1 files changed, 540 insertions, 0 deletions

diff --git a/drivers/gpio/gpio-stmpe.c b/drivers/gpio/gpio-stmpe.c
new file mode 100644
index 000000000..0fa4f0a93
--- /dev/null
+++ b/drivers/gpio/gpio-stmpe.c
@@ -0,0 +1,540 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) ST-Ericsson SA 2010
+ *
+ * Author: Rabin Vincent <rabin.vincent@stericsson.com> for ST-Ericsson
+ */
+
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/gpio/driver.h>
+#include <linux/interrupt.h>
+#include <linux/of.h>
+#include <linux/mfd/stmpe.h>
+#include <linux/seq_file.h>
+#include <linux/bitops.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 };
+
+enum { LSB, CSB, MSB };
+
+#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 int stmpe_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(chip);
+	struct stmpe *stmpe = stmpe_gpio->stmpe;
+	u8 reg = stmpe->regs[STMPE_IDX_GPMR_LSB + (offset / 8)];
+	u8 mask = BIT(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 = gpiochip_get_data(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 = BIT(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_get_direction(struct gpio_chip *chip,
+				    unsigned offset)
+{
+	struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(chip);
+	struct stmpe *stmpe = stmpe_gpio->stmpe;
+	u8 reg = stmpe->regs[STMPE_IDX_GPDR_LSB] - (offset / 8);
+	u8 mask = BIT(offset % 8);
+	int ret;
+
+	ret = stmpe_reg_read(stmpe, reg);
+	if (ret < 0)
+		return ret;
+
+	if (ret & mask)
+		return GPIO_LINE_DIRECTION_OUT;
+
+	return GPIO_LINE_DIRECTION_IN;
+}
+
+static int stmpe_gpio_direction_output(struct gpio_chip *chip,
+					 unsigned offset, int val)
+{
+	struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(chip);
+	struct stmpe *stmpe = stmpe_gpio->stmpe;
+	u8 reg = stmpe->regs[STMPE_IDX_GPDR_LSB + (offset / 8)];
+	u8 mask = BIT(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 = gpiochip_get_data(chip);
+	struct stmpe *stmpe = stmpe_gpio->stmpe;
+	u8 reg = stmpe->regs[STMPE_IDX_GPDR_LSB + (offset / 8)];
+	u8 mask = BIT(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 = gpiochip_get_data(chip);
+	struct stmpe *stmpe = stmpe_gpio->stmpe;
+
+	if (stmpe_gpio->norequest_mask & BIT(offset))
+		return -EINVAL;
+
+	return stmpe_set_altfunc(stmpe, BIT(offset), STMPE_BLOCK_GPIO);
+}
+
+static const struct gpio_chip template_chip = {
+	.label			= "stmpe",
+	.owner			= THIS_MODULE,
+	.get_direction		= stmpe_gpio_get_direction,
+	.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 = gpiochip_get_data(gc);
+	int offset = d->hwirq;
+	int regoffset = offset / 8;
+	int mask = BIT(offset % 8);
+
+	if (type & IRQ_TYPE_LEVEL_LOW || type & IRQ_TYPE_LEVEL_HIGH)
+		return -EINVAL;
+
+	/* STMPE801 and STMPE 1600 don't have RE and FE registers */
+	if (stmpe_gpio->stmpe->partnum == STMPE801 ||
+	    stmpe_gpio->stmpe->partnum == STMPE1600)
+		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 = gpiochip_get_data(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 = gpiochip_get_data(gc);
+	struct stmpe *stmpe = stmpe_gpio->stmpe;
+	int num_banks = DIV_ROUND_UP(stmpe->num_gpios, 8);
+	static const u8 regmap[CACHE_NR_REGS][CACHE_NR_BANKS] = {
+		[REG_RE][LSB] = STMPE_IDX_GPRER_LSB,
+		[REG_RE][CSB] = STMPE_IDX_GPRER_CSB,
+		[REG_RE][MSB] = STMPE_IDX_GPRER_MSB,
+		[REG_FE][LSB] = STMPE_IDX_GPFER_LSB,
+		[REG_FE][CSB] = STMPE_IDX_GPFER_CSB,
+		[REG_FE][MSB] = STMPE_IDX_GPFER_MSB,
+		[REG_IE][LSB] = STMPE_IDX_IEGPIOR_LSB,
+		[REG_IE][CSB] = STMPE_IDX_IEGPIOR_CSB,
+		[REG_IE][MSB] = STMPE_IDX_IEGPIOR_MSB,
+	};
+	int i, j;
+
+	/*
