OMAP3+: VC: make I2C config programmable with PMIC-specific settings

Remove hard-coded I2C configuration in favor of settings that can be
configured from PMIC-specific values.  Currently only high-speed mode
and the master-code value are supported, since they were the only
fields currently used, but extending this is now trivial.

Thanks to Nishanth Menon <nm@ti.com> for reporting/fixing a sparse
problem and making omap_vc_i2c_init() static, as well as finding and
fixing a problem with the shift/mask of mcode.

Signed-off-by: Kevin Hilman <khilman@ti.com>

6 files changed, 66 insertions, 7 deletions

diff --git a/arch/arm/mach-omap2/omap_twl.c b/arch/arm/mach-omap2/omap_twl.c
index e467d4565a2d..6b247d183299 100644
--- a/arch/arm/mach-omap2/omap_twl.c
+++ b/arch/arm/mach-omap2/omap_twl.c
@@ -159,6 +159,7 @@ static struct omap_voltdm_pmic omap3_mpu_pmic = {
         .vp_timeout_us          = OMAP3_VP_VLIMITTO_TIMEOUT_US,
         .i2c_slave_addr         = OMAP3_SRI2C_SLAVE_ADDR,
         .volt_reg_addr          = OMAP3_VDD_MPU_SR_CONTROL_REG,
+        .i2c_high_speed         = true,
         .vsel_to_uv             = twl4030_vsel_to_uv,
         .uv_to_vsel             = twl4030_uv_to_vsel,
 };
@@ -179,6 +180,7 @@ static struct omap_voltdm_pmic omap3_core_pmic = {
         .vp_timeout_us          = OMAP3_VP_VLIMITTO_TIMEOUT_US,
         .i2c_slave_addr         = OMAP3_SRI2C_SLAVE_ADDR,
         .volt_reg_addr          = OMAP3_VDD_CORE_SR_CONTROL_REG,
+        .i2c_high_speed         = true,
         .vsel_to_uv             = twl4030_vsel_to_uv,
         .uv_to_vsel             = twl4030_uv_to_vsel,
 };
@@ -199,6 +201,7 @@ static struct omap_voltdm_pmic omap4_mpu_pmic = {
         .vp_timeout_us          = OMAP4_VP_VLIMITTO_TIMEOUT_US,
         .i2c_slave_addr         = OMAP4_SRI2C_SLAVE_ADDR,
         .volt_reg_addr          = OMAP4_VDD_MPU_SR_VOLT_REG,
+        .i2c_high_speed         = true,
         .vsel_to_uv             = twl6030_vsel_to_uv,
         .uv_to_vsel             = twl6030_uv_to_vsel,
 };
@@ -219,6 +222,7 @@ static struct omap_voltdm_pmic omap4_iva_pmic = {
         .vp_timeout_us          = OMAP4_VP_VLIMITTO_TIMEOUT_US,
         .i2c_slave_addr         = OMAP4_SRI2C_SLAVE_ADDR,
         .volt_reg_addr          = OMAP4_VDD_IVA_SR_VOLT_REG,
+        .i2c_high_speed         = true,
         .vsel_to_uv             = twl6030_vsel_to_uv,
         .uv_to_vsel             = twl6030_uv_to_vsel,
 };
diff --git a/arch/arm/mach-omap2/vc.c b/arch/arm/mach-omap2/vc.c
index 4ac761440d62..5d545632388d 100644
--- a/arch/arm/mach-omap2/vc.c
+++ b/arch/arm/mach-omap2/vc.c
@@ -208,13 +208,6 @@ static void __init omap3_vc_init_channel(struct voltagedomain *voltdm)
         if (is_initialized)
                 return;
 
