[ARM] S3C64XX: GPIO library support

Add gpiolib registration for the GPIOs available on the
S3C64XX platform
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

arch/arm/plat-s3c64xx/Makefile

@@ -17,6 +17,7 @@ obj-y				+= cpu.o
 obj-y				+= irq.o
 obj-y				+= irq-eint.o
 obj-y				+= clock.o
+obj-y				+= gpiolib.o
 
 # CPU support
 

arch/arm/plat-s3c64xx/gpiolib.c

+/* arch/arm/plat-s3c64xx/gpiolib.c
+ *
+ * Copyright 2008 Openmoko, Inc.
+ * Copyright 2008 Simtec Electronics
+ *      Ben Dooks <ben@simtec.co.uk>
+ *      http://armlinux.simtec.co.uk/
+ *
+ * S3C64XX - GPIOlib support 
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/kernel.h>
+#include <linux/irq.h>
+#include <linux/io.h>
+
+#include <mach/map.h>
+#include <mach/gpio.h>
+
+#include <plat/gpio-core.h>
+#include <plat/regs-gpio.h>
+
+/* GPIO bank summary:
+ *
+ * Bank	GPIOs	Style	SlpCon	ExtInt Group
+ * A	8	4Bit	Yes	1
+ * B	7	4Bit	Yes	1
+ * C	8	4Bit	Yes	2
+ * D	5	4Bit	Yes	3
+ * E	5	4Bit	Yes	None
+ * F	16	2Bit	Yes	4 [1]
+ * G	7	4Bit	Yes	5
+ * H	10	4Bit[2]	Yes	6
+ * I	16	2Bit	Yes	None
+ * J	12	2Bit	Yes	None
+ * K	16	4Bit[2]	No	None
+ * L	15	4Bit[2] No	None
+ * M	6	4Bit	No	IRQ_EINT
+ * N	16	2Bit	No	IRQ_EINT
+ * O	16	2Bit	Yes	7
+ * P	15	2Bit	Yes	8
+ * Q	9	2Bit	Yes	9
+ *
+ * [1] BANKF pins 14,15 do not form part of the external interrupt sources
+ * [2] BANK has two control registers, GPxCON0 and GPxCON1
+ */
+
+#define OFF_GPCON	(0x00)
+#define OFF_GPDAT	(0x04)
+
+#define con_4bit_shift(__off) ((__off) * 4)
+
+/* The s3c64xx_gpiolib_4bit routines are to control the gpio banks where
+ * the gpio configuration register (GPxCON) has 4 bits per GPIO, as the
+ * following example:
+ *
+ * base + 0x00: Control register, 4 bits per gpio
+ *	        gpio n: 4 bits starting at (4*n)
+ *		0000 = input, 0001 = output, others mean special-function
+ * base + 0x04: Data register, 1 bit per gpio
+ *		bit n: data bit n
+ *
+ * Note, since the data register is one bit per gpio and is at base + 0x4
+ * we can use s3c_gpiolib_get and s3c_gpiolib_set to change the state of
+ * the output.
+*/
+
+static int s3c64xx_gpiolib_4bit_input(struct gpio_chip *chip, unsigned offset)
+{
+	struct s3c_gpio_chip *ourchip = to_s3c_gpio(chip);
+	void __iomem *base = ourchip->base;
+	unsigned long con;
+
+	con = __raw_readl(base + OFF_GPCON);
+	con &= ~(0xf << con_4bit_shift(offset));
+	__raw_writel(con, base + OFF_GPCON);
+
+	return 0;
+}
+
+static int s3c64xx_gpiolib_4bit_output(struct gpio_chip *chip,
+				       unsigned offset, int value)
+{
+	struct s3c_gpio_chip *ourchip = to_s3c_gpio(chip);
+	void __iomem *base = ourchip->base;
+	unsigned long con;
+	unsigned long dat;
+
+	con = __raw_readl(base + OFF_GPCON);
+	con &= ~(0xf << con_4bit_shift(offset));
+	con |= 0x1 << con_4bit_shift(offset);
+
+	dat = __raw_readl(base + OFF_GPDAT);
+	if (value)
