summaryrefslogtreecommitdiffstats
path: root/drivers/gpio/stmpe-gpio.c
diff options
context:
space:
mode:
authorRabin Vincent2010-07-02 13:22:09 +0200
committerSamuel Ortiz2010-08-12 11:27:55 +0200
commit03f822f5e5f5924f4ad372d3e698855c6a9275e0 (patch)
treeb8b89861d0f39eb181b866980c0f456341df8a84 /drivers/gpio/stmpe-gpio.c
parentmfd: Add STMPE I/O Expander support (diff)
downloadkernel-qcow2-linux-03f822f5e5f5924f4ad372d3e698855c6a9275e0.tar.gz
kernel-qcow2-linux-03f822f5e5f5924f4ad372d3e698855c6a9275e0.tar.xz
kernel-qcow2-linux-03f822f5e5f5924f4ad372d3e698855c6a9275e0.zip
gpio: Add STMPE GPIO driver
Add support for the GPIOs on STMPE I/O Expanders. [l.fu@pengutronix.de: fix set direction input] [l.fu@pengutronix.de: set GPIO alternate function while requesting] Acked-by: Luotao Fu <l.fu@pengutronix.de> Acked-by: Linus Walleij <linus.walleij@stericsson.com> Signed-off-by: Rabin Vincent <rabin.vincent@stericsson.com> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Diffstat (limited to 'drivers/gpio/stmpe-gpio.c')
-rw-r--r--drivers/gpio/stmpe-gpio.c399
1 files changed, 399 insertions, 0 deletions
diff --git a/drivers/gpio/stmpe-gpio.c b/drivers/gpio/stmpe-gpio.c
new file mode 100644
index 000000000000..4e1f1b9d5e67
--- /dev/null
+++ b/drivers/gpio/stmpe-gpio.c
@@ -0,0 +1,399 @@
+/*
+ * Copyright (C) ST-Ericsson SA 2010
+ *
+ * License Terms: GNU General Public License, version 2
+ * Author: Rabin Vincent <rabin.vincent@stericsson.com> for ST-Ericsson
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/gpio.h>
+#include <linux/irq.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/stmpe.h>
+
+/*
+ * These registers are modified under the irq bus lock and cached to avoid
+ * unnecessary writes in bus_sync_unlock.
+ */
+enum { REG_RE, REG_FE, REG_IE };
+
+#define CACHE_NR_REGS 3
+#define CACHE_NR_BANKS (STMPE_NR_GPIOS / 8)
+
+struct stmpe_gpio {
+ struct gpio_chip chip;
+ struct stmpe *stmpe;
+ struct device *dev;
+ struct mutex irq_lock;
+
+ int irq_base;
+
+ /* Caches of interrupt control registers for bus_lock */
+ u8 regs[CACHE_NR_REGS][CACHE_NR_BANKS];
+ u8 oldregs[CACHE_NR_REGS][CACHE_NR_BANKS];
+};
+
+static inline struct stmpe_gpio *to_stmpe_gpio(struct gpio_chip *chip)
+{
+ return container_of(chip, struct stmpe_gpio, chip);
+}
+
+static int stmpe_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+ struct stmpe_gpio *stmpe_gpio = to_stmpe_gpio(chip);
+ struct stmpe *stmpe = stmpe_gpio->stmpe;
+ u8 reg = stmpe->regs[STMPE_IDX_GPMR_LSB] - (offset / 8);
+ u8 mask = 1 << (offset % 8);
+ int ret;
+
+ ret = stmpe_reg_read(stmpe, reg);
+ if (ret < 0)
+ return ret;
+
+ return ret & mask;
+}
+
+static void stmpe_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
+{
+ struct stmpe_gpio *stmpe_gpio = to_stmpe_gpio(chip);
+ struct stmpe *stmpe = stmpe_gpio->stmpe;
