From: Kamel Bouhara <kamel.bouhara@bootlin.com>
Add core driver to support MAX7360 i2c chip, multi function device
with keypad, GPIO, PWM, GPO and rotary encoder submodules.
Signed-off-by: Kamel Bouhara <kamel.bouhara@bootlin.com>
Co-developed-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
---
drivers/mfd/Kconfig | 14 ++++
drivers/mfd/Makefile | 1 +
drivers/mfd/max7360.c | 185 ++++++++++++++++++++++++++++++++++++++++++++
include/linux/mfd/max7360.h | 112 +++++++++++++++++++++++++++
4 files changed, 312 insertions(+)
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 6b0682af6e32..ef02a1c4322c 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -2439,5 +2439,19 @@ config MFD_UPBOARD_FPGA
To compile this driver as a module, choose M here: the module will be
called upboard-fpga.
+config MFD_MAX7360
+ tristate "Maxim MAX7360 I2C IO Expander"
+ depends on I2C
+ select MFD_CORE
+ select REGMAP_I2C
+ select REGMAP_IRQ
+ help
+ Say yes here to add support for Maxim MAX7360 device, embedding
+ keypad, rotary encoder, PWM and GPIO features.
+
+ This driver provides common support for accessing the device;
+ additional drivers must be enabled in order to use the functionality
+ of the device.
+
endmenu
endif
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 9220eaf7cf12..db2bd232c150 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -163,6 +163,7 @@ obj-$(CONFIG_MFD_DA9063) += da9063.o
obj-$(CONFIG_MFD_DA9150) += da9150-core.o
obj-$(CONFIG_MFD_MAX14577) += max14577.o
+obj-$(CONFIG_MFD_MAX7360) += max7360.o
obj-$(CONFIG_MFD_MAX77541) += max77541.o
obj-$(CONFIG_MFD_MAX77620) += max77620.o
obj-$(CONFIG_MFD_MAX77650) += max77650.o
diff --git a/drivers/mfd/max7360.c b/drivers/mfd/max7360.c
new file mode 100644
index 000000000000..9f489a798f94
--- /dev/null
+++ b/drivers/mfd/max7360.c
@@ -0,0 +1,185 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Maxim MAX7360 Core Driver
+ *
+ * Copyright 2025 Bootlin
+ *
+ * Author: Kamel Bouhara <kamel.bouhara@bootlin.com>
+ * Author: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
+ */
+
+#include <linux/bits.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/max7360.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/types.h>
+
+static const struct mfd_cell max7360_cells[] = {
+ {
+ .name = "max7360-pinctrl",
+ },
+ {
+ .name = "max7360-pwm",
+ },
+ {
+ .name = "max7360-gpo",
+ .of_compatible = "maxim,max7360-gpo",
+ },
+ {
+ .name = "max7360-gpio",
+ .of_compatible = "maxim,max7360-gpio",
+ },
+ {
+ .name = "max7360-keypad",
+ },
+ {
+ .name = "max7360-rotary",
+ },
+};
+
+static const struct regmap_range max7360_volatile_ranges[] = {
+ {
+ .range_min = MAX7360_REG_KEYFIFO,
+ .range_max = MAX7360_REG_KEYFIFO,
+ }, {
+ .range_min = MAX7360_REG_I2C_TIMEOUT,
+ .range_max = MAX7360_REG_RTR_CNT,
+ },
+};
+
+static const struct regmap_access_table max7360_volatile_table = {
+ .yes_ranges = max7360_volatile_ranges,
+ .n_yes_ranges = ARRAY_SIZE(max7360_volatile_ranges),
+};
+
+static const struct regmap_config max7360_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .max_register = MAX7360_REG_PWMCFG(MAX7360_PORT_PWM_COUNT - 1),
+ .volatile_table = &max7360_volatile_table,
+ .cache_type = REGCACHE_MAPLE,
+};
+
+static int max7360_mask_irqs(struct regmap *regmap)
+{
+ struct device *dev = regmap_get_device(regmap);
+ unsigned int val;
+ int ret;
+
+ /*
+ * GPIO/PWM interrupts are not masked on reset: mask the during probe,
+ * avoiding repeated spurious interrupts if the corresponding drivers
+ * are not present.
