* [PATCH 27/32] gpio: Add support for the FXL6408 GPIO expander.
[not found] <1464817421-8519-1-git-send-email-kraxel@redhat.com>
@ 2016-06-01 21:43 ` Gerd Hoffmann
[not found] ` <1464817421-8519-28-git-send-email-kraxel-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
` (2 more replies)
0 siblings, 3 replies; 5+ messages in thread
From: Gerd Hoffmann @ 2016-06-01 21:43 UTC (permalink / raw)
To: linux-rpi-kernel
Cc: Eric Anholt, Florian Fainelli, Ray Jui, Scott Branden,
Rob Herring, Pawel Moll, Mark Rutland, Ian Campbell, Kumar Gala,
Catalin Marinas, Will Deacon, Linus Walleij, Alexandre Courbot,
open list:BROADCOM BCM281XX/BCM11XXX/BCM216XX ARM ARCHITE...,
open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS,
moderated list:ARM64 PORT AARCH64 ARCHITECTURE, open list,
open list:GPIO SUBSYSTEM
From: Eric Anholt <eric@anholt.net>
This commit needs to be split up and cleaned up. Also we should add
interrupt support before pushing upstream.
Signed-off-by: Eric Anholt <eric@anholt.net>
Conflicts:
arch/arm64/boot/dts/broadcom/bcm2837-rpi-3-b.dts
---
arch/arm64/boot/dts/broadcom/bcm2837-rpi-3-b.dts | 16 ++
drivers/gpio/Kconfig | 6 +
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-fxl6408.c | 244 +++++++++++++++++++++++
4 files changed, 267 insertions(+)
create mode 100644 drivers/gpio/gpio-fxl6408.c
diff --git a/arch/arm64/boot/dts/broadcom/bcm2837-rpi-3-b.dts b/arch/arm64/boot/dts/broadcom/bcm2837-rpi-3-b.dts
index 099dd48d..4bc191e 100644
--- a/arch/arm64/boot/dts/broadcom/bcm2837-rpi-3-b.dts
+++ b/arch/arm64/boot/dts/broadcom/bcm2837-rpi-3-b.dts
@@ -39,3 +39,19 @@
&hdmi {
hpd-gpios = <&gpio 46 GPIO_ACTIVE_LOW>;
};
+
+/* Connect the GPIO expander to I2C1 */
+&i2c0 {
+ pinctrl-names = "default";
+ pinctrl-0 = <&i2c0_gpio44>;
+
+ gpio_expander: gpio@43 {
+ gpio-controller;
+ #gpio-cells = <2>;
+ reg = <0x43>;
+ compatible = "fcs,fxl6408";
+ };
+};
+
+bt {
+};
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 48da857..34056cd 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -665,6 +665,12 @@ config GPIO_ADNP
enough to represent all pins, but the driver will assume a
register layout for 64 pins (8 registers).
+config GPIO_FXL6408
+ tristate "FXL6408 I2C GPIO expander"
+ help
+ This option enables support for 8 GPIOs found
+ on the Fairchild Semiconductor FXL6408.
+
config GPIO_MAX7300
tristate "Maxim MAX7300 GPIO expander"
select GPIO_MAX730X
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 991598e..59a25ef 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -43,6 +43,7 @@ obj-$(CONFIG_GPIO_EM) += gpio-em.o
obj-$(CONFIG_GPIO_EP93XX) += gpio-ep93xx.o
obj-$(CONFIG_GPIO_ETRAXFS) += gpio-etraxfs.o
obj-$(CONFIG_GPIO_F7188X) += gpio-f7188x.o
+obj-$(CONFIG_GPIO_FXL6408) += gpio-fxl6408.o
obj-$(CONFIG_GPIO_GE_FPGA) += gpio-ge.o
obj-$(CONFIG_GPIO_GRGPIO) += gpio-grgpio.o
obj-$(CONFIG_GPIO_ICH) += gpio-ich.o
diff --git a/drivers/gpio/gpio-fxl6408.c b/drivers/gpio/gpio-fxl6408.c
new file mode 100644
index 0000000..02b2816
--- /dev/null
+++ b/drivers/gpio/gpio-fxl6408.c
@@ -0,0 +1,244 @@
+/*
+ * Copyright (C) 2016 Broadcom Limited.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ */
+
+/**
+ * DOC: FXL6408 I2C to GPIO expander.
