OMAP3+: VC: abstract out channel configuration

VC channel configuration is programmed based on settings coming from
the PMIC configuration.

Currently, the VC channel to PMIC mapping is a simple one-to-one
mapping.  Whenever a VC channel parameter is configured (i2c slave
addres, PMIC register address, on/ret/off command), the corresponding
bits are enabled in the VC channel configuration register.

If necessary, the programmability of channel configuration settings
could be extended to board/PMIC files, however, because this patch
changes the channel configuration to be programmed based on existing
values from the PMIC settings, it may not be required.

Also note that starting with OMAP4, where there are more than 2
channels, one channel is identified as the "default" channel.  When
any of the bits in the channel config for the other channels are zero,
it means to use the default channel.  The OMAP4 TRM (at least through
NDA version Q) is wrong in describing which is the default channel.
The default channel on OMAP4 is MPU, not CORE as decribed in the TRM.

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

arch/arm/mach-omap2/vc.c

@@ -19,6 +19,52 @@
 #include "prm-regbits-44xx.h"
 #include "prm44xx.h"
 
+/*
+ * Channel configuration bits, common for OMAP3 & 4
+ * OMAP3 register: PRM_VC_CH_CONF
+ * OMAP4 register: PRM_VC_CFG_CHANNEL
+ */
+#define CFG_CHANNEL_SA    BIT(0)
+#define CFG_CHANNEL_RAV   BIT(1)
+#define CFG_CHANNEL_RAC   BIT(2)
+#define CFG_CHANNEL_RACEN BIT(3)
+#define CFG_CHANNEL_CMD   BIT(4)
+#define CFG_CHANNEL_MASK 0x3f
+
+/**
+ * omap_vc_config_channel - configure VC channel to PMIC mappings
+ * @voltdm: pointer to voltagdomain defining the desired VC channel
+ *
+ * Configures the VC channel to PMIC mappings for the following
+ * PMIC settings
+ * - i2c slave address (SA)
+ * - voltage configuration address (RAV)
+ * - command configuration address (RAC) and enable bit (RACEN)
+ * - command values for ON, ONLP, RET and OFF (CMD)
+ *
+ * This function currently only allows flexible configuration of the
+ * non-default channel.  Starting with OMAP4, there are more than 2
+ * channels, with one defined as the default (on OMAP4, it's MPU.)
+ * Only the non-default channel can be configured.
+ */
+static int omap_vc_config_channel(struct voltagedomain *voltdm)
+{
+	struct omap_vc_channel *vc = voltdm->vc;
+
+	/*
+	 * For default channel, the only configurable bit is RACEN.
+	 * All others must stay at zero (see function comment above.)
+	 */
+	if (vc->flags & OMAP_VC_CHANNEL_DEFAULT)
+		vc->cfg_channel &= CFG_CHANNEL_RACEN;
+
+	voltdm->rmw(CFG_CHANNEL_MASK << vc->cfg_channel_sa_shift,
+		    vc->cfg_channel << vc->cfg_channel_sa_shift,
+		    vc->common->cfg_channel_reg);
+
+	return 0;
+}
+
 /* Voltage scale and accessory APIs */
 int omap_vc_pre_scale(struct voltagedomain *voltdm,
 		      unsigned long target_volt,
@@ -166,8 +212,6 @@ static void __init omap3_vc_init_channel(struct voltagedomain *voltdm)
 	 * Generic VC parameters init
 	 * XXX This data should be abstracted out
 	 */
-	voltdm->write(OMAP3430_CMD1_MASK | OMAP3430_RAV1_MASK,
-		       OMAP3_PRM_VC_CH_CONF_OFFSET);
 	voltdm->write(OMAP3430_MCODE_SHIFT | OMAP3430_HSEN_MASK,
 		       OMAP3_PRM_VC_I2C_CFG_OFFSET);
 
@@ -186,15 +230,6 @@ static void __init omap4_vc_init_channel(struct voltagedomain *voltdm)
 	if (is_initialized)
 		return;
 
