[PATCH V12 2/2] gpio: max77620: add gpio driver for MAX77620/MAX20024

From: Laxman Dewangan
Date: Fri May 13 2016 - 01:31:56 EST


MAXIM Semiconductor's PMIC, MAX77620/MAX20024 has 8 GPIO
pins. It also supports interrupts from these pins.

Add GPIO driver for these pins to control via GPIO APIs.

Signed-off-by: Laxman Dewangan <ldewangan@xxxxxxxxxx>
Reviewed-by: Linus Walleij <linus.walleij@xxxxxxxxxx>

---
This as part of the max77620 series and mfd patch are already applied.
This can go in subsystem branch.

Changes from V1:
- Use the gpiochip_add_data and get the chip data from core APIs.
- Cleanups based on comment received on mfd/rtc.
- Avoid duplication on error message.

Changes form V2:
- Run coccicheck and checkpatch in strict mode for the alignment.
- update based on api changes from core.

Changes from V3:
- Change all sys initcall to module driver.
- change the max77620_read argument to unisgned int from u8.

Changes from V4:
- Added DT binding document as devicetree/bindings/gpio/gpio-max77620.txt

Changes from V5:
- Separate out DT binding doc for gpio.
- Added reviewed by for Linus W

Changes from V6/V7:
- None

Changes from V8:
- Run checkpatch --strict and fix error. Mostly to use unsigned int instead
of unsigned.
- Use linux/gpio/driver.h

Changes from V9:
- Use devm_regmap_add_irq_chip() and devm_gpiochip_add_data()

Changes from V10:
None

Changes from V11:
- Change bool to tristate in CONFIG
---
drivers/gpio/Kconfig | 9 ++
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-max77620.c | 238 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 248 insertions(+)
create mode 100644 drivers/gpio/gpio-max77620.c

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 48da857..9244381 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -870,6 +870,15 @@ config GPIO_LP3943
LP3943 can be used as a GPIO expander which provides up to 16 GPIOs.
Open drain outputs are required for this usage.