+		dat |= 1 << offset;
+	else
+		dat &= ~(1 << offset);
+
+	__raw_writel(dat, base + OFF_GPDAT);
+	__raw_writel(con, base + OFF_GPCON);
+	__raw_writel(dat, base + OFF_GPDAT);
+
+	return 0;
+}
+
+/* The next set of routines are for the case where the GPIO configuration
+ * registers are 4 bits per GPIO but there is more than one register (the
+ * bank has more than 8 GPIOs.
+ *
+ * This case is the similar to the 4 bit case, but the registers are as
+ * follows:
+ *
+ * base + 0x00: Control register, 4 bits per gpio (lower 8 GPIOs)
+ *	        gpio n: 4 bits starting at (4*n)
+ *		0000 = input, 0001 = output, others mean special-function
+ * base + 0x04: Control register, 4 bits per gpio (up to 8 additions GPIOs)
+ *	        gpio n: 4 bits starting at (4*n)
+ *		0000 = input, 0001 = output, others mean special-function
+ * base + 0x08: Data register, 1 bit per gpio
+ *		bit n: data bit n
+ *
+ * To allow us to use the s3c_gpiolib_get and s3c_gpiolib_set routines we
+ * store the 'base + 0x4' address so that these routines see the data
+ * register at ourchip->base + 0x04.
+*/
+
+static int s3c64xx_gpiolib_4bit2_input(struct gpio_chip *chip, unsigned offset)
+{
+	struct s3c_gpio_chip *ourchip = to_s3c_gpio(chip);
+	void __iomem *base = ourchip->base;
+	void __iomem *regcon = base;
+	unsigned long con;
+
+	if (offset > 7)
+		offset -= 8;
+	else
+		regcon -= 4;
+
+	con = __raw_readl(regcon);
+	con &= ~(0xf << con_4bit_shift(offset));
+	__raw_writel(con, regcon);
+
+	return 0;
+
+}
+
+static int s3c64xx_gpiolib_4bit2_output(struct gpio_chip *chip,
+				       unsigned offset, int value)
+{
+	struct s3c_gpio_chip *ourchip = to_s3c_gpio(chip);
+	void __iomem *base = ourchip->base;
+	void __iomem *regcon = base;
+	unsigned long con;
+	unsigned long dat;
+
+	if (offset > 7)
+		offset -= 8;
+	else
+		regcon -= 4;
+
+	con = __raw_readl(regcon);
+	con &= ~(0xf << con_4bit_shift(offset));
+	con |= 0x1 << con_4bit_shift(offset);
+
+	dat = __raw_readl(base + OFF_GPDAT);
+	if (value)
+		dat |= 1 << offset;
+	else
+		dat &= ~(1 << offset);
+
+	__raw_writel(dat, base + OFF_GPDAT);
+	__raw_writel(con, regcon);
+	__raw_writel(dat, base + OFF_GPDAT);
+
+	return 0;
+}
+
+static struct s3c_gpio_chip gpio_4bit[] = {
+	{
+		.base	= S3C64XX_GPA_BASE,
+		.chip	= {
+			.base	= S3C64XX_GPA(0),
+			.ngpio	= S3C64XX_GPIO_A_NR,
+			.label	= "GPA",
+		},
+	}, {
+		.base	= S3C64XX_GPB_BASE,
+		.chip	= {
+			.base	= S3C64XX_GPB(0),
+			.ngpio	= S3C64XX_GPIO_B_NR,
+			.label	= "GPB",
+		},
+	}, {
+		.base	= S3C64XX_GPC_BASE,
+		.chip	= {
+			.base	= S3C64XX_GPC(0),
+			.ngpio	= S3C64XX_GPIO_C_NR,
+			.label	= "GPC",
+		},
+	}, {
+		.base	= S3C64XX_GPD_BASE,
+		.chip	= {
+			.base	= S3C64XX_GPD(0),
+			.ngpio	= S3C64XX_GPIO_D_NR,
+			.label	= "GPD",
+		},
+	}, {
+		.base	= S3C64XX_GPE_BASE,
+		.chip	= {
+			.base	= S3C64XX_GPE(0),
