Davinci: tnetv107x initial gpio support

This patch adds support for the tnetv107x gpio controller.

Key differences between davinci and tnetv107x controllers:
 - register map - davinci's controller is organized into banks of 32 gpios,
   tnetv107x has a single space with arrays of registers for in, out,
   direction, etc.
 - davinci's controller has separate set/clear registers for output, tnetv107x
   has a single direct mapped register.

This patch does not yet add gpio irq support on this controller.

Signed-off-by: Cyril Chemparathy <cyril@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

3 files changed, 221 insertions, 7 deletions

diff --git a/arch/arm/mach-davinci/Makefile b/arch/arm/mach-davinci/Makefile
index 1c7bcfe..62c5116 100644
--- a/arch/arm/mach-davinci/Makefile
+++ b/arch/arm/mach-davinci/Makefile
@@ -17,6 +17,7 @@ obj-$(CONFIG_ARCH_DAVINCI_DM365)	+= dm365.o devices.o
 obj-$(CONFIG_ARCH_DAVINCI_DA830)        += da830.o devices-da8xx.o
 obj-$(CONFIG_ARCH_DAVINCI_DA850)        += da850.o devices-da8xx.o
 obj-$(CONFIG_ARCH_DAVINCI_TNETV107X)    += tnetv107x.o devices-tnetv107x.o
+obj-$(CONFIG_ARCH_DAVINCI_TNETV107X)    += gpio-tnetv107x.o
 
 obj-$(CONFIG_AINTC)			+= irq.o
 obj-$(CONFIG_CP_INTC)			+= cp_intc.o
diff --git a/arch/arm/mach-davinci/gpio-tnetv107x.c b/arch/arm/mach-davinci/gpio-tnetv107x.c
new file mode 100644
index 0000000..d102986
--- /dev/null
+++ b/arch/arm/mach-davinci/gpio-tnetv107x.c
@@ -0,0 +1,205 @@
+/*
+ * Texas Instruments TNETV107X GPIO Controller
+ *
+ * Copyright (C) 2010 Texas Instruments
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/gpio.h>
+
+#include <mach/common.h>
+#include <mach/tnetv107x.h>
+
+struct tnetv107x_gpio_regs {
+	u32	idver;
+	u32	data_in[3];
+	u32	data_out[3];
+	u32	direction[3];
+	u32	enable[3];
+};
+
+#define gpio_reg_index(gpio)	((gpio) >> 5)
+#define gpio_reg_bit(gpio)	BIT((gpio) & 0x1f)
+
+#define gpio_reg_rmw(reg, mask, val)	\
+	__raw_writel((__raw_readl(reg) & ~(mask)) | (val), (reg))
+
+#define gpio_reg_set_bit(reg, gpio)	\
+	gpio_reg_rmw((reg) + gpio_reg_index(gpio), 0, gpio_reg_bit(gpio))
+
+#define gpio_reg_clear_bit(reg, gpio)	\
+	gpio_reg_rmw((reg) + gpio_reg_index(gpio), gpio_reg_bit(gpio), 0)
+
+#define gpio_reg_get_bit(reg, gpio)	\
+	(__raw_readl((reg) + gpio_reg_index(gpio)) & gpio_reg_bit(gpio))
+
+#define chip2controller(chip)		\
+	container_of(chip, struct davinci_gpio_controller, chip)
+
+#define TNETV107X_GPIO_CTLRS	DIV_ROUND_UP(TNETV107X_N_GPIO, 32)
+
+static struct davinci_gpio_controller chips[TNETV107X_GPIO_CTLRS];
+
+static int tnetv107x_gpio_request(struct gpio_chip *chip, unsigned offset)
+{
+	struct davinci_gpio_controller *ctlr = chip2controller(chip);
+	struct tnetv107x_gpio_regs __iomem *regs = ctlr->regs;
+	unsigned gpio = chip->base + offset;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ctlr->lock, flags);
+
+	gpio_reg_set_bit(&regs->enable, gpio);
+
+	spin_unlock_irqrestore(&ctlr->lock, flags);
+
+	return 0;
+}
+
+static void tnetv107x_gpio_free(struct gpio_chip *chip, unsigned offset)
+{
+	struct davinci_gpio_controller *ctlr = chip2controller(chip);
+	struct tnetv107x_gpio_regs __iomem *regs = ctlr->regs;
+	unsigned gpio = chip->base + offset;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ctlr->lock, flags);
+
+	gpio_reg_clear_bit(&regs->enable, gpio);
+
+	spin_unlock_irqrestore(&ctlr->lock, flags);
+}
+
+static int tnetv107x_gpio_dir_in(struct gpio_chip *chip, unsigned offset)
+{
+	struct davinci_gpio_controller *ctlr = chip2controller(chip);
+	struct tnetv107x_gpio_regs __iomem *regs = ctlr->regs;
+	unsigned gpio = chip->base + offset;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ctlr->lock, flags);
+
+	gpio_reg_set_bit(&regs->direction, gpio);
+
+	spin_unlock_irqrestore(&ctlr->lock, flags);
+
+	return 0;
+}
+
+static int tnetv107x_gpio_dir_out(struct gpio_chip *chip,
+		unsigned offset, int value)
+{
+	struct davinci_gpio_controller *ctlr = chip2controller(chip);
+	struct tnetv107x_gpio_regs __iomem *regs = ctlr->regs;
+	unsigned gpio = chip->base + offset;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ctlr->lock, flags);
+
+	if (value)
+		gpio_reg_set_bit(&regs->data_out, gpio);
+	else
+		gpio_reg_clear_bit(&regs->data_out, gpio);
+
+	gpio_reg_clear_bit(&regs->direction, gpio);
+
+	spin_unlock_irqrestore(&ctlr->lock, flags);
+
+	return 0;
+}
+
+static int tnetv107x_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+	struct davinci_gpio_controller *ctlr = chip2controller(chip);
+	struct tnetv107x_gpio_regs __iomem *regs = ctlr->regs;
+	unsigned gpio = chip->base + offset;
+	int ret;
+
+	ret = gpio_reg_get_bit(&regs->data_in, gpio);
+
+	return ret ? 1 : 0;
+}
+
+static void tnetv107x_gpio_set(struct gpio_chip *chip,
+		unsigned offset, int value)
+{
+	struct davinci_gpio_controller *ctlr = chip2controller(chip);
+	struct tnetv107x_gpio_regs __iomem *regs = ctlr->regs;
+	unsigned gpio = chip->base + offset;
+	unsigned long flags;
+
+	spin_lock_irqsave(&ctlr->lock, flags);
+
+	if (value)
+		gpio_reg_set_bit(&regs->data_out, gpio);
+	else
+		gpio_reg_clear_bit(&regs->data_out, gpio);
+
+	spin_unlock_irqrestore(&ctlr->lock, flags);
+}
+
+static int __init tnetv107x_gpio_setup(void)
+{
+	int i, base;
+	unsigned ngpio;
+	struct davinci_soc_info *soc_info = &davinci_soc_info;
+	struct tnetv107x_gpio_regs *regs;
+	struct davinci_gpio_controller *ctlr;
+
+	if (soc_info->gpio_type != GPIO_TYPE_TNETV107X)
+		return 0;
+
+	ngpio = soc_info->gpio_num;
+	if (ngpio == 0) {
+		pr_err("GPIO setup:  how many GPIOs?\n");
+		return -EINVAL;
+	}
+
+	if (WARN_ON(TNETV107X_N_GPIO < ngpio))
+		ngpio = TNETV107X_N_GPIO;
+
+	regs = ioremap(soc_info->gpio_base, SZ_4K);
+	if (WARN_ON(!regs))
+		return -EINVAL;
+
+	for (i = 0, base = 0; base < ngpio; i++, base += 32) {
+		ctlr = &chips[i];
+
+		ctlr->chip.label	= "tnetv107x";
+		ctlr->chip.can_sleep	= 0;
+		ctlr->chip.base		= base;
+		ctlr->chip.ngpio	= ngpio - base;
+		if (ctlr->chip.ngpio > 32)
+			ctlr->chip.ngpio = 32;
+
+		ctlr->chip.request		= tnetv107x_gpio_request;
+		ctlr->chip.free			= tnetv107x_gpio_free;
+		ctlr->chip.direction_input	= tnetv107x_gpio_dir_in;
+		ctlr->chip.get			= tnetv107x_gpio_get;
+		ctlr->chip.direction_output	= tnetv107x_gpio_dir_out;
+		ctlr->chip.set			= tnetv107x_gpio_set;
+
+		spin_lock_init(&ctlr->lock);
+
+		ctlr->regs	= regs;
+		ctlr->set_data	= &regs->data_out[i];
+		ctlr->clr_data	= &regs->data_out[i];
+		ctlr->in_data	= &regs->data_in[i];
+
+		gpiochip_add(&ctlr->chip);
+	}
+
+	soc_info->gpio_ctlrs = chips;
+	soc_info->gpio_ctlrs_num = DIV_ROUND_UP(ngpio, 32);
+	return 0;
+}
+pure_initcall(tnetv107x_gpio_setup);
diff --git a/arch/arm/mach-davinci/include/mach/gpio.h b/arch/arm/mach-davinci/include/mach/gpio.h
index 504cc18..fbece12 100644
--- a/arch/arm/mach-davinci/include/mach/gpio.h
+++ b/arch/arm/mach-davinci/include/mach/gpio.h
@@ -25,6 +25,7 @@
 
