Resend as plain test -- with additional comments.
On Dec 21, 2010, at 4:37 AM, zhangfei gao wrote:
> v3: sync to mmc-next
>
> Emmc speed could double if using ddr50 mode, help check
>
> From 895c3d15a200d5f5803f992dab46ff114ad26f90 Mon Sep 17 00:00:00 2001
> From: Zhangfei Gao <zhangfei.gao@xxxxxxxxxxx>
> Date: Tue, 21 Dec 2010 19:51:38 -0500
> Subject: [PATCH] mmc: sdhci support emmc ddr50 mode
>
> 1. spec sdhc 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
> 3. According to spec sdhc 3.0, uhs mode, including emmc ddr50 takes
> effect only when 1.8v Signaling Enable bit, which used for providing
> 1.8v.
> So emmc ddr50 mode works after 1.8v switching process, though emmc
> ddr50 could work at high voltage such as 3.3v if external pmic provide
> voltage.
> Limitation: emmc ddr50 mode only workable when both host and emmc
> card support 1.70-1.90v
signaling voltage is not the same as card voltage. card voltage can be 3.3v and
signaling voltage 1.8v.
> 4. According to JESD84, power down and power up is required to
> provide low voltage 1.70-1.90v to mmc.
>
> Verified: toshiba emmc on mmp2, with io voltage at 1.8v provided by
> external pmic.
>
> Signed-off-by: Zhangfei Gao <zhangfei.gao@xxxxxxxxxxx>
> ---
> drivers/mmc/core/core.c | 13 +++++++++++++
> drivers/mmc/core/core.h | 1 +
> drivers/mmc/core/mmc.c | 6 +++++-
> drivers/mmc/host/sdhci.c | 44 +++++++++++++++++++++++++++++++++++++++++---
> drivers/mmc/host/sdhci.h | 14 +++++++++++++-
> 5 files changed, 73 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index a8e89f3..fd657f1 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -1012,6 +1012,19 @@ static void mmc_power_off(struct mmc_host *host)
> }
>
> /*
> + * mmc select low voltage 1.70-1.95v
> + */
> +void mmc_select_low_voltage(struct mmc_host *host, u32 ocr)
> +{
> + if (!(ocr & MMC_VDD_165_195))
> + return;
> +
> + mmc_power_off(host);
> + host->ocr = ocr & host->ocr_avail;
> + mmc_power_up(host);
> +}
> +
> +/*
> * Cleanup when the last reference to the bus operator is dropped.
> */
> static void __mmc_release_bus(struct mmc_host *host)
> diff --git a/drivers/mmc/core/core.h b/drivers/mmc/core/core.h
> index 026c975..b05c20a 100644
> --- a/drivers/mmc/core/core.h
> +++ b/drivers/mmc/core/core.h
> @@ -41,6 +41,7 @@ void mmc_set_bus_width(struct mmc_host *host,
> unsigned int width);
> void mmc_set_bus_width_ddr(struct mmc_host *host, unsigned int width,
> unsigned int ddr);
> u32 mmc_select_voltage(struct mmc_host *host, u32 ocr);
> +void mmc_select_low_voltage(struct mmc_host *host, u32 ocr);
> void mmc_set_timing(struct mmc_host *host, unsigned int timing);
>
> static inline void mmc_delay(unsigned int ms)
> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
> index 86cac0d..8779339 100644
> --- a/drivers/mmc/core/mmc.c
> +++ b/drivers/mmc/core/mmc.c
> @@ -790,7 +790,11 @@ int mmc_attach_mmc(struct mmc_host *host, u32 ocr)
> ocr &= ~0x7F;
> }
>
> - host->ocr = mmc_select_voltage(host, ocr);
> + if ((ocr & MMC_VDD_165_195)
> + && (host->ocr_avail & MMC_VDD_165_195))
> + mmc_select_low_voltage(host, ocr);
> + else
> + host->ocr = mmc_select_voltage(host, ocr);
>
The patch for dual voltage cards should be a separate patch. It is independent of
support for dual data rate.
> /*
> * Can we support the voltage of the card?
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index d5febe5..aafbb42 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -986,6 +986,22 @@ 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);
> + }
> +}
> +
> static void sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
> {
> int div;
> @@ -1084,6 +1100,18 @@ static void sdhci_set_power(struct sdhci_host
> *host, unsigned short power)
> return;
> }
>
> + if ((pwr == SDHCI_POWER_180) &&
> + (host->mmc->caps & MMC_CAP_1_8V_DDR)) {
> + 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);
> + }
> +
power to the card can be at 3.3v and signaling at 1.8v. This is a legal combination.
The
> + if ((pwr == SDHCI_POWER_180) &&
> + (host->mmc->caps & MMC_CAP_1_8V_DDR)) {
should be reworked.
> /*
> * Spec says that we should clear the power reg before setting
> * a new value. Some controllers don't seem to like this though.
> @@ -1180,6 +1208,7 @@ 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);
> @@ -1744,7 +1773,7 @@ EXPORT_SYMBOL_GPL(sdhci_alloc_host);
> int sdhci_add_host(struct sdhci_host *host)
> {
> struct mmc_host *mmc;
> - unsigned int caps, ocr_avail;
> + unsigned int caps, caps_h = 0, ocr_avail;
> int ret;
>
> WARN_ON(host == NULL);
> @@ -1767,8 +1796,17 @@ int sdhci_add_host(struct sdhci_host *host)
> host->version);
> }
>
> - caps = (host->quirks & SDHCI_QUIRK_MISSING_CAPS) ? host->caps :
> - sdhci_readl(host, SDHCI_CAPABILITIES);
> + if (host->quirks & SDHCI_QUIRK_MISSING_CAPS)
> + caps = host->caps;
> + else {
> + caps = sdhci_readl(host, SDHCI_CAPABILITIES);
> + caps_h = sdhci_readl(host, SDHCI_CAPABILITIES_1);
> + }
> +
> + 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 6e0969e..c4bd5dd 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -145,7 +145,14 @@
>
> #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
> @@ -167,6 +174,9 @@
> #define SDHCI_CAN_64BIT 0x10000000
>
> #define SDHCI_CAPABILITIES_1 0x44
> +#define SDHCI_CAN_SDR50 0x00000001
> +#define SDHCI_CAN_SDR104 0x00000002
> +#define SDHCI_CAN_DDR50 0x00000004
>
> #define SDHCI_MAX_CURRENT 0x48
>
> @@ -222,6 +232,8 @@ 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);
> };
>
> #ifdef CONFIG_MMC_SDHCI_IO_ACCESSORS
> --
> 1.7.0.4
> <0001-mmc-sdhci-support-emmc-ddr50-mode.patch>
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