Nishanth Menon <nm@xxxxxx> writes:
> Patch "OMAP3+: VC: abstract out channel configuration" abstracts out
> VC channel configuration. However, TRM has it's little surprises such
> as the following for channel_cfg:
> CFG_CHANNEL_SA BIT(0)
> CFG_CHANNEL_RAV BIT(1)
> CFG_CHANNEL_RAC BIT(2)
> CFG_CHANNEL_RACEN BIT(3)
> CFG_CHANNEL_CMD BIT(4)
> is valid for core and iva, *but* for mpu, the channel offsets are as follows:
> CFG_CHANNEL_SA BIT(0)
> CFG_CHANNEL_CMD BIT(1)
> CFG_CHANNEL_RAV BIT(2)
> CFG_CHANNEL_RAC BIT(3)
> CFG_CHANNEL_RACEN BIT(4)
>
> To handle this on the fly, add a structure to describe this and use the
> structure for vc definition.
>
> Signed-off-by: Nishanth Menon <nm@xxxxxx>
You're going to be irritated with me (again), but I changed my mind on
this one.
Initially I thought that this was intentional and that OMAP5+ was going
to have the bit fields in yet a different way, so I wanted to have this
very flexible at a per-channel level. It turns out that this one
channel really is a mutant. Somebody fat-fingered this in Bitwise and
resulted in a single anomaly.
Now that I know this is a single mutant case, I prefer handling it as an
exception (kinda like you did in your original version.)
The RFC/patch below (currently at the tip of voltdm_nm, but only compile
tested) is my version of solving the problem to handle it as an
exception case. What do you think?
Kevin
>From 6df1f45d4b2a732083992e47596c67e6bdd0311f Mon Sep 17 00:00:00 2001
From: Kevin Hilman <khilman@xxxxxx>
Date: Thu, 2 Jun 2011 17:28:13 -0700
Subject: [RFC/PATCH] OMAP3+: PM: VC: handle mutant channel config for OMAP4 MPU channel
On OMAP3+, all VC channels have the the same bitfield ordering for all
VC channels, except the OMAP4 MPU channel. This appears to be a freak
accident as all other VC channel (including OMAP5) have the standard
configuration. Handle the mutant case by adding a per-channel flag
to signal the deformity and handle it during VC init.
Special thanks to Nishanth Menon <nm@xxxxxx> for finding this problem
and for proposing the initial solution.
Cc: Nishanth Menon <nm@xxxxxx>
Signed-off-by: Kevin Hilman <khilman@xxxxxx>
---
arch/arm/mach-omap2/vc.c | 62 +++++++++++++++++++++++++++++--------
arch/arm/mach-omap2/vc.h | 1 +
arch/arm/mach-omap2/vc44xx_data.c | 2 +-
3 files changed, 51 insertions(+), 14 deletions(-)
diff --git a/arch/arm/mach-omap2/vc.c b/arch/arm/mach-omap2/vc.c
index d027864..c4edc62 100644
--- a/arch/arm/mach-omap2/vc.c
+++ b/arch/arm/mach-omap2/vc.c
@@ -10,17 +10,51 @@
#include "prm-regbits-44xx.h"
#include "prm44xx.h"
-/*
- * Channel configuration bits, common for OMAP3 & 4
+/**
+ * struct omap_vc_channel_cfg - describe the cfg_channel bitfield
+ * @sa: bit for slave address
+ * @rav: bit for voltage configuration register
+ * @rac: bit for command configuration register
+ * @racen: enable bit for RAC
+ * @cmd: bit for command value set selection
+ *
+ * Channel configuration bits, common for OMAP3+
* OMAP3 register: PRM_VC_CH_CONF
* OMAP4 register: PRM_VC_CFG_CHANNEL
+ * OMAP5 register: PRM_VC_SMPS_<voltdm>_CONFIG
*/
-#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
+struct omap_vc_channel_cfg {
+ u8 sa;
+ u8 rav;
+ u8 rac;
+ u8 racen;
+ u8 cmd;
+};
+
+static struct omap_vc_channel_cfg vc_default_channel_cfg = {
+ .sa = BIT(0),
+ .rav = BIT(1),
+ .rac = BIT(2),
+ .racen = BIT(3),
+ .cmd = BIT(4),
+};
+
+/*
+ * On OMAP3+, all VC channels have the above default bitfield
+ * configuration, except the OMAP4 MPU channel. This appears
+ * to be a freak accident as every other VC channel has the
+ * default configuration, thus creating a mutant channel config.
