[PATCH] gpio: mcp230xx: Introduce new driver
Sebastian Reichel
sebastian.reichel at collabora.com
Tue Jul 6 18:33:38 CEST 2021
Introduce driver for I2C based MCP230xx GPIO chips, which are
quite common and already well supported by the Linux kernel.
Signed-off-by: Sebastian Reichel <sebastian.reichel at collabora.com>
---
drivers/gpio/Kconfig | 10 ++
drivers/gpio/Makefile | 1 +
drivers/gpio/mcp230xx_gpio.c | 235 +++++++++++++++++++++++++++++++++++
3 files changed, 246 insertions(+)
create mode 100644 drivers/gpio/mcp230xx_gpio.c
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index de4dc51d4b48..f93e736639bb 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -179,6 +179,16 @@ config LPC32XX_GPIO
help
Support for the LPC32XX GPIO driver.
+config MCP230XX_GPIO
+ bool "MCP230XX GPIO driver"
+ depends on DM
+ help
+ Support for Microchip's MCP230XX I2C connected GPIO devices.
+ The following chips are supported:
+ - MCP23008
+ - MCP23017
+ - MCP23018
+
config MSCC_SGPIO
bool "Microsemi Serial GPIO driver"
depends on DM_GPIO && SOC_VCOREIII
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 8541ba0b0aec..00ffcc753534 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -24,6 +24,7 @@ obj-$(CONFIG_KIRKWOOD_GPIO) += kw_gpio.o
obj-$(CONFIG_KONA_GPIO) += kona_gpio.o
obj-$(CONFIG_MARVELL_GPIO) += mvgpio.o
obj-$(CONFIG_MARVELL_MFP) += mvmfp.o
+obj-$(CONFIG_MCP230XX_GPIO) += mcp230xx_gpio.o
obj-$(CONFIG_MXC_GPIO) += mxc_gpio.o
obj-$(CONFIG_MXS_GPIO) += mxs_gpio.o
obj-$(CONFIG_PCA953X) += pca953x.o
diff --git a/drivers/gpio/mcp230xx_gpio.c b/drivers/gpio/mcp230xx_gpio.c
new file mode 100644
index 000000000000..44def86ca7d9
--- /dev/null
+++ b/drivers/gpio/mcp230xx_gpio.c
@@ -0,0 +1,235 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2021, Collabora Ltd.
+ * Copyright (C) 2021, General Electric Company
+ * Author(s): Sebastian Reichel <sebastian.reichel at collabora.com>
+ */
+
+#define LOG_CATEGORY UCLASS_GPIO
+
+#include <common.h>
+#include <errno.h>
+#include <dm.h>
+#include <i2c.h>
+#include <asm/gpio.h>
+#include <dm/device_compat.h>
+#include <dt-bindings/gpio/gpio.h>
+
+enum mcp230xx_type {
+ UNKNOWN = 0,
+ MCP23008,
+ MCP23017,
+ MCP23018,
+};
+
+#define MCP230XX_IODIR 0x00
+#define MCP230XX_GPPU 0x06
+#define MCP230XX_GPIO 0x09
+#define MCP230XX_OLAT 0x0a
+
+#define BANKSIZE 8
+
+static int mcp230xx_read(struct udevice *dev, uint reg, uint offset)
+{
+ struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
+ int bank = offset / BANKSIZE;
+ int mask = 1 << (offset % BANKSIZE);
+ int shift = (uc_priv->gpio_count / BANKSIZE) - 1;
+ int ret;
+
+ ret = dm_i2c_reg_read(dev, (reg << shift) + bank);
+ if (ret < 0)
+ return ret;
+ return !!(ret & mask);
+}
+
+static int mcp230xx_write(struct udevice *dev, uint reg, uint offset, bool val)
+{
+ struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
+ int bank = offset / BANKSIZE;
+ int mask = 1 << (offset % BANKSIZE);
+ int shift = (uc_priv->gpio_count / BANKSIZE) - 1;
+ int regval;
+
+ regval = dm_i2c_reg_read(dev, (reg << shift) + bank);
+ if (regval < 0)
+ return regval;
+
+ regval &= ~mask;
+ if (val)
+ regval |= mask;
+
+ return dm_i2c_reg_write(dev, (reg << shift) + bank, regval);
+}
+
+static int mcp230xx_get_value(struct udevice *dev, uint offset)
+{
+ int ret;
+
+ ret = mcp230xx_read(dev, MCP230XX_GPIO, offset);
+ if (ret < 0) {
+ dev_err(dev, "%s error: %d\n", __func__, ret);
+ return ret;
+ }
+
+ return ret;
+}
+
+static int mcp230xx_set_value(struct udevice *dev, uint offset, int val)
+{
+ int ret;
+
+ ret = mcp230xx_write(dev, MCP230XX_GPIO, offset, val);
+ if (ret < 0) {