+			.ngpio	= S3C64XX_GPIO_E_NR,
+			.label	= "GPE",
+		},
+	}, {
+		.base	= S3C64XX_GPG_BASE,
+		.chip	= {
+			.base	= S3C64XX_GPG(0),
+			.ngpio	= S3C64XX_GPIO_G_NR,
+			.label	= "GPG",
+		},
+	}, {
+		.base	= S3C64XX_GPM_BASE,
+		.chip	= {
+			.base	= S3C64XX_GPM(0),
+			.ngpio	= S3C64XX_GPIO_M_NR,
+			.label	= "GPM",
+		},
+	},
+};
+
+static struct s3c_gpio_chip gpio_4bit2[] = {
+	{
+		.base	= S3C64XX_GPH_BASE + 0x4,
+		.chip	= {
+			.base	= S3C64XX_GPH(0),
+			.ngpio	= S3C64XX_GPIO_H_NR,
+			.label	= "GPH",
+		},
+	}, {
+		.base	= S3C64XX_GPK_BASE + 0x4,
+		.chip	= {
+			.base	= S3C64XX_GPK(0),
+			.ngpio	= S3C64XX_GPIO_K_NR,
+			.label	= "GPK",
+		},
+	}, {
+		.base	= S3C64XX_GPL_BASE + 0x4,
+		.chip	= {
+			.base	= S3C64XX_GPL(0),
+			.ngpio	= S3C64XX_GPIO_L_NR,
+			.label	= "GPL",
+		},
+	},
+};
+
+static struct s3c_gpio_chip gpio_2bit[] = {
+	{
+		.base	= S3C64XX_GPF_BASE,
+		.chip	= {
+			.base	= S3C64XX_GPF(0),
+			.ngpio	= S3C64XX_GPIO_F_NR,
+			.label	= "GPF",
+		},
+	}, {
+		.base	= S3C64XX_GPI_BASE,
+		.chip	= {
+			.base	= S3C64XX_GPI(0),
+			.ngpio	= S3C64XX_GPIO_I_NR,
+			.label	= "GPI",
+		},
+	}, {
+		.base	= S3C64XX_GPJ_BASE,
+		.chip	= {
+			.base	= S3C64XX_GPJ(0),
+			.ngpio	= S3C64XX_GPIO_J_NR,
+			.label	= "GPJ",
+		},
+	}, {
+		.base	= S3C64XX_GPN_BASE,
+		.chip	= {
+			.base	= S3C64XX_GPN(0),
+			.ngpio	= S3C64XX_GPIO_N_NR,
+			.label	= "GPN",
+		},
+	}, {
+		.base	= S3C64XX_GPO_BASE,
+		.chip	= {
+			.base	= S3C64XX_GPO(0),
+			.ngpio	= S3C64XX_GPIO_O_NR,
+			.label	= "GPO",
+		},
+	}, {
+		.base	= S3C64XX_GPP_BASE,
+		.chip	= {
+			.base	= S3C64XX_GPP(0),
+			.ngpio	= S3C64XX_GPIO_P_NR,
+			.label	= "GPP",
+		},
+	}, {
+		.base	= S3C64XX_GPQ_BASE,
+		.chip	= {
+			.base	= S3C64XX_GPQ(0),
+			.ngpio	= S3C64XX_GPIO_Q_NR,
+			.label	= "GPQ",
+		},
+	},
+};
+
+static __init void s3c64xx_gpiolib_add_4bit(struct s3c_gpio_chip *chip)
+{
+	chip->chip.direction_input = s3c64xx_gpiolib_4bit_input;
+	chip->chip.direction_output = s3c64xx_gpiolib_4bit_output;
+}
+
+static __init void s3c64xx_gpiolib_add_4bit2(struct s3c_gpio_chip *chip)
+{
+	chip->chip.direction_input = s3c64xx_gpiolib_4bit2_input;
+	chip->chip.direction_output = s3c64xx_gpiolib_4bit2_output;
+}
+
+static __init void s3c64xx_gpiolib_add(struct s3c_gpio_chip *chips,
+				       int nr_chips,
+				       void (*fn)(struct s3c_gpio_chip *))
+{
+	for (; nr_chips > 0; nr_chips--, chips++) {
+		if (fn)
+			(fn)(chips);
+		s3c_gpiolib_add(chips);
+	}
+}
+
+static __init int s3c64xx_gpiolib_init(void)
+{
+	s3c64xx_gpiolib_add(gpio_4bit, ARRAY_SIZE(gpio_4bit),
+			    s3c64xx_gpiolib_add_4bit);
+
+	s3c64xx_gpiolib_add(gpio_4bit2, ARRAY_SIZE(gpio_4bit2),
+			    s3c64xx_gpiolib_add_4bit2);
+
+	s3c64xx_gpiolib_add(gpio_2bit, ARRAY_SIZE(gpio_2bit), NULL);
+
+	return 0;
+}
+
+arch_initcall(s3c64xx_gpiolib_init);

