cubieboard: Configure system voltages from devicetree

Change-Id: I93bac9bf94f5bafcd3ff0c3d5763b31d3ee9959b
Signed-off-by: Alexandru Gagniuc <mr.nuke.me@gmail.com>
Reviewed-on: http://review.coreboot.org/4640
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>

src/mainboard/cubietech/cubieboard/Kconfig

@@ -5,6 +5,7 @@ config BOARD_SPECIFIC_OPTIONS # dummy
 	select ARCH_ARMV7
 	select CPU_ALLWINNER_A10
 	select BOARD_ROMSIZE_KB_4096
+	select DRIVER_XPOWERS_AXP209
 
 config MAINBOARD_DIR
 	string

src/mainboard/cubietech/cubieboard/devicetree.cb

@@ -1,3 +1,12 @@
 chip cpu/allwinner/a10
 	device cpu_cluster 0 on end
+
+	chip drivers/xpowers/axp209	# AXP209 is on I²C 0
+		device i2c 0x34 on end
+		register "dcdc2_voltage_mv" = "1400"	# Vcore
+		register "dcdc3_voltage_mv" = "1250"	# DLL Vdd
+		register "ldo2_voltage_mv" = "3000"	# AVCC
+		register "ldo3_voltage_mv" = "2800"	# NC?
+		register "ldo4_voltage_mv" = "2800"	# CSI1-IO-2V8
+	end
 end

src/mainboard/cubietech/cubieboard/romstage.c

@@ -6,9 +6,67 @@
  */
 
 #include <console/console.h>
+#include <cpu/allwinner/a10/clock.h>
+#include <cpu/allwinner/a10/gpio.h>
+#include <cpu/allwinner/a10/twi.h>
+#define __SIMPLE_DEVICE__
+#include <device/device.h>
+#include <drivers/xpowers/axp209/axp209.h>
+#include <drivers/xpowers/axp209/chip.h>
+
+
+#define GPB_TWI0_FUNC			2
+#define GPB_TWI0_PINS			((1 << 0) | (1 << 1))
+
+#define AXP209_BUS	0
+
+static enum cb_err cubieboard_setup_power(void)
+{
+	enum cb_err err;
+	const struct device * pmu;
+	const struct drivers_xpowers_axp209_config *cfg;
+
+	/* Find the AXP209 in devicetree */
+	pmu = dev_find_slot_on_smbus(AXP209_BUS, AXP209_I2C_ADDR);
+	if (!pmu) {
+		printk(BIOS_ERR, "AXP209 not found in devicetree.cb\n");
+		return CB_ERR;
+	}
+
+	cfg = pmu->chip_info;
+
+	/* Mux TWI0 pins */
+	gpio_set_multipin_func(GPB, GPB_TWI0_PINS, GPB_TWI0_FUNC);
+	/* Enable TWI0 */
+	a1x_periph_clock_enable(A1X_CLKEN_TWI0);
+	a1x_twi_init(AXP209_BUS, 400000);
+
+	if ((err = axp209_init(AXP209_BUS)) != CB_SUCCESS) {
+		printk(BIOS_ERR, "PMU initialization failed\n");
+		return err;
+	}
+
+	if ((err = axp209_set_voltages(AXP209_BUS, cfg)) != CB_SUCCESS) {
+		printk(BIOS_WARNING, "Power setup incomplete: "
+				     "CPU may hang when increasing clock\n");
+		return err;
+	}
+
+	printk(BIOS_SPEW, "VDD CPU (DCDC2): %imv\n", cfg->dcdc2_voltage_mv);
+	printk(BIOS_SPEW, "VDD DLL (DCDC3): %imv\n", cfg->dcdc3_voltage_mv);
+	printk(BIOS_SPEW, "AVCC    (LDO2) : %imv\n", cfg->ldo2_voltage_mv);
+	printk(BIOS_SPEW, "CSI1-IO (LDO4) : %imv\n", cfg->ldo4_voltage_mv);
+	printk(BIOS_SPEW, "(LDO3) : %imv\n", cfg->ldo3_voltage_mv);
+
+	return CB_SUCCESS;
+}
 
 void main(void)
 {
 	console_init();
 	printk(BIOS_INFO, "You have managed to succesfully load romstage.\n");
+
+	/* Configure power rails */
+	cubieboard_setup_power();
+
 }