sunxi: gpio: Add support for gpio pins on the AXP209 pmic

Some boards use GPIO-s on the pmic, one example of this is the A13-OLinuXino
board, which uses gpio0 of the axp209 for the lcd-power signal.

This commit adds support for gpio pins on the AXP209 pmic, the sunxi_gpio.c
changes are universal, adding gpio support for the other AXP pmics (when
necessary) should be a matter of adding the necessary axp_gpio_foo functions
to their resp. drivers, and add "#define AXP_GPIO" to their header file.

Note this commit only adds support for the non device-model version of the
gpio code, patches for adding support to the device-model version are very
welcome.

The string representation for these gpio-s is AXP0-#, the 0 in the AXP0 prefix
is there in case we need to support gpio-s on more then 1 pmic in the future.
At least A80 boards have 2 pmics, and we may end up needing to support gpio-s
on both.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>

arch/arm/include/asm/arch-sunxi/gpio.h

@@ -114,6 +114,7 @@ enum sunxi_gpio_number {
 	SUNXI_GPIO_I_START = SUNXI_GPIO_NEXT(SUNXI_GPIO_H),
 	SUNXI_GPIO_L_START = 352,
 	SUNXI_GPIO_M_START = SUNXI_GPIO_NEXT(SUNXI_GPIO_L),
+	SUNXI_GPIO_AXP0_START = 1024,
 };
 
 /* SUNXI GPIO number definitions */
@@ -129,6 +130,8 @@ enum sunxi_gpio_number {
 #define SUNXI_GPL(_nr)	(SUNXI_GPIO_L_START + (_nr))
 #define SUNXI_GPM(_nr)	(SUNXI_GPIO_M_START + (_nr))
 
+#define SUNXI_GPAXP0(_nr)	(SUNXI_GPIO_AXP0_START + (_nr))
+
 /* GPIO pin function config */
 #define SUNXI_GPIO_INPUT	0
 #define SUNXI_GPIO_OUTPUT	1

drivers/gpio/sunxi_gpio.c

@@ -18,6 +18,9 @@
 #include <asm/io.h>
 #include <asm/gpio.h>
 #include <dm/device-internal.h>
+#ifdef CONFIG_AXP209_POWER
+#include <axp209.h>
+#endif
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -73,6 +76,10 @@ int gpio_free(unsigned gpio)
 
 int gpio_direction_input(unsigned gpio)
 {
+#ifdef AXP_GPIO
+	if (gpio >= SUNXI_GPIO_AXP0_START)
+		return axp_gpio_direction_input(gpio - SUNXI_GPIO_AXP0_START);
+#endif
 	sunxi_gpio_set_cfgpin(gpio, SUNXI_GPIO_INPUT);
 
 	return 0;
@@ -80,6 +87,11 @@ int gpio_direction_input(unsigned gpio)
 
 int gpio_direction_output(unsigned gpio, int value)
 {
+#ifdef AXP_GPIO
+	if (gpio >= SUNXI_GPIO_AXP0_START)
+		return axp_gpio_direction_output(gpio - SUNXI_GPIO_AXP0_START,
+						 value);
+#endif
 	sunxi_gpio_set_cfgpin(gpio, SUNXI_GPIO_OUTPUT);
 
 	return sunxi_gpio_output(gpio, value);
@@ -87,11 +99,19 @@ int gpio_direction_output(unsigned gpio, int value)
 
 int gpio_get_value(unsigned gpio)
 {
+#ifdef AXP_GPIO
+	if (gpio >= SUNXI_GPIO_AXP0_START)
+		return axp_gpio_get_value(gpio - SUNXI_GPIO_AXP0_START);
+#endif
 	return sunxi_gpio_input(gpio);
 }
 
 int gpio_set_value(unsigned gpio, int value)
 {
+#ifdef AXP_GPIO
+	if (gpio >= SUNXI_GPIO_AXP0_START)
+		return axp_gpio_set_value(gpio - SUNXI_GPIO_AXP0_START, value);
+#endif
 	return sunxi_gpio_output(gpio, value);
 }
 