+config GPIO_MAX77620
+ tristate "GPIO support for PMIC MAX77620 and MAX20024"
+ depends on MFD_MAX77620
+ help
+ GPIO driver for MAX77620 and MAX20024 PMIC from Maxim Semiconductor.
+ MAX77620 PMIC has 8 pins that can be configured as GPIOs. The
+ driver also provides interrupt support for each of the gpios.
+ Say yes here to enable the max77620 to be used as gpio controller.
+
config GPIO_MSIC
bool "Intel MSIC mixed signal gpio support"
depends on MFD_INTEL_MSIC
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 991598e..6e111fc 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -61,6 +61,7 @@ obj-$(CONFIG_GPIO_MAX730X) += gpio-max730x.o
obj-$(CONFIG_GPIO_MAX7300) += gpio-max7300.o
obj-$(CONFIG_GPIO_MAX7301) += gpio-max7301.o
obj-$(CONFIG_GPIO_MAX732X) += gpio-max732x.o
+obj-$(CONFIG_GPIO_MAX77620) += gpio-max77620.o
obj-$(CONFIG_GPIO_MB86S7X) += gpio-mb86s7x.o
obj-$(CONFIG_GPIO_MENZ127) += gpio-menz127.o
obj-$(CONFIG_GPIO_MC33880) += gpio-mc33880.o
diff --git a/drivers/gpio/gpio-max77620.c b/drivers/gpio/gpio-max77620.c
new file mode 100644
index 0000000..d927562
--- /dev/null
+++ b/drivers/gpio/gpio-max77620.c
@@ -0,0 +1,238 @@
+/*
+ * MAXIM MAX77620 GPIO driver
+ *
+ * Copyright (c) 2016, NVIDIA CORPORATION. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ */
+
+#include <linux/gpio/driver.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/max77620.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#define GPIO_REG_ADDR(offset) (MAX77620_REG_GPIO0 + offset)
+
+struct max77620_gpio {
+ struct gpio_chip gpio_chip;
+ struct regmap *rmap;
+ struct device *dev;
+ int gpio_irq;
+ int irq_base;
+ int gpio_base;
+};
+
+static const struct regmap_irq max77620_gpio_irqs[] = {
+ REGMAP_IRQ_REG(0, 0, MAX77620_IRQ_LVL2_GPIO_EDGE0),
+ REGMAP_IRQ_REG(1, 0, MAX77620_IRQ_LVL2_GPIO_EDGE1),
+ REGMAP_IRQ_REG(2, 0, MAX77620_IRQ_LVL2_GPIO_EDGE2),
+ REGMAP_IRQ_REG(3, 0, MAX77620_IRQ_LVL2_GPIO_EDGE3),
+ REGMAP_IRQ_REG(4, 0, MAX77620_IRQ_LVL2_GPIO_EDGE4),
+ REGMAP_IRQ_REG(5, 0, MAX77620_IRQ_LVL2_GPIO_EDGE5),
+ REGMAP_IRQ_REG(6, 0, MAX77620_IRQ_LVL2_GPIO_EDGE6),
+ REGMAP_IRQ_REG(7, 0, MAX77620_IRQ_LVL2_GPIO_EDGE7),
+};
+
+static struct regmap_irq_chip max77620_gpio_irq_chip = {
+ .name = "max77620-gpio",
+ .irqs = max77620_gpio_irqs,
+ .num_irqs = ARRAY_SIZE(max77620_gpio_irqs),
+ .num_regs = 1,
+ .irq_reg_stride = 1,
+ .status_base = MAX77620_REG_IRQ_LVL2_GPIO,
+};
+
+static int max77620_gpio_dir_input(struct gpio_chip *gc, unsigned int offset)
+{
+ struct max77620_gpio *mgpio = gpiochip_get_data(gc);
+ int ret;
+
+ ret = regmap_update_bits(mgpio->rmap, GPIO_REG_ADDR(offset),
+ MAX77620_CNFG_GPIO_DIR_MASK,
+ MAX77620_CNFG_GPIO_DIR_INPUT);
+ if (ret < 0)
+ dev_err(mgpio->dev, "CNFG_GPIOx dir update failed: %d\n", ret);
+
+ return ret;
+}
+
+static int max77620_gpio_get(struct gpio_chip *gc, unsigned int offset)
+{
+ struct max77620_gpio *mgpio = gpiochip_get_data(gc);
+ unsigned int val;
+ int ret;
+
+ ret = regmap_read(mgpio->rmap, GPIO_REG_ADDR(offset), &val);
+ if (ret < 0) {
+ dev_err(mgpio->dev, "CNFG_GPIOx read failed: %d\n", ret);
+ return ret;
+ }
+
+ return !!(val & MAX77620_CNFG_GPIO_INPUT_VAL_MASK);
+}
+
+static int max77620_gpio_dir_output(struct gpio_chip *gc, unsigned int offset,
+ int value)
+{
+ struct max77620_gpio *mgpio = gpiochip_get_data(gc);
+ u8 val;
+ int ret;
+
+ val = (value) ? MAX77620_CNFG_GPIO_OUTPUT_VAL_HIGH :
+ MAX77620_CNFG_GPIO_OUTPUT_VAL_LOW;
+
+ ret = regmap_update_bits(mgpio->rmap, GPIO_REG_ADDR(offset),
+ MAX77620_CNFG_GPIO_OUTPUT_VAL_MASK, val);
+ if (ret < 0) {
+ dev_err(mgpio->dev, "CNFG_GPIOx val update failed: %d\n", ret);
+ return ret;
+ }
+
+ ret = regmap_update_bits(mgpio->rmap, GPIO_REG_ADDR(offset),
+ MAX77620_CNFG_GPIO_DIR_MASK,
+ MAX77620_CNFG_GPIO_DIR_OUTPUT);
+ if (ret < 0)
+ dev_err(mgpio->dev, "CNFG_GPIOx dir update failed: %d\n", ret);
