On Mon, Dec 6, 2010 at 10:10 PM, Philip Rakity <prakity@xxxxxxxxxxx> wrote:
>
> On Dec 6, 2010, at 4:15 AM, Zhangfei Gao wrote:
>
>> From f2194b46c2c3ded86009d36a4a8b4eebb7d0b9eb Mon Sep 17 00:00:00 2001
>> From: Zhangfei Gao <zhangfei.gao@xxxxxxxxxxx>
>> Date: Fri, 3 Dec 2010 07:21:15 -0500
>> Subject: [PATCH] mmc: sdhci support emmc ddr50 mode
>>
>> 1. spec 3.0 does not claim support 1.2v ddr mode
>> 2. Call back function set_power is added, since some controller count
>> on external pmic to provide power
>>
>> Signed-off-by: Zhangfei Gao <zhangfei.gao@xxxxxxxxxxx>
>> ---
>> drivers/mmc/core/core.c | 8 ++++++++
>> drivers/mmc/host/sdhci.c | 36 +++++++++++++++++++++++++++++++++++-
>> drivers/mmc/host/sdhci.h | 14 ++++++++++++--
>> include/linux/mmc/mmc.h | 1 +
>> include/linux/mmc/sdhci.h | 2 ++
>> 5 files changed, 58 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
>> index 8bf542c..8f172cd 100644
>> --- a/drivers/mmc/core/core.c
>> +++ b/drivers/mmc/core/core.c
>> @@ -1573,6 +1573,14 @@ void mmc_rescan(struct work_struct *work)
>> */
>> err = mmc_send_op_cond(host, 0, &ocr);
>> if (!err) {
>> + if ((ocr & MMC_CARD_1_8V)
>> + && (host->ocr_avail & MMC_CARD_1_8V)) {
>> + /* switch voltage to 1.8v */
>> + mmc_power_off(host);
>> + host->ocr = ocr & host->ocr_avail;
>> + mmc_power_up(host);
>> + }
>> +
>
> is the 1.2v case missing ?
ocr does not support 1.2.
>
> /*
> * Mask off any voltages we don't support and select
> * the lowest voltage
> */
> u32 mmc_select_voltage(struct mmc_host *host, u32 ocr)
>
> Doesn't this code already handle the voltage correctly ?
mmc_select_voltage can not meet the requirement, if switch voltage,
power down and power up is needed, time delay is required waiting for
voltage to be stable.
>
>
>> if (mmc_attach_mmc(host, ocr))
>> mmc_power_off(host);
>> goto out;
>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>> index a25db42..b7ad2f6 100644
>> --- a/drivers/mmc/host/sdhci.c
>> +++ b/drivers/mmc/host/sdhci.c
>> @@ -982,6 +982,22 @@ static void sdhci_finish_command(struct sdhci_host *host)
>> host->cmd = NULL;
>> }
>>
>> +static void sdhci_set_ddr(struct sdhci_host *host, unsigned int ddr)
>> +{
>> + u16 con;
>> +
>> + if (ddr == MMC_SDR_MODE)
>> + return;
>> +
>> + con = sdhci_readw(host, SDHCI_HOST_CONTROL2);
>> + if (con & SDHCI_CTRL2_1_8V) {
>> + con &= ~SDHCI_CTRL2_UHS_MASK;
>> + if (ddr & MMC_1_8V_DDR_MODE)
>> + con |= SDHCI_CTRL2_DDR50;
>> + sdhci_writew(host, con, SDHCI_HOST_CONTROL2);
>> + }
>> +}
>> +
>
>
> The host controller should not enable the CAP if 1.8V is not supported. DDR should not be
> invoked if CAP is not set. Thus
set_ddr is called with para ddr, it would not enter here if CAP is not set.
>
>> + if (con & SDHCI_CTRL2_1_8V) {
>
> and
>> + if (ddr & MMC_1_8V_DDR_MODE)
>
> are not needed.
>
> This code should move to driver specific function since tuning may be done on some systems and
> some systems (not mmp2) may need to delay the 5ms for voltage to be stable. Would prefer a
> host->ops callback.
5ms is considered in power up, that's the reason not put in set_ios
with call back.
>
>> static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
>> {
>> int div;
>> @@ -1080,6 +1096,17 @@ static void sdhci_set_power(struct sdhci_host
>> *host, unsigned short power)
>> return;
>> }
>>
>> + if (pwr == SDHCI_POWER_180) {
>> + u16 con;
>> +
>> + con = sdhci_readw(host, SDHCI_HOST_CONTROL2);
>> + con |= SDHCI_CTRL2_1_8V;
>> + sdhci_writew(host, con, SDHCI_HOST_CONTROL2);
>> +
>> + if (host->ops->set_power)
>> + host->ops->set_power(host, pwr);
>> + }
>> +
>
> This code should be moved to sdhci_set_ddr (aboe). Not needed if voltage is 1.8v and card
> is not running ddr.
