On Tue, Dec 7, 2010 at 9:50 PM, Philip Rakity <prakity@xxxxxxxxxxx> wrote:
>
> On Dec 7, 2010, at 5:49 PM, zhangfei gao wrote:
>
>> On Tue, Dec 7, 2010 at 7:20 PM, Philip Rakity <prakity@xxxxxxxxxxx> wrote:
>>>
>>> From 4f521dd851066e6f65cbf3b866502a2a308eb980 Mon Sep 17 00:00:00 2001
>>> From: Philip Rakity <prakity@xxxxxxxxxxx>
>>> Date: Tue, 7 Dec 2010 09:05:39 -0800
>>> Subject: [PATCH V2] sdhci: support H/W clock gating in Marvell PXA driver
>>>
>>> This code is based on sdhci-pxa in mmc-next on Dec 2, 2010.
>>>
>>> If cpu_is_mmp2() then enable MMC capability MMC_CAP_HW_CLOCK_GATING
>>>
>>> Code may need changing based on the ongoing work on sdhci-pxa but since that
>>> code is NOT in mmc-next better to have something that can work.
>>>
>>> This code tested on Marvell Linux
>>>
>>> Signed-off-by: Philip Rakity <prakity@xxxxxxxxxxx>
>>> Signed-off-by: Mark F. Brown <markb@xxxxxxxxxxx>
>>> ---
>>> drivers/mmc/host/sdhci-pxa.c | 33 +++++++++++++++++++++++++++------
>>> 1 files changed, 27 insertions(+), 6 deletions(-)
>>>
>>> diff --git a/drivers/mmc/host/sdhci-pxa.c b/drivers/mmc/host/sdhci-pxa.c
>>> index 5a61208..5cf47fd 100644
>>> --- a/drivers/mmc/host/sdhci-pxa.c
>>> +++ b/drivers/mmc/host/sdhci-pxa.c
>>> @@ -25,6 +25,7 @@
>>> #include <linux/io.h>
>>> #include <linux/err.h>
>>> #include <plat/sdhci.h>
>>> +#include <mach/cputype.h>
>>> #include "sdhci.h"
>>>
>>> #define DRIVER_NAME "sdhci-pxa"
>>> @@ -46,10 +47,27 @@ struct sdhci_pxa {
>>> * SDHCI core callbacks *
>>> * *
>>> \*****************************************************************************/
>>> +#ifdef CONFIG_MMC_CLKGATE
>>> +static void hardware_clk_gating(struct sdhci_host *host)
>>> +{
>>> + unsigned short tmp;
>>> + int enable;
>>> +
>>> + enable = host->mmc->clk_gated;
>>> + tmp = readw(host->ioaddr + SD_FIFO_PARAM);
>>> +
>>> + if (enable)
>>> + tmp &= ~DIS_PAD_SD_CLK_GATE;
>>> + else
>>> + tmp |= DIS_PAD_SD_CLK_GATE;
>>> +
>>> + writew(tmp, host->ioaddr + SD_FIFO_PARAM);
>>> +}
>>> +#endif
>>> +
>>> static void set_clock(struct sdhci_host *host, unsigned int clock)
>>> {
>>> struct sdhci_pxa *pxa = sdhci_priv(host);
>>> - u32 tmp = 0;
>>>
>>> if (clock == 0) {
>>> if (pxa->clk_enable) {
>>> @@ -58,11 +76,6 @@ static void set_clock(struct sdhci_host *host, unsigned int clock)
>>> }
>>> } else {
>>> if (0 == pxa->clk_enable) {
>>> - if (pxa->pdata->flags & PXA_FLAG_DISABLE_CLOCK_GATING) {
>>> - tmp = readl(host->ioaddr + SD_FIFO_PARAM);
>>> - tmp |= DIS_PAD_SD_CLK_GATE;
>>> - writel(tmp, host->ioaddr + SD_FIFO_PARAM);
>>> - }
>>> clk_enable(pxa->clk);
>>> pxa->clk_enable = 1;
>>> }
>>> @@ -71,6 +84,9 @@ static void set_clock(struct sdhci_host *host, unsigned int clock)
>>>
>>> static struct sdhci_ops sdhci_pxa_ops = {
>>> .set_clock = set_clock,
>>> +#ifdef CONFIG_MMC_CLKGATE
>>> + .platform_hw_clk_gate = hardware_clk_gating,
>>> +#endif
>>> };
>>>
>>> /*****************************************************************************\
>>> @@ -145,6 +161,11 @@ static int __devinit sdhci_pxa_probe(struct platform_device *pdev)
>>> if (pdata->flags & PXA_FLAG_SD_8_BIT_CAPABLE_SLOT)
>>> host->mmc->caps |= MMC_CAP_8_BIT_DATA;
>>>
>>> +#ifdef CONFIG_MMC_CLKGATE
>>> + if (cpu_is_mmp2())
>>> + host->mmc->caps |= MMC_CAP_HW_CLOCK_GATING;
>>> +#endif
>>> +
>>> ret = sdhci_add_host(host);
>>> if (ret) {
>>> dev_err(&pdev->dev, "failed to add host\n");
>>> --
>>> 1.6.0.4
>>>
>> 1. could you pls follow the interface we discussed before in order to
>> prevent the register's difference, .platform_hw_clk_gate could be
>> overwrited and transfered from platform, example send before, like
>> get_ro.
>
> We are not in agreement with your proposed implementation. The callbacks in the
> driver specific code calling callbacks in the arch code makes the code
> difficult to follow.
>
> It would be much simpler to create 3 entries in kConfig
> one for mmp2
> one for pxa910
> one for pxa168
> then factor out the common code. The could then be reused and put it into
> a separate file and linked with the SOC specific code to provide the functionality needed.
> Rather than the approach of moving
> everything into the arch directory.
>
> It is not clear to us that the approach that you are following can handle the differences
> in silicon between the pxa168 and pxa910/mmp2.
>
>
>> 2. we have to fully verify the hardware clk gating internally before
>> sending the code.
>
> code tested under marvell 2.6.32 linux.
Thanks a lot, just wander could sdio be supported, since marvell8787
requires around 10 clock cycles after cmd53 finished.
>
>>>
>>>
>>>
>>> On Dec 7, 2010, at 4:16 PM, Chris Ball wrote:
>>>
>>>> Hi Philip,
>>>>
>>>> On Tue, Dec 07, 2010 at 02:46:25PM -0800, Philip Rakity wrote:
>>>>> 8 bit width support dependency removed. Code applies directly to mmc-next
>>>>> Patches 2/3 and 3/3 unchanged
>>>>
>>>> The submitted patches 2/3 and 3/3 are identical -- is there a separate
>>>> third patch that's unsent so far, or did you mean to send only two?
>>>>
>>>> Thanks,
>>>>
>>>> --
>>>> Chris Ball <cjb@xxxxxxxxxx> <http://printf.net/>
>>>> One Laptop Per Child
>>>> --
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>>>
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>
>
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