+ *
+ * This chip has has 8 GPIO lines out of it, and is controlled by an
+ * I2C bus (a pair of lines), providing 4x expansion of GPIO lines.
+ * It also provides an interrupt line out for notifying of
+ * statechanges.
+ *
+ * Any preconfigured state will be left in place until the GPIO lines
+ * get activated. At power on, everything is treated as an input.
+ *
+ * Documentation can be found at:
+ * https://www.fairchildsemi.com/datasheets/FX/FXL6408.pdf
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/gpio.h>
+#include <linux/i2c.h>
+#include <linux/slab.h>
+#include <linux/of_platform.h>
+
+#define FXL6408_DEVICE_ID 0x01
+# define FXL6408_RST_INT BIT(1)
+# define FXL6408_SW_RST BIT(0)
+
+/* Bits set here indicate that the GPIO is an output. */
+#define FXL6408_IO_DIR 0x03
+/* Bits set here, when the corresponding bit of IO_DIR is set, drive
+ * the output high instead of low.
+ */
+#define FXL6408_OUTPUT 0x05
+/* Bits here make the output High-Z, instead of the OUTPUT value. */
+#define FXL6408_OUTPUT_HIGH_Z 0x07
+/* Bits here define the expected input state of the GPIO.
+ * INTERRUPT_STAT bits will be set when the INPUT transitions away
+ * from this value.
+ */
+#define FXL6408_INPUT_DEFAULT_STATE 0x09
+/* Bits here enable either pull up or pull down according to
+ * FXL6408_PULL_DOWN.
+ */
+#define FXL6408_PULL_ENABLE 0x0b
+/* Bits set here (when the corresponding PULL_ENABLE is set) enable a
+ * pull-up instead of a pull-down.
+ */
+#define FXL6408_PULL_UP 0x0d
+/* Returns the current status (1 = HIGH) of the input pins. */
+#define FXL6408_INPUT_STATUS 0x0f
+/* Mask of pins which can generate interrupts. */
+#define FXL6408_INTERRUPT_MASK 0x11
+/* Mask of pins which have generated an interrupt. Cleared on read. */
+#define FXL6408_INTERRUPT_STAT 0x13
+
+struct fxl6408_chip {
+ struct gpio_chip gpio_chip;
+ struct i2c_client *client;
+ struct mutex i2c_lock;
+
+ /* Caches of register values so we don't have to read-modify-write. */
+ u8 reg_io_dir;
+ u8 reg_output;
+};
+
+static int fxl6408_gpio_direction_input(struct gpio_chip *gc, unsigned off)
+{
+ struct fxl6408_chip *chip = gpiochip_get_data(gc);
+
+ mutex_lock(&chip->i2c_lock);
+ chip->reg_io_dir &= ~BIT(off);
+ i2c_smbus_write_byte_data(chip->client, FXL6408_IO_DIR,
+ chip->reg_io_dir);
+ mutex_unlock(&chip->i2c_lock);
+
+ return 0;
+}
+
+static int fxl6408_gpio_direction_output(struct gpio_chip *gc,
+ unsigned off, int val)
+{
+ struct fxl6408_chip *chip = gpiochip_get_data(gc);
+
+ mutex_lock(&chip->i2c_lock);
+ chip->reg_io_dir |= BIT(off);
+ i2c_smbus_write_byte_data(chip->client, FXL6408_IO_DIR,
+ chip->reg_io_dir);
+ mutex_unlock(&chip->i2c_lock);
+
+ return 0;
+}
+
+static int fxl6408_gpio_get_direction(struct gpio_chip *gc, unsigned off)
+{
+ struct fxl6408_chip *chip = gpiochip_get_data(gc);
+
+ return (chip->reg_io_dir & BIT(off)) == 0;
+}
+
+static int fxl6408_gpio_get_value(struct gpio_chip *gc, unsigned off)
+{
+ struct fxl6408_chip *chip = gpiochip_get_data(gc);
+ u8 reg;
+
+ mutex_lock(&chip->i2c_lock);
+ reg = i2c_smbus_read_byte_data(chip->client, FXL6408_INPUT_STATUS);
+ mutex_unlock(&chip->i2c_lock);
+
+ return (reg & BIT(off)) != 0;
+}
+
+static void fxl6408_gpio_set_value(struct gpio_chip *gc, unsigned off, int val)
+{
+ struct fxl6408_chip *chip = gpiochip_get_data(gc);
+
+ mutex_lock(&chip->i2c_lock);
+
+ if (val)
+ chip->reg_output |= BIT(off);
+ else
+ chip->reg_output &= BIT(off);
+
+ i2c_smbus_write_byte_data(chip->client, FXL6408_OUTPUT,
+ chip->reg_output);
+ mutex_unlock(&chip->i2c_lock);
+}
+
+
+static void fxl6408_gpio_set_multiple(struct gpio_chip *gc,
+ unsigned long *mask, unsigned long *bits)
+{
+ struct fxl6408_chip *chip = gpiochip_get_data(gc);
+
+ mutex_lock(&chip->i2c_lock);
+ chip->reg_output = (chip->reg_output & ~mask[0]) | bits[0];
+ i2c_smbus_write_byte_data(chip->client, FXL6408_OUTPUT,
+ chip->reg_output);
+ mutex_unlock(&chip->i2c_lock);
+}
+
+static int fxl6408_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct device *dev = &client->dev;
+ struct fxl6408_chip *chip;
+ struct gpio_chip *gc;
+ int ret;
+ u8 device_id;
+
+ /* Check the device ID register to see if it's responding.
