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>

1 files changed, 58 insertions, 12 deletions

diff --git a/arch/arm/mach-omap2/vc.c b/arch/arm/mach-omap2/vc.c
index 72c9cb64a42b..1791f79112bf 100644
--- a/arch/arm/mach-omap2/vc.c
+++ b/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;
@@ -232,6 +269,7 @@ 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.
@@ -239,10 +277,14 @@ void __init omap_vc_init_channel(struct voltagedomain *voltdm)
         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,