diff options
Diffstat (limited to 'drivers/misc/eeprom/digsy_mtc_eeprom.c')
| -rw-r--r-- | drivers/misc/eeprom/digsy_mtc_eeprom.c | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/drivers/misc/eeprom/digsy_mtc_eeprom.c b/drivers/misc/eeprom/digsy_mtc_eeprom.c new file mode 100644 index 000000000..fbde2516c --- /dev/null +++ b/drivers/misc/eeprom/digsy_mtc_eeprom.c @@ -0,0 +1,106 @@ +/* + * EEPROMs access control driver for display configuration EEPROMs + * on DigsyMTC board. + * + * (C) 2011 DENX Software Engineering, Anatolij Gustschin <agust@denx.de> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * FIXME: this driver is used on a device-tree probed platform: it + * should be defined as a bit-banged SPI device and probed from the device + * tree and not like this with static grabbing of a few numbered GPIO + * lines at random. + * + * Add proper SPI and EEPROM in arch/powerpc/boot/dts/digsy_mtc.dts + * and delete this driver. + */ + +#include <linux/gpio.h> +#include <linux/gpio/machine.h> +#include <linux/init.h> +#include <linux/platform_device.h> +#include <linux/spi/spi.h> +#include <linux/spi/spi_gpio.h> +#include <linux/eeprom_93xx46.h> + +#define GPIO_EEPROM_CLK 216 +#define GPIO_EEPROM_CS 210 +#define GPIO_EEPROM_DI 217 +#define GPIO_EEPROM_DO 249 +#define GPIO_EEPROM_OE 255 +#define EE_SPI_BUS_NUM 1 + +static void digsy_mtc_op_prepare(void *p) +{ + /* enable */ + gpio_set_value(GPIO_EEPROM_OE, 0); +} + +static void digsy_mtc_op_finish(void *p) +{ + /* disable */ + gpio_set_value(GPIO_EEPROM_OE, 1); +} + +struct eeprom_93xx46_platform_data digsy_mtc_eeprom_data = { + .flags = EE_ADDR8, + .prepare = digsy_mtc_op_prepare, + .finish = digsy_mtc_op_finish, +}; + +static struct spi_gpio_platform_data eeprom_spi_gpio_data = { + .num_chipselect = 1, +}; + +static struct platform_device digsy_mtc_eeprom = { + .name = "spi_gpio", + .id = EE_SPI_BUS_NUM, + .dev = { + .platform_data = &eeprom_spi_gpio_data, + }, +}; + +static struct gpiod_lookup_table eeprom_spi_gpiod_table = { + .dev_id = "spi_gpio", + .table = { + GPIO_LOOKUP("gpio@b00", GPIO_EEPROM_CLK, + "sck", GPIO_ACTIVE_HIGH), + GPIO_LOOKUP("gpio@b00", GPIO_EEPROM_DI, + "mosi", GPIO_ACTIVE_HIGH), + GPIO_LOOKUP("gpio@b00", GPIO_EEPROM_DO, + "miso", GPIO_ACTIVE_HIGH), + GPIO_LOOKUP("gpio@b00", GPIO_EEPROM_CS, + "cs", GPIO_ACTIVE_HIGH), + { }, + }, +}; + +static struct spi_board_info digsy_mtc_eeprom_info[] __initdata = { + { + .modalias = "93xx46", + .max_speed_hz = 1000000, + .bus_num = EE_SPI_BUS_NUM, + .chip_select = 0, + .mode = SPI_MODE_0, + .platform_data = &digsy_mtc_eeprom_data, + }, +}; + +static int __init digsy_mtc_eeprom_devices_init(void) +{ + int ret; + + ret = gpio_request_one(GPIO_EEPROM_OE, GPIOF_OUT_INIT_HIGH, + "93xx46 EEPROMs OE"); + if (ret) { + pr_err("can't request gpio %d\n", GPIO_EEPROM_OE); + return ret; + } + gpiod_add_lookup_table(&eeprom_spi_gpiod_table); + spi_register_board_info(digsy_mtc_eeprom_info, + ARRAY_SIZE(digsy_mtc_eeprom_info)); + return platform_device_register(&digsy_mtc_eeprom); +} +device_initcall(digsy_mtc_eeprom_devices_init); |