+ */
+ for (unsigned int i = 0; i < MAX7360_PORT_PWM_COUNT; i++) {
+ ret = regmap_write_bits(regmap, MAX7360_REG_PWMCFG(i),
+ MAX7360_PORT_CFG_INTERRUPT_MASK,
+ MAX7360_PORT_CFG_INTERRUPT_MASK);
+ if (ret) {
+ dev_err(dev, "Failed to write max7360 port configuration");
+ return ret;
+ }
+ }
+
+ /* Read GPIO in register, to ACK any pending IRQ. */
+ ret = regmap_read(regmap, MAX7360_REG_GPIOIN, &val);
+ if (ret)
+ dev_err(dev, "Failed to read gpio values: %d\n", ret);
+
+ return ret;
+}
+
+static int max7360_reset(struct regmap *regmap)
+{
+ struct device *dev = regmap_get_device(regmap);
+ int ret;
+
+ ret = regmap_write(regmap, MAX7360_REG_GPIOCFG,
+ MAX7360_GPIO_CFG_GPIO_RST);
+ if (ret) {
+ dev_err(dev, "Failed to reset GPIO configuration: %x\n", ret);
+ return ret;
+ }
+
+ ret = regcache_drop_region(regmap, MAX7360_REG_GPIOCFG,
+ MAX7360_REG_GPIO_LAST);
+ if (ret) {
+ dev_err(dev, "Failed to drop regmap cache: %x\n", ret);
+ return ret;
+ }
+
+ ret = regmap_write(regmap, MAX7360_REG_SLEEP, 0);
+ if (ret) {
+ dev_err(dev, "Failed to reset autosleep configuration: %x\n", ret);
+ return ret;
+ }
+
+ ret = regmap_write(regmap, MAX7360_REG_DEBOUNCE, 0);
+ if (ret) {
+ dev_err(dev, "Failed to reset GPO port count: %x\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int max7360_probe(struct i2c_client *client)
+{
+ struct device *dev = &client->dev;
+ struct regmap *regmap;
+ int ret;
+
+ regmap = devm_regmap_init_i2c(client, &max7360_regmap_config);
+ if (IS_ERR(regmap))
+ return dev_err_probe(dev, PTR_ERR(regmap),
+ "Failed to initialise regmap\n");
+
+ i2c_set_clientdata(client, regmap);
+
+ ret = max7360_reset(regmap);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to reset device\n");
+
+ /* Get the device out of shutdown mode. */
+ ret = regmap_write_bits(regmap, MAX7360_REG_GPIOCFG,
+ MAX7360_GPIO_CFG_GPIO_EN,
+ MAX7360_GPIO_CFG_GPIO_EN);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to enable GPIO and PWM module\n");
+
+ ret = max7360_mask_irqs(regmap);
+ if (ret)
+ return dev_err_probe(dev, ret, "Could not mask interrupts\n");
+
+ ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
+ max7360_cells, ARRAY_SIZE(max7360_cells),
+ NULL, 0, NULL);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to register child devices\n");
+
+ return 0;
+}
+
+static const struct of_device_id max7360_dt_match[] = {
+ { .compatible = "maxim,max7360" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, max7360_dt_match);
+
+static struct i2c_driver max7360_driver = {
+ .driver = {
+ .name = "max7360",
+ .of_match_table = max7360_dt_match,
+ },
+ .probe = max7360_probe,
+};
+module_i2c_driver(max7360_driver);
+
+MODULE_DESCRIPTION("Maxim MAX7360 I2C IO Expander core driver");
+MODULE_AUTHOR("Kamel Bouhara <kamel.bouhara@bootlin.com>");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/mfd/max7360.h b/include/linux/mfd/max7360.h
new file mode 100644
index 000000000000..c5a90fa5b76b
--- /dev/null
+++ b/include/linux/mfd/max7360.h
@@ -0,0 +1,112 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef __LINUX_MFD_MAX7360_H
+#define __LINUX_MFD_MAX7360_H
+
+#include <linux/bits.h>
+#include <linux/types.h>
+
+struct device;
+
+#define MAX7360_MAX_KEY_ROWS 8
+#define MAX7360_MAX_KEY_COLS 8
+#define MAX7360_MAX_KEY_NUM (MAX7360_MAX_KEY_ROWS * MAX7360_MAX_KEY_COLS)
+#define MAX7360_ROW_SHIFT 3
+
+#define MAX7360_MAX_GPIO 8
+#define MAX7360_MAX_GPO 6
+#define MAX7360_PORT_PWM_COUNT 8
+#define MAX7360_PORT_RTR_PIN (MAX7360_PORT_PWM_COUNT - 1)
+
+/*
+ * MAX7360 registers
+ */
+#define MAX7360_REG_KEYFIFO 0x00
+#define MAX7360_REG_CONFIG 0x01
+#define MAX7360_REG_DEBOUNCE 0x02
+#define MAX7360_REG_INTERRUPT 0x03
+#define MAX7360_REG_PORTS 0x04
+#define MAX7360_REG_KEYREP 0x05
+#define MAX7360_REG_SLEEP 0x06
+
+/*
+ * MAX7360 GPIO registers
+ *
+ * All these registers are reset together when writing bit 3 of
+ * MAX7360_REG_GPIOCFG.