+ int which = val ? STMPE_IDX_GPSR_LSB : STMPE_IDX_GPCR_LSB;
+ u8 reg = stmpe->regs[which] - (offset / 8);
+ u8 mask = 1 << (offset % 8);
+
+ stmpe_reg_write(stmpe, reg, mask);
+}
+
+static int stmpe_gpio_direction_output(struct gpio_chip *chip,
+ unsigned offset, int val)
+{
+ struct stmpe_gpio *stmpe_gpio = to_stmpe_gpio(chip);
+ struct stmpe *stmpe = stmpe_gpio->stmpe;
+ u8 reg = stmpe->regs[STMPE_IDX_GPDR_LSB] - (offset / 8);
+ u8 mask = 1 << (offset % 8);
+
+ stmpe_gpio_set(chip, offset, val);
+
+ return stmpe_set_bits(stmpe, reg, mask, mask);
+}
+
+static int stmpe_gpio_direction_input(struct gpio_chip *chip,
+ unsigned offset)
+{
+ struct stmpe_gpio *stmpe_gpio = to_stmpe_gpio(chip);
+ struct stmpe *stmpe = stmpe_gpio->stmpe;
+ u8 reg = stmpe->regs[STMPE_IDX_GPDR_LSB] - (offset / 8);
+ u8 mask = 1 << (offset % 8);
+
+ return stmpe_set_bits(stmpe, reg, mask, 0);
+}
+
+static int stmpe_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
+{
+ struct stmpe_gpio *stmpe_gpio = to_stmpe_gpio(chip);
+
+ return stmpe_gpio->irq_base + offset;
+}
+
+static int stmpe_gpio_request(struct gpio_chip *chip, unsigned offset)
+{
+ struct stmpe_gpio *stmpe_gpio = to_stmpe_gpio(chip);
+ struct stmpe *stmpe = stmpe_gpio->stmpe;
+
+ return stmpe_set_altfunc(stmpe, 1 << offset, STMPE_BLOCK_GPIO);
+}
+
+static struct gpio_chip template_chip = {
+ .label = "stmpe",
+ .owner = THIS_MODULE,
+ .direction_input = stmpe_gpio_direction_input,
+ .get = stmpe_gpio_get,
+ .direction_output = stmpe_gpio_direction_output,
+ .set = stmpe_gpio_set,
+ .to_irq = stmpe_gpio_to_irq,
+ .request = stmpe_gpio_request,
+ .can_sleep = 1,
+};
+
+static int stmpe_gpio_irq_set_type(unsigned int irq, unsigned int type)
+{
+ struct stmpe_gpio *stmpe_gpio = get_irq_chip_data(irq);
+ int offset = irq - stmpe_gpio->irq_base;
+ int regoffset = offset / 8;
+ int mask = 1 << (offset % 8);
+
+ if (type == IRQ_TYPE_LEVEL_LOW || type == IRQ_TYPE_LEVEL_HIGH)
+ return -EINVAL;
+
+ if (type == IRQ_TYPE_EDGE_RISING)
+ stmpe_gpio->regs[REG_RE][regoffset] |= mask;
+ else
+ stmpe_gpio->regs[REG_RE][regoffset] &= ~mask;
+
+ if (type == IRQ_TYPE_EDGE_FALLING)
+ stmpe_gpio->regs[REG_FE][regoffset] |= mask;
+ else
+ stmpe_gpio->regs[REG_FE][regoffset] &= ~mask;
+
+ return 0;
+}
+
+static void stmpe_gpio_irq_lock(unsigned int irq)
+{
+ struct stmpe_gpio *stmpe_gpio = get_irq_chip_data(irq);
+
+ mutex_lock(&stmpe_gpio->irq_lock);
+}
+
+static void stmpe_gpio_irq_sync_unlock(unsigned int irq)
+{
+ struct stmpe_gpio *stmpe_gpio = get_irq_chip_data(irq);
+ struct stmpe *stmpe = stmpe_gpio->stmpe;
+ int num_banks = DIV_ROUND_UP(stmpe->num_gpios, 8);
+ static const u8 regmap[] = {
+ [REG_RE] = STMPE_IDX_GPRER_LSB,
+ [REG_FE] = STMPE_IDX_GPFER_LSB,
+ [REG_IE] = STMPE_IDX_IEGPIOR_LSB,
+ };
+ int i, j;
+
+ for (i = 0; i < CACHE_NR_REGS; i++) {
+ for (j = 0; j < num_banks; j++) {
