Initial import

1 files changed, 454 insertions, 0 deletions

diff --git a/drivers/gpio/gpio-stmpe.c b/drivers/gpio/gpio-stmpe.c
new file mode 100644
index 000000000..dabfb99dd
--- /dev/null
+++ b/drivers/gpio/gpio-stmpe.c
@@ -0,0 +1,454 @@
+/*
+ * 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/interrupt.h>
+#include <linux/of.h>
+#include <linux/mfd/stmpe.h>
+#include <linux/seq_file.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
+/* No variant has more than 24 GPIOs */
+#define CACHE_NR_BANKS	(24 / 8)
+
+struct stmpe_gpio {
+	struct gpio_chip chip;
+	struct stmpe *stmpe;
+	struct device *dev;
+	struct mutex irq_lock;
+	u32 norequest_mask;
+	/* 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);
+
+	/*
+	 * Some variants have single register for gpio set/clear functionality.
+	 * For them we need to write 0 to clear and 1 to set.
+	 */
+	if (stmpe->regs[STMPE_IDX_GPSR_LSB] == stmpe->regs[STMPE_IDX_GPCR_LSB])
+		stmpe_set_bits(stmpe, reg, mask, val ? mask : 0);
+	else
+		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_request(struct gpio_chip *chip, unsigned offset)
+{
+	struct stmpe_gpio *stmpe_gpio = to_stmpe_gpio(chip);
+	struct stmpe *stmpe = stmpe_gpio->stmpe;
+
+	if (stmpe_gpio->norequest_mask & (1 << offset))
+		return -EINVAL;
+
+	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,
+	.request		= stmpe_gpio_request,
+	.can_sleep		= true,
+};
+
+static int stmpe_gpio_irq_set_type(struct irq_data *d, unsigned int type)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct stmpe_gpio *stmpe_gpio = to_stmpe_gpio(gc);
+	int offset = d->hwirq;
+	int regoffset = offset / 8;
+	int mask = 1 << (offset % 8);
+
+	if (type & IRQ_TYPE_LEVEL_LOW || type & IRQ_TYPE_LEVEL_HIGH)
+		return -EINVAL;
+
+	/* STMPE801 doesn't have RE and FE registers */
+	if (stmpe_gpio->stmpe->partnum == STMPE801)
+		return 0;
+
+	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(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct stmpe_gpio *stmpe_gpio = to_stmpe_gpio(gc);
+
+	mutex_lock(&stmpe_gpio->irq_lock);
+}
+
+static void stmpe_gpio_irq_sync_unlock(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct stmpe_gpio *stmpe_gpio = to_stmpe_gpio(gc);
+	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++) {
+		/* STMPE801 doesn't have RE and FE registers */
+		if ((stmpe->partnum == STMPE801) &&
+				(i != REG_IE))
+			continue;
+
+		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(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct stmpe_gpio *stmpe_gpio = to_stmpe_gpio(gc);
+	int offset = d->hwirq;
+	int regoffset = offset / 8;
+	int mask = 1 << (offset % 8);
+
+	stmpe_gpio->regs[REG_IE][regoffset] &= ~mask;
+}
+
+static void stmpe_gpio_irq_unmask(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct stmpe_gpio *stmpe_gpio = to_stmpe_gpio(gc);
+	int offset = d->hwirq;
+	int regoffset = offset / 8;
+	int mask = 1 << (offset % 8);
+
+	stmpe_gpio->regs[REG_IE][regoffset] |= mask;
+}
+
+static void stmpe_dbg_show_one(struct seq_file *s,
+			       struct gpio_chip *gc,
+			       unsigned offset, unsigned gpio)
+{
+	struct stmpe_gpio *stmpe_gpio = to_stmpe_gpio(gc);
+	struct stmpe *stmpe = stmpe_gpio->stmpe;
+	const char *label = gpiochip_is_requested(gc, offset);
+	int num_banks = DIV_ROUND_UP(stmpe->num_gpios, 8);
+	bool val = !!stmpe_gpio_get(gc, offset);
+	u8 dir_reg = stmpe->regs[STMPE_IDX_GPDR_LSB] - (offset / 8);
+	u8 mask = 1 << (offset % 8);
+	int ret;
+	u8 dir;
+
+	ret = stmpe_reg_read(stmpe, dir_reg);
+	if (ret < 0)
+		return;
+	dir = !!(ret & mask);
+
+	if (dir) {
+		seq_printf(s, " gpio-%-3d (%-20.20s) out %s",
+			   gpio, label ?: "(none)",
+			   val ? "hi" : "lo");
+	} else {
+		u8 edge_det_reg = stmpe->regs[STMPE_IDX_GPEDR_MSB] + num_banks - 1 - (offset / 8);
+		u8 rise_reg = stmpe->regs[STMPE_IDX_GPRER_LSB] - (offset / 8);
