[RFC PATCH 07/12] gpio: amd-fch: add oftree probing support

Enrico Weigelt, metux IT consult
2021-02-08T22:27:36Z

Add support for probing via device tree.
---
drivers/gpio/gpio-amd-fch.c | 58 +++++++++++++++++++++++++
include/dt-bindings/gpio/amd-fch-gpio.h | 36 +++++++++++++++
include/linux/platform_data/gpio/gpio-amd-fch.h | 24 ++--------
3 files changed, 98 insertions(+), 20 deletions(-)
create mode 100644 include/dt-bindings/gpio/amd-fch-gpio.h

diff --git a/drivers/gpio/gpio-amd-fch.c b/drivers/gpio/gpio-amd-fch.c
index 2a21354ed6a0..32024f99dae5 100644
--- a/drivers/gpio/gpio-amd-fch.c
+++ b/drivers/gpio/gpio-amd-fch.c
@@ -136,12 +136,61 @@ static int amd_fch_gpio_request(struct gpio_chip *chip,
return 0;
}

+static struct amd_fch_gpio_pdata *load_pdata(struct device *dev)
+{
+ struct amd_fch_gpio_pdata *pdata;
+ int ret;
+
+ pdata = devm_kzalloc(dev, sizeof(struct amd_fch_gpio_pdata),
+ GFP_KERNEL);
+ if (!pdata)
+ goto nomem;
+
+ pdata->gpio_num = of_property_count_elems_of_size(dev->of_node,
+ "gpio-regs",
+ sizeof(u32));
+ pdata->gpio_reg = devm_kzalloc(dev, sizeof(int)*pdata->gpio_num,
+ GFP_KERNEL);
+ if (!pdata->gpio_reg)
+ goto nomem;
+
+ pdata->gpio_names = devm_kzalloc(dev, sizeof(char*)*pdata->gpio_num,
+ GFP_KERNEL);
+ if (!pdata->gpio_names)
+ goto nomem;
+
+ ret = of_property_read_variable_u32_array(dev->of_node, "gpio-regs",
+ pdata->gpio_reg,
+ pdata->gpio_num,
+ pdata->gpio_num);
+ if (ret != pdata->gpio_num) {
+ dev_err(dev, "failed reading gpio-regs from DT: %d\n", ret);
+ return NULL;
+ }
+
+ ret = of_property_read_string_array(dev->of_node, "gpio-line-names",
+ pdata->gpio_names, pdata->gpio_num);
+ if (ret != pdata->gpio_num) {
+ dev_err(dev, "failed reading gpio-names from DT: %d\n", ret);
+ return NULL;
+ }
+
+ return pdata;
+
+nomem:
+ dev_err(dev, "load_pdata: failed allocating memory\n");
+ return NULL;
+}
+
static int amd_fch_gpio_probe(struct platform_device *pdev)
{
struct amd_fch_gpio_priv *priv;
struct amd_fch_gpio_pdata *pdata;

pdata = dev_get_platdata(&pdev->dev);
+ if (!pdata)
+ pdata = load_pdata(&pdev->dev);
+
if (!pdata) {
dev_err(&pdev->dev, "no platform_data\n");
return -ENOENT;
@@ -165,6 +214,9 @@ static int amd_fch_gpio_probe(struct platform_device *pdev)
priv->gc.get_direction = amd_fch_gpio_get_direction;
priv->gc.get = amd_fch_gpio_get;
priv->gc.set = amd_fch_gpio_set;
+#ifdef CONFIG_OF_GPIO
+ priv->gc.of_node = pdev->dev.of_node;
+#endif

spin_lock_init(&priv->lock);

@@ -177,9 +229,15 @@ static int amd_fch_gpio_probe(struct platform_device *pdev)
return devm_gpiochip_add_data(&pdev->dev, &priv->gc, priv);
}

