Kevin Hilman wrote, on 02/02/2011 04:11 AM:
Shweta Gulati<shweta.gulati@xxxxxx> writes:
From: Thara Gopinath<thara@xxxxxx>
The smartreflex bit on twl4030 needs to be enabled by default irrespective
of whether smartreflex module is enabled on the OMAP side or not.
This is because without this bit enabled the voltage scaling through
vp forceupdate does not function properly on OMAP3.API added
'omap3_twl_set_sr_bit' with parameter to set/clear SR bit. It is cleared
for platforms where voltage is not scaled using vpforceupdate
or vc_bypass Method. In those cases 'omap3_twl_set_sr_bit' is called
from board file, to make sure this bit is not overwritten in
'omap3_twl_init', a flag 'twl_sr_enable'
is added.
As Sanjeev pointed out, the use of 'irrespective' above is confusing, in
fact the whole changelog is kind of confusing.
The changelog states that it has to always be enabled, but then goes on
to describe the situation(s) where it would be disabled.
Here's my rephrasing of how I understand the above changelog
- enable: *always* be enabled
- enable: needed for VP force update
- disable: platforms using VP forced update or VP bypass
-ECONFUSED
Kevin
How about this as the commit log?
The smartreflex bit on twl4030 specifies if the setting of voltage
is done over the I2C_SR path. Given that there are platforms that
do not use I2C_SR path for voltage scaling, a new function
'omap3_twl_set_sr_bit' with parameter to set/clear SR bit has been
provided for flexibility. It is called with appropriate param
for platforms where voltage is not scaled using I2C_SR path
from board file, to make sure this bit is not overwritten in
'omap3_twl_init'.
This patch is based on LO PM Branch and Smartreflex has been
tested on OMAP3430 SDP, OMAP3630 SDP and boot tested on
OMAP2430 SDP.
this belongs into the diffstat.
Attached is a modified version of this patch - i'vent tested it though..
but basically improves the logic a little:
*) made the comments more generic to ensure that this is more of I2C_SR
path as far as TWL is concerned(yes, from OMAP perspective it is vp
forceupdate/bypass), but it is more of an OMAP problem than omap_twl.c
problem.
*) modified the function call sequences to prevent rentry even if board
file calls with various other params
*) shifted to using bool
*) use init and initdata to free up the space once we are done with init
sequence
etc...
Do let me know if this is good enough.
--
Regards,
Nishanth Menon
>From 6474825fd3800f296da6103e198f563938572f67 Mon Sep 17 00:00:00 2001
From: Thara Gopinath <thara@xxxxxx>
Date: Mon, 24 Jan 2011 11:07:26 +0530
Subject: [PATCH] OMAP3: PM: Set/clear T2 bit for Smartreflex on TWL
The smartreflex bit on twl4030 specifies if the setting of voltage
is done over the I2C_SR path. Given that there are platforms that
do not use I2C_SR path for voltage scaling, a new function
'omap3_twl_set_sr_bit' with parameter to set/clear SR bit has been
provided for flexibility. It is called with appropriate param
for platforms where voltage is not scaled using I2C_SR path
from board file, to make sure this bit is not overwritten in
'omap3_twl_init'.
Signed-off-by: Thara Gopinath <thara@xxxxxx>
Signed-off-by: Nishanth Menon <nm@xxxxxx>
Signed-off-by: Shweta Gulati <shweta.gulati@xxxxxx>
---
This patch is based on LO PM Branch and Smartreflex has been
tested on OMAP3430 SDP, OMAP3630 SDP and boot tested on
OMAP2430 SDP.
arch/arm/mach-omap2/omap_twl.c | 60 ++++++++++++++++++++++++++++++++++++++++
arch/arm/mach-omap2/pm.h | 1 +
2 files changed, 61 insertions(+), 0 deletions(-)
diff --git a/arch/arm/mach-omap2/omap_twl.c b/arch/arm/mach-omap2/omap_twl.c
index 00e1d2b..8b24839 100644
--- a/arch/arm/mach-omap2/omap_twl.c
+++ b/arch/arm/mach-omap2/omap_twl.c
@@ -59,8 +59,15 @@
static bool is_offset_valid;
static u8 smps_offset;
+/*
+ * Flag to ensure Smartreflex bit in TWL
+ * being cleared in board file is not overwritten.