+ * This also clears RST_INT as a side effect, so we won't get
+ * the "we've been power cycled" interrupt once we enable
+ * interrupts.
+ */
+ device_id = i2c_smbus_read_byte_data(client, FXL6408_DEVICE_ID);
+ if (device_id < 0) {
+ dev_err(dev, "FXL6408 probe returned %d\n", device_id);
+ return device_id;
+ } else if (device_id >> 5 != 5) {
+ dev_err(dev, "FXL6408 probe returned DID: 0x%02x\n", device_id);
+ return -ENODEV;
+ }
+
+ /* Disable High-Z of outputs, so that our OUTPUT updates
+ * actually take effect.
+ */
+ i2c_smbus_write_byte_data(client, FXL6408_OUTPUT_HIGH_Z, 0);
+
+ chip = devm_kzalloc(dev, sizeof(struct fxl6408_chip), GFP_KERNEL);
+ if (chip == NULL)
+ return -ENOMEM;
+
+ chip->client = client;
+ mutex_init(&chip->i2c_lock);
+ chip->reg_io_dir = i2c_smbus_read_byte_data(client, FXL6408_IO_DIR);
+ chip->reg_output = i2c_smbus_read_byte_data(client, FXL6408_OUTPUT);
+
+ gc = &chip->gpio_chip;
+ gc->direction_input = fxl6408_gpio_direction_input;
+ gc->direction_output = fxl6408_gpio_direction_output;
+ gc->get_direction = fxl6408_gpio_get_direction;
+ gc->get = fxl6408_gpio_get_value;
+ gc->set = fxl6408_gpio_set_value;
+ gc->set_multiple = fxl6408_gpio_set_multiple;
+ gc->can_sleep = true;
+
+ gc->base =-1;
+ gc->ngpio = 8;
+ gc->label = chip->client->name;
+ gc->parent = dev;
+ gc->owner = THIS_MODULE;
+
+ ret = gpiochip_add_data(gc, chip);
+ if (ret)
+ return ret;
+
+ i2c_set_clientdata(client, chip);
+ return 0;
+}
+
+static int fxl6408_remove(struct i2c_client *client)
+{
+ struct fxl6408_chip *chip = i2c_get_clientdata(client);
+
+ gpiochip_remove(&chip->gpio_chip);
+
+ return 0;
+}
+
+static const struct of_device_id fxl6408_dt_ids[] = {
+ { .compatible = "fcs,fxl6408" },
+ { }
+};
+
+MODULE_DEVICE_TABLE(of, fxl6408_dt_ids);
+
+static const struct i2c_device_id fxl6408_id[] = {
+ { "fxl6408", 0 },
+ { },
+};
+MODULE_DEVICE_TABLE(i2c, fxl6408_id);
+
+static struct i2c_driver fxl6408_driver = {
+ .driver = {
+ .name = "fxl6408",
+ .of_match_table = fxl6408_dt_ids,
+ },
+ .probe = fxl6408_probe,
+ .remove = fxl6408_remove,
+ .id_table = fxl6408_id,
+};
+
+module_i2c_driver(fxl6408_driver);
+
+MODULE_AUTHOR("Eric Anholt <eric@anholt.net>");
+MODULE_DESCRIPTION("GPIO expander driver for FXL6408");
+MODULE_LICENSE("GPL");
--
1.8.3.1
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