+static const struct of_device_id amd_fch_gpio_of_match[] = {
+ { .compatible = "amd,fch-gpio" },
+ {}
+};
+
static struct platform_driver amd_fch_gpio_driver = {
.driver = {
.name = AMD_FCH_GPIO_DRIVER_NAME,
+ .of_match_table = amd_fch_gpio_of_match,
},
.probe = amd_fch_gpio_probe,
};
diff --git a/include/dt-bindings/gpio/amd-fch-gpio.h b/include/dt-bindings/gpio/amd-fch-gpio.h
new file mode 100644
index 000000000000..7a47e6debcdb
--- /dev/null
+++ b/include/dt-bindings/gpio/amd-fch-gpio.h
@@ -0,0 +1,36 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+
+/*
+ * AMD FCH gpio platform data definitions
+ *
+ * Copyright (C) 2020 metux IT consult
+ * Author: Enrico Weigelt <info@metux.net>
+ *
+ */
+
+#ifndef __DT_BINDINGS_GPIO_AMD_FCH_REGS_H
+#define __DT_BINDINGS_GPIO_AMD_FCH_REGS_H
+
+/*
+ * gpio registers addresses
+ *
+ * these regs need to be assigned by board setup, since they're wired
+ * in very board specifici was, rarely documented, this should not be
+ * available to users.
+ */
+#define AMD_FCH_GPIO_REG_GPIO49 0x40
+#define AMD_FCH_GPIO_REG_GPIO50 0x41
+#define AMD_FCH_GPIO_REG_GPIO51 0x42
+#define AMD_FCH_GPIO_REG_GPIO55_DEVSLP0 0x43
+#define AMD_FCH_GPIO_REG_GPIO57 0x44
+#define AMD_FCH_GPIO_REG_GPIO58 0x45
+#define AMD_FCH_GPIO_REG_GPIO59_DEVSLP1 0x46
+#define AMD_FCH_GPIO_REG_GPIO64 0x47
+#define AMD_FCH_GPIO_REG_GPIO68 0x48
+#define AMD_FCH_GPIO_REG_GPIO66_SPKR 0x5B
+#define AMD_FCH_GPIO_REG_GPIO71 0x4D
+#define AMD_FCH_GPIO_REG_GPIO32_GE1 0x59
+#define AMD_FCH_GPIO_REG_GPIO33_GE2 0x5A
+#define AMT_FCH_GPIO_REG_GEVT22 0x09
+
+#endif /* __DT_BINDINGS_GPIO_AMD_FCH_REGS_H */
diff --git a/include/linux/platform_data/gpio/gpio-amd-fch.h b/include/linux/platform_data/gpio/gpio-amd-fch.h
index 255d51c9d36d..336f7387e82c 100644
--- a/include/linux/platform_data/gpio/gpio-amd-fch.h
+++ b/include/linux/platform_data/gpio/gpio-amd-fch.h
@@ -11,25 +11,9 @@
#ifndef __LINUX_PLATFORM_DATA_GPIO_AMD_FCH_H
#define __LINUX_PLATFORM_DATA_GPIO_AMD_FCH_H

-#define AMD_FCH_GPIO_DRIVER_NAME "gpio_amd_fch"
+#include <dt-bindings/gpio/amd-fch-gpio.h>

-/*
- * gpio register index definitions
- */
-#define AMD_FCH_GPIO_REG_GPIO49 0x40
-#define AMD_FCH_GPIO_REG_GPIO50 0x41
-#define AMD_FCH_GPIO_REG_GPIO51 0x42
-#define AMD_FCH_GPIO_REG_GPIO55_DEVSLP0 0x43
-#define AMD_FCH_GPIO_REG_GPIO57 0x44
-#define AMD_FCH_GPIO_REG_GPIO58 0x45
-#define AMD_FCH_GPIO_REG_GPIO59_DEVSLP1 0x46
-#define AMD_FCH_GPIO_REG_GPIO64 0x47
-#define AMD_FCH_GPIO_REG_GPIO68 0x48
-#define AMD_FCH_GPIO_REG_GPIO66_SPKR 0x5B
-#define AMD_FCH_GPIO_REG_GPIO71 0x4D
-#define AMD_FCH_GPIO_REG_GPIO32_GE1 0x59
-#define AMD_FCH_GPIO_REG_GPIO33_GE2 0x5A
-#define AMT_FCH_GPIO_REG_GEVT22 0x09
+#define AMD_FCH_GPIO_DRIVER_NAME "gpio_amd_fch"

/*
* struct amd_fch_gpio_pdata - GPIO chip platform data
@@ -39,8 +23,8 @@
*/
struct amd_fch_gpio_pdata {
int gpio_num;
- int *gpio_reg;
- const char * const *gpio_names;
+ u32 *gpio_reg;
+ const char * *gpio_names;
};

#endif /* __LINUX_PLATFORM_DATA_GPIO_AMD_FCH_H */
--
2.11.0