+	 * STMPE1600: to be able to get IRQ from pins,
+	 * a read must be done on GPMR register, or a write in
+	 * GPSR or GPCR registers
+	 */
+	if (stmpe->partnum == STMPE1600) {
+		stmpe_reg_read(stmpe, stmpe->regs[STMPE_IDX_GPMR_LSB]);
+		stmpe_reg_read(stmpe, stmpe->regs[STMPE_IDX_GPMR_CSB]);
+	}
+
+	for (i = 0; i < CACHE_NR_REGS; i++) {
+		/* STMPE801 and STMPE1600 don't have RE and FE registers */
+		if ((stmpe->partnum == STMPE801 ||
+		     stmpe->partnum == STMPE1600) &&
+		     (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 = gpiochip_get_data(gc);
+	int offset = d->hwirq;
+	int regoffset = offset / 8;
+	int mask = BIT(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 = gpiochip_get_data(gc);
+	int offset = d->hwirq;
+	int regoffset = offset / 8;
+	int mask = BIT(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 = gpiochip_get_data(gc);
+	struct stmpe *stmpe = stmpe_gpio->stmpe;
+	const char *label = gpiochip_is_requested(gc, offset);
+	bool val = !!stmpe_gpio_get(gc, offset);
+	u8 bank = offset / 8;
+	u8 dir_reg = stmpe->regs[STMPE_IDX_GPDR_LSB + bank];
+	u8 mask = BIT(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;
+		u8 rise_reg;
+		u8 fall_reg;
+		u8 irqen_reg;
+
+		static const char * const edge_det_values[] = {
+			"edge-inactive",
+			"edge-asserted",
+			"not-supported"
+		};
+		static const char * const rise_values[] = {
+			"no-rising-edge-detection",
+			"rising-edge-detection",
+			"not-supported"
+		};
+		static const char * const fall_values[] = {
+			"no-falling-edge-detection",
+			"falling-edge-detection",
+			"not-supported"
+		};
+		#define NOT_SUPPORTED_IDX 2
+		u8 edge_det = NOT_SUPPORTED_IDX;
+		u8 rise = NOT_SUPPORTED_IDX;
+		u8 fall = NOT_SUPPORTED_IDX;
+		bool irqen;
+
+		switch (stmpe->partnum) {
+		case STMPE610:
+		case STMPE811:
+		case STMPE1601:
+		case STMPE2401:
+		case STMPE2403:
+			edge_det_reg = stmpe->regs[STMPE_IDX_GPEDR_LSB + bank];
+			ret = stmpe_reg_read(stmpe, edge_det_reg);
+			if (ret < 0)
+				return;
+			edge_det = !!(ret & mask);
+			fallthrough;
+		case STMPE1801:
+			rise_reg = stmpe->regs[STMPE_IDX_GPRER_LSB + bank];
+			fall_reg = stmpe->regs[STMPE_IDX_GPFER_LSB + bank];
+
+			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);
+			fallthrough;
+		case STMPE801:
+		case STMPE1600:
+			irqen_reg = stmpe->regs[STMPE_IDX_IEGPIOR_LSB + bank];
+			break;
+
+		default:
+			return;
+		}
+
+		ret = stmpe_reg_read(stmpe, irqen_reg);
+		if (ret < 0)
+			return;
+		irqen = !!(ret & mask);
+
+		seq_printf(s, " gpio-%-3d (%-20.20s) in  %s %13s %13s %25s %25s",
+			   gpio, label ?: "(none)",
+			   val ? "hi" : "lo",
+			   edge_det_values[edge_det],
+			   irqen ? "IRQ-enabled" : "IRQ-disabled",
+			   rise_values[rise],
+			   fall_values[fall]);
+	}
+}
+
+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_putc(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,
+};
+
+#define MAX_GPIOS 24
+
+static irqreturn_t stmpe_gpio_irq(int irq, void *dev)
+{
+	struct stmpe_gpio *stmpe_gpio = dev;
+	struct stmpe *stmpe = stmpe_gpio->stmpe;
+	u8 statmsbreg;
+	int num_banks = DIV_ROUND_UP(stmpe->num_gpios, 8);
+	u8 status[DIV_ROUND_UP(MAX_GPIOS, 8)];
+	int ret;
+	int i;
+
+	/*
+	 * the stmpe_block_read() call below, imposes to set statmsbreg
+	 * with the register located at the lowest address. As STMPE1600
+	 * variant is the only one which respect registers address's order
+	 * (LSB regs located at lowest address than MSB ones) whereas all
+	 * the others have a registers layout with MSB located before the
+	 * LSB regs.