+		u8 fall_reg = stmpe->regs[STMPE_IDX_GPFER_LSB] - (offset / 8);
+		u8 irqen_reg = stmpe->regs[STMPE_IDX_IEGPIOR_LSB] - (offset / 8);
+		bool edge_det;
+		bool rise;
+		bool fall;
+		bool irqen;
+
+		ret = stmpe_reg_read(stmpe, edge_det_reg);
+		if (ret < 0)
+			return;
+		edge_det = !!(ret & mask);
+		ret = stmpe_reg_read(stmpe, rise_reg);
+		if (ret < 0)
+			return;
+		rise = !!(ret & mask);
+		ret = stmpe_reg_read(stmpe, fall_reg);
+		if (ret < 0)
+			return;
+		fall = !!(ret & mask);
+		ret = stmpe_reg_read(stmpe, irqen_reg);
+		if (ret < 0)
+			return;
+		irqen = !!(ret & mask);
+
+		seq_printf(s, " gpio-%-3d (%-20.20s) in  %s %s %s%s%s",
+			   gpio, label ?: "(none)",
+			   val ? "hi" : "lo",
+			   edge_det ? "edge-asserted" : "edge-inactive",
+			   irqen ? "IRQ-enabled" : "",
+			   rise ? " rising-edge-detection" : "",
+			   fall ? " falling-edge-detection" : "");
+	}
+}
+
+static void stmpe_dbg_show(struct seq_file *s, struct gpio_chip *gc)
+{
+	unsigned i;
+	unsigned gpio = gc->base;
+
+	for (i = 0; i < gc->ngpio; i++, gpio++) {
+		stmpe_dbg_show_one(s, gc, i, gpio);
+		seq_printf(s, "\n");
+	}
+}
+
+static struct irq_chip stmpe_gpio_irq_chip = {
+	.name			= "stmpe-gpio",
+	.irq_bus_lock		= stmpe_gpio_irq_lock,
+	.irq_bus_sync_unlock	= stmpe_gpio_irq_sync_unlock,
+	.irq_mask		= stmpe_gpio_irq_mask,
+	.irq_unmask		= stmpe_gpio_irq_unmask,
+	.irq_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;
+			int child_irq = irq_find_mapping(stmpe_gpio->chip.irqdomain,
+							 line);
+
+			handle_nested_irq(child_irq);
+			stat &= ~(1 << bit);
+		}
+
+		stmpe_reg_write(stmpe, statmsbreg + i, status[i]);
+
+		/* Edge detect register is not present on 801 */
+		if (stmpe->partnum != STMPE801)
+			stmpe_reg_write(stmpe, stmpe->regs[STMPE_IDX_GPEDR_MSB]
+					+ i, status[i]);
+	}
+
+	return IRQ_HANDLED;
+}
+
+static int stmpe_gpio_probe(struct platform_device *pdev)
+{
+	struct stmpe *stmpe = dev_get_drvdata(pdev->dev.parent);
+	struct device_node *np = pdev->dev.of_node;
+	struct stmpe_gpio *stmpe_gpio;
+	int ret;
+	int irq = 0;
+
+	irq = platform_get_irq(pdev, 0);
+
+	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.of_node = np;
+	stmpe_gpio->chip.base = -1;
+
+	if (IS_ENABLED(CONFIG_DEBUG_FS))
+                stmpe_gpio->chip.dbg_show = stmpe_dbg_show;
+
+	of_property_read_u32(np, "st,norequest-mask",
+			&stmpe_gpio->norequest_mask);
+
+	if (irq < 0)
+		dev_info(&pdev->dev,
+			"device configured in no-irq mode: "
+			"irqs are not available\n");
+
+	ret = stmpe_enable(stmpe, STMPE_BLOCK_GPIO);
+	if (ret)
+		goto out_free;
+
+	ret = gpiochip_add(&stmpe_gpio->chip);
+	if (ret) {
+		dev_err(&pdev->dev, "unable to add gpiochip: %d\n", ret);
+		goto out_disable;
+	}
+
+	if (irq > 0) {
+		ret = devm_request_threaded_irq(&pdev->dev, 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_disable;
+		}
+		ret =  gpiochip_irqchip_add(&stmpe_gpio->chip,
+					    &stmpe_gpio_irq_chip,
+					    0,
+					    handle_simple_irq,
+					    IRQ_TYPE_NONE);
+		if (ret) {
+			dev_err(&pdev->dev,
+				"could not connect irqchip to gpiochip\n");
+			goto out_disable;
+		}
+
+		gpiochip_set_chained_irqchip(&stmpe_gpio->chip,
+					     &stmpe_gpio_irq_chip,
+					     irq,
+					     NULL);
+	}
+
+	platform_set_drvdata(pdev, stmpe_gpio);
+
+	return 0;
+
+out_disable:
+	stmpe_disable(stmpe, STMPE_BLOCK_GPIO);
+	gpiochip_remove(&stmpe_gpio->chip);
+out_free:
+	kfree(stmpe_gpio);
+	return ret;
+}
+
+static int stmpe_gpio_remove(struct platform_device *pdev)
+{
+	struct stmpe_gpio *stmpe_gpio = platform_get_drvdata(pdev);
+	struct stmpe *stmpe = stmpe_gpio->stmpe;
+
+	gpiochip_remove(&stmpe_gpio->chip);
+	stmpe_disable(stmpe, STMPE_BLOCK_GPIO);
+	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		= 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>");