+ dev_err(dev, "%s error: %d\n", __func__, ret);
+ return ret;
+ }
+
+ return ret;
+}
+
+static int mcp230xx_get_flags(struct udevice *dev, unsigned int offset,
+ ulong *flags)
+{
+ int direction, pullup;
+
+ pullup = mcp230xx_read(dev, MCP230XX_GPPU, offset);
+ if (pullup < 0) {
+ dev_err(dev, "%s error: %d\n", __func__, pullup);
+ return pullup;
+ }
+
+ direction = mcp230xx_read(dev, MCP230XX_IODIR, offset);
+ if (direction < 0) {
+ dev_err(dev, "%s error: %d\n", __func__, direction);
+ return direction;
+ }
+
+ *flags = direction ? GPIOD_IS_IN : GPIOD_IS_OUT;
+
+ if (pullup)
+ *flags |= GPIOD_PULL_UP;
+
+ return 0;
+}
+
+static int mcp230xx_set_flags(struct udevice *dev, uint offset, ulong flags)
+{
+ int direction = !(flags & GPIOD_IS_OUT);
+ int pullup = !!(flags & GPIOD_PULL_UP);
+ ulong supported_mask;
+ int ret;
+
+ /* Note: active-low is ignored (handled by core) */
+ supported_mask = GPIOD_ACTIVE_LOW | GPIOD_IS_IN | GPIOD_IS_OUT | GPIOD_PULL_UP;
+ if (flags & ~supported_mask)
+ return -EINVAL;
+
+ ret = mcp230xx_write(dev, MCP230XX_GPPU, offset, pullup);
+ if (ret) {
+ dev_err(dev, "%s error: %d\n", __func__, ret);
+ return ret;
+ }
+
+ ret = mcp230xx_write(dev, MCP230XX_IODIR, offset, direction);
+ if (ret) {
+ dev_err(dev, "%s error: %d\n", __func__, ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static int mcp230xx_direction_input(struct udevice *dev, uint offset)
+{
+ return mcp230xx_set_flags(dev, offset, GPIOD_IS_IN);
+}
+
+static int mcp230xx_direction_output(struct udevice *dev, uint offset, int val)
+{
+ int ret = mcp230xx_set_value(dev, offset, val);
+ if (ret < 0) {
+ dev_err(dev, "%s error: %d\n", __func__, ret);
+ return ret;
+ }
+ return mcp230xx_set_flags(dev, offset, GPIOD_IS_OUT);
+}
+
+static int mcp230xx_get_function(struct udevice *dev, uint offset)
+{
+ int ret;
+
+ ret = mcp230xx_read(dev, MCP230XX_IODIR, offset);
+ if (ret < 0) {
+ dev_err(dev, "%s error: %d\n", __func__, ret);
+ return ret;
+ }
+
+ return ret ? GPIOF_INPUT : GPIOF_OUTPUT;
+}
+
+static const struct dm_gpio_ops mcp230xx_ops = {
+ .direction_input = mcp230xx_direction_input,
+ .direction_output = mcp230xx_direction_output,
+ .get_value = mcp230xx_get_value,
+ .set_value = mcp230xx_set_value,
+ .get_function = mcp230xx_get_function,
+ .set_flags = mcp230xx_set_flags,
+ .get_flags = mcp230xx_get_flags,
+};
+
+static int mcp230xx_probe(struct udevice *dev)
+{
+ struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
+ char name[32], label[8], *str;
+ int addr, gpio_count, size;
+ const u8 *tmp;
+
+ switch (dev_get_driver_data(dev)) {
+ case MCP23008:
+ gpio_count = 8;
+ break;
+ case MCP23017:
+ case MCP23018:
+ gpio_count = 16;
+ break;
+ default:
+ return -ENODEV;
+ }
+
+ addr = dev_read_addr(dev);
+ tmp = dev_read_prop(dev, "label", &size);
+ if (tmp) {
+ memcpy(label, tmp, sizeof(label) - 1);
+ label[sizeof(label) - 1] = '\0';
+ snprintf(name, sizeof(name), "%s@%x_", label, addr);
+ } else {
+ snprintf(name, sizeof(name), "gpio@%x_", addr);
+ }
+
+ str = strdup(name);
+ if (!str)
+ return -ENOMEM;
+
+ uc_priv->bank_name = str;
+ uc_priv->gpio_count = gpio_count;
+
+ dev_dbg(dev, "%s is ready\n", str);
+
+ return 0;
+}
+
+static const struct udevice_id mcp230xx_ids[] = {
+ { .compatible = "microchip,mcp23008", .data = MCP23008, },
+ { .compatible = "microchip,mcp23017", .data = MCP23017, },
+ { .compatible = "microchip,mcp23018", .data = MCP23018, },
+ { }
+};
+
+U_BOOT_DRIVER(mcp230xx) = {
+ .name = "mcp230xx",
+ .id = UCLASS_GPIO,
+ .ops = &mcp230xx_ops,
+ .probe = mcp230xx_probe,
+ .of_match = mcp230xx_ids,
+};
--
2.30.2
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