+ */
+static bool __initdata twl_sr_enable_autoinit;
+#define TWL4030_DCDC_GLOBAL_CFG 0x06
#define REG_SMPS_OFFSET 0xE0
+#define SMARTREFLEX_ENABLE BIT(3)
static unsigned long twl4030_vsel_to_uv(const u8 vsel)
{
@@ -269,6 +276,18 @@ int __init omap3_twl_init(void)
omap3_core_volt_info.vp_vddmax = OMAP3630_VP2_VLIMITTO_VDDMAX;
}
+ /*
+ * The smartreflex bit on twl4030 specifies if the setting of voltage
+ * is done over the I2C_SR path. Since this setting is independent of
+ * the actual usage of smartreflex AVS module, we enable TWL SR bit
+ * by default irrespective of whether smartreflex AVS module is enabled
+ * on the OMAP side or not. This is because without this bit enabled,
+ * the voltage scaling through vp forceupdate/bypass mechanism of
+ * voltage scaling will not function on TWL over I2C_SR.
+ */
+ if (!twl_sr_enable_autoinit)
+ omap3_twl_set_sr_bit(true);
+
voltdm = omap_voltage_domain_lookup("mpu");
omap_voltage_register_pmic(voltdm, &omap3_mpu_volt_info);
@@ -277,3 +296,44 @@ int __init omap3_twl_init(void)
return 0;
}
+
+/**
+ * omap3_twl_set_sr_bit() - Set/Clear SR bit on TWL
+ * @enable: enable SR mode in twl or not
+ *
+ * If 'enable' is true, enables Smartreflex bit on TWL 4030 to make sure
+ * voltage scaling through OMAP SR works. Else, the smartreflex bit
+ * on twl4030 is cleared as there are platforms which use OMAP3 and T2 but
+ * use Synchronized Scaling Hardware Strategy (ENABLE_VMODE=1) and Direct
+ * Strategy Software Scaling Mode (ENABLE_VMODE=0), for setting the voltages,
+ * in those scenarios this bit is to be cleared (enable = false).
+ *
+ * Returns 0 on sucess, error is returned if I2C read/write fails.
+ */
+int __init omap3_twl_set_sr_bit(bool enable)
+{
+ u8 temp;
+ int ret;
+ if (twl_sr_enable_autoinit)
+ pr_warning("%s: unexpected multiple calls\n", __func__);
+
+ ret = twl_i2c_read_u8(TWL4030_MODULE_PM_RECEIVER, &temp,
+ TWL4030_DCDC_GLOBAL_CFG);
+ if (ret)
+ goto err;
+
+ if (enable)
+ temp |= SMARTREFLEX_ENABLE;
+ else
+ temp &= ~SMARTREFLEX_ENABLE;
+
+ ret = twl_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER, temp,
+ TWL4030_DCDC_GLOBAL_CFG);
+ if (!ret) {
+ twl_sr_enable_autoinit = true;
+ return 0;
+ }
+err:
+ pr_err("%s: Error access to TWL4030 (%d)\n", __func__, ret);
+ return ret;
+}
diff --git a/arch/arm/mach-omap2/pm.h b/arch/arm/mach-omap2/pm.h
index 1c1b0ab..2f4f2f1 100644
--- a/arch/arm/mach-omap2/pm.h
+++ b/arch/arm/mach-omap2/pm.h
@@ -127,6 +127,7 @@ static inline void omap_enable_smartreflex_on_init(void) {}
#ifdef CONFIG_TWL4030_CORE
extern int omap3_twl_init(void);
extern int omap4_twl_init(void);
+extern int omap3_twl_set_sr_bit(bool);
#else
static inline int omap3_twl_init(void)
{
--
1.7.1
