[PATCH v14 07/10] gpio: max7360: Add MAX7360 gpio support

Mathieu Dubois-Briand
2025-08-24T11:58:21Z

Add driver for Maxim Integrated MAX7360 GPIO/GPO controller.

Two sets of GPIOs are provided by the device:
- Up to 8 GPIOs, shared with the PWM and rotary encoder functionalities.
These GPIOs also provide interrupts on input changes.
- Up to 6 GPOs, on unused keypad columns pins.

Co-developed-by: Kamel Bouhara <kamel.bouhara@bootlin.com>
Signed-off-by: Kamel Bouhara <kamel.bouhara@bootlin.com>
Acked-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
---
drivers/gpio/Kconfig | 12 +++
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-max7360.c | 257 ++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 270 insertions(+)

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index e43abb322fa6..6cf57a18dbe7 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -1492,6 +1492,18 @@ config GPIO_MADERA
help
Support for GPIOs on Cirrus Logic Madera class codecs.

+config GPIO_MAX7360
+ tristate "MAX7360 GPIO support"
+ depends on MFD_MAX7360
+ select GPIO_REGMAP
+ select REGMAP_IRQ
+ help
+ Allows to use MAX7360 I/O Expander PWM lines as GPIO and keypad COL
+ lines as GPO.
+
+ This driver can also be built as a module. If so, the module will be
+ called gpio-max7360.
+
config GPIO_MAX77620
tristate "GPIO support for PMIC MAX77620 and MAX20024"
depends on MFD_MAX77620
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 379f55e9ed1e..52abba3ef81c 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -106,6 +106,7 @@ obj-$(CONFIG_GPIO_MAX7300) += gpio-max7300.o
obj-$(CONFIG_GPIO_MAX7301) += gpio-max7301.o
obj-$(CONFIG_GPIO_MAX730X) += gpio-max730x.o
obj-$(CONFIG_GPIO_MAX732X) += gpio-max732x.o
+obj-$(CONFIG_GPIO_MAX7360) += gpio-max7360.o
obj-$(CONFIG_GPIO_MAX77620) += gpio-max77620.o
obj-$(CONFIG_GPIO_MAX77650) += gpio-max77650.o
obj-$(CONFIG_GPIO_MAX77759) += gpio-max77759.o
diff --git a/drivers/gpio/gpio-max7360.c b/drivers/gpio/gpio-max7360.c
new file mode 100644
index 000000000000..db92a43776a9
--- /dev/null
+++ b/drivers/gpio/gpio-max7360.c
@@ -0,0 +1,257 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2025 Bootlin
+ *
+ * Author: Kamel BOUHARA <kamel.bouhara@bootlin.com>
+ * Author: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bitmap.h>
+#include <linux/err.h>
+#include <linux/gpio/driver.h>
+#include <linux/gpio/regmap.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/max7360.h>
+#include <linux/minmax.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+
+#define MAX7360_GPIO_PORT 1
+#define MAX7360_GPIO_COL 2
+
+struct max7360_gpio_plat_data {
+ unsigned int function;
+};
+
+static struct max7360_gpio_plat_data max7360_gpio_port_plat = { .function = MAX7360_GPIO_PORT };
+static struct max7360_gpio_plat_data max7360_gpio_col_plat = { .function = MAX7360_GPIO_COL };
+
+static int max7360_get_available_gpos(struct device *dev, unsigned int *available_gpios)
+{
+ u32 columns;
+ int ret;
+
+ ret = device_property_read_u32(dev->parent, "keypad,num-columns", &columns);
+ if (ret) {
+ dev_err(dev, "Failed to read columns count\n");
+ return ret;
+ }
+
