shweta gulati wrote, on 01/19/2011 11:07 AM:
could we improve $subject?
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. There are two
APIs being added 'omap3_twl_enable_sr' to set SR bit and other API
'omap3_twl_disable_sr' to disable SR bit for platforms where voltage
is not scaled using vpforceupdate or vc_bypass Method.
I cant see how disable_sr is usable, further as discussed in
http://marc.info/?l=linux-omap&m=129424774929498&w=2 we decided to
introduce api *if needed*. does any one need it?
This patch is based on LO PM Branch and Smartreflex has been
tested on OMAP3430 SDP, OMAP3630 SDP and boot tested on
OMAP2430 SDP.
Signed-off-by: Shweta Gulati<shweta.gulati@xxxxxx>
Signed-off-by: Thara Gopinath<thara@xxxxxx>
---
arch/arm/mach-omap2/omap_twl.c | 46 ++++++++++++++++++++++++++++++++++++++++
arch/arm/mach-omap2/pm.h | 2 +
2 files changed, 48 insertions(+), 0 deletions(-)
diff --git a/arch/arm/mach-omap2/omap_twl.c b/arch/arm/mach-omap2/omap_twl.c
index 00e1d2b..5b3ca56 100644
--- a/arch/arm/mach-omap2/omap_twl.c
+++ b/arch/arm/mach-omap2/omap_twl.c
@@ -60,7 +60,9 @@
static bool is_offset_valid;
static u8 smps_offset;
+#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 +271,15 @@ int __init omap3_twl_init(void)
omap3_core_volt_info.vp_vddmax = OMAP3630_VP2_VLIMITTO_VDDMAX;
}
+ /*
+ * 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.
+ */
+ omap3_twl_enable_sr();
I am a bit lost:omap3_twl_init is called from pm.c
omap2_common_pm_late_init right? as per
http://marc.info/?l=linux-omap&m=129424774929498&w=2
we could optionally override this bit from board file using some api -
with this being done in pm_late_init, what chance does the board file
have to do something else?
+
voltdm = omap_voltage_domain_lookup("mpu");
omap_voltage_register_pmic(voltdm,&omap3_mpu_volt_info);
@@ -277,3 +288,38 @@ int __init omap3_twl_init(void)
return 0;
}
+
+/*
+ * The smartreflex bit on twl4030 is enabled in twl_init
+ * but 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 of T2, in those scenarios this bit
+ * is to be cleared.
+ */
please read Documentation/kernel-doc-nano-HOWTO.txt line 54 to see how
to use function comment header
+void omap3_twl_disable_sr()
a) why is this not returning int? i2c reads and writes can fail.
b) there is no usage of this function - why have it?
+{
+ u8 temp;
+
+ twl_i2c_read_u8(TWL4030_MODULE_PM_RECEIVER,&temp,
+ TWL4030_DCDC_GLOBAL_CFG);
+ temp&= ~SMARTREFLEX_ENABLE;
+ twl_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER, temp,
+ TWL4030_DCDC_GLOBAL_CFG);
+}
+
+/*
+ * To enable Smartreflex bit on TWl 4030 to make sure
+ * voltage scaling through Vp forceupdate works.
+ */
+
and here.
+void omap3_twl_enable_sr()
a) __init?
b) why is this not returning int? i2c reads and writes can fail.
+{
+ u8 temp;
+
+ twl_i2c_read_u8(TWL4030_MODULE_PM_RECEIVER,&temp,
+ TWL4030_DCDC_GLOBAL_CFG);
+ temp |= SMARTREFLEX_ENABLE;
+ twl_i2c_write_u8(TWL4030_MODULE_PM_RECEIVER, temp,
+ TWL4030_DCDC_GLOBAL_CFG);
+}
diff --git a/arch/arm/mach-omap2/pm.h b/arch/arm/mach-omap2/pm.h
index 704766b..8500356 100644
--- a/arch/arm/mach-omap2/pm.h
+++ b/arch/arm/mach-omap2/pm.h
@@ -127,6 +127,8 @@ 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 void omap3_twl_disable_sr(void);
+extern void omap3_twl_enable_sr(void);
#else
static inline int omap3_twl_init(void)
{
--
Regards,
Nishanth Menon
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