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Message-ID: <1345545940-2232-5-git-send-email-sourav.poddar@ti.com>
Date: Tue, 21 Aug 2012 16:15:40 +0530
From: Sourav Poddar <sourav.poddar@...com>
To: <devicetree-discuss@...ts.ozlabs.org>,
<linux-arm-kernel@...ts.infradead.org>,
<linux-omap@...r.kernel.org>, <linux-kernel@...r.kernel.org>,
<linux-input@...r.kernel.org>, <sourav.poddar@...com>
Subject: [RFC/PATCH 4/4] gpio: smscece: Add support for gpio IO expander feature
smsc can be used as an gpio io expander device also. So adding
support for configuring smsc pins as a gpio.
Cc: Benoit Cousson <b-cousson@...com>
Cc: Felipe Balbi <balbi@...com>
Cc: Santosh Shilimkar <santosh.shilimkar@...com>
Signed-off-by: Sourav Poddar <sourav.poddar@...com>
---
drivers/gpio/Kconfig | 7 +
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-smscece.c | 373 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 381 insertions(+), 0 deletions(-)
create mode 100644 drivers/gpio/gpio-smscece.c
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index b16c8a7..e883929 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -444,6 +444,13 @@ config GPIO_ADP5588_IRQ
Say yes here to enable the adp5588 to be used as an interrupt
controller. It requires the driver to be built in the kernel.
+config GPIO_SMSCECE
+ tristate "SMSCECE 1099 I2C GPIO expander"
+ depends on I2C
+ help
+ This option enables support for 18 GPIOs found
+ on SMSC ECE 1099 GPIO Expanders.
+
comment "PCI GPIO expanders:"
config GPIO_CS5535
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 153cace..7c803c5 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -12,6 +12,7 @@ obj-$(CONFIG_GPIO_74X164) += gpio-74x164.o
obj-$(CONFIG_GPIO_AB8500) += gpio-ab8500.o
obj-$(CONFIG_GPIO_ADP5520) += gpio-adp5520.o
obj-$(CONFIG_GPIO_ADP5588) += gpio-adp5588.o
+obj-$(CONFIG_GPIO_SMSCECE) += gpio-smscece.o
obj-$(CONFIG_GPIO_AMD8111) += gpio-amd8111.o
obj-$(CONFIG_GPIO_ARIZONA) += gpio-arizona.o
obj-$(CONFIG_GPIO_BT8XX) += gpio-bt8xx.o
diff --git a/drivers/gpio/gpio-smscece.c b/drivers/gpio/gpio-smscece.c
new file mode 100644
index 0000000..0cb0959
--- /dev/null
+++ b/drivers/gpio/gpio-smscece.c
@@ -0,0 +1,373 @@
+/*
+ * GPIO Chip driver for smsc
+ * SMSC I/O Expander and QWERTY Keypad Controller
+ *
+ * Copyright 2012 Texas Instruments Inc.
