1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * EEPROMs access control driver for display configuration EEPROMs 4 * on DigsyMTC board. 5 * 6 * (C) 2011 DENX Software Engineering, Anatolij Gustschin <agust@denx.de> 7 * 8 * FIXME: this driver is used on a device-tree probed platform: it 9 * should be defined as a bit-banged SPI device and probed from the device 10 * tree and not like this with static grabbing of a few numbered GPIO 11 * lines at random. 12 * 13 * Add proper SPI and EEPROM in arch/powerpc/boot/dts/digsy_mtc.dts 14 * and delete this driver. 15 */ 16 17 #include <linux/gpio.h> 18 #include <linux/gpio/machine.h> 19 #include <linux/init.h> 20 #include <linux/platform_device.h> 21 #include <linux/spi/spi.h> 22 #include <linux/spi/spi_gpio.h> 23 #include <linux/eeprom_93xx46.h> 24 25 #define GPIO_EEPROM_CLK 216 26 #define GPIO_EEPROM_CS 210 27 #define GPIO_EEPROM_DI 217 28 #define GPIO_EEPROM_DO 249 29 #define GPIO_EEPROM_OE 255 30 #define EE_SPI_BUS_NUM 1 31 32 static void digsy_mtc_op_prepare(void *p) 33 { 34 /* enable */ 35 gpio_set_value(GPIO_EEPROM_OE, 0); 36 } 37 38 static void digsy_mtc_op_finish(void *p) 39 { 40 /* disable */ 41 gpio_set_value(GPIO_EEPROM_OE, 1); 42 } 43 44 struct eeprom_93xx46_platform_data digsy_mtc_eeprom_data = { 45 .flags = EE_ADDR8, 46 .prepare = digsy_mtc_op_prepare, 47 .finish = digsy_mtc_op_finish, 48 }; 49 50 static struct spi_gpio_platform_data eeprom_spi_gpio_data = { 51 .num_chipselect = 1, 52 }; 53 54 static struct platform_device digsy_mtc_eeprom = { 55 .name = "spi_gpio", 56 .id = EE_SPI_BUS_NUM, 57 .dev = { 58 .platform_data = &eeprom_spi_gpio_data, 59 }, 60 }; 61 62 static struct gpiod_lookup_table eeprom_spi_gpiod_table = { 63 .dev_id = "spi_gpio", 64 .table = { 65 GPIO_LOOKUP("gpio@b00", GPIO_EEPROM_CLK, 66 "sck", GPIO_ACTIVE_HIGH), 67 GPIO_LOOKUP("gpio@b00", GPIO_EEPROM_DI, 68 "mosi", GPIO_ACTIVE_HIGH), 69 GPIO_LOOKUP("gpio@b00", GPIO_EEPROM_DO, 70 "miso", GPIO_ACTIVE_HIGH), 71 GPIO_LOOKUP("gpio@b00", GPIO_EEPROM_CS, 72 "cs", GPIO_ACTIVE_HIGH), 73 { }, 74 }, 75 }; 76 77 static struct spi_board_info digsy_mtc_eeprom_info[] __initdata = { 78 { 79 .modalias = "93xx46", 80 .max_speed_hz = 1000000, 81 .bus_num = EE_SPI_BUS_NUM, 82 .chip_select = 0, 83 .mode = SPI_MODE_0, 84 .platform_data = &digsy_mtc_eeprom_data, 85 }, 86 }; 87 88 static int __init digsy_mtc_eeprom_devices_init(void) 89 { 90 int ret; 91 92 ret = gpio_request_one(GPIO_EEPROM_OE, GPIOF_OUT_INIT_HIGH, 93 "93xx46 EEPROMs OE"); 94 if (ret) { 95 pr_err("can't request gpio %d\n", GPIO_EEPROM_OE); 96 return ret; 97 } 98 gpiod_add_lookup_table(&eeprom_spi_gpiod_table); 99 spi_register_board_info(digsy_mtc_eeprom_info, 100 ARRAY_SIZE(digsy_mtc_eeprom_info)); 101 return platform_device_register(&digsy_mtc_eeprom); 102 } 103 device_initcall(digsy_mtc_eeprom_devices_init); 104