sunxi: Add axp209 pmic support

Add support for the x-powers axp209 pmic which is found on most A10, A13 and
A20 boards.

And enable AXP209 support for the Cubietruck and Cubieboard boards.

Signed-off-by: Henrik Nordstrom <henrik@henriknordstrom.net>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>
diff --git a/drivers/power/axp209.c b/drivers/power/axp209.c
new file mode 100644
index 0000000..9798e5b
--- /dev/null
+++ b/drivers/power/axp209.c
@@ -0,0 +1,167 @@
+/*
+ * (C) Copyright 2012
+ * Henrik Nordstrom <henrik@henriknordstrom.net>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <i2c.h>
+#include <axp209.h>
+
+enum axp209_reg {
+	AXP209_POWER_STATUS = 0x00,
+	AXP209_CHIP_VERSION = 0x03,
+	AXP209_DCDC2_VOLTAGE = 0x23,
+	AXP209_DCDC3_VOLTAGE = 0x27,
+	AXP209_LDO24_VOLTAGE = 0x28,
+	AXP209_LDO3_VOLTAGE = 0x29,
+	AXP209_IRQ_STATUS5 = 0x4c,
+	AXP209_SHUTDOWN = 0x32,
+};
+
+#define AXP209_POWER_STATUS_ON_BY_DC	(1 << 0)
+
+#define AXP209_IRQ5_PEK_UP		(1 << 6)
+#define AXP209_IRQ5_PEK_DOWN		(1 << 5)
+
+#define AXP209_POWEROFF			(1 << 7)
+
+static int axp209_write(enum axp209_reg reg, u8 val)
+{
+	return i2c_write(0x34, reg, 1, &val, 1);
+}
+
+static int axp209_read(enum axp209_reg reg, u8 *val)
+{
+	return i2c_read(0x34, reg, 1, val, 1);
+}
+
+static u8 axp209_mvolt_to_cfg(int mvolt, int min, int max, int div)
+{
+	if (mvolt < min)
+		mvolt = min;
+	else if (mvolt > max)
+		mvolt = max;
+
+	return (mvolt - min) / div;
+}
+
+int axp209_set_dcdc2(int mvolt)
+{
+	int rc;
+	u8 cfg, current;
+
+	cfg = axp209_mvolt_to_cfg(mvolt, 700, 2275, 25);
+
+	/* Do we really need to be this gentle? It has built-in voltage slope */
+	while ((rc = axp209_read(AXP209_DCDC2_VOLTAGE, &current)) == 0 &&
+	       current != cfg) {
+		if (current < cfg)
+			current++;
+		else
+			current--;
+
+		rc = axp209_write(AXP209_DCDC2_VOLTAGE, current);
+		if (rc)
+			break;
+	}
+
+	return rc;
+}
+
+int axp209_set_dcdc3(int mvolt)
+{
+	u8 cfg = axp209_mvolt_to_cfg(mvolt, 700, 3500, 25);
+
+	return axp209_write(AXP209_DCDC3_VOLTAGE, cfg);
+}
+
+int axp209_set_ldo2(int mvolt)
+{
+	int rc;
+	u8 cfg, reg;
+
+	cfg = axp209_mvolt_to_cfg(mvolt, 1800, 3300, 100);
+
+	rc = axp209_read(AXP209_LDO24_VOLTAGE, &reg);
+	if (rc)
+		return rc;
+
+	/* LDO2 configuration is in upper 4 bits */
+	reg = (reg & 0x0f) | (cfg << 4);
+	return axp209_write(AXP209_LDO24_VOLTAGE, reg);
+}
+
+int axp209_set_ldo3(int mvolt)
+{
+	u8 cfg;
+
+	if (mvolt == -1)
+		cfg = 0x80;	/* determined by LDO3IN pin */
+	else
+		cfg = axp209_mvolt_to_cfg(mvolt, 700, 2275, 25);
+
+	return axp209_write(AXP209_LDO3_VOLTAGE, cfg);
+}
+
+int axp209_set_ldo4(int mvolt)
+{
+	int rc;
+	static const int vindex[] = {
+		1250, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2500,
+		2700, 2800, 3000, 3100, 3200, 3300
+	};
+	u8 cfg, reg;
+
+	/* Translate mvolt to register cfg value, requested <= selected */
+	for (cfg = 15; vindex[cfg] > mvolt && cfg > 0; cfg--);
+
+	rc = axp209_read(AXP209_LDO24_VOLTAGE, &reg);
+	if (rc)
+		return rc;
+
+	/* LDO4 configuration is in lower 4 bits */
+	reg = (reg & 0xf0) | (cfg << 0);
+	return axp209_write(AXP209_LDO24_VOLTAGE, reg);
+}
+
+int axp209_init(void)
+{
+	u8 ver;
+	int rc;
+
+	rc = axp209_read(AXP209_CHIP_VERSION, &ver);
+	if (rc)
+		return rc;
+
+	/* Low 4 bits is chip version */
+	ver &= 0x0f;
+
+	if (ver != 0x1)
+		return -1;
+
+	return 0;
+}
+
+int axp209_poweron_by_dc(void)
+{
+	u8 v;
+
+	if (axp209_read(AXP209_POWER_STATUS, &v))
+		return 0;
+
+	return (v & AXP209_POWER_STATUS_ON_BY_DC);
+}
+
+int axp209_power_button(void)
+{
+	u8 v;
+
+	if (axp209_read(AXP209_IRQ_STATUS5, &v))
+		return 0;
+
+	axp209_write(AXP209_IRQ_STATUS5, AXP209_IRQ5_PEK_DOWN);
+
+	return v & AXP209_IRQ5_PEK_DOWN;
+}