+
+ return ret;
+}
+
+static int max77620_gpio_set_debounce(struct gpio_chip *gc,
+ unsigned int offset,
+ unsigned int debounce)
+{
+ struct max77620_gpio *mgpio = gpiochip_get_data(gc);
+ u8 val;
+ int ret;
+
+ switch (debounce) {
+ case 0:
+ val = MAX77620_CNFG_GPIO_DBNC_None;
+ break;
+ case 1 ... 8:
+ val = MAX77620_CNFG_GPIO_DBNC_8ms;
+ break;
+ case 9 ... 16:
+ val = MAX77620_CNFG_GPIO_DBNC_16ms;
+ break;
+ case 17 ... 32:
+ val = MAX77620_CNFG_GPIO_DBNC_32ms;
+ break;
+ default:
+ dev_err(mgpio->dev, "Illegal value %u\n", debounce);
+ return -EINVAL;
+ }
+
+ ret = regmap_update_bits(mgpio->rmap, GPIO_REG_ADDR(offset),
+ MAX77620_CNFG_GPIO_DBNC_MASK, val);
+ if (ret < 0)
+ dev_err(mgpio->dev, "CNFG_GPIOx_DBNC update failed: %d\n", ret);
+
+ return ret;
+}
+
+static void max77620_gpio_set(struct gpio_chip *gc, unsigned int offset,
+ int value)
+{
+ struct max77620_gpio *mgpio = gpiochip_get_data(gc);
+ u8 val;
+ int ret;
+
+ val = (value) ? MAX77620_CNFG_GPIO_OUTPUT_VAL_HIGH :
+ MAX77620_CNFG_GPIO_OUTPUT_VAL_LOW;
+
+ ret = regmap_update_bits(mgpio->rmap, GPIO_REG_ADDR(offset),
+ MAX77620_CNFG_GPIO_OUTPUT_VAL_MASK, val);
+ if (ret < 0)
+ dev_err(mgpio->dev, "CNFG_GPIO_OUT update failed: %d\n", ret);
+}
+
+static int max77620_gpio_to_irq(struct gpio_chip *gc, unsigned int offset)
+{
+ struct max77620_gpio *mgpio = gpiochip_get_data(gc);
+ struct max77620_chip *chip = dev_get_drvdata(mgpio->dev->parent);
+
+ return regmap_irq_get_virq(chip->gpio_irq_data, offset);
+}
+
+static int max77620_gpio_probe(struct platform_device *pdev)
+{
+ struct max77620_chip *chip = dev_get_drvdata(pdev->dev.parent);
+ struct max77620_gpio *mgpio;
+ int gpio_irq;
+ int ret;
+
+ gpio_irq = platform_get_irq(pdev, 0);
+ if (gpio_irq <= 0) {
+ dev_err(&pdev->dev, "GPIO irq not available %d\n", gpio_irq);
+ return -ENODEV;
+ }
+
+ mgpio = devm_kzalloc(&pdev->dev, sizeof(*mgpio), GFP_KERNEL);
+ if (!mgpio)
+ return -ENOMEM;
+
+ mgpio->rmap = chip->rmap;
+ mgpio->dev = &pdev->dev;
+ mgpio->gpio_irq = gpio_irq;
+
+ mgpio->gpio_chip.label = pdev->name;
+ mgpio->gpio_chip.parent = &pdev->dev;
+ mgpio->gpio_chip.direction_input = max77620_gpio_dir_input;
+ mgpio->gpio_chip.get = max77620_gpio_get;
+ mgpio->gpio_chip.direction_output = max77620_gpio_dir_output;
+ mgpio->gpio_chip.set_debounce = max77620_gpio_set_debounce;
+ mgpio->gpio_chip.set = max77620_gpio_set;
+ mgpio->gpio_chip.to_irq = max77620_gpio_to_irq;
+ mgpio->gpio_chip.ngpio = MAX77620_GPIO_NR;
+ mgpio->gpio_chip.can_sleep = 1;
+ mgpio->gpio_chip.base = -1;
+ mgpio->irq_base = -1;
+#ifdef CONFIG_OF_GPIO
+ mgpio->gpio_chip.of_node = pdev->dev.parent->of_node;
+#endif
+
+ platform_set_drvdata(pdev, mgpio);
+
+ ret = devm_gpiochip_add_data(&pdev->dev, &mgpio->gpio_chip, mgpio);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "gpio_init: Failed to add max77620_gpio\n");
+ return ret;
+ }
+
+ mgpio->gpio_base = mgpio->gpio_chip.base;
+ ret = devm_regmap_add_irq_chip(&pdev->dev, chip->rmap, mgpio->gpio_irq,
+ IRQF_ONESHOT, mgpio->irq_base,
+ &max77620_gpio_irq_chip,
+ &chip->gpio_irq_data);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Failed to add gpio irq_chip %d\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static const struct platform_device_id max77620_gpio_devtype[] = {
+ { .name = "max77620-gpio", },
+ {},
+};
+MODULE_DEVICE_TABLE(platform, max77620_gpio_devtype);
+
+static struct platform_driver max77620_gpio_driver = {
+ .driver.name = "max77620-gpio",
+ .probe = max77620_gpio_probe,
+ .id_table = max77620_gpio_devtype,
+};
+
+module_platform_driver(max77620_gpio_driver);
+
+MODULE_DESCRIPTION("GPIO interface for MAX77620 and MAX20024 PMIC");
+MODULE_AUTHOR("Laxman Dewangan <ldewangan@xxxxxxxxxx>");
+MODULE_AUTHOR("Chaitanya Bandi <bandik@xxxxxxxxxx>");
+MODULE_ALIAS("platform:max77620-gpio");
+MODULE_LICENSE("GPL v2");
--
2.1.4