+ u8 old = stmpe_gpio->oldregs[i][j];
+ u8 new = stmpe_gpio->regs[i][j];
+
+ if (new == old)
+ continue;
+
+ stmpe_gpio->oldregs[i][j] = new;
+ stmpe_reg_write(stmpe, stmpe->regs[regmap[i]] - j, new);
+ }
+ }
+
+ mutex_unlock(&stmpe_gpio->irq_lock);
+}
+
+static void stmpe_gpio_irq_mask(unsigned int irq)
+{
+ struct stmpe_gpio *stmpe_gpio = get_irq_chip_data(irq);
+ int offset = irq - stmpe_gpio->irq_base;
+ int regoffset = offset / 8;
+ int mask = 1 << (offset % 8);
+
+ stmpe_gpio->regs[REG_IE][regoffset] &= ~mask;
+}
+
+static void stmpe_gpio_irq_unmask(unsigned int irq)
+{
+ struct stmpe_gpio *stmpe_gpio = get_irq_chip_data(irq);
+ int offset = irq - stmpe_gpio->irq_base;
+ int regoffset = offset / 8;
+ int mask = 1 << (offset % 8);
+
+ stmpe_gpio->regs[REG_IE][regoffset] |= mask;
+}
+
+static struct irq_chip stmpe_gpio_irq_chip = {
+ .name = "stmpe-gpio",
+ .bus_lock = stmpe_gpio_irq_lock,
+ .bus_sync_unlock = stmpe_gpio_irq_sync_unlock,
+ .mask = stmpe_gpio_irq_mask,
+ .unmask = stmpe_gpio_irq_unmask,
+ .set_type = stmpe_gpio_irq_set_type,
+};
+
+static irqreturn_t stmpe_gpio_irq(int irq, void *dev)
+{
+ struct stmpe_gpio *stmpe_gpio = dev;
+ struct stmpe *stmpe = stmpe_gpio->stmpe;
+ u8 statmsbreg = stmpe->regs[STMPE_IDX_ISGPIOR_MSB];
+ int num_banks = DIV_ROUND_UP(stmpe->num_gpios, 8);
+ u8 status[num_banks];
+ int ret;
+ int i;
+
+ ret = stmpe_block_read(stmpe, statmsbreg, num_banks, status);
+ if (ret < 0)
+ return IRQ_NONE;
+
+ for (i = 0; i < num_banks; i++) {
+ int bank = num_banks - i - 1;
+ unsigned int enabled = stmpe_gpio->regs[REG_IE][bank];
+ unsigned int stat = status[i];
+
+ stat &= enabled;
+ if (!stat)
+ continue;
+
+ while (stat) {
+ int bit = __ffs(stat);
+ int line = bank * 8 + bit;
+
+ handle_nested_irq(stmpe_gpio->irq_base + line);
+ stat &= ~(1 << bit);
+ }
+
+ stmpe_reg_write(stmpe, statmsbreg + i, status[i]);
+ stmpe_reg_write(stmpe, stmpe->regs[STMPE_IDX_GPEDR_MSB] + i,
+ status[i]);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static int __devinit stmpe_gpio_irq_init(struct stmpe_gpio *stmpe_gpio)
+{
+ int base = stmpe_gpio->irq_base;
+ int irq;
+
+ for (irq = base; irq < base + stmpe_gpio->chip.ngpio; irq++) {
+ set_irq_chip_data(irq, stmpe_gpio);
+ set_irq_chip_and_handler(irq, &stmpe_gpio_irq_chip,
+ handle_simple_irq);
+ set_irq_nested_thread(irq, 1);
+#ifdef CONFIG_ARM
+ set_irq_flags(irq, IRQF_VALID);
+#else
+ set_irq_noprobe(irq);
+#endif
+ }
+
+ return 0;
+}
+
+static void stmpe_gpio_irq_remove(struct stmpe_gpio *stmpe_gpio)
+{
+ int base = stmpe_gpio->irq_base;
+ int irq;
+
+ for (irq = base; irq < base + stmpe_gpio->chip.ngpio; irq++) {
+#ifdef CONFIG_ARM
+ set_irq_flags(irq, 0);
+#endif
+ set_irq_chip_and_handler(irq, NULL, NULL);
+ set_irq_chip_data(irq, NULL);
+ }
+}
+
+static int __devinit stmpe_gpio_probe(struct platform_device *pdev)
