On Wed, Aug 11, 2010 at 3:44 AM, zhangfei gao <zhangfei.gao@xxxxxxxxx> wrote:
> On Wed, Aug 11, 2010 at 12:32 AM, Matt Fleming <matt@xxxxxxxxxxxxxxxxx> wrote:
>> On Mon, Aug 09, 2010 at 08:33:16PM +0800, zhangfei gao wrote:
>>>
>>> Thanks for your careful review, in our platform, we use max/min for
>>> the max_div, so miss this modification :(
>>> Update the patch, help review again.
>>
>> What do you mean? Where does max/min come from? It would definitely
>> be best if everybody uses the same code to calculate max_div. Have
>> you tested the max_div changes? Are you now using this patch on
>> your platform or are you still maintaining a patch to do it a
>> different way?
>>
>> If you've got a separate patch and it does this things better
>> than the way we currently do them, get it upstream! :-)
>>
Hi, Matt
Originally, the div step by *2, and in fact the step should be +2.
However in such case, div start from 2 would be more accurate, so
modify to the following.
Though start from 1 is also OK, since >>2 would get the same result.
- for (div = 1;div < 256;div *= 2) {
+ if (host->version >= SDHCI_SPEC_300)
+ max_div = 2046;
+ else
+ max_div = 256;
+
+ if(host->max_clk <= clock)
+ div = 1;
+ for (div = 2; div < max_div; div += 2) {
Thanks
updated patch:
>From b17eb3ca9dd23af63ada240e8f77bdd873e853a7 Mon Sep 17 00:00:00 2001
From: Zhangfei Gao <zgao6@xxxxxxxxxxx>
Date: Fri, 6 Aug 2010 07:10:01 +0800
Subject: [PATCH] sdhc: support 10-bit divided clock Mode
Signed-off-by: Zhangfei Gao <zgao6@xxxxxxxxxxx>
Reviewed-by: Matt Fleming <matt@xxxxxxxxxxxxxxxxx>
---
drivers/mmc/host/sdhci.c | 16 ++++++++++++----
drivers/mmc/host/sdhci.h | 4 ++++
2 files changed, 16 insertions(+), 4 deletions(-)
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 7855121..ccfbc40 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -983,7 +983,7 @@ static void sdhci_finish_command(struct sdhci_host *host)
static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
{
- int div;
+ int div, max_div;
u16 clk;
unsigned long timeout;
@@ -1001,13 +1001,21 @@ static void sdhci_set_clock(struct sdhci_host
*host, unsigned int clock)
if (clock == 0)
goto out;
- for (div = 1;div < 256;div *= 2) {
+ if (host->version >= SDHCI_SPEC_300)
+ max_div = 2046;
+ else
+ max_div = 256;
+
+ if(host->max_clk <= clock)
+ div = 1;
+ for (div = 2; div < max_div; div += 2) {
if ((host->max_clk / div) <= clock)
break;
}
div >>= 1;
- clk = div << SDHCI_DIVIDER_SHIFT;
+ clk = (div & SDHCI_DIV_MASK) << SDHCI_DIVIDER_SHIFT;
+ clk |= ((div & SDHCI_DIV_HI_MASK) >> SDHCI_DIVIDER_SHIFT) <<
SDHCI_DIVIDER_SHIFT_HI;
clk |= SDHCI_CLOCK_INT_EN;
sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
@@ -1707,7 +1715,7 @@ int sdhci_add_host(struct sdhci_host *host)
host->version = sdhci_readw(host, SDHCI_HOST_VERSION);
host->version = (host->version & SDHCI_SPEC_VER_MASK)
>> SDHCI_SPEC_VER_SHIFT;
- if (host->version > SDHCI_SPEC_200) {
+ if (host->version > SDHCI_SPEC_300) {
printk(KERN_ERR "%s: Unknown controller version (%d). "
