msm: add gpio driver for single-core SoCs.

Install a gpiolib driver supporting the on-chip gpios for
single-core MSMs in the 7x00 family, including 7x00A, 7x25, 7x27,
7x30, 8x50, and 8x50a.

As part of the ongoing effort to converge on a common code base,
this driver is based on the Google-Android msmgpio driver, whose
authors include Brian Swetland and Arve Hjønnevåg.

Cc: Arve Hjønnevåg <arve@android.com>
Cc: H Hartley Sweeten <hartleys@visionengravers.com>
Cc: Ryan Mallon <ryan@bluewatersys.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Gregory Bean <gbean@codeaurora.org>
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>

1 files changed, 358 insertions, 0 deletions

diff --git a/arch/arm/mach-msm/gpio.c b/arch/arm/mach-msm/gpio.c
new file mode 100644
index 000000000000..5040f1cb64f9
--- /dev/null
+++ b/arch/arm/mach-msm/gpio.c
@@ -0,0 +1,358 @@
+/* linux/arch/arm/mach-msm/gpio.c
+ *
+ * Copyright (C) 2007 Google, Inc.
+ * Copyright (c) 2009-2010, Code Aurora Forum. All rights reserved.
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/bitops.h>
+#include <linux/gpio.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include "gpio_hw.h"
+
+#define FIRST_GPIO_IRQ MSM_GPIO_TO_INT(0)
+
+#define MSM_GPIO_BANK(bank, first, last)				\
+	{								\
+		.regs = {						\
+			.out =         MSM_GPIO_OUT_##bank,		\
+			.in =          MSM_GPIO_IN_##bank,		\
+			.int_status =  MSM_GPIO_INT_STATUS_##bank,	\
+			.int_clear =   MSM_GPIO_INT_CLEAR_##bank,	\
+			.int_en =      MSM_GPIO_INT_EN_##bank,		\
+			.int_edge =    MSM_GPIO_INT_EDGE_##bank,	\
+			.int_pos =     MSM_GPIO_INT_POS_##bank,		\
+			.oe =          MSM_GPIO_OE_##bank,		\
+		},							\
+		.chip = {						\
+			.base = (first),				\
+			.ngpio = (last) - (first) + 1,			\
+			.get = msm_gpio_get,				\
+			.set = msm_gpio_set,				\
+			.direction_input = msm_gpio_direction_input,	\
+			.direction_output = msm_gpio_direction_output,	\
+			.to_irq = msm_gpio_to_irq,			\
+		}							\
+	}
+
+#define MSM_GPIO_BROKEN_INT_CLEAR 1
+
+struct msm_gpio_regs {
+	void __iomem *out;
+	void __iomem *in;
+	void __iomem *int_status;
+	void __iomem *int_clear;
+	void __iomem *int_en;
+	void __iomem *int_edge;
+	void __iomem *int_pos;
+	void __iomem *oe;
+};
+
+struct msm_gpio_chip {
+	spinlock_t		lock;
+	struct gpio_chip	chip;
+	struct msm_gpio_regs	regs;
+#if MSM_GPIO_BROKEN_INT_CLEAR
+	unsigned                int_status_copy;
+#endif
+	unsigned int            both_edge_detect;
+	unsigned int            int_enable[2]; /* 0: awake, 1: sleep */
+};
+
+static int msm_gpio_write(struct msm_gpio_chip *msm_chip,
+			  unsigned offset, unsigned on)
+{
+	unsigned mask = BIT(offset);
+	unsigned val;
+
+	val = readl(msm_chip->regs.out);
+	if (on)
+		writel(val | mask, msm_chip->regs.out);
+	else
+		writel(val & ~mask, msm_chip->regs.out);
+	return 0;
+}
+
