gpio_msm: Move Qualcomm MSM v2 gpio driver into drivers

Migrate the driver for the v7-based MSM chips into drivers/gpio.  The
driver is unchanged, only moved.

Change-Id: I810db5b50b71cdca4e869aa0d0310f7f48781a55
Signed-off-by: David Brown <davidb@codeaurora.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org>

1 files changed, 433 insertions, 0 deletions

diff --git a/drivers/gpio/gpio-msm-v2.c b/drivers/gpio/gpio-msm-v2.c
new file mode 100644
index 0000000..5cb1227
--- /dev/null
+++ b/drivers/gpio/gpio-msm-v2.c
@@ -0,0 +1,433 @@
+/* Copyright (c) 2010-2011, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ */
+#define pr_fmt(fmt) "%s: " fmt, __func__
+
+#include <linux/bitmap.h>
+#include <linux/bitops.h>
+#include <linux/gpio.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/spinlock.h>
+
+#include <asm/mach/irq.h>
+
+#include <mach/msm_gpiomux.h>
+#include <mach/msm_iomap.h>
+
+/* Bits of interest in the GPIO_IN_OUT register.
+ */
+enum {
+	GPIO_IN  = 0,
+	GPIO_OUT = 1
+};
+
+/* Bits of interest in the GPIO_INTR_STATUS register.
+ */
+enum {
+	INTR_STATUS = 0,
+};
+
+/* Bits of interest in the GPIO_CFG register.
+ */
+enum {
+	GPIO_OE = 9,
+};
+
+/* Bits of interest in the GPIO_INTR_CFG register.
+ * When a GPIO triggers, two separate decisions are made, controlled
+ * by two separate flags.
+ *
+ * - First, INTR_RAW_STATUS_EN controls whether or not the GPIO_INTR_STATUS
+ * register for that GPIO will be updated to reflect the triggering of that
+ * gpio.  If this bit is 0, this register will not be updated.
+ * - Second, INTR_ENABLE controls whether an interrupt is triggered.
+ *
+ * If INTR_ENABLE is set and INTR_RAW_STATUS_EN is NOT set, an interrupt
+ * can be triggered but the status register will not reflect it.
+ */
+enum {
+	INTR_ENABLE        = 0,
+	INTR_POL_CTL       = 1,
+	INTR_DECT_CTL      = 2,
+	INTR_RAW_STATUS_EN = 3,
+};
+
+/* Codes of interest in GPIO_INTR_CFG_SU.
+ */
+enum {
+	TARGET_PROC_SCORPION = 4,
+	TARGET_PROC_NONE     = 7,
+};
+
+
+#define GPIO_INTR_CFG_SU(gpio)    (MSM_TLMM_BASE + 0x0400 + (0x04 * (gpio)))
+#define GPIO_CONFIG(gpio)         (MSM_TLMM_BASE + 0x1000 + (0x10 * (gpio)))
+#define GPIO_IN_OUT(gpio)         (MSM_TLMM_BASE + 0x1004 + (0x10 * (gpio)))
+#define GPIO_INTR_CFG(gpio)       (MSM_TLMM_BASE + 0x1008 + (0x10 * (gpio)))
+#define GPIO_INTR_STATUS(gpio)    (MSM_TLMM_BASE + 0x100c + (0x10 * (gpio)))
+
+/**
+ * struct msm_gpio_dev: the MSM8660 SoC GPIO device structure
+ *
+ * @enabled_irqs: a bitmap used to optimize the summary-irq handler.  By
+ * keeping track of which gpios are unmasked as irq sources, we avoid
+ * having to do readl calls on hundreds of iomapped registers each time
+ * the summary interrupt fires in order to locate the active interrupts.
+ *
+ * @wake_irqs: a bitmap for tracking which interrupt lines are enabled
+ * as wakeup sources.  When the device is suspended, interrupts which are
+ * not wakeup sources are disabled.
+ *
+ * @dual_edge_irqs: a bitmap used to track which irqs are configured
+ * as dual-edge, as this is not supported by the hardware and requires
+ * some special handling in the driver.