+{
+ struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent);
+ struct stmpe_gpio_platform_data *pdata;
+ struct stmpe_gpio *stmpe_gpio;
+ int ret;
+ int irq;
+
+ pdata = stmpe->pdata->gpio;
+ if (!pdata)
+ return -ENODEV;
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0)
+ return irq;
+
+ stmpe_gpio = kzalloc(sizeof(struct stmpe_gpio), GFP_KERNEL);
+ if (!stmpe_gpio)
+ return -ENOMEM;
+
+ mutex_init(&stmpe_gpio->irq_lock);
+
+ stmpe_gpio->dev = &pdev->dev;
+ stmpe_gpio->stmpe = stmpe;
+
+ stmpe_gpio->chip = template_chip;
+ stmpe_gpio->chip.ngpio = stmpe->num_gpios;
+ stmpe_gpio->chip.dev = &pdev->dev;
+ stmpe_gpio->chip.base = pdata ? pdata->gpio_base : -1;
+
+ stmpe_gpio->irq_base = stmpe->irq_base + STMPE_INT_GPIO(0);
+
+ ret = stmpe_enable(stmpe, STMPE_BLOCK_GPIO);
+ if (ret)
+ return ret;
+
+ ret = stmpe_gpio_irq_init(stmpe_gpio);
+ if (ret)
+ goto out_free;
+
+ ret = request_threaded_irq(irq, NULL, stmpe_gpio_irq, IRQF_ONESHOT,
+ "stmpe-gpio", stmpe_gpio);
+ if (ret) {
+ dev_err(&pdev->dev, "unable to get irq: %d\n", ret);
+ goto out_removeirq;
+ }
+
+ ret = gpiochip_add(&stmpe_gpio->chip);
+ if (ret) {
+ dev_err(&pdev->dev, "unable to add gpiochip: %d\n", ret);
+ goto out_freeirq;
+ }
+
+ if (pdata && pdata->setup)
+ pdata->setup(stmpe, stmpe_gpio->chip.base);
+
+ platform_set_drvdata(pdev, stmpe_gpio);
+
+ return 0;
+
+out_freeirq:
+ free_irq(irq, stmpe_gpio);
+out_removeirq:
+ stmpe_gpio_irq_remove(stmpe_gpio);
+out_free:
+ kfree(stmpe_gpio);
+ return ret;
+}
+
+static int __devexit stmpe_gpio_remove(struct platform_device *pdev)
+{
+ struct stmpe_gpio *stmpe_gpio = platform_get_drvdata(pdev);
+ struct stmpe *stmpe = stmpe_gpio->stmpe;
+ struct stmpe_gpio_platform_data *pdata = stmpe->pdata->gpio;
+ int irq = platform_get_irq(pdev, 0);
+ int ret;
+
+ if (pdata && pdata->remove)
+ pdata->remove(stmpe, stmpe_gpio->chip.base);
+
+ ret = gpiochip_remove(&stmpe_gpio->chip);
+ if (ret < 0) {
+ dev_err(stmpe_gpio->dev,
+ "unable to remove gpiochip: %d\n", ret);
+ return ret;
+ }
+
+ stmpe_disable(stmpe, STMPE_BLOCK_GPIO);
+
+ free_irq(irq, stmpe_gpio);
+ stmpe_gpio_irq_remove(stmpe_gpio);
+ platform_set_drvdata(pdev, NULL);
+ kfree(stmpe_gpio);
+
+ return 0;
+}
+
+static struct platform_driver stmpe_gpio_driver = {
+ .driver.name = "stmpe-gpio",
+ .driver.owner = THIS_MODULE,
+ .probe = stmpe_gpio_probe,
+ .remove = __devexit_p(stmpe_gpio_remove),
+};
+
+static int __init stmpe_gpio_init(void)
+{
+ return platform_driver_register(&stmpe_gpio_driver);
+}
+subsys_initcall(stmpe_gpio_init);
+
+static void __exit stmpe_gpio_exit(void)
+{
+ platform_driver_unregister(&stmpe_gpio_driver);
+}
+module_exit(stmpe_gpio_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("STMPExxxx GPIO driver");
+MODULE_AUTHOR("Rabin Vincent <rabin.vincent@stericsson.com>");