107 lines
2.8 KiB
C
Executable file
107 lines
2.8 KiB
C
Executable file
/*
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* EEPROMs access control driver for display configuration EEPROMs
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* on DigsyMTC board.
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*
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* (C) 2011 DENX Software Engineering, Anatolij Gustschin <agust@denx.de>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* FIXME: this driver is used on a device-tree probed platform: it
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* should be defined as a bit-banged SPI device and probed from the device
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* tree and not like this with static grabbing of a few numbered GPIO
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* lines at random.
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*
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* Add proper SPI and EEPROM in arch/powerpc/boot/dts/digsy_mtc.dts
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* and delete this driver.
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*/
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#include <linux/gpio.h>
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#include <linux/gpio/machine.h>
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#include <linux/init.h>
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#include <linux/platform_device.h>
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#include <linux/spi/spi.h>
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#include <linux/spi/spi_gpio.h>
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#include <linux/eeprom_93xx46.h>
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#define GPIO_EEPROM_CLK 216
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#define GPIO_EEPROM_CS 210
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#define GPIO_EEPROM_DI 217
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#define GPIO_EEPROM_DO 249
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#define GPIO_EEPROM_OE 255
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#define EE_SPI_BUS_NUM 1
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static void digsy_mtc_op_prepare(void *p)
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{
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/* enable */
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gpio_set_value(GPIO_EEPROM_OE, 0);
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}
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static void digsy_mtc_op_finish(void *p)
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{
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/* disable */
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gpio_set_value(GPIO_EEPROM_OE, 1);
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}
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struct eeprom_93xx46_platform_data digsy_mtc_eeprom_data = {
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.flags = EE_ADDR8,
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.prepare = digsy_mtc_op_prepare,
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.finish = digsy_mtc_op_finish,
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};
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static struct spi_gpio_platform_data eeprom_spi_gpio_data = {
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.num_chipselect = 1,
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};
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static struct platform_device digsy_mtc_eeprom = {
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.name = "spi_gpio",
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.id = EE_SPI_BUS_NUM,
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.dev = {
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.platform_data = &eeprom_spi_gpio_data,
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},
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};
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static struct gpiod_lookup_table eeprom_spi_gpiod_table = {
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.dev_id = "spi_gpio",
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.table = {
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GPIO_LOOKUP("gpio@b00", GPIO_EEPROM_CLK,
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"sck", GPIO_ACTIVE_HIGH),
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GPIO_LOOKUP("gpio@b00", GPIO_EEPROM_DI,
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"mosi", GPIO_ACTIVE_HIGH),
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GPIO_LOOKUP("gpio@b00", GPIO_EEPROM_DO,
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"miso", GPIO_ACTIVE_HIGH),
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GPIO_LOOKUP("gpio@b00", GPIO_EEPROM_CS,
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"cs", GPIO_ACTIVE_HIGH),
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{ },
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},
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};
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static struct spi_board_info digsy_mtc_eeprom_info[] __initdata = {
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{
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.modalias = "93xx46",
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.max_speed_hz = 1000000,
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.bus_num = EE_SPI_BUS_NUM,
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.chip_select = 0,
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.mode = SPI_MODE_0,
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.platform_data = &digsy_mtc_eeprom_data,
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},
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};
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static int __init digsy_mtc_eeprom_devices_init(void)
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{
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int ret;
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ret = gpio_request_one(GPIO_EEPROM_OE, GPIOF_OUT_INIT_HIGH,
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"93xx46 EEPROMs OE");
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if (ret) {
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pr_err("can't request gpio %d\n", GPIO_EEPROM_OE);
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return ret;
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}
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gpiod_add_lookup_table(&eeprom_spi_gpiod_table);
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spi_register_board_info(digsy_mtc_eeprom_info,
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ARRAY_SIZE(digsy_mtc_eeprom_info));
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return platform_device_register(&digsy_mtc_eeprom);
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}
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device_initcall(digsy_mtc_eeprom_devices_init);
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