : reset direction_output failed\n", __FILE__); /* active high */ gpio_set_value(st54spi->power_or_nreset_gpio, default_value); } if (st54spi->power_or_nreset_gpio_mode == POWER_MODE_ST54H) { #ifndef MODULE dev_info(&spi->dev, "%s : Register with st21nfc driver, %p\n", __func__, st54spi); st21nfc_register_st54spi_cb(st54spi_st21nfc_cb, st54spi); #else dev_info(&spi->dev, "%s : st54spi as module cannot use ST54H fully\n", __func__); #endif } return status; } static int st54spi_remove(struct spi_device *spi) { struct st54spi_data *st54spi = spi_get_drvdata(spi); if (st54spi->power_or_nreset_gpio_mode == POWER_MODE_ST54H) { #ifndef MODULE dev_info(&st54spi->spi->dev, "%s : Unregister from st21nfc driver\n", __func__); st21nfc_unregister_st54spi_cb(); #endif } /* make sure ops on existing fds can abort cleanly */ spin_lock_irq(&st54spi->spi_lock); st54spi->spi = NULL; st54spi->spi_reset = NULL; spin_unlock_irq(&st54spi->spi_lock); /* prevent new opens */ mutex_lock(&device_list_lock); list_del(&st54spi->device_entry); device_destroy(st54spi_class, st54spi->devt); clear_bit(MINOR(st54spi->devt), minors); if (st54spi->users == 0) kfree(st54spi); mutex_unlock(&device_list_lock); return 0; } static struct spi_driver st54spi_spi_driver = { .driver = { .name = "st54spi", .of_match_table = of_match_ptr(st54spi_dt_ids), .acpi_match_table = ACPI_PTR(st54spi_acpi_ids), }, .probe = st54spi_probe, .remove = st54spi_remove, /* NOTE: suspend/resume methods are not necessary here. * We don't do anything except pass the requests to/from * the underlying controller. The refrigerator handles * most issues; the controller driver handles the rest. */ }; /*-------------------------------------------------------------------------*/ static int __init st54spi_init(void) { int status; pr_info("Loading st54spi driver\n"); /* Claim our 256 reserved device numbers. Then register a class * that will key udev/mdev to add/remove /dev nodes. Last, register * the driver which manages those device numbers. */ BUILD_BUG_ON(N_SPI_MINORS > 256); spidev_major = __register_chrdev(0, 0, N_SPI_MINORS, "spi", &st54spi_fops); pr_info("Loading st54spi driver, major: %d\n", spidev_major); st54spi_class = class_create(THIS_MODULE, "spidev"); if (IS_ERR(st54spi_class)) { unregister_chrdev(spidev_major, st54spi_spi_driver.driver.name); return PTR_ERR(st54spi_class); } status = spi_register_driver(&st54spi_spi_driver); if (status < 0) { class_destroy(st54spi_class); unregister_chrdev(spidev_major, st54spi_spi_driver.driver.name); } pr_info("Loading st54spi driver: %d\n", status); return status; } module_init(st54spi_init); static void __exit st54spi_exit(void) { spi_unregister_driver(&st54spi_spi_driver); class_destroy(st54spi_class); unregister_chrdev(spidev_major, st54spi_spi_driver.driver.name); } module_exit(st54spi_exit); MODULE_AUTHOR("Andrea Paterniani, "); MODULE_DESCRIPTION("User mode SPI device interface"); MODULE_LICENSE("GPL"); MODULE_ALIAS("spi:st54spi");