+ */
+static struct omap_vc_channel_cfg vc_mutant_channel_cfg = {
+ .sa = BIT(0),
+ .rav = BIT(2),
+ .rac = BIT(3),
+ .racen = BIT(4),
+ .cmd = BIT(1),
+};
+
+static struct omap_vc_channel_cfg *vc_cfg_bits = &vc_default_channel_cfg;
+#define CFG_CHANNEL_MASK 0x1f
/**
* omap_vc_config_channel - configure VC channel to PMIC mappings
@@ -47,7 +81,7 @@ static int omap_vc_config_channel(struct voltagedomain *voltdm)
* All others must stay at zero (see function comment above.)
*/
if (vc->flags & OMAP_VC_CHANNEL_DEFAULT)
- vc->cfg_channel &= CFG_CHANNEL_RACEN;
+ vc->cfg_channel &= vc_cfg_bits->racen;
voltdm->rmw(CFG_CHANNEL_MASK << vc->cfg_channel_sa_shift,
vc->cfg_channel << vc->cfg_channel_sa_shift,
@@ -264,6 +298,8 @@ void __init omap_vc_init_channel(struct voltagedomain *voltdm)
}
vc->cfg_channel = 0;
+ if (vc->flags & OMAP_VC_CHANNEL_CFG_MUTANT)
+ vc_cfg_bits = vc_mutant_channel_cfg;
/* get PMIC/board specific settings */
vc->i2c_slave_addr = voltdm->pmic->i2c_slave_addr;
@@ -275,7 +311,7 @@ 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;
+ vc->cfg_channel |= vc_cfg_bits->sa;
/*
* Configure the PMIC register addresses.
@@ -283,13 +319,13 @@ 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);
- vc->cfg_channel |= CFG_CHANNEL_RAV;
+ vc->cfg_channel |= vc_cfg_bits->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;
+ vc->cfg_channel |= vc_cfg_bits->rac | vc_cfg_bits->racen;
}
/* Set up the on, inactive, retention and off voltage */
@@ -302,7 +338,7 @@ 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;
+ vc->cfg_channel |= vc_cfg_bits->cmd;
/* Channel configuration */
omap_vc_config_channel(voltdm);
diff --git a/arch/arm/mach-omap2/vc.h b/arch/arm/mach-omap2/vc.h
index e7d410c..e16dacf 100644
--- a/arch/arm/mach-omap2/vc.h
+++ b/arch/arm/mach-omap2/vc.h
@@ -64,6 +64,7 @@ struct omap_vc_common {
/* omap_vc_channel.flags values */
#define OMAP_VC_CHANNEL_DEFAULT BIT(0)
+#define OMAP_VC_CHANNEL_CFG_MUTANT BIT(1)
/**
* struct omap_vc_channel - VC per-instance data
diff --git a/arch/arm/mach-omap2/vc44xx_data.c b/arch/arm/mach-omap2/vc44xx_data.c
index 148be18..0a4fc37 100644
--- a/arch/arm/mach-omap2/vc44xx_data.c
+++ b/arch/arm/mach-omap2/vc44xx_data.c
@@ -52,7 +52,7 @@ static const struct omap_vc_common omap4_vc_common = {
/* VC instance data for each controllable voltage line */
struct omap_vc_channel omap4_vc_mpu = {
- .flags = OMAP_VC_CHANNEL_DEFAULT,
+ .flags = OMAP_VC_CHANNEL_DEFAULT | OMAP_VC_CHANNEL_CFG_MUTANT,
.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,
--
1.7.4
--
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