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+#include <linux/gpio.h>
+#include <linux/interrupt.h>
+#include <linux/irqdomain.h>
+#include <linux/irq.h>
+#include <linux/mfd/smsc.h>
+#include <linux/err.h>
+
+struct smsc_gpio {
+ struct device *dev;
+ struct smsc *smsc;
+ struct gpio_chip gpio_chip;
+ struct mutex lock; /* protect cached dir, dat_out */
+ /* protect serialized access to the interrupt controller bus */
+ struct mutex irq_lock;
+ unsigned gpio_start;
+ int type;
+ int flags;
+ int irq;
+ int irq_base;
+ unsigned int gpio_base;
+ unsigned int dat_out[5];
+ unsigned int dir[5];
+ unsigned int int_lvl[5];
+ unsigned int int_en[5];
+ unsigned int irq_mask[5];
+ unsigned int irq_stat[5];
+};
+
+static int smsc_gpio_get_value(struct gpio_chip *chip, unsigned off)
+{
+ struct smsc_gpio *sg =
+ container_of(chip, struct smsc_gpio, gpio_chip);
+ unsigned int get;
+ return !!(smsc_read(sg->dev,
+ (SMSC_GPIO_DATA_IN_START + SMSC_BANK(off)) & SMSC_BIT(off),
+ &get));
+}
+
+static void smsc_gpio_set_value(struct gpio_chip *chip,
+ unsigned off, int val)
+{
+ unsigned bank, bit;
+ struct smsc_gpio *sg =
+ container_of(chip, struct smsc_gpio, gpio_chip);
+
+ bank = SMSC_BANK(off);
+ bit = SMSC_BIT(off);
+
+ mutex_lock(&sg->lock);
+ if (val)
+ sg->dat_out[bank] |= bit;
+ else
+ sg->dat_out[bank] &= ~bit;
+
+ smsc_write(sg->dev, SMSC_GPIO_DATA_OUT_START + bank,
+ sg->dat_out[bank]);
+ mutex_unlock(&sg->lock);
+}
+
+static int smsc_gpio_direction_input(struct gpio_chip *chip, unsigned off)
+{
+ unsigned int reg;
+ struct smsc_gpio *sg =
+ container_of(chip, struct smsc_gpio, gpio_chip);
+ int reg_dir;
+
+ mutex_lock(&sg->lock);
+ reg_dir = SMSC_CFG_START + off;
+ smsc_read(sg->dev, reg_dir, ®);
+ reg |= SMSC_GPIO_INPUT_LOW;
+ mutex_unlock(&sg->lock);
+
+ return smsc_write(sg->dev, reg_dir, reg);
+}
+
+static int smsc_gpio_direction_output(struct gpio_chip *chip,
+ unsigned off, int val)
+{
+ unsigned int reg;
+ struct smsc_gpio *sg =
+ container_of(chip, struct smsc_gpio, gpio_chip);
+ int reg_dir;
+
+ mutex_lock(&sg->lock);
+ reg_dir = SMSC_CFG_START + off;
+ smsc_read(sg->dev, reg_dir, ®);
+ reg |= SMSC_GPIO_OUTPUT_PP;
+ mutex_unlock(&sg->lock);
+
+ return smsc_write(sg->dev, reg_dir, reg);
+}
+
+static int smsc_gpio_to_irq(struct gpio_chip *chip, unsigned off)
+{
+ struct smsc_gpio *sg =
+ container_of(chip, struct smsc_gpio, gpio_chip);
+ return sg->irq_base + off;
+}
+
+static void smsc_irq_bus_lock(struct irq_data *d)
+{
+ struct smsc_gpio *sg = irq_data_get_irq_chip_data(d);
+
+ mutex_lock(&sg->irq_lock);
+}
+
+static void smsc_irq_bus_sync_unlock(struct irq_data *d)
+{
+ struct smsc_gpio *sg = irq_data_get_irq_chip_data(d);
+ int i;
+
+ for (i = 0; i < SMSC_BANK(SMSC_MAXGPIO); i++)
+ if (sg->int_en[i] ^ sg->irq_mask[i]) {
+ sg->int_en[i] = sg->irq_mask[i];