+ *available_gpios = min(MAX7360_MAX_GPO, MAX7360_MAX_KEY_COLS - columns);
+
+ return 0;
+}
+
+static int max7360_gpo_init_valid_mask(struct gpio_chip *gc,
+ unsigned long *valid_mask,
+ unsigned int ngpios)
+{
+ unsigned int available_gpios;
+ int ret;
+
+ ret = max7360_get_available_gpos(gc->parent, &available_gpios);
+ if (ret)
+ return ret;
+
+ bitmap_clear(valid_mask, 0, MAX7360_MAX_KEY_COLS - available_gpios);
+
+ return 0;
+}
+
+static int max7360_set_gpos_count(struct device *dev, struct regmap *regmap)
+{
+ /*
+ * MAX7360 COL0 to COL7 pins can be used either as keypad columns,
+ * general purpose output or a mix of both.
+ * By default, all pins are used as keypad, here we update this
+ * configuration to allow to use some of them as GPIOs.
+ */
+ unsigned int available_gpios;
+ unsigned int val;
+ int ret;
+
+ ret = max7360_get_available_gpos(dev, &available_gpios);
+ if (ret)
+ return ret;
+
+ /*
+ * Configure which GPIOs will be used for keypad.
+ * MAX7360_REG_DEBOUNCE contains configuration both for keypad debounce
+ * timings and gpos/keypad columns repartition. Only the later is
+ * modified here.
+ */
+ val = FIELD_PREP(MAX7360_PORTS, available_gpios);
+ ret = regmap_write_bits(regmap, MAX7360_REG_DEBOUNCE, MAX7360_PORTS, val);
+ if (ret)
+ dev_err(dev, "Failed to write max7360 columns/gpos configuration");
+
+ return ret;
+}
+
+static int max7360_gpio_reg_mask_xlate(struct gpio_regmap *gpio,
+ unsigned int base, unsigned int offset,
+ unsigned int *reg, unsigned int *mask)
+{
+ if (base == MAX7360_REG_PWMBASE) {
+ /*
+ * GPIO output is using PWM duty cycle registers: one register
+ * per line, with value being either 0 or 255.
+ */
+ *reg = base + offset;
+ *mask = GENMASK(7, 0);
+ } else {
+ *reg = base;
+ *mask = BIT(offset);
+ }
+
+ return 0;
+}
+
+static const struct regmap_irq max7360_regmap_irqs[MAX7360_MAX_GPIO] = {
+ REGMAP_IRQ_REG(0, 0, BIT(0)),
+ REGMAP_IRQ_REG(1, 0, BIT(1)),
+ REGMAP_IRQ_REG(2, 0, BIT(2)),
+ REGMAP_IRQ_REG(3, 0, BIT(3)),
+ REGMAP_IRQ_REG(4, 0, BIT(4)),
+ REGMAP_IRQ_REG(5, 0, BIT(5)),
+ REGMAP_IRQ_REG(6, 0, BIT(6)),
+ REGMAP_IRQ_REG(7, 0, BIT(7)),
+};
+
+static int max7360_handle_mask_sync(const int index,
+ const unsigned int mask_buf_def,
+ const unsigned int mask_buf,
+ void *const irq_drv_data)
+{
+ struct regmap *regmap = irq_drv_data;
+ int ret;
+
+ for (unsigned int i = 0; i < MAX7360_MAX_GPIO; i++) {
+ ret = regmap_assign_bits(regmap, MAX7360_REG_PWMCFG(i),
+ MAX7360_PORT_CFG_INTERRUPT_MASK, mask_buf & BIT(i));
+ if (ret)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int max7360_gpio_probe(struct platform_device *pdev)
+{
+ const struct max7360_gpio_plat_data *plat_data;
+ struct gpio_regmap_config gpio_config = { };
+ struct regmap_irq_chip *irq_chip;
+ struct device *dev = &pdev->dev;
+ struct regmap *regmap;
+ unsigned int outconf;
+ int ret;
+
+ regmap = dev_get_regmap(dev->parent, NULL);
+ if (!regmap)
+ return dev_err_probe(dev, -ENODEV, "could not get parent regmap\n");
+
+ plat_data = device_get_match_data(dev);
+ if (plat_data->function == MAX7360_GPIO_PORT) {
+ if (device_property_read_bool(dev, "interrupt-controller")) {