@@ -101,6 +121,16 @@ int sunxi_name_to_gpio(const char *name)
 	int groupsize = 9 * 32;
 	long pin;
 	char *eptr;
+
+#ifdef AXP_GPIO
+	if (strncasecmp(name, "AXP0-", 5) == 0) {
+		name += 5;
+		pin = simple_strtol(name, &eptr, 10);
+		if (!*name || *eptr)
+			return -1;
+		return SUNXI_GPIO_AXP0_START + pin;
+	}
+#endif
 	if (*name == 'P' || *name == 'p')
 		name++;
 	if (*name >= 'A') {

drivers/power/axp209.c

@@ -18,6 +18,11 @@ enum axp209_reg {
 	AXP209_LDO3_VOLTAGE = 0x29,
 	AXP209_IRQ_STATUS5 = 0x4c,
 	AXP209_SHUTDOWN = 0x32,
+	AXP209_GPIO0_CTRL = 0x90,
+	AXP209_GPIO1_CTRL = 0x92,
+	AXP209_GPIO2_CTRL = 0x93,
+	AXP209_GPIO_STATE = 0x94,
+	AXP209_GPIO3_CTRL = 0x95,
 };
 
 #define AXP209_POWER_STATUS_ON_BY_DC	(1 << 0)
@@ -27,6 +32,15 @@ enum axp209_reg {
 
 #define AXP209_POWEROFF			(1 << 7)
 
+#define AXP209_GPIO_OUTPUT_LOW		0x00 /* Drive pin low */
+#define AXP209_GPIO_OUTPUT_HIGH		0x01 /* Drive pin high */
+#define AXP209_GPIO_INPUT		0x02 /* Float pin */
+
+/* GPIO3 is different from the others */
+#define AXP209_GPIO3_OUTPUT_LOW		0x00 /* Drive pin low, Output mode */
+#define AXP209_GPIO3_OUTPUT_HIGH	0x02 /* Float pin, Output mode */
+#define AXP209_GPIO3_INPUT		0x06 /* Float pin, Input mode */
+
 static int axp209_write(enum axp209_reg reg, u8 val)
 {
 	return i2c_write(0x34, reg, 1, &val, 1);
@@ -165,3 +179,61 @@ int axp209_power_button(void)
 
 	return v & AXP209_IRQ5_PEK_DOWN;
 }
+
+static u8 axp209_get_gpio_ctrl_reg(unsigned int pin)
+{
+	switch (pin) {
+	case 0: return AXP209_GPIO0_CTRL;
+	case 1: return AXP209_GPIO1_CTRL;
+	case 2: return AXP209_GPIO2_CTRL;
+	case 3: return AXP209_GPIO3_CTRL;
+	}
+	return 0;
+}
+
+int axp_gpio_direction_input(unsigned int pin)
+{
+	u8 reg = axp209_get_gpio_ctrl_reg(pin);
+	/* GPIO3 is "special" */
+	u8 val = (pin == 3) ? AXP209_GPIO3_INPUT : AXP209_GPIO_INPUT;
+
+	return axp209_write(reg, val);
+}
+
+int axp_gpio_direction_output(unsigned int pin, unsigned int val)
+{
+	u8 reg = axp209_get_gpio_ctrl_reg(pin);
+
+	if (val) {
+		val = (pin == 3) ? AXP209_GPIO3_OUTPUT_HIGH :
+				   AXP209_GPIO_OUTPUT_HIGH;
+	} else {
+		val = (pin == 3) ? AXP209_GPIO3_OUTPUT_LOW :
+				   AXP209_GPIO_OUTPUT_LOW;
+	}
+
+	return axp209_write(reg, val);
+}
+
+int axp_gpio_get_value(unsigned int pin)
+{
+	u8 val, mask;
+	int rc;
+
+	if (pin == 3) {
+		rc = axp209_read(AXP209_GPIO3_CTRL, &val);
+		mask = 1;
+	} else {
+		rc = axp209_read(AXP209_GPIO_STATE, &val);
+		mask = 1 << (pin + 4);
+	}
+	if (rc)
+		return rc;
+
+	return (val & mask) ? 1 : 0;
+}
+
+int axp_gpio_set_value(unsigned int pin, unsigned int val)
+{
+	return axp_gpio_direction_output(pin, val);
+}

include/axp209.h

@@ -4,6 +4,8 @@
  * SPDX-License-Identifier:	GPL-2.0+
  */
 
+#define AXP_GPIO
+
 extern int axp209_set_dcdc2(int mvolt);
 extern int axp209_set_dcdc3(int mvolt);
 extern int axp209_set_ldo2(int mvolt);
@@ -12,3 +14,8 @@ extern int axp209_set_ldo4(int mvolt);
 extern int axp209_init(void);
 extern int axp209_poweron_by_dc(void);
 extern int axp209_power_button(void);
+
+extern int axp_gpio_direction_input(unsigned int pin);
+extern int axp_gpio_direction_output(unsigned int pin, unsigned int val);
+extern int axp_gpio_get_value(unsigned int pin);
+extern int axp_gpio_set_value(unsigned int pin, unsigned int val);