+static void msm_gpio_update_both_edge_detect(struct msm_gpio_chip *msm_chip)
+{
+	int loop_limit = 100;
+	unsigned pol, val, val2, intstat;
+	do {
+		val = readl(msm_chip->regs.in);
+		pol = readl(msm_chip->regs.int_pos);
+		pol = (pol & ~msm_chip->both_edge_detect) |
+		      (~val & msm_chip->both_edge_detect);
+		writel(pol, msm_chip->regs.int_pos);
+		intstat = readl(msm_chip->regs.int_status);
+		val2 = readl(msm_chip->regs.in);
+		if (((val ^ val2) & msm_chip->both_edge_detect & ~intstat) == 0)
+			return;
+	} while (loop_limit-- > 0);
+	printk(KERN_ERR "msm_gpio_update_both_edge_detect, "
+	       "failed to reach stable state %x != %x\n", val, val2);
+}
+
+static int msm_gpio_clear_detect_status(struct msm_gpio_chip *msm_chip,
+					unsigned offset)
+{
+	unsigned bit = BIT(offset);
+
+#if MSM_GPIO_BROKEN_INT_CLEAR
+	/* Save interrupts that already triggered before we loose them. */
+	/* Any interrupt that triggers between the read of int_status */
+	/* and the write to int_clear will still be lost though. */
+	msm_chip->int_status_copy |= readl(msm_chip->regs.int_status);
+	msm_chip->int_status_copy &= ~bit;
+#endif
+	writel(bit, msm_chip->regs.int_clear);
+	msm_gpio_update_both_edge_detect(msm_chip);
+	return 0;
+}
+
+static int msm_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+	struct msm_gpio_chip *msm_chip;
+	unsigned long irq_flags;
+
+	msm_chip = container_of(chip, struct msm_gpio_chip, chip);
+	spin_lock_irqsave(&msm_chip->lock, irq_flags);
+	writel(readl(msm_chip->regs.oe) & ~BIT(offset), msm_chip->regs.oe);
+	spin_unlock_irqrestore(&msm_chip->lock, irq_flags);
+	return 0;
+}
+
+static int
+msm_gpio_direction_output(struct gpio_chip *chip, unsigned offset, int value)
+{
+	struct msm_gpio_chip *msm_chip;
+	unsigned long irq_flags;
+
+	msm_chip = container_of(chip, struct msm_gpio_chip, chip);
+	spin_lock_irqsave(&msm_chip->lock, irq_flags);
+	msm_gpio_write(msm_chip, offset, value);
+	writel(readl(msm_chip->regs.oe) | BIT(offset), msm_chip->regs.oe);
+	spin_unlock_irqrestore(&msm_chip->lock, irq_flags);
+	return 0;
+}
+
+static int msm_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	struct msm_gpio_chip *msm_chip;
+
+	msm_chip = container_of(chip, struct msm_gpio_chip, chip);
+	return (readl(msm_chip->regs.in) & (1U << offset)) ? 1 : 0;
+}
+
+static void msm_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+	struct msm_gpio_chip *msm_chip;
+	unsigned long irq_flags;
+
+	msm_chip = container_of(chip, struct msm_gpio_chip, chip);
+	spin_lock_irqsave(&msm_chip->lock, irq_flags);
+	msm_gpio_write(msm_chip, offset, value);
+	spin_unlock_irqrestore(&msm_chip->lock, irq_flags);
+}
+
+static int msm_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
+{
+	return MSM_GPIO_TO_INT(chip->base + offset);
+}
+
+struct msm_gpio_chip msm_gpio_chips[] = {
+#if defined(CONFIG_ARCH_MSM7X00A)
+	MSM_GPIO_BANK(0,   0,  15),