+ */
+#define MAX7360_REG_GPIOCFG 0x40
+#define MAX7360_REG_GPIOCTRL 0x41
+#define MAX7360_REG_GPIODEB 0x42
+#define MAX7360_REG_GPIOCURR 0x43
+#define MAX7360_REG_GPIOOUTM 0x44
+#define MAX7360_REG_PWMCOM 0x45
+#define MAX7360_REG_RTRCFG 0x46
+#define MAX7360_REG_I2C_TIMEOUT 0x48
+#define MAX7360_REG_GPIOIN 0x49
+#define MAX7360_REG_RTR_CNT 0x4A
+#define MAX7360_REG_PWMBASE 0x50
+#define MAX7360_REG_PWMCFGBASE 0x58
+
+#define MAX7360_REG_GPIO_LAST 0x5F
+
+#define MAX7360_REG_PWM(x) (MAX7360_REG_PWMBASE + (x))
+#define MAX7360_REG_PWMCFG(x) (MAX7360_REG_PWMCFGBASE + (x))
+
+/*
+ * Configuration register bits
+ */
+#define MAX7360_FIFO_EMPTY 0x3f
+#define MAX7360_FIFO_OVERFLOW 0x7f
+#define MAX7360_FIFO_RELEASE BIT(6)
+#define MAX7360_FIFO_COL GENMASK(5, 3)
+#define MAX7360_FIFO_ROW GENMASK(2, 0)
+
+#define MAX7360_CFG_SLEEP BIT(7)
+#define MAX7360_CFG_INTERRUPT BIT(5)
+#define MAX7360_CFG_KEY_RELEASE BIT(3)
+#define MAX7360_CFG_WAKEUP BIT(1)
+#define MAX7360_CFG_TIMEOUT BIT(0)
+
+#define MAX7360_DEBOUNCE GENMASK(4, 0)
+#define MAX7360_DEBOUNCE_MIN 9
+#define MAX7360_DEBOUNCE_MAX 40
+#define MAX7360_PORTS GENMASK(8, 5)
+
+#define MAX7360_INTERRUPT_TIME_MASK GENMASK(4, 0)
+#define MAX7360_INTERRUPT_FIFO_MASK GENMASK(7, 5)
+
+#define MAX7360_PORT_CFG_INTERRUPT_MASK BIT(7)
+#define MAX7360_PORT_CFG_INTERRUPT_EDGES BIT(6)
+#define MAX7360_PORT_CFG_COMMON_PWM BIT(5)
+
+/*
+ * Autosleep register values
+ */
+#define MAX7360_AUTOSLEEP_8192MS 0x01
+#define MAX7360_AUTOSLEEP_4096MS 0x02
+#define MAX7360_AUTOSLEEP_2048MS 0x03
+#define MAX7360_AUTOSLEEP_1024MS 0x04
+#define MAX7360_AUTOSLEEP_512MS 0x05
+#define MAX7360_AUTOSLEEP_256MS 0x06
+
+#define MAX7360_GPIO_CFG_RTR_EN BIT(7)
+#define MAX7360_GPIO_CFG_GPIO_EN BIT(4)
+#define MAX7360_GPIO_CFG_GPIO_RST BIT(3)
+
+#define MAX7360_ROT_DEBOUNCE GENMASK(3, 0)
+#define MAX7360_ROT_DEBOUNCE_MIN 0
+#define MAX7360_ROT_DEBOUNCE_MAX 15
+#define MAX7360_ROT_INTCNT GENMASK(6, 4)
+#define MAX7360_ROT_INTCNT_DLY BIT(7)
+
+#define MAX7360_INT_INTI 0
+#define MAX7360_INT_INTK 1
+
+#define MAX7360_INT_GPIO 0
+#define MAX7360_INT_KEYPAD 1
+#define MAX7360_INT_ROTARY 2
+
+#define MAX7360_NR_INTERNAL_IRQS 3
+
+#endif
--
2.39.5On Tue, Mar 18, 2025 at 05:26:18PM +0100, mathieu.dubois-briand@bootlin.com wrote: > From: Kamel Bouhara <kamel.bouhara@bootlin.com> > > Add core driver to support MAX7360 i2c chip, multi function device > with keypad, GPIO, PWM, GPO and rotary encoder submodules. ... + array_size.h > +#include <linux/bits.h> > +#include <linux/delay.h> > +#include <linux/device.h> Since it won;t make v6.15-rc1 anyway the above can be better specified as device/devres.h dev_printk.h as device.h is monstrous. + err.h > +#include <linux/i2c.h> > +#include <linux/interrupt.h> > +#include <linux/mfd/core.h> > +#include <linux/mfd/max7360.h> + mod_devicetable.h > +#include <linux/module.h> > +#include <linux/regmap.h> > +#include <linux/types.h> ... > + ret = regmap_write(regmap, MAX7360_REG_GPIOCFG, > + MAX7360_GPIO_CFG_GPIO_RST); I would suggest to leave it as a single line. In this and similar cases when it is ~83 characters, it's still fine (and even for strict 80 there is a documented exception) ... > + return ret; > + } > + > + return 0; Just return ret; ? > + ret = max7360_mask_irqs(regmap); > + if (ret) > + return dev_err_probe(dev, ret, "Could