+ smsc_write(sg->dev, SMSC_GPIO_INT_MASK_START + i,
+ sg->int_en[i]);
+ }
+
+ mutex_unlock(&sg->irq_lock);
+}
+
+static void smsc_irq_mask(struct irq_data *d)
+{
+ struct smsc_gpio *sg = irq_data_get_irq_chip_data(d);
+ unsigned gpio = d->irq - sg->irq_base;
+
+ sg->irq_mask[SMSC_BANK(gpio)] &= ~SMSC_BIT(gpio);
+}
+
+static void smsc_irq_unmask(struct irq_data *d)
+{
+ struct smsc_gpio *sg = irq_data_get_irq_chip_data(d);
+ unsigned gpio = d->irq - sg->irq_base;
+
+ sg->irq_mask[SMSC_BANK(gpio)] |= SMSC_BIT(gpio);
+}
+
+static int smsc_irq_set_type(struct irq_data *d, unsigned int type)
+{
+ struct smsc_gpio *sg = irq_data_get_irq_chip_data(d);
+ uint16_t gpio = d->irq - sg->irq_base;
+ unsigned bank, bit;
+
+ if ((type & IRQ_TYPE_EDGE_BOTH)) {
+ dev_err(sg->dev, "irq %d: unsupported type %d\n",
+ d->irq, type);
+ return -EINVAL;
+ }
+
+ bank = SMSC_BANK(gpio);
+ bit = SMSC_BIT(gpio);
+
+ if (type & IRQ_TYPE_LEVEL_HIGH)
+ sg->int_lvl[bank] |= bit;
+ else if (type & IRQ_TYPE_LEVEL_LOW)
+ sg->int_lvl[bank] &= ~bit;
+ else
+ return -EINVAL;
+
+ smsc_gpio_direction_input(&sg->gpio_chip, gpio);
+ smsc_write(sg->dev, SMSC_CFG_START + gpio,
+ sg->int_lvl[bank]);
+
+ return 0;
+}
+
+static struct irq_chip smsc_irq_chip = {
+ .name = "smsc",
+ .irq_mask = smsc_irq_mask,
+ .irq_unmask = smsc_irq_unmask,
+ .irq_bus_lock = smsc_irq_bus_lock,
+ .irq_bus_sync_unlock = smsc_irq_bus_sync_unlock,
+ .irq_set_type = smsc_irq_set_type,
+};
+
+static int smsc_gpio_read_intstat(struct smsc_gpio *sg,
+ unsigned int *buf, int i)
+{
+ int ret = smsc_read(sg->dev,
+ SMSC_GPIO_INT_STAT_START + i, buf);
+
+ if (ret < 0)
+ dev_err(sg->dev, "Read INT_STAT Error\n");
+
+ return ret;
+}
+
+static irqreturn_t smsc_irq_handler(int irq, void *devid)
+{
+ struct smsc_gpio *sg = devid;
+ unsigned int status, bank, pending;
+ int ret;
+ smsc_read(sg->dev, GRP_INT_STAT, &status);
+
+ if (!(status & SMSC_GPI_INT))
+ goto out;
+
+ for (bank = 0; bank <= SMSC_BANK(SMSC_MAXGPIO);
+ bank++) {
+ pending = sg->irq_stat[bank] & sg->irq_mask[bank];
+ ret = smsc_gpio_read_intstat(sg,
+ &sg->irq_stat[bank], bank);
+ if (ret < 0)
+ memset(&sg->irq_stat[bank], 0,
+ ARRAY_SIZE(sg->irq_stat));
+
+ while (pending) {
+ unsigned long bit = __ffs(pending);
+ unsigned int irq;
+
+ pending &= ~BIT(bit);
+ irq = bit + sg->irq_base;
+ handle_nested_irq(irq);
+ }
+ }
+
+out:
+ smsc_write(sg->dev, GRP_INT_STAT, status); /* Status is W1C */
+
+ return IRQ_HANDLED;
+}
+
+static int smsc_irq_setup(struct smsc_gpio *sg)
+{
+ unsigned gpio;
+ int ret;
+
+ mutex_init(&sg->irq_lock);
+
+ for (gpio = 0; gpio < sg->gpio_chip.ngpio; gpio++) {
+ int irq = gpio + sg->irq_base;
+ irq_set_chip_data(irq, sg);
+ irq_set_chip_and_handler(irq, &smsc_irq_chip,
+ handle_level_irq);
+ irq_set_nested_thread(irq, 1);
+#ifdef CONFIG_ARM
+ set_irq_flags(irq, IRQF_VALID);