+	MSM_GPIO_BANK(1,  16,  42),
+	MSM_GPIO_BANK(2,  43,  67),
+	MSM_GPIO_BANK(3,  68,  94),
+	MSM_GPIO_BANK(4,  95, 106),
+	MSM_GPIO_BANK(5, 107, 121),
+#elif defined(CONFIG_ARCH_MSM7X25) || defined(CONFIG_ARCH_MSM7X27)
+	MSM_GPIO_BANK(0,   0,  15),
+	MSM_GPIO_BANK(1,  16,  42),
+	MSM_GPIO_BANK(2,  43,  67),
+	MSM_GPIO_BANK(3,  68,  94),
+	MSM_GPIO_BANK(4,  95, 106),
+	MSM_GPIO_BANK(5, 107, 132),
+#elif defined(CONFIG_ARCH_MSM7X30)
+	MSM_GPIO_BANK(0,   0,  15),
+	MSM_GPIO_BANK(1,  16,  43),
+	MSM_GPIO_BANK(2,  44,  67),
+	MSM_GPIO_BANK(3,  68,  94),
+	MSM_GPIO_BANK(4,  95, 106),
+	MSM_GPIO_BANK(5, 107, 133),
+	MSM_GPIO_BANK(6, 134, 150),
+	MSM_GPIO_BANK(7, 151, 181),
+#elif defined(CONFIG_ARCH_QSD8X50)
+	MSM_GPIO_BANK(0,   0,  15),
+	MSM_GPIO_BANK(1,  16,  42),
+	MSM_GPIO_BANK(2,  43,  67),
+	MSM_GPIO_BANK(3,  68,  94),
+	MSM_GPIO_BANK(4,  95, 103),
+	MSM_GPIO_BANK(5, 104, 121),
+	MSM_GPIO_BANK(6, 122, 152),
+	MSM_GPIO_BANK(7, 153, 164),
+#endif
+};
+
+static void msm_gpio_irq_ack(unsigned int irq)
+{
+	unsigned long irq_flags;
+	struct msm_gpio_chip *msm_chip = get_irq_chip_data(irq);
+	spin_lock_irqsave(&msm_chip->lock, irq_flags);
+	msm_gpio_clear_detect_status(msm_chip,
+				     irq - gpio_to_irq(msm_chip->chip.base));
+	spin_unlock_irqrestore(&msm_chip->lock, irq_flags);
+}
+
+static void msm_gpio_irq_mask(unsigned int irq)
+{
+	unsigned long irq_flags;
+	struct msm_gpio_chip *msm_chip = get_irq_chip_data(irq);
+	unsigned offset = irq - gpio_to_irq(msm_chip->chip.base);
+
+	spin_lock_irqsave(&msm_chip->lock, irq_flags);
+	/* level triggered interrupts are also latched */
+	if (!(readl(msm_chip->regs.int_edge) & BIT(offset)))
+		msm_gpio_clear_detect_status(msm_chip, offset);
+	msm_chip->int_enable[0] &= ~BIT(offset);
+	writel(msm_chip->int_enable[0], msm_chip->regs.int_en);
+	spin_unlock_irqrestore(&msm_chip->lock, irq_flags);
+}
+
+static void msm_gpio_irq_unmask(unsigned int irq)
+{
+	unsigned long irq_flags;
+	struct msm_gpio_chip *msm_chip = get_irq_chip_data(irq);
+	unsigned offset = irq - gpio_to_irq(msm_chip->chip.base);
+
+	spin_lock_irqsave(&msm_chip->lock, irq_flags);
+	/* level triggered interrupts are also latched */
+	if (!(readl(msm_chip->regs.int_edge) & BIT(offset)))
+		msm_gpio_clear_detect_status(msm_chip, offset);
+	msm_chip->int_enable[0] |= BIT(offset);
+	writel(msm_chip->int_enable[0], msm_chip->regs.int_en);
+	spin_unlock_irqrestore(&msm_chip->lock, irq_flags);
+}
+
+static int msm_gpio_irq_set_wake(unsigned int irq, unsigned int on)
+{
+	unsigned long irq_flags;
+	struct msm_gpio_chip *msm_chip = get_irq_chip_data(irq);
+	unsigned offset = irq - gpio_to_irq(msm_chip->chip.base);
+
+	spin_lock_irqsave(&msm_chip->lock, irq_flags);
+
+	if (on)
+		msm_chip->int_enable[1] |= BIT(offset);
+	else
+		msm_chip->int_enable[1] &= ~BIT(offset);
+
+	spin_unlock_irqrestore(&msm_chip->lock, irq_flags);
