linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH] davinci: MMC: Adding support for 8bit MMC cards
@ 2009-12-28 12:04 Vipin Bhandari
  2009-12-30 11:00 ` Sergei Shtylyov
  0 siblings, 1 reply; 3+ messages in thread
From: Vipin Bhandari @ 2009-12-28 12:04 UTC (permalink / raw)
  To: linux-kernel
  Cc: davinci-linux-open-source, drzeus-mmc, david-b, akpm, Vipin Bhandari

This patch adds the support for 8bit MMC cards. The controller
data width is configurable depending on the wires setting in the
platform data structure.

MMC 8bit is tested on OMAPL137 and MMC 4bit is tested on OMAPL138 EVM.

Signed-off-by: Vipin Bhandari <vipin.bhandari@ti.com>
---

 This patch has been generated against latest Linus's kernel.

 drivers/mmc/host/davinci_mmc.c |   45 +++++++++++++++++++++++++++++++--------
 1 files changed, 35 insertions(+), 10 deletions(-)

diff --git a/drivers/mmc/host/davinci_mmc.c b/drivers/mmc/host/davinci_mmc.c
index dd45e7c..3bd0ba2 100644
--- a/drivers/mmc/host/davinci_mmc.c
+++ b/drivers/mmc/host/davinci_mmc.c
@@ -73,6 +73,7 @@
 /* DAVINCI_MMCCTL definitions */
 #define MMCCTL_DATRST         (1 << 0)
 #define MMCCTL_CMDRST         (1 << 1)
+#define MMCCTL_WIDTH_8_BIT    (1 << 8)
 #define MMCCTL_WIDTH_4_BIT    (1 << 2)
 #define MMCCTL_DATEG_DISABLED (0 << 6)
 #define MMCCTL_DATEG_RISING   (1 << 6)
@@ -791,22 +792,42 @@ static void calculate_clk_divider(struct mmc_host *mmc, struct mmc_ios *ios)
 
 static void mmc_davinci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 {
-	unsigned int mmc_pclk = 0;
 	struct mmc_davinci_host *host = mmc_priv(mmc);
 
-	mmc_pclk = host->mmc_input_clk;
 	dev_dbg(mmc_dev(host->mmc),
 		"clock %dHz busmode %d powermode %d Vdd %04x\n",
 		ios->clock, ios->bus_mode, ios->power_mode,
 		ios->vdd);
-	if (ios->bus_width == MMC_BUS_WIDTH_4) {
-		dev_dbg(mmc_dev(host->mmc), "Enabling 4 bit mode\n");
-		writel(readl(host->base + DAVINCI_MMCCTL) | MMCCTL_WIDTH_4_BIT,
-			host->base + DAVINCI_MMCCTL);
-	} else {
-		dev_dbg(mmc_dev(host->mmc), "Disabling 4 bit mode\n");
-		writel(readl(host->base + DAVINCI_MMCCTL) & ~MMCCTL_WIDTH_4_BIT,
+
+	switch (ios->bus_width) {
+	case MMC_BUS_WIDTH_8:
+		dev_dbg(mmc_dev(host->mmc), "Enabling 8 bit mode\n");
+		writel((readl(host->base + DAVINCI_MMCCTL) &
+			~MMCCTL_WIDTH_4_BIT) | MMCCTL_WIDTH_8_BIT,
 			host->base + DAVINCI_MMCCTL);
+		break;
+	case MMC_BUS_WIDTH_4:
+		dev_dbg(mmc_dev(host->mmc), "Enabling 4 bit mode\n");
+		if (host->version == MMC_CTLR_VERSION_2)
+			writel((readl(host->base + DAVINCI_MMCCTL) &
+				~MMCCTL_WIDTH_8_BIT) | MMCCTL_WIDTH_4_BIT,
+				host->base + DAVINCI_MMCCTL);
+		else
+			writel(readl(host->base + DAVINCI_MMCCTL) |
+				MMCCTL_WIDTH_4_BIT,
+				host->base + DAVINCI_MMCCTL);
+		break;
+	case MMC_BUS_WIDTH_1:
+		dev_dbg(mmc_dev(host->mmc), "Enabling 1 bit mode\n");
+		if (host->version == MMC_CTLR_VERSION_2)
+			writel(readl(host->base + DAVINCI_MMCCTL) &
+				~(MMCCTL_WIDTH_8_BIT | MMCCTL_WIDTH_4_BIT),
+				host->base + DAVINCI_MMCCTL);
+		else
+			writel(readl(host->base + DAVINCI_MMCCTL) &
+				~MMCCTL_WIDTH_4_BIT,
+				host->base + DAVINCI_MMCCTL);
+		break;
 	}
 
 	calculate_clk_divider(mmc, ios);
@@ -1189,10 +1210,14 @@ static int __init davinci_mmcsd_probe(struct platform_device *pdev)
 