+#else
+ irq_set_noprobe(irq);
+#endif
+ }
+
+ ret = request_threaded_irq(sg->irq, NULL,
+ smsc_irq_handler, sg->flags,
+ "smsc_gpio", sg);
+ if (ret) {
+ dev_err(sg->dev, "failed to request irq %d\n",
+ sg->irq);
+ }
+
+ sg->gpio_chip.to_irq = smsc_gpio_to_irq;
+
+ return 0;
+}
+
+static int __devinit smsc_gpio_probe(struct platform_device *pdev)
+{
+ struct smsc_gpio *sg;
+ struct gpio_chip *gc;
+ struct smsc *smsc = dev_get_drvdata(pdev->dev.parent);
+ int ret, i, temp;
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ int irq_base;
+
+ sg = devm_kzalloc(dev, sizeof(*sg), GFP_KERNEL);
+ if (sg == NULL) {
+ dev_err(&pdev->dev, "failed to alloc memory\n");
+ return -ENOMEM;
+ }
+
+ sg->irq = platform_get_irq(pdev, 0);
+ if (np) {
+ of_property_read_u32(np, "gpio,base", &temp);
+ of_property_read_u32(np, "flags", &sg->flags);
+ }
+
+ gc = &sg->gpio_chip;
+ gc->direction_input = smsc_gpio_direction_input;
+ gc->direction_output = smsc_gpio_direction_output;
+ gc->get = smsc_gpio_get_value;
+ gc->set = smsc_gpio_set_value;
+ gc->can_sleep = 1;
+
+ gc->base = temp;
+ gc->ngpio = SMSC_MAXGPIO;
+ gc->owner = THIS_MODULE;
+
+ sg->smsc = smsc;
+ sg->dev = dev;
+ mutex_init(&sg->lock);
+
+ for (i = 0; i <= SMSC_BANK(SMSC_MAXGPIO); i++)
+ smsc_read(sg->dev, SMSC_GPIO_DATA_OUT_START + i,
+ &sg->dat_out[i]);
+
+ for (i = 0; i < SMSC_MAXGPIO; i++)
+ smsc_read(sg->dev, SMSC_CFG_START + i, &sg->dir[i]);
+
+ irq_base = irq_alloc_descs(-1, 0, sg->gpio_chip.ngpio, 0);
+ if (IS_ERR_VALUE(irq_base)) {
+ dev_err(sg->dev, "Fail to allocate IRQ descs\n");
+ return irq_base;
+ }
+ sg->irq_base = irq_base;
+
+ irq_domain_add_legacy(pdev->dev.of_node, sg->gpio_chip.ngpio,
+ sg->irq_base, 0, &irq_domain_simple_ops, NULL);
+
+ ret = smsc_irq_setup(sg);
+ if (ret)
+ goto err;
+
+ ret = gpiochip_add(&sg->gpio_chip);
+ if (ret)
+ goto err;
+
+ return 0;
+
+err:
+ kfree(sg);
+
+ return ret;
+}
+
+static int __devexit smsc_gpio_remove(struct platform_device *pdev)
+{
+ struct smsc_gpio *sg = dev_get_drvdata(&pdev->dev);
+ int ret;
+
+ ret = gpiochip_remove(&sg->gpio_chip);
+ if (ret) {
+ dev_err(&pdev->dev, "gpiochip_remove failed %d\n", ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+static const struct of_device_id smsc_gpio_dt_match[] = {
+ { .compatible = "smsc,gpio" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, smsc_gpio_dt_match);
+
+static struct platform_driver smsc_gpio_driver = {
+ .driver = {
+ .name = "smsc_gpio",
+ .of_match_table = of_match_ptr(smsc_gpio_dt_match),
+ },
+ .probe = smsc_gpio_probe,
+ .remove = __devexit_p(smsc_gpio_remove),
+};
+
+module_platform_driver(smsc_gpio_driver);
+
+MODULE_AUTHOR("Sourav Poddar <sourav.poddar@...com>");
+MODULE_DESCRIPTION("GPIO SMSC Driver");
+MODULE_LICENSE("GPL v2");
--
1.7.1
--
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