No defect to set SDHCI_CTRL2_1_8V if choose 1.8v.
>
>> /*
>> * Spec says that we should clear the power reg before setting
>> * a new value. Some controllers don't seem to like this though.
>> @@ -1176,6 +1203,7 @@ static void sdhci_set_ios(struct mmc_host *mmc,
>> struct mmc_ios *ios)
>> }
>>
>> sdhci_set_clock(host, ios->clock);
>> + sdhci_set_ddr(host, ios->ddr);
>>
>> if (ios->power_mode == MMC_POWER_OFF)
>> sdhci_set_power(host, -1);
>> @@ -1736,7 +1764,7 @@ EXPORT_SYMBOL_GPL(sdhci_alloc_host);
>> int sdhci_add_host(struct sdhci_host *host)
>> {
>> struct mmc_host *mmc;
>> - unsigned int caps;
>> + unsigned int caps, caps_h;
>> int ret;
>>
>> WARN_ON(host == NULL);
>> @@ -1761,6 +1789,12 @@ int sdhci_add_host(struct sdhci_host *host)
>>
>> caps = (host->quirks & SDHCI_QUIRK_MISSING_CAPS) ? host->caps :
>> sdhci_readl(host, SDHCI_CAPABILITIES);
>> + caps_h = sdhci_readl(host, SDHCI_CAPABILITIES_H);
>> +
>> + if (caps & SDHCI_CAN_VDD_180) {
>> + if (caps_h & SDHCI_CAN_SDR50)
>> + mmc->caps |= (MMC_CAP_1_8V_DDR);
>> + }
>>
>> if (host->quirks & SDHCI_QUIRK_FORCE_DMA)
>> host->flags |= SDHCI_USE_SDMA;
>> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
>> index b689cc6..28c460a 100644
>> --- a/drivers/mmc/host/sdhci.h
>> +++ b/drivers/mmc/host/sdhci.h
>> @@ -144,7 +144,14 @@
>>
>> #define SDHCI_ACMD12_ERR 0x3C
>>
>> -/* 3E-3F reserved */
>> +#define SDHCI_HOST_CONTROL2 0x3E
>> +#define SDHCI_CTRL2_UHS_MASK 0x0007
>> +#define SDHCI_CTRL2_SDR12 0x0000
>> +#define SDHCI_CTRL2_SDR25 0x0001
>> +#define SDHCI_CTRL2_SDR50 0x0002
>> +#define SDHCI_CTRL2_SDR104 0x0003
>> +#define SDHCI_CTRL2_DDR50 0x0004
>> +#define SDHCI_CTRL2_1_8V 0x0008
>>
>> #define SDHCI_CAPABILITIES 0x40
>> #define SDHCI_TIMEOUT_CLK_MASK 0x0000003F
>> @@ -165,7 +172,10 @@
>> #define SDHCI_CAN_VDD_180 0x04000000
>> #define SDHCI_CAN_64BIT 0x10000000
>>
>> -/* 44-47 reserved for more caps */
>> +#define SDHCI_CAPABILITIES_H 0x44
>> +#define SDHCI_CAN_SDR50 0x00000001
>> +#define SDHCI_CAN_SDR104 0x00000002
>> +#define SDHCI_CAN_DDR50 0x00000004
>>
>> #define SDHCI_MAX_CURRENT 0x48
>>
>> diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
>> index 956fbd8..bd09b19 100644
>> --- a/include/linux/mmc/mmc.h
>> +++ b/include/linux/mmc/mmc.h
>> @@ -202,6 +202,7 @@ struct _mmc_csd {
>> * OCR bits are mostly in host.h
>> */
>> #define MMC_CARD_BUSY 0x80000000 /* Card Power up status bit */
>> +#define MMC_CARD_1_8V 0x00000080 /* Card 1.70-1.95V support bit */
>>
>> /*
>> * Card Command Classes (CCC)
>> diff --git a/include/linux/mmc/sdhci.h b/include/linux/mmc/sdhci.h
>> index 86e8380..57bcda9 100644
>> --- a/include/linux/mmc/sdhci.h
>> +++ b/include/linux/mmc/sdhci.h
>> @@ -163,6 +163,8 @@ struct sdhci_ops {
>> void (*platform_send_init_74_clocks)(struct sdhci_host *host,
>> u8 power_mode);
>> unsigned int (*get_ro)(struct sdhci_host *host);
>> + unsigned int (*set_power)(struct sdhci_host *host,
>> + unsigned short power);
>> };
>>
>>
>> --
>> 1.7.0.4
>>
>> Update the condition of voltage switch.
>> + if ((ocr & MMC_CARD_1_8V)
>> + && (host->ocr_avail & MMC_CARD_1_8V)) {
>> + /* switch voltage to 1.8v */
>>
>> Any comments are welcome.
>> --
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>
>
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