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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/misc/eeprom/digsy_mtc_eeprom.c
parentInitial commit. (diff)
downloadlinux-upstream.tar.xz
linux-upstream.zip
Adding upstream version 6.1.76.upstream/6.1.76upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/misc/eeprom/digsy_mtc_eeprom.c')
-rw-r--r--drivers/misc/eeprom/digsy_mtc_eeprom.c103
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 000000000..f1f766b70
--- /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);