not mask interrupts\n"); Hmm... As far as I can read this masks GPIO interrups. Does it do anything else? If it's covered by the GPIO/pin control drivers, one want probably to see that to be done there in the respective callback (init_hw_irq or alike, I don't remember the name by heart). ... > +#ifndef __LINUX_MFD_MAX7360_H > +#define __LINUX_MFD_MAX7360_H > + > +#include <linux/bits.h> > +#include <linux/types.h> Do you need types.h here? I don't see for what... > +struct device; Neither this. Perhaps it's for the following changes? Then add when required, not now. > +#endif -- With Best Regards, Andy Shevchenko
On Wed Mar 19, 2025 at 12:10 PM CET, Andy Shevchenko wrote: > On Tue, Mar 18, 2025 at 05:26:18PM +0100, mathieu.dubois-briand@bootlin.com wrote: > > From: Kamel Bouhara <kamel.bouhara@bootlin.com> > > + ret = max7360_mask_irqs(regmap); > > + if (ret) > > + return dev_err_probe(dev, ret, "Could not mask interrupts\n"); > > Hmm... As far as I can read this masks GPIO interrups. Does it do anything > else? If it's covered by the GPIO/pin control drivers, one want probably to > see that to be done there in the respective callback (init_hw_irq or alike, > I don't remember the name by heart). > Hum, I'm not sure I can do that. So the "inti" interrupt line is shared across the GPIO and the rotary encoder functionalities. On reset, GPIO interrupts are not masked. This means, if we do the masking in the GPIO driver and the GPIO driver is not loaded but the rotary encoder driver is, the rotary encoder driver might get a lot of spurious interrupts. So I believe it makes sense to mask the interrupts here, setting the chip in a sane configuration, whatever child drivers are present. Any thought about that? -- Mathieu Dubois-Briand, Bootlin Embedded Linux and Kernel engineering https://bootlin.com
On Tue, Mar 25, 2025 at 05:26:12PM +0100, Mathieu Dubois-Briand wrote: > On Wed Mar 19, 2025 at 12:10 PM CET, Andy Shevchenko wrote: > > On Tue, Mar 18, 2025 at 05:26:18PM +0100, mathieu.dubois-briand@bootlin.com wrote: > > > From: Kamel Bouhara <kamel.bouhara@bootlin.com> > > > + ret = max7360_mask_irqs(regmap); > > > + if (ret) > > > + return dev_err_probe(dev, ret, "Could not mask interrupts\n"); > > > > Hmm... As far as I can read this masks GPIO interrups. Does it do anything > > else? If it's covered by the GPIO/pin control drivers, one want probably to > > see that to be done there in the respective callback (init_hw_irq or alike, > > I don't remember the name by heart). > > Hum, I'm not sure I can do that. > > So the "inti" interrupt line is shared across the GPIO and the rotary > encoder functionalities. > > On reset, GPIO interrupts are not masked. This means, if we do the > masking in the GPIO driver and the GPIO driver is not loaded but the > rotary encoder driver is, the rotary encoder driver might get a lot of > spurious interrupts. > > So I believe it makes sense to mask the interrupts here, setting the > chip in a sane configuration, whatever child drivers are present. > > Any thought about that? Okay, this makes sense. I forgot if you have any comment in the code (probably not if I asked the question), but in any case the above can be added on top of the function explaining this. -- With Best Regards, Andy Shevchenko
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