-        /*
-         * Generic VC parameters init
-         * XXX This data should be abstracted out
-         */
-        voltdm->write(OMAP3430_MCODE_SHIFT | OMAP3430_HSEN_MASK,
-                       OMAP3_PRM_VC_I2C_CFG_OFFSET);
-
         omap3_vfsm_init(voltdm);
 
         is_initialized = true;
@@ -237,6 +230,48 @@ static void __init omap4_vc_init_channel(struct voltagedomain *voltdm)
         is_initialized = true;
 }
 
+/**
+ * omap_vc_i2c_init - initialize I2C interface to PMIC
+ * @voltdm: voltage domain containing VC data
+ *
+ * Use PMIC supplied seetings for I2C high-speed mode and
+ * master code (if set) and program the VC I2C configuration
+ * register.
+ *
+ * The VC I2C configuration is common to all VC channels,
+ * so this function only configures I2C for the first VC
+ * channel registers.  All other VC channels will use the
+ * same configuration.
+ */
+static void __init omap_vc_i2c_init(struct voltagedomain *voltdm)
+{
+        struct omap_vc_channel *vc = voltdm->vc;
+        static bool initialized;
+        static bool i2c_high_speed;
+        u8 mcode;
+
+        if (initialized) {
+                if (voltdm->pmic->i2c_high_speed != i2c_high_speed)
+                        pr_warn("%s: I2C config for all channels must match.",
+                                __func__);
+                return;
+        }
+
+        i2c_high_speed = voltdm->pmic->i2c_high_speed;
+        if (i2c_high_speed)
+                voltdm->rmw(vc->common->i2c_cfg_hsen_mask,
+                            vc->common->i2c_cfg_hsen_mask,
+                            vc->common->i2c_cfg_reg);
+
+        mcode = voltdm->pmic->i2c_mcode;
+        if (mcode)
+                voltdm->rmw(vc->common->i2c_mcode_mask,
+                            mcode << __ffs(vc->common->i2c_mcode_mask),
+                            vc->common->i2c_cfg_reg);
+
+        initialized = true;
+}
+
 void __init omap_vc_init_channel(struct voltagedomain *voltdm)
 {
         struct omap_vc_channel *vc = voltdm->vc;
@@ -305,6 +340,8 @@ void __init omap_vc_init_channel(struct voltagedomain *voltdm)
                     vc->setup_time << __ffs(voltdm->vfsm->voltsetup_mask),
                     voltdm->vfsm->voltsetup_reg);
 
+        omap_vc_i2c_init(voltdm);
+
         if (cpu_is_omap34xx())
                 omap3_vc_init_channel(voltdm);
         else if (cpu_is_omap44xx())
diff --git a/arch/arm/mach-omap2/vc.h b/arch/arm/mach-omap2/vc.h
index fd385285a3bf..c86301330b75 100644
--- a/arch/arm/mach-omap2/vc.h
+++ b/arch/arm/mach-omap2/vc.h
@@ -37,6 +37,9 @@ struct voltagedomain;
  * @cmd_ret_shift: RET field shift in PRM_VC_CMD_VAL_* register
  * @cmd_off_shift: OFF field shift in PRM_VC_CMD_VAL_* register
  * @cfg_channel_reg: VC channel configuration register
+ * @i2c_cfg_reg: I2C configuration register offset
+ * @i2c_cfg_hsen_mask: high-speed mode bit field mask in I2C config register
+ * @i2c_mcode_mask: MCODE field mask for I2C config register
  *
  * XXX One of cmd_on_mask and cmd_on_shift are not needed
  * XXX VALID should probably be a shift, not a mask
@@ -56,6 +59,9 @@ struct omap_vc_common {
         u8 cmd_ret_shift;
         u8 cmd_off_shift;
         u8 cfg_channel_reg;
+        u8 i2c_cfg_reg;
+        u8 i2c_cfg_hsen_mask;
+        u8 i2c_mcode_mask;
 };
 
