1 files changed, 103 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 0000000000..f1f766b709
--- /dev/null
+++ b/drivers/misc/eeprom/digsy_mtc_eeprom.c
@@ -0,0 +1,103 @@
+// 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);