+ */
+struct msm_gpio_dev {
+	struct gpio_chip gpio_chip;
+	DECLARE_BITMAP(enabled_irqs, NR_GPIO_IRQS);
+	DECLARE_BITMAP(wake_irqs, NR_GPIO_IRQS);
+	DECLARE_BITMAP(dual_edge_irqs, NR_GPIO_IRQS);
+};
+
+static DEFINE_SPINLOCK(tlmm_lock);
+
+static inline struct msm_gpio_dev *to_msm_gpio_dev(struct gpio_chip *chip)
+{
+	return container_of(chip, struct msm_gpio_dev, gpio_chip);
+}
+
+static inline void set_gpio_bits(unsigned n, void __iomem *reg)
+{
+	writel(readl(reg) | n, reg);
+}
+
+static inline void clear_gpio_bits(unsigned n, void __iomem *reg)
+{
+	writel(readl(reg) & ~n, reg);
+}
+
+static int msm_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	return readl(GPIO_IN_OUT(offset)) & BIT(GPIO_IN);
+}
+
+static void msm_gpio_set(struct gpio_chip *chip, unsigned offset, int val)
+{
+	writel(val ? BIT(GPIO_OUT) : 0, GPIO_IN_OUT(offset));
+}
+
+static int msm_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
+{
+	unsigned long irq_flags;
+
+	spin_lock_irqsave(&tlmm_lock, irq_flags);
+	clear_gpio_bits(BIT(GPIO_OE), GPIO_CONFIG(offset));
+	spin_unlock_irqrestore(&tlmm_lock, irq_flags);
+	return 0;
+}
+
+static int msm_gpio_direction_output(struct gpio_chip *chip,
+				unsigned offset,
+				int val)
+{
+	unsigned long irq_flags;
+
+	spin_lock_irqsave(&tlmm_lock, irq_flags);
+	msm_gpio_set(chip, offset, val);
+	set_gpio_bits(BIT(GPIO_OE), GPIO_CONFIG(offset));
+	spin_unlock_irqrestore(&tlmm_lock, irq_flags);
+	return 0;
+}
+
+static int msm_gpio_request(struct gpio_chip *chip, unsigned offset)
+{
+	return msm_gpiomux_get(chip->base + offset);
+}
+
+static void msm_gpio_free(struct gpio_chip *chip, unsigned offset)
+{
+	msm_gpiomux_put(chip->base + offset);
+}
+
+static int msm_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
+{
+	return MSM_GPIO_TO_INT(chip->base + offset);
+}
+
+static inline int msm_irq_to_gpio(struct gpio_chip *chip, unsigned irq)
+{
+	return irq - MSM_GPIO_TO_INT(chip->base);
+}
+
+static struct msm_gpio_dev msm_gpio = {
+	.gpio_chip = {
+		.base             = 0,
+		.ngpio            = NR_GPIO_IRQS,
+		.direction_input  = msm_gpio_direction_input,
+		.direction_output = msm_gpio_direction_output,
+		.get              = msm_gpio_get,
+		.set              = msm_gpio_set,
+		.to_irq           = msm_gpio_to_irq,
+		.request          = msm_gpio_request,
+		.free             = msm_gpio_free,
+	},
+};
+
+/* For dual-edge interrupts in software, since the hardware has no
+ * such support:
+ *
+ * At appropriate moments, this function may be called to flip the polarity
+ * settings of both-edge irq lines to try and catch the next edge.
+ *
+ * The attempt is considered successful if:
+ * - the status bit goes high, indicating that an edge was caught, or
+ * - the input value of the gpio doesn't change during the attempt.
+ * If the value changes twice during the process, that would cause the first
+ * test to fail but would force the second, as two opposite
+ * transitions would cause a detection no matter the polarity setting.
+ *
+ * The do-loop tries to sledge-hammer closed the timing hole between
+ * the initial value-read and the polarity-write - if the line value changes
+ * during that window, an interrupt is lost, the new polarity setting is
+ * incorrect, and the first success test will fail, causing a retry.
+ *
+ * Algorithm comes from Google's msmgpio driver, see mach-msm/gpio.c.