+ /*
+ * Port GPIOs with interrupt-controller property: add IRQ
+ * controller.
+ */
+ gpio_config.regmap_irq_flags = IRQF_ONESHOT | IRQF_SHARED;
+ gpio_config.regmap_irq_line =
+ fwnode_irq_get_byname(dev_fwnode(dev->parent), "inti");
+ if (gpio_config.regmap_irq_line < 0)
+ return dev_err_probe(dev, gpio_config.regmap_irq_line,
+ "Failed to get IRQ\n");
+
+ /* Create custom IRQ configuration. */
+ irq_chip = devm_kzalloc(dev, sizeof(*irq_chip), GFP_KERNEL);
+ gpio_config.regmap_irq_chip = irq_chip;
+ if (!irq_chip)
+ return -ENOMEM;
+
+ irq_chip->name = dev_name(dev);
+ irq_chip->status_base = MAX7360_REG_GPIOIN;
+ irq_chip->status_is_level = true;
+ irq_chip->num_regs = 1;
+ irq_chip->num_irqs = MAX7360_MAX_GPIO;
+ irq_chip->irqs = max7360_regmap_irqs;
+ irq_chip->handle_mask_sync = max7360_handle_mask_sync;
+ irq_chip->irq_drv_data = regmap;
+
+ for (unsigned int i = 0; i < MAX7360_MAX_GPIO; i++) {
+ ret = regmap_write_bits(regmap, MAX7360_REG_PWMCFG(i),
+ MAX7360_PORT_CFG_INTERRUPT_EDGES,
+ MAX7360_PORT_CFG_INTERRUPT_EDGES);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to enable interrupts\n");
+ }
+ }
+
+ /*
+ * Port GPIOs: set output mode configuration (constant-current or not).
+ * This property is optional.
+ */
+ ret = device_property_read_u32(dev, "maxim,constant-current-disable", &outconf);
+ if (!ret) {
+ ret = regmap_write(regmap, MAX7360_REG_GPIOOUTM, outconf);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Failed to set constant-current configuration\n");
+ }
+ }
+
+ /* Add gpio device. */
+ gpio_config.parent = dev;
+ gpio_config.regmap = regmap;
+ if (plat_data->function == MAX7360_GPIO_PORT) {
+ gpio_config.ngpio = MAX7360_MAX_GPIO;
+ gpio_config.reg_dat_base = GPIO_REGMAP_ADDR(MAX7360_REG_GPIOIN);
+ gpio_config.reg_set_base = GPIO_REGMAP_ADDR(MAX7360_REG_PWMBASE);
+ gpio_config.reg_dir_out_base = GPIO_REGMAP_ADDR(MAX7360_REG_GPIOCTRL);
+ gpio_config.ngpio_per_reg = MAX7360_MAX_GPIO;
+ gpio_config.reg_mask_xlate = max7360_gpio_reg_mask_xlate;
+ } else {
+ ret = max7360_set_gpos_count(dev, regmap);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to set GPOS pin count\n");
+
+ gpio_config.reg_set_base = GPIO_REGMAP_ADDR(MAX7360_REG_PORTS);
+ gpio_config.ngpio = MAX7360_MAX_KEY_COLS;
+ gpio_config.init_valid_mask = max7360_gpo_init_valid_mask;
+ }
+
+ return PTR_ERR_OR_ZERO(devm_gpio_regmap_register(dev, &gpio_config));
+}
+
+static const struct of_device_id max7360_gpio_of_match[] = {
+ {
+ .compatible = "maxim,max7360-gpo",
+ .data = &max7360_gpio_col_plat
+ }, {
+ .compatible = "maxim,max7360-gpio",
+ .data = &max7360_gpio_port_plat
+ }, {
+ }
+};
+MODULE_DEVICE_TABLE(of, max7360_gpio_of_match);
+
+static struct platform_driver max7360_gpio_driver = {
+ .driver = {
+ .name = "max7360-gpio",
+ .of_match_table = max7360_gpio_of_match,
+ },
+ .probe = max7360_gpio_probe,
+};
+module_platform_driver(max7360_gpio_driver);
+
+MODULE_DESCRIPTION("MAX7360 GPIO driver");
+MODULE_AUTHOR("Kamel BOUHARA <kamel.bouhara@bootlin.com>");
+MODULE_AUTHOR("Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>");
+MODULE_LICENSE("GPL");

--
2.39.5