"You may experience problems.\n", mmc_hostname(mmc),
host->version);
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 036cfae..d7ef7e4 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -86,6 +86,9 @@
#define SDHCI_CLOCK_CONTROL 0x2C
#define SDHCI_DIVIDER_SHIFT 8
+#define SDHCI_DIVIDER_SHIFT_HI 6
+#define SDHCI_DIV_MASK 0xFF
+#define SDHCI_DIV_HI_MASK 0x300
#define SDHCI_CLOCK_CARD_EN 0x0004
#define SDHCI_CLOCK_INT_STABLE 0x0002
#define SDHCI_CLOCK_INT_EN 0x0001
@@ -178,6 +181,7 @@
#define SDHCI_SPEC_VER_SHIFT 0
#define SDHCI_SPEC_100 0
#define SDHCI_SPEC_200 1
+#define SDHCI_SPEC_300 2
struct sdhci_ops;
--
1.7.0.4
From b17eb3ca9dd23af63ada240e8f77bdd873e853a7 Mon Sep 17 00:00:00 2001
From: Zhangfei Gao <zgao6@xxxxxxxxxxx>
Date: Fri, 6 Aug 2010 07:10:01 +0800
Subject: [PATCH] sdhc: support 10-bit divided clock Mode
Signed-off-by: Zhangfei Gao <zgao6@xxxxxxxxxxx>
Reviewed-by: Matt Fleming <matt@xxxxxxxxxxxxxxxxx>
---
drivers/mmc/host/sdhci.c | 16 ++++++++++++----
drivers/mmc/host/sdhci.h | 4 ++++
2 files changed, 16 insertions(+), 4 deletions(-)
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 7855121..ccfbc40 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -983,7 +983,7 @@ static void sdhci_finish_command(struct sdhci_host *host)
static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
{
- int div;
+ int div, max_div;
u16 clk;
unsigned long timeout;
@@ -1001,13 +1001,21 @@ static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
if (clock == 0)
goto out;
- for (div = 1;div < 256;div *= 2) {
+ if (host->version >= SDHCI_SPEC_300)
+ max_div = 2046;
+ else
+ max_div = 256;
+
+ if(host->max_clk <= clock)
+ div = 1;
+ for (div = 2; div < max_div; div += 2) {
if ((host->max_clk / div) <= clock)
break;
}
div >>= 1;
- clk = div << SDHCI_DIVIDER_SHIFT;
+ clk = (div & SDHCI_DIV_MASK) << SDHCI_DIVIDER_SHIFT;
+ clk |= ((div & SDHCI_DIV_HI_MASK) >> SDHCI_DIVIDER_SHIFT) << SDHCI_DIVIDER_SHIFT_HI;
clk |= SDHCI_CLOCK_INT_EN;
sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
@@ -1707,7 +1715,7 @@ int sdhci_add_host(struct sdhci_host *host)
host->version = sdhci_readw(host, SDHCI_HOST_VERSION);
host->version = (host->version & SDHCI_SPEC_VER_MASK)
>> SDHCI_SPEC_VER_SHIFT;
- if (host->version > SDHCI_SPEC_200) {
+ if (host->version > SDHCI_SPEC_300) {
printk(KERN_ERR "%s: Unknown controller version (%d). "
"You may experience problems.\n", mmc_hostname(mmc),
host->version);
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 036cfae..d7ef7e4 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -86,6 +86,9 @@
#define SDHCI_CLOCK_CONTROL 0x2C
#define SDHCI_DIVIDER_SHIFT 8
+#define SDHCI_DIVIDER_SHIFT_HI 6
+#define SDHCI_DIV_MASK 0xFF
+#define SDHCI_DIV_HI_MASK 0x300
#define SDHCI_CLOCK_CARD_EN 0x0004
#define SDHCI_CLOCK_INT_STABLE 0x0002
#define SDHCI_CLOCK_INT_EN 0x0001
@@ -178,6 +181,7 @@
#define SDHCI_SPEC_VER_SHIFT 0
#define SDHCI_SPEC_100 0
#define SDHCI_SPEC_200 1
+#define SDHCI_SPEC_300 2
struct sdhci_ops;
--
1.7.0.4