+ */
+static void msm_gpio_update_dual_edge_pos(unsigned gpio)
+{
+	int loop_limit = 100;
+	unsigned val, val2, intstat;
+
+	do {
+		val = readl(GPIO_IN_OUT(gpio)) & BIT(GPIO_IN);
+		if (val)
+			clear_gpio_bits(BIT(INTR_POL_CTL), GPIO_INTR_CFG(gpio));
+		else
+			set_gpio_bits(BIT(INTR_POL_CTL), GPIO_INTR_CFG(gpio));
+		val2 = readl(GPIO_IN_OUT(gpio)) & BIT(GPIO_IN);
+		intstat = readl(GPIO_INTR_STATUS(gpio)) & BIT(INTR_STATUS);
+		if (intstat || val == val2)
+			return;
+	} while (loop_limit-- > 0);
+	pr_err("dual-edge irq failed to stabilize, "
+	       "interrupts dropped. %#08x != %#08x\n",
+	       val, val2);
+}
+
+static void msm_gpio_irq_ack(struct irq_data *d)
+{
+	int gpio = msm_irq_to_gpio(&msm_gpio.gpio_chip, d->irq);
+
+	writel(BIT(INTR_STATUS), GPIO_INTR_STATUS(gpio));
+	if (test_bit(gpio, msm_gpio.dual_edge_irqs))
+		msm_gpio_update_dual_edge_pos(gpio);
+}
+
+static void msm_gpio_irq_mask(struct irq_data *d)
+{
+	int gpio = msm_irq_to_gpio(&msm_gpio.gpio_chip, d->irq);
+	unsigned long irq_flags;
+
+	spin_lock_irqsave(&tlmm_lock, irq_flags);
+	writel(TARGET_PROC_NONE, GPIO_INTR_CFG_SU(gpio));
+	clear_gpio_bits(INTR_RAW_STATUS_EN | INTR_ENABLE, GPIO_INTR_CFG(gpio));
+	__clear_bit(gpio, msm_gpio.enabled_irqs);
+	spin_unlock_irqrestore(&tlmm_lock, irq_flags);
+}
+
+static void msm_gpio_irq_unmask(struct irq_data *d)
+{
+	int gpio = msm_irq_to_gpio(&msm_gpio.gpio_chip, d->irq);
+	unsigned long irq_flags;
+
+	spin_lock_irqsave(&tlmm_lock, irq_flags);
+	__set_bit(gpio, msm_gpio.enabled_irqs);
+	set_gpio_bits(INTR_RAW_STATUS_EN | INTR_ENABLE, GPIO_INTR_CFG(gpio));
+	writel(TARGET_PROC_SCORPION, GPIO_INTR_CFG_SU(gpio));
+	spin_unlock_irqrestore(&tlmm_lock, irq_flags);
+}
+
+static int msm_gpio_irq_set_type(struct irq_data *d, unsigned int flow_type)
+{
+	int gpio = msm_irq_to_gpio(&msm_gpio.gpio_chip, d->irq);
+	unsigned long irq_flags;
+	uint32_t bits;
+
+	spin_lock_irqsave(&tlmm_lock, irq_flags);
+
+	bits = readl(GPIO_INTR_CFG(gpio));
+
+	if (flow_type & IRQ_TYPE_EDGE_BOTH) {
+		bits |= BIT(INTR_DECT_CTL);
+		__irq_set_handler_locked(d->irq, handle_edge_irq);
+		if ((flow_type & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH)
+			__set_bit(gpio, msm_gpio.dual_edge_irqs);
+		else
+			__clear_bit(gpio, msm_gpio.dual_edge_irqs);
+	} else {
+		bits &= ~BIT(INTR_DECT_CTL);
+		__irq_set_handler_locked(d->irq, handle_level_irq);
+		__clear_bit(gpio, msm_gpio.dual_edge_irqs);
+	}
+
+	if (flow_type & (IRQ_TYPE_EDGE_RISING | IRQ_TYPE_LEVEL_HIGH))
+		bits |= BIT(INTR_POL_CTL);
+	else
+		bits &= ~BIT(INTR_POL_CTL);
+
+	writel(bits, GPIO_INTR_CFG(gpio));
+
+	if ((flow_type & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH)
+		msm_gpio_update_dual_edge_pos(gpio);
+
+	spin_unlock_irqrestore(&tlmm_lock, irq_flags);
+
+	return 0;
+}
+
+/*
+ * When the summary IRQ is raised, any number of GPIO lines may be high.
+ * It is the job of the summary handler to find all those GPIO lines
+ * which have been set as summary IRQ lines and which are triggered,
+ * and to call their interrupt handlers.