 	/* REVISIT:  someday, support IRQ-driven card detection.  */
 	mmc->caps |= MMC_CAP_NEEDS_POLL;
+	mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY;
 
-	if (!pdata || pdata->wires == 4 || pdata->wires == 0)
+	if (pdata && (pdata->wires == 4 || pdata->wires == 0))
 		mmc->caps |= MMC_CAP_4_BIT_DATA;
 
+	if (pdata && (pdata->wires == 8))
+		mmc->caps |= (MMC_CAP_4_BIT_DATA | MMC_CAP_8_BIT_DATA);
+
 	host->version = pdata->version;
 
 	mmc->ops = &mmc_davinci_ops;
-- 
1.5.6


^ permalink raw reply related	[flat|nested] 3+ messages in thread
* Re: [PATCH] davinci: MMC: Adding support for 8bit MMC cards
  2009-12-28 12:04 [PATCH] davinci: MMC: Adding support for 8bit MMC cards Vipin Bhandari
@ 2009-12-30 11:00 ` Sergei Shtylyov
  2010-01-06  0:04   ` Kevin Hilman
  0 siblings, 1 reply; 3+ messages in thread
From: Sergei Shtylyov @ 2009-12-30 11:00 UTC (permalink / raw)
  To: Vipin Bhandari; +Cc: linux-kernel, davinci-linux-open-source, akpm, drzeus-mmc

Hello.

Vipin Bhandari wrote:

   [Re-replying to all, as I only replied to Vipin the first time.]

> This patch adds the support for 8bit MMC cards. The controller
> data width is configurable depending on the wires setting in the
> platform data structure.
>
> MMC 8bit is tested on OMAPL137 and MMC 4bit is tested on OMAPL138 EVM.
>
> Signed-off-by: Vipin Bhandari <vipin.bhandari@ti.com>
>   

   This has been done by MV in the internal tree but as you code is 
significantly differenet from that one, I'm not asking you about the 
missing MV signoffs...

> diff --git a/drivers/mmc/host/davinci_mmc.c 
> b/drivers/mmc/host/davinci_mmc.c
> index dd45e7c..3bd0ba2 100644
> --- a/drivers/mmc/host/davinci_mmc.c
> +++ b/drivers/mmc/host/davinci_mmc.c
> @@ -73,6 +73,7 @@
>  /* DAVINCI_MMCCTL definitions */
>  #define MMCCTL_DATRST         (1 << 0)
>  #define MMCCTL_CMDRST         (1 << 1)
> +#define MMCCTL_WIDTH_8_BIT    (1 << 8)
>  #define MMCCTL_WIDTH_4_BIT    (1 << 2)
>  #define MMCCTL_DATEG_DISABLED (0 << 6)
>  #define MMCCTL_DATEG_RISING   (1 << 6)
> @@ -791,22 +792,42 @@ static void calculate_clk_divider(struct 
> mmc_host *mmc, struct mmc_ios *ios)
>  
>  static void mmc_davinci_set_ios(struct mmc_host *mmc, struct mmc_ios 
> *ios)
>  {
> -    unsigned int mmc_pclk = 0;
>      struct mmc_davinci_host *host = mmc_priv(mmc);
>  
> -    mmc_pclk = host->mmc_input_clk;
>      dev_dbg(mmc_dev(host->mmc),
>          "clock %dHz busmode %d powermode %d Vdd %04x\n",
>          ios->clock, ios->bus_mode, ios->power_mode,
>          ios->vdd);
> -    if (ios->bus_width == MMC_BUS_WIDTH_4) {
> -        dev_dbg(mmc_dev(host->mmc), "Enabling 4 bit mode\n");
> -        writel(readl(host->base + DAVINCI_MMCCTL) | MMCCTL_WIDTH_4_BIT,
> -            host->base + DAVINCI_MMCCTL);
> -    } else {
> -        dev_dbg(mmc_dev(host->mmc), "Disabling 4 bit mode\n");
> -        writel(readl(host->base + DAVINCI_MMCCTL) & ~MMCCTL_WIDTH_4_BIT,
> +
> +    switch (ios->bus_width) {
> +    case MMC_BUS_WIDTH_8:
> +        dev_dbg(mmc_dev(host->mmc), "Enabling 8 bit mode\n");
> +        writel((readl(host->base + DAVINCI_MMCCTL) &
> +            ~MMCCTL_WIDTH_4_BIT) | MMCCTL_WIDTH_8_BIT,
>              host->base + DAVINCI_MMCCTL);
> +        break;
> +    case MMC_BUS_WIDTH_4:
> +        dev_dbg(mmc_dev(host->mmc), "Enabling 4 bit mode\n");
> +        if (host->version == MMC_CTLR_VERSION_2)
> +            writel((readl(host->base + DAVINCI_MMCCTL) &
> +                ~MMCCTL_WIDTH_8_BIT) | MMCCTL_WIDTH_4_BIT,
> +                host->base + DAVINCI_MMCCTL);
> +        else
> +            writel(readl(host->base + DAVINCI_MMCCTL) |
> +                MMCCTL_WIDTH_4_BIT,
> +                host->base + DAVINCI_MMCCTL);
>   