-	/*
-	 * Generic VC parameters init
-	 * XXX This data should be abstracted out
-	 */
-	vc_val = (OMAP4430_RAV_VDD_MPU_L_MASK | OMAP4430_CMD_VDD_MPU_L_MASK |
-		  OMAP4430_RAV_VDD_IVA_L_MASK | OMAP4430_CMD_VDD_IVA_L_MASK |
-		  OMAP4430_RAV_VDD_CORE_L_MASK | OMAP4430_CMD_VDD_CORE_L_MASK);
-	voltdm->write(vc_val, OMAP4_PRM_VC_CFG_CHANNEL_OFFSET);
-
 	/* XXX These are magic numbers and do not belong! */
 	vc_val = (0x60 << OMAP4430_SCLL_SHIFT | 0x26 << OMAP4430_SCLH_SHIFT);
 	voltdm->write(vc_val, OMAP4_PRM_VC_CFG_I2C_CLK_OFFSET);
@@ -222,6 +257,8 @@ void __init omap_vc_init_channel(struct voltagedomain *voltdm)
 		return;
 	}
 
+	vc->cfg_channel = 0;
+
 	/* get PMIC/board specific settings */
 	vc->i2c_slave_addr = vdd->pmic_info->i2c_slave_addr;
 	vc->volt_reg_addr = vdd->pmic_info->volt_reg_addr;
@@ -232,17 +269,22 @@ void __init omap_vc_init_channel(struct voltagedomain *voltdm)
 	voltdm->rmw(vc->smps_sa_mask,
 		    vc->i2c_slave_addr << __ffs(vc->smps_sa_mask),
 		    vc->common->smps_sa_reg);
+	vc->cfg_channel |= CFG_CHANNEL_SA;
 
 	/*
 	 * Configure the PMIC register addresses.
 	 */
 	voltdm->rmw(vc->smps_volra_mask,
 		    vc->volt_reg_addr << __ffs(vc->smps_volra_mask),
 		    vc->common->smps_volra_reg);
-	if (vc->cmd_reg_addr)
+	vc->cfg_channel |= CFG_CHANNEL_RAV;
+
+	if (vc->cmd_reg_addr) {
 		voltdm->rmw(vc->smps_cmdra_mask,
 			    vc->cmd_reg_addr << __ffs(vc->smps_cmdra_mask),
 			    vc->common->smps_cmdra_reg);
+		vc->cfg_channel |= CFG_CHANNEL_RAC | CFG_CHANNEL_RACEN;
+	}
 
 	/* Set up the on, inactive, retention and off voltage */
 	on_vsel = vdd->pmic_info->uv_to_vsel(vdd->pmic_info->on_volt);
@@ -254,6 +296,10 @@ void __init omap_vc_init_channel(struct voltagedomain *voltdm)
 	       (ret_vsel << vc->common->cmd_ret_shift) |
 	       (off_vsel << vc->common->cmd_off_shift));
 	voltdm->write(val, vc->cmdval_reg);
+	vc->cfg_channel |= CFG_CHANNEL_CMD;
+
+	/* Channel configuration */
+	omap_vc_config_channel(voltdm);
 
 	/* Configure the setup times */
 	voltdm->rmw(voltdm->vfsm->voltsetup_mask,

arch/arm/mach-omap2/vc.h

@@ -54,8 +54,12 @@ struct omap_vc_common {
 	u8 cmd_onlp_shift;
 	u8 cmd_ret_shift;
 	u8 cmd_off_shift;
+	u8 cfg_channel_reg;
 };
 
+/* omap_vc_channel.flags values */
+#define OMAP_VC_CHANNEL_DEFAULT BIT(0)
+
 /**
  * struct omap_vc_channel - VC per-instance data
  * @i2c_slave_addr: I2C slave address of PMIC for this VC channel
@@ -67,20 +71,24 @@ struct omap_vc_common {
  * @smps_volra_mask: VOLRA* bitmask in the PRM_VC_VOL_RA register
  * @smps_cmdra_mask: CMDRA* bitmask in the PRM_VC_CMD_RA register
  * @cmdval_reg: register for on/ret/off voltage level values for this channel
+ * @flags: VC channel-specific flags (optional)
  */
 struct omap_vc_channel {
 	/* channel state */
 	u16 i2c_slave_addr;
 	u16 volt_reg_addr;
 	u16 cmd_reg_addr;
 	u16 setup_time;
+	u8 cfg_channel;
 