 /* omap_vc_channel.flags values */
@@ -68,6 +74,7 @@ struct omap_vc_common {
  * @cmd_reg_addr: command configuration register address
  * @setup_time: setup time (in sys_clk cycles) of regulator for this channel
  * @cfg_channel: current value of VC channel configuration register
+ * @i2c_high_speed: whether or not to use I2C high-speed mode
  *
  * @common: pointer to VC common data for this platform
  * @smps_sa_mask: i2c slave address bitmask in the PRM_VC_SMPS_SA register
@@ -84,6 +91,7 @@ struct omap_vc_channel {
         u16 cmd_reg_addr;
         u16 setup_time;
         u8 cfg_channel;
+        bool i2c_high_speed;
 
         /* register access data */
         const struct omap_vc_common *common;
diff --git a/arch/arm/mach-omap2/vc3xxx_data.c b/arch/arm/mach-omap2/vc3xxx_data.c
index f4449eb59841..95d7701300cb 100644
--- a/arch/arm/mach-omap2/vc3xxx_data.c
+++ b/arch/arm/mach-omap2/vc3xxx_data.c
@@ -44,6 +44,9 @@ static struct omap_vc_common omap3_vc_common = {
         .cmd_ret_shift   = OMAP3430_VC_CMD_RET_SHIFT,
         .cmd_off_shift   = OMAP3430_VC_CMD_OFF_SHIFT,
         .cfg_channel_reg = OMAP3_PRM_VC_CH_CONF_OFFSET,
+        .i2c_cfg_hsen_mask = OMAP3430_HSEN_MASK,
+        .i2c_cfg_reg     = OMAP3_PRM_VC_I2C_CFG_OFFSET,
+        .i2c_mcode_mask  = OMAP3430_MCODE_MASK,
 };
 
 struct omap_vc_channel omap3_vc_mpu = {
diff --git a/arch/arm/mach-omap2/vc44xx_data.c b/arch/arm/mach-omap2/vc44xx_data.c
index 1610bdedee6b..148be18397f8 100644
--- a/arch/arm/mach-omap2/vc44xx_data.c
+++ b/arch/arm/mach-omap2/vc44xx_data.c
@@ -45,6 +45,9 @@ static const struct omap_vc_common omap4_vc_common = {
         .cmd_ret_shift = OMAP4430_RET_SHIFT,
         .cmd_off_shift = OMAP4430_OFF_SHIFT,
         .cfg_channel_reg = OMAP4_PRM_VC_CFG_CHANNEL_OFFSET,
+        .i2c_cfg_reg = OMAP4_PRM_VC_CFG_I2C_MODE_OFFSET,
+        .i2c_cfg_hsen_mask = OMAP4430_HSMODEEN_MASK,
+        .i2c_mcode_mask  = OMAP4430_HSMCODE_MASK,
 };
 
 /* VC instance data for each controllable voltage line */
diff --git a/arch/arm/mach-omap2/voltage.h b/arch/arm/mach-omap2/voltage.h
index 43ee7bf57969..a36d2cfa5ca7 100644
--- a/arch/arm/mach-omap2/voltage.h
+++ b/arch/arm/mach-omap2/voltage.h
@@ -103,6 +103,8 @@ struct omap_volt_data {
  * @i2c_slave_addr: I2C slave address of PMIC
  * @volt_reg_addr: voltage configuration register address
  * @cmd_reg_addr: command (on, on-LP, ret, off) configuration register address
+ * @i2c_high_speed: whether VC uses I2C high-speed mode to PMIC
+ * @i2c_mcode: master code value for I2C high-speed preamble transmission
  * @vsel_to_uv: PMIC API to convert vsel value to actual voltage in uV.
  * @uv_to_vsel: PMIC API to convert voltage in uV to vsel value.
  */
@@ -123,6 +125,8 @@ struct omap_voltdm_pmic {
         u8 vp_vddmin;
         u8 vp_vddmax;
         u8 vp_timeout_us;
+        bool i2c_high_speed;
+        u8 i2c_mcode;
         unsigned long (*vsel_to_uv) (const u8 vsel);
         u8 (*uv_to_vsel) (unsigned long uV);
 };