+ */
+static void msm_summary_irq_handler(unsigned int irq, struct irq_desc *desc)
+{
+	unsigned long i;
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+
+	chained_irq_enter(chip, desc);
+
+	for (i = find_first_bit(msm_gpio.enabled_irqs, NR_GPIO_IRQS);
+	     i < NR_GPIO_IRQS;
+	     i = find_next_bit(msm_gpio.enabled_irqs, NR_GPIO_IRQS, i + 1)) {
+		if (readl(GPIO_INTR_STATUS(i)) & BIT(INTR_STATUS))
+			generic_handle_irq(msm_gpio_to_irq(&msm_gpio.gpio_chip,
+							   i));
+	}
+
+	chained_irq_exit(chip, desc);
+}
+
+static int msm_gpio_irq_set_wake(struct irq_data *d, unsigned int on)
+{
+	int gpio = msm_irq_to_gpio(&msm_gpio.gpio_chip, d->irq);
+
+	if (on) {
+		if (bitmap_empty(msm_gpio.wake_irqs, NR_GPIO_IRQS))
+			irq_set_irq_wake(TLMM_SCSS_SUMMARY_IRQ, 1);
+		set_bit(gpio, msm_gpio.wake_irqs);
+	} else {
+		clear_bit(gpio, msm_gpio.wake_irqs);
+		if (bitmap_empty(msm_gpio.wake_irqs, NR_GPIO_IRQS))
+			irq_set_irq_wake(TLMM_SCSS_SUMMARY_IRQ, 0);
+	}
+
+	return 0;
+}
+
+static struct irq_chip msm_gpio_irq_chip = {
+	.name		= "msmgpio",
+	.irq_mask	= msm_gpio_irq_mask,
+	.irq_unmask	= msm_gpio_irq_unmask,
+	.irq_ack	= msm_gpio_irq_ack,
+	.irq_set_type	= msm_gpio_irq_set_type,
+	.irq_set_wake	= msm_gpio_irq_set_wake,
+};
+
+static int __devinit msm_gpio_probe(struct platform_device *dev)
+{
+	int i, irq, ret;
+
+	bitmap_zero(msm_gpio.enabled_irqs, NR_GPIO_IRQS);
+	bitmap_zero(msm_gpio.wake_irqs, NR_GPIO_IRQS);
+	bitmap_zero(msm_gpio.dual_edge_irqs, NR_GPIO_IRQS);
+	msm_gpio.gpio_chip.label = dev->name;
+	ret = gpiochip_add(&msm_gpio.gpio_chip);
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < msm_gpio.gpio_chip.ngpio; ++i) {
+		irq = msm_gpio_to_irq(&msm_gpio.gpio_chip, i);
+		irq_set_chip_and_handler(irq, &msm_gpio_irq_chip,
+					 handle_level_irq);
+		set_irq_flags(irq, IRQF_VALID);
+	}
+
+	irq_set_chained_handler(TLMM_SCSS_SUMMARY_IRQ,
+				msm_summary_irq_handler);
+	return 0;
+}
+
+static int __devexit msm_gpio_remove(struct platform_device *dev)
+{
+	int ret = gpiochip_remove(&msm_gpio.gpio_chip);
+
+	if (ret < 0)
+		return ret;
+
+	irq_set_handler(TLMM_SCSS_SUMMARY_IRQ, NULL);
+
+	return 0;
+}
+
+static struct platform_driver msm_gpio_driver = {
+	.probe = msm_gpio_probe,
+	.remove = __devexit_p(msm_gpio_remove),
+	.driver = {
+		.name = "msmgpio",
+		.owner = THIS_MODULE,
+	},
+};
+
+static struct platform_device msm_device_gpio = {
+	.name = "msmgpio",
+	.id   = -1,
+};
+
+static int __init msm_gpio_init(void)
+{
+	int rc;
+
+	rc = platform_driver_register(&msm_gpio_driver);
+	if (!rc) {
+		rc = platform_device_register(&msm_device_gpio);
+		if (rc)
+			platform_driver_unregister(&msm_gpio_driver);
+	}
+
+	return rc;
+}
+
+static void __exit msm_gpio_exit(void)
+{
+	platform_device_unregister(&msm_device_gpio);
+	platform_driver_unregister(&msm_gpio_driver);
+}
+
+postcore_initcall(msm_gpio_init);
+module_exit(msm_gpio_exit);
+
+MODULE_AUTHOR("Gregory Bean <gbean@codeaurora.org>");
+MODULE_DESCRIPTION("Driver for Qualcomm MSM TLMMv2 SoC GPIOs");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:msmgpio");