 	/* register access data */
 	const struct omap_vc_common *common;
 	u32 smps_sa_mask;
 	u32 smps_volra_mask;
 	u32 smps_cmdra_mask;
 	u8 cmdval_reg;
+	u8 cfg_channel_sa_shift;
+	u8 flags;
 };
 
 extern struct omap_vc_channel omap3_vc_mpu;

arch/arm/mach-omap2/vc3xxx_data.c

@@ -43,6 +43,7 @@ static struct omap_vc_common omap3_vc_common = {
 	.cmd_onlp_shift	 = OMAP3430_VC_CMD_ONLP_SHIFT,
 	.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,
 };
 
 struct omap_vc_channel omap3_vc_mpu = {
@@ -51,6 +52,7 @@ struct omap_vc_channel omap3_vc_mpu = {
 	.smps_sa_mask = OMAP3430_PRM_VC_SMPS_SA_SA0_MASK,
 	.smps_volra_mask = OMAP3430_VOLRA0_MASK,
 	.smps_cmdra_mask = OMAP3430_CMDRA0_MASK,
+	.cfg_channel_sa_shift = OMAP3430_PRM_VC_SMPS_SA_SA0_SHIFT,
 };
 
 struct omap_vc_channel omap3_vc_core = {
@@ -59,4 +61,5 @@ struct omap_vc_channel omap3_vc_core = {
 	.smps_sa_mask = OMAP3430_PRM_VC_SMPS_SA_SA1_MASK,
 	.smps_volra_mask = OMAP3430_VOLRA1_MASK,
 	.smps_cmdra_mask = OMAP3430_CMDRA1_MASK,
+	.cfg_channel_sa_shift = OMAP3430_PRM_VC_SMPS_SA_SA1_SHIFT,
 };

arch/arm/mach-omap2/vc44xx_data.c

@@ -44,15 +44,18 @@ static const struct omap_vc_common omap4_vc_common = {
 	.cmd_onlp_shift = OMAP4430_ONLP_SHIFT,
 	.cmd_ret_shift = OMAP4430_RET_SHIFT,
 	.cmd_off_shift = OMAP4430_OFF_SHIFT,
+	.cfg_channel_reg = OMAP4_PRM_VC_CFG_CHANNEL_OFFSET,
 };
 
 /* VC instance data for each controllable voltage line */
 struct omap_vc_channel omap4_vc_mpu = {
+	.flags = OMAP_VC_CHANNEL_DEFAULT,
 	.common = &omap4_vc_common,
 	.cmdval_reg = OMAP4_PRM_VC_VAL_CMD_VDD_MPU_L_OFFSET,
 	.smps_sa_mask = OMAP4430_SA_VDD_MPU_L_PRM_VC_SMPS_SA_MASK,
 	.smps_volra_mask = OMAP4430_VOLRA_VDD_MPU_L_MASK,
 	.smps_cmdra_mask = OMAP4430_CMDRA_VDD_MPU_L_MASK,
+	.cfg_channel_sa_shift = OMAP4430_SA_VDD_MPU_L_SHIFT,
 };
 
 struct omap_vc_channel omap4_vc_iva = {
@@ -61,6 +64,7 @@ struct omap_vc_channel omap4_vc_iva = {
 	.smps_sa_mask = OMAP4430_SA_VDD_IVA_L_PRM_VC_SMPS_SA_MASK,
 	.smps_volra_mask = OMAP4430_VOLRA_VDD_IVA_L_MASK,
 	.smps_cmdra_mask = OMAP4430_CMDRA_VDD_IVA_L_MASK,
+	.cfg_channel_sa_shift = OMAP4430_SA_VDD_IVA_L_SHIFT,
 };
 
 struct omap_vc_channel omap4_vc_core = {
@@ -69,5 +73,6 @@ struct omap_vc_channel omap4_vc_core = {
 	.smps_sa_mask = OMAP4430_SA_VDD_CORE_L_0_6_MASK,
 	.smps_volra_mask = OMAP4430_VOLRA_VDD_CORE_L_MASK,
 	.smps_cmdra_mask = OMAP4430_CMDRA_VDD_CORE_L_MASK,
+	.cfg_channel_sa_shift = OMAP4430_SA_VDD_CORE_L_SHIFT,
 };