+	 */
+	if (stmpe->partnum == STMPE1600)
+		statmsbreg = stmpe->regs[STMPE_IDX_ISGPIOR_LSB];
+	else
+		statmsbreg = stmpe->regs[STMPE_IDX_ISGPIOR_MSB];
+
+	ret = stmpe_block_read(stmpe, statmsbreg, num_banks, status);
+	if (ret < 0)
+		return IRQ_NONE;
+
+	for (i = 0; i < num_banks; i++) {
+		int bank = (stmpe_gpio->stmpe->partnum == STMPE1600) ? i :
+			   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.irq.domain,
+							 line);
+
+			handle_nested_irq(child_irq);
+			stat &= ~BIT(bit);
+		}
+
+		/*
+		 * interrupt status register write has no effect on
+		 * 801/1801/1600, bits are cleared when read.
+		 * Edge detect register is not present on 801/1600/1801
+		 */
+		if (stmpe->partnum != STMPE801 && stmpe->partnum != STMPE1600 &&
+		    stmpe->partnum != STMPE1801) {
+			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 void stmpe_init_irq_valid_mask(struct gpio_chip *gc,
+				      unsigned long *valid_mask,
+				      unsigned int ngpios)
+{
+	struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(gc);
+	int i;
+
+	if (!stmpe_gpio->norequest_mask)
+		return;
+
+	/* Forbid unused lines to be mapped as IRQs */
+	for (i = 0; i < sizeof(u32); i++) {
+		if (stmpe_gpio->norequest_mask & BIT(i))
+			clear_bit(i, valid_mask);
+	}
+}
+
+static void stmpe_gpio_disable(void *stmpe)
+{
+	stmpe_disable(stmpe, STMPE_BLOCK_GPIO);
+}
+
+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, irq;
+
+	if (stmpe->num_gpios > MAX_GPIOS) {
+		dev_err(&pdev->dev, "Need to increase maximum GPIO number\n");
+		return -EINVAL;
+	}
+
+	stmpe_gpio = devm_kzalloc(&pdev->dev, sizeof(*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.parent = &pdev->dev;
+	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);
+
+	irq = platform_get_irq(pdev, 0);
+	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)
+		return ret;
+
+	ret = devm_add_action_or_reset(&pdev->dev, stmpe_gpio_disable, stmpe);
+	if (ret)
+		return ret;
+
+	if (irq > 0) {
+		struct gpio_irq_chip *girq;
+
+		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);
+			return ret;
+		}
+
+		girq = &stmpe_gpio->chip.irq;
+		girq->chip = &stmpe_gpio_irq_chip;
+		/* This will let us handle the parent IRQ in the driver */
+		girq->parent_handler = NULL;
+		girq->num_parents = 0;
+		girq->parents = NULL;
+		girq->default_type = IRQ_TYPE_NONE;
+		girq->handler = handle_simple_irq;
+		girq->threaded = true;
+		girq->init_valid_mask = stmpe_init_irq_valid_mask;
+	}
+
+	return devm_gpiochip_add_data(&pdev->dev, &stmpe_gpio->chip, stmpe_gpio);
+}
+
+static struct platform_driver stmpe_gpio_driver = {
+	.driver = {
+		.suppress_bind_attrs	= true,
+		.name			= "stmpe-gpio",
+	},
+	.probe		= stmpe_gpio_probe,
+};
+
+static int __init stmpe_gpio_init(void)
+{
+	return platform_driver_register(&stmpe_gpio_driver);
+}
+subsys_initcall(stmpe_gpio_init);