ARM: OMAP2+: Configure voltage controller for cpcap to low-speed

Looks like the i2c timings in high-speed mode do not work properly to
allow us to clear I2C_DISABLE bits for PRM_VOLTCTRL register and the
device reboots if I2C_DISABLE bits are cleared.

Let's configure the voltage controller i2c for low-speed mode as done in
the Motorola Mapphone Android Linux kernel. This saves us about 7mW of
power during retention compared to the high-speed values.

Let's also change the low-speed warning to pr_info about relying on the
bootloader configured low-speed values like we currently do.

Cc: Merlijn Wajer <merlijn@wizzup.org>
Cc: Pavel Machek <pavel@ucw.cz>
Cc: Sebastian Reichel <sre@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>

diff --git a/arch/arm/mach-omap2/pmic-cpcap.c b/arch/arm/mach-omap2/pmic-cpcap.c
index 3cdf40e..3958f8c 100644 (file)
--- a/arch/arm/mach-omap2/pmic-cpcap.c
+++ b/arch/arm/mach-omap2/pmic-cpcap.c
@@ -61,7 +61,7 @@ static struct omap_voltdm_pmic omap_cpcap_core = {
        .i2c_slave_addr = 0x02,
        .volt_reg_addr = 0x00,
        .cmd_reg_addr = 0x01,
-       .i2c_high_speed = true,
+       .i2c_high_speed = false,
        .vsel_to_uv = omap_cpcap_vsel_to_uv,
        .uv_to_vsel = omap_cpcap_uv_to_vsel,
 };
@@ -78,7 +78,7 @@ static struct omap_voltdm_pmic omap_cpcap_iva = {
        .i2c_slave_addr = 0x44,
        .volt_reg_addr = 0x0,
        .cmd_reg_addr = 0x01,
-       .i2c_high_speed = true,
+       .i2c_high_speed = false,
        .vsel_to_uv = omap_cpcap_vsel_to_uv,
        .uv_to_vsel = omap_cpcap_uv_to_vsel,
 };
@@ -125,7 +125,7 @@ static struct omap_voltdm_pmic omap443x_max8952_mpu = {
        .i2c_slave_addr = 0x60,
        .volt_reg_addr = 0x03,
        .cmd_reg_addr = 0x03,
-       .i2c_high_speed = true,
+       .i2c_high_speed = false,
        .vsel_to_uv = omap_max8952_vsel_to_uv,
        .uv_to_vsel = omap_max8952_uv_to_vsel,
 };
@@ -212,7 +212,7 @@ static struct omap_voltdm_pmic omap4_fan_core = {
        .vddmax = 1375000,
        .vp_timeout_us = OMAP4_VP_VLIMITTO_TIMEOUT_US,
        .i2c_slave_addr = 0x4A,
-       .i2c_high_speed = true,
+       .i2c_high_speed = false,
        .volt_reg_addr = 0x01,
        .cmd_reg_addr = 0x01,
        .vsel_to_uv = omap_fan535508_vsel_to_uv,
@@ -232,7 +232,7 @@ static struct omap_voltdm_pmic omap4_fan_iva = {
        .i2c_slave_addr = 0x48,
        .volt_reg_addr = 0x01,
        .cmd_reg_addr = 0x01,
-       .i2c_high_speed = true,
+       .i2c_high_speed = false,
        .vsel_to_uv = omap_fan535503_vsel_to_uv,
        .uv_to_vsel = omap_fan535503_uv_to_vsel,
 };
@@ -263,3 +263,11 @@ int __init omap4_cpcap_init(void)
 
        return 0;
 }
+
+static int __init cpcap_late_init(void)
+{
+       omap4_vc_set_pmic_signaling(PWRDM_POWER_RET);
+
+       return 0;
+}
+omap_late_initcall(cpcap_late_init);

diff --git a/arch/arm/mach-omap2/vc.c b/arch/arm/mach-omap2/vc.c
index 888b8ee..86f1ac4 100644 (file)
--- a/arch/arm/mach-omap2/vc.c
+++ b/arch/arm/mach-omap2/vc.c
@@ -670,7 +670,7 @@ static void __init omap4_vc_i2c_timing_init(struct voltagedomain *voltdm)
        const struct i2c_init_data *i2c_data;
 
        if (!voltdm->pmic->i2c_high_speed) {
-               pr_warn("%s: only high speed supported!\n", __func__);
+               pr_info("%s: using bootloader low-speed timings\n", __func__);
                return;
        }