arch/arm/plat-s3c64xx/include/plat/regs-gpio.h

+/* linux/arch/arm/plat-s3c64xx/include/mach/regs-gpio.h
+ *
+ * Copyright 2008 Openmoko, Inc.
+ * Copyright 2008 Simtec Electronics
+ *      Ben Dooks <ben@simtec.co.uk>
+ *      http://armlinux.simtec.co.uk/
+ *
+ * S3C64XX - GPIO register definitions
+ */
+
+#ifndef __ASM_PLAT_S3C64XX_REGS_GPIO_H
+#define __ASM_PLAT_S3C64XX_REGS_GPIO_H __FILE__
+
+/* Base addresses for each of the banks */
+
+#define S3C64XX_GPA_BASE	(S3C64XX_VA_GPIO + 0x0000)
+#define S3C64XX_GPB_BASE	(S3C64XX_VA_GPIO + 0x0020)
+#define S3C64XX_GPC_BASE	(S3C64XX_VA_GPIO + 0x0040)
+#define S3C64XX_GPD_BASE	(S3C64XX_VA_GPIO + 0x0060)
+#define S3C64XX_GPE_BASE	(S3C64XX_VA_GPIO + 0x0080)
+#define S3C64XX_GPF_BASE	(S3C64XX_VA_GPIO + 0x00A0)
+#define S3C64XX_GPG_BASE	(S3C64XX_VA_GPIO + 0x00C0)
+#define S3C64XX_GPH_BASE	(S3C64XX_VA_GPIO + 0x00E0)
+#define S3C64XX_GPI_BASE	(S3C64XX_VA_GPIO + 0x0100)
+#define S3C64XX_GPJ_BASE	(S3C64XX_VA_GPIO + 0x0120)
+#define S3C64XX_GPK_BASE	(S3C64XX_VA_GPIO + 0x0800)
+#define S3C64XX_GPL_BASE	(S3C64XX_VA_GPIO + 0x0810)
+#define S3C64XX_GPM_BASE	(S3C64XX_VA_GPIO + 0x0820)
+#define S3C64XX_GPN_BASE	(S3C64XX_VA_GPIO + 0x0830)
+#define S3C64XX_GPO_BASE	(S3C64XX_VA_GPIO + 0x0140)
+#define S3C64XX_GPP_BASE	(S3C64XX_VA_GPIO + 0x0160)
+#define S3C64XX_GPQ_BASE	(S3C64XX_VA_GPIO + 0x0180)
+
+#endif /* __ASM_PLAT_S3C64XX_REGS_GPIO_H */
+