 enum davinci_gpio_type {
 	GPIO_TYPE_DAVINCI = 0,
+	GPIO_TYPE_TNETV107X,
 };
 
 /*
@@ -87,9 +88,13 @@ static inline u32 __gpio_mask(unsigned gpio)
 	return 1 << (gpio % 32);
 }
 
-/* The get/set/clear functions will inline when called with constant
+/*
+ * The get/set/clear functions will inline when called with constant
  * parameters referencing built-in GPIOs, for low-overhead bitbanging.
  *
+ * gpio_set_value() will inline only on traditional Davinci style controllers
+ * with distinct set/clear registers.
+ *
  * Otherwise, calls with variable parameters or referencing external
  * GPIOs (e.g. on GPIO expander chips) use outlined functions.
  */
@@ -100,12 +105,15 @@ static inline void gpio_set_value(unsigned gpio, int value)
 		u32				mask;
 
 		ctlr = __gpio_to_controller(gpio);
-		mask = __gpio_mask(gpio);
-		if (value)
-			__raw_writel(mask, ctlr->set_data);
-		else
-			__raw_writel(mask, ctlr->clr_data);
-		return;
+
+		if (ctlr->set_data != ctlr->clr_data) {
+			mask = __gpio_mask(gpio);
+			if (value)
+				__raw_writel(mask, ctlr->set_data);
+			else
+				__raw_writel(mask, ctlr->clr_data);
+			return;
+		}
 	}
 
 	__gpio_set_value(gpio, value);