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>

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,
 };

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())

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;

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 = {

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 */

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);
 };