+	return 0;
+}
+
+static int msm_gpio_irq_set_type(unsigned int irq, unsigned int flow_type)
+{
+	unsigned long irq_flags;
+	struct msm_gpio_chip *msm_chip = get_irq_chip_data(irq);
+	unsigned offset = irq - gpio_to_irq(msm_chip->chip.base);
+	unsigned val, mask = BIT(offset);
+
+	spin_lock_irqsave(&msm_chip->lock, irq_flags);
+	val = readl(msm_chip->regs.int_edge);
+	if (flow_type & IRQ_TYPE_EDGE_BOTH) {
+		writel(val | mask, msm_chip->regs.int_edge);
+		irq_desc[irq].handle_irq = handle_edge_irq;
+	} else {
+		writel(val & ~mask, msm_chip->regs.int_edge);
+		irq_desc[irq].handle_irq = handle_level_irq;
+	}
+	if ((flow_type & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) {
+		msm_chip->both_edge_detect |= mask;
+		msm_gpio_update_both_edge_detect(msm_chip);
+	} else {
+		msm_chip->both_edge_detect &= ~mask;
+		val = readl(msm_chip->regs.int_pos);
+		if (flow_type & (IRQF_TRIGGER_RISING | IRQF_TRIGGER_HIGH))
+			writel(val | mask, msm_chip->regs.int_pos);
+		else
+			writel(val & ~mask, msm_chip->regs.int_pos);
+	}
+	spin_unlock_irqrestore(&msm_chip->lock, irq_flags);
+	return 0;
+}
+
+static void msm_gpio_irq_handler(unsigned int irq, struct irq_desc *desc)
+{
+	int i, j, mask;
+	unsigned val;
+
+	for (i = 0; i < ARRAY_SIZE(msm_gpio_chips); i++) {
+		struct msm_gpio_chip *msm_chip = &msm_gpio_chips[i];
+		val = readl(msm_chip->regs.int_status);
+		val &= msm_chip->int_enable[0];
+		while (val) {
+			mask = val & -val;
+			j = fls(mask) - 1;
+			/* printk("%s %08x %08x bit %d gpio %d irq %d\n",
+				__func__, v, m, j, msm_chip->chip.start + j,
+				FIRST_GPIO_IRQ + msm_chip->chip.start + j); */
+			val &= ~mask;
+			generic_handle_irq(FIRST_GPIO_IRQ +
+					   msm_chip->chip.base + j);
+		}
+	}
+	desc->chip->ack(irq);
+}
+
+static struct irq_chip msm_gpio_irq_chip = {
+	.name      = "msmgpio",
+	.ack       = msm_gpio_irq_ack,
+	.mask      = msm_gpio_irq_mask,
+	.unmask    = msm_gpio_irq_unmask,
+	.set_wake  = msm_gpio_irq_set_wake,
+	.set_type  = msm_gpio_irq_set_type,
+};
+
+static int __init msm_init_gpio(void)
+{
+	int i, j = 0;
+
+	for (i = FIRST_GPIO_IRQ; i < FIRST_GPIO_IRQ + NR_GPIO_IRQS; i++) {
+		if (i - FIRST_GPIO_IRQ >=
+			msm_gpio_chips[j].chip.base +
+			msm_gpio_chips[j].chip.ngpio)
+			j++;
+		set_irq_chip_data(i, &msm_gpio_chips[j]);
+		set_irq_chip(i, &msm_gpio_irq_chip);
+		set_irq_handler(i, handle_edge_irq);
+		set_irq_flags(i, IRQF_VALID);
+	}
+
+	for (i = 0; i < ARRAY_SIZE(msm_gpio_chips); i++) {
+		spin_lock_init(&msm_gpio_chips[i].lock);
+		writel(0, msm_gpio_chips[i].regs.int_en);
+		gpiochip_add(&msm_gpio_chips[i].chip);
+	}
+
+	set_irq_chained_handler(INT_GPIO_GROUP1, msm_gpio_irq_handler);
+	set_irq_chained_handler(INT_GPIO_GROUP2, msm_gpio_irq_handler);
+	set_irq_wake(INT_GPIO_GROUP1, 1);
+	set_irq_wake(INT_GPIO_GROUP2, 2);
+	return 0;
+}
+
+postcore_initcall(msm_init_gpio);