linux/drivers/misc/eeprom/digsy_mtc_eeprom.c

104 lines
2.6 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* EEPROMs access control driver for display configuration EEPROMs
* on DigsyMTC board.
*
* (C) 2011 DENX Software Engineering, Anatolij Gustschin <agust@denx.de>
*
* 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);