   I don't think it makes sense to check for host->version just to not 
clear the bit which is reserved for original DaVinci. There's nothing 
criminal in clearing a reserved bit, so I'm suggesting that you remove 
the check.

> +        break;
> +    case MMC_BUS_WIDTH_1:
> +        dev_dbg(mmc_dev(host->mmc), "Enabling 1 bit mode\n");
> +        if (host->version == MMC_CTLR_VERSION_2)
> +            writel(readl(host->base + DAVINCI_MMCCTL) &
> +                ~(MMCCTL_WIDTH_8_BIT | MMCCTL_WIDTH_4_BIT),
> +                host->base + DAVINCI_MMCCTL);
> +        else
> +            writel(readl(host->base + DAVINCI_MMCCTL) &
> +                ~MMCCTL_WIDTH_4_BIT,
> +                host->base + DAVINCI_MMCCTL);
>   

   Same comment here...

> +        break;
>   

   It'll result less code if you read/write the register only once -- 
before/after the *switch* statement respectively.

>      }
>  
>      calculate_clk_divider(mmc, ios);
> @@ -1189,10 +1210,14 @@ static int __init davinci_mmcsd_probe(struct 
> platform_device *pdev)
>  
>      /* REVISIT:  someday, support IRQ-driven card detection.  */
>      mmc->caps |= MMC_CAP_NEEDS_POLL;
> +    mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY;
>   

    Does this flag have to do with the bus width at all? :-/

WBR, Sergei



^ permalink raw reply	[flat|nested] 3+ messages in thread
* Re: [PATCH] davinci: MMC: Adding support for 8bit MMC cards
  2009-12-30 11:00 ` Sergei Shtylyov
@ 2010-01-06  0:04   ` Kevin Hilman
  0 siblings, 0 replies; 3+ messages in thread
From: Kevin Hilman @ 2010-01-06  0:04 UTC (permalink / raw)
  To: Sergei Shtylyov
  Cc: Vipin Bhandari, linux-kernel, davinci-linux-open-source, akpm,
	drzeus-mmc

Sergei Shtylyov <sshtylyov@ru.mvista.com> writes:

> Hello.
>
> Vipin Bhandari wrote:
>
>   [Re-replying to all, as I only replied to Vipin the first time.]
>
>> This patch adds the support for 8bit MMC cards. The controller
>> data width is configurable depending on the wires setting in the
>> platform data structure.
>>
>> MMC 8bit is tested on OMAPL137 and MMC 4bit is tested on OMAPL138 EVM.
>>
>> Signed-off-by: Vipin Bhandari <vipin.bhandari@ti.com>
>>   
>
>   This has been done by MV in the internal tree but as you code is
> significantly differenet from that one, I'm not asking you about the
> missing MV signoffs...
>
>> diff --git a/drivers/mmc/host/davinci_mmc.c
>> b/drivers/mmc/host/davinci_mmc.c
>> index dd45e7c..3bd0ba2 100644
>> --- a/drivers/mmc/host/davinci_mmc.c
>> +++ b/drivers/mmc/host/davinci_mmc.c
>> @@ -73,6 +73,7 @@
>>  /* DAVINCI_MMCCTL definitions */
>>  #define MMCCTL_DATRST         (1 << 0)
>>  #define MMCCTL_CMDRST         (1 << 1)
>> +#define MMCCTL_WIDTH_8_BIT    (1 << 8)
>>  #define MMCCTL_WIDTH_4_BIT    (1 << 2)
>>  #define MMCCTL_DATEG_DISABLED (0 << 6)
>>  #define MMCCTL_DATEG_RISING   (1 << 6)
>> @@ -791,22 +792,42 @@ static void calculate_clk_divider(struct
>> mmc_host *mmc, struct mmc_ios *ios)
>>   static void mmc_davinci_set_ios(struct mmc_host *mmc, struct
>> mmc_ios *ios)
>>  {
>> -    unsigned int mmc_pclk = 0;
>>      struct mmc_davinci_host *host = mmc_priv(mmc);
>>  -    mmc_pclk = host->mmc_input_clk;
>>      dev_dbg(mmc_dev(host->mmc),
>>          "clock %dHz busmode %d powermode %d Vdd %04x\n",
>>          ios->clock, ios->bus_mode, ios->power_mode,
>>          ios->vdd);
>> -    if (ios->bus_width == MMC_BUS_WIDTH_4) {
>> -        dev_dbg(mmc_dev(host->mmc), "Enabling 4 bit mode\n");
>> -        writel(readl(host->base + DAVINCI_MMCCTL) | MMCCTL_WIDTH_4_BIT,
>> -            host->base + DAVINCI_MMCCTL);
>> -    } else {
>> -        dev_dbg(mmc_dev(host->mmc), "Disabling 4 bit mode\n");
>> -        writel(readl(host->base + DAVINCI_MMCCTL) & ~MMCCTL_WIDTH_4_BIT,
>> +
>> +    switch (ios->bus_width) {
>> +    case MMC_BUS_WIDTH_8:
>> +        dev_dbg(mmc_dev(host->mmc), "Enabling 8 bit mode\n");
>> +        writel((readl(host->base + DAVINCI_MMCCTL) &
>> +            ~MMCCTL_WIDTH_4_BIT) | MMCCTL_WIDTH_8_BIT,
>>              host->base + DAVINCI_MMCCTL);
>> +        break;
>> +    case MMC_BUS_WIDTH_4:
>> +        dev_dbg(mmc_dev(host->mmc), "Enabling 4 bit mode\n");
>> +        if (host->version == MMC_CTLR_VERSION_2)
>> +            writel((readl(host->base + DAVINCI_MMCCTL) &
>> +                ~MMCCTL_WIDTH_8_BIT) | MMCCTL_WIDTH_4_BIT,
>> +                host->base + DAVINCI_MMCCTL);
>> +        else
>> +            writel(readl(host->base + DAVINCI_MMCCTL) |
>> +                MMCCTL_WIDTH_4_BIT,
>> +                host->base + DAVINCI_MMCCTL);
>>   
>
>   I don't think it makes sense to check for host->version just to not
> clear the bit which is reserved for original DaVinci. There's nothing
> criminal in clearing a reserved bit, so I'm suggesting that you remove
> the check.

There's nothing criminal... yet... until some new version of the
controller uses that bit for something else.  I think it's always best
to not touch reserved bits unless there is a good, well tested, reason
not to, such as performance etc.

Kevin


>> +        break;
>> +    case MMC_BUS_WIDTH_1:
>> +        dev_dbg(mmc_dev(host->mmc), "Enabling 1 bit mode\n");
>> +        if (host->version == MMC_CTLR_VERSION_2)
>> +            writel(readl(host->base + DAVINCI_MMCCTL) &
>> +                ~(MMCCTL_WIDTH_8_BIT | MMCCTL_WIDTH_4_BIT),
>> +                host->base + DAVINCI_MMCCTL);
>> +        else
>> +            writel(readl(host->base + DAVINCI_MMCCTL) &
>> +                ~MMCCTL_WIDTH_4_BIT,
>> +                host->base + DAVINCI_MMCCTL);
>>   
>
>   Same comment here...
>
>> +        break;
>>   
>
>   It'll result less code if you read/write the register only once -- 
> before/after the *switch* statement respectively.
>
>>      }
>>       calculate_clk_divider(mmc, ios);
>> @@ -1189,10 +1210,14 @@ static int __init davinci_mmcsd_probe(struct
>> platform_device *pdev)
>>       /* REVISIT:  someday, support IRQ-driven card detection.  */
>>      mmc->caps |= MMC_CAP_NEEDS_POLL;
>> +    mmc->caps |= MMC_CAP_WAIT_WHILE_BUSY;
>>   
>
>    Does this flag have to do with the bus width at all? :-/
>
> WBR, Sergei
>
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/

^ permalink raw reply	[flat|nested] 3+ messages in thread
end of thread, other threads:[~2010-01-06  0:12 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2009-12-28 12:04 [PATCH] davinci: MMC: Adding support for 8bit MMC cards Vipin Bhandari
2009-12-30 11:00 ` Sergei Shtylyov
2010-01-06  0:04   ` Kevin Hilman

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).