Re: [PATCH 01/12] mmc: sdhci: add support for auto CMD23

zhangfei gao
2011-02-18T10:45:29Z

On Tue, Feb 15, 2011 at 4:34 AM, Arindam Nath <arindam.nath@amd.com> wrote:
> Host Controller v3.00 and later support Auto CMD23 in the Transfer
> Mode register. Since Auto CMD23 can be used with or without DMA,
> and if used with DMA, it should _only_ be ADMA, we check against
> SDHCI_USE_SDMA not being set. This flag is reset when SDHCI_USE_ADMA
> is set.
>
> A new definition for SDHCI_ARGUMENT2 register has been added
> in v3.00 spec, which is the same as SDHCI_DMA_ADDRESS. We program the
> block count for CMD23 in SDHCI_ARGUMENT2, so we don't need CMD12 to
> stop multiple block transfers. But during error recovery procedure,
> we will need to send Abort command, so we use a global variable
> abort_cmd to save the stop command to be used later.
>
> Two bits are added to SCR register as per the Physical Layer Spec v3.01,
> which specify whether the card supports CMD20 and/or CMD23. We use this
> as one of the conditions to decide whether to enable Auto CMD23 or not.
>
> Signed-off-by: Arindam Nath <arindam.nath@amd.com>
> ---
>  drivers/mmc/core/sd.c    |    6 ++++
>  drivers/mmc/host/sdhci.c |   66 +++++++++++++++++++++++++++++++++++++++++++--
>  drivers/mmc/host/sdhci.h |    2 +
>  include/linux/mmc/card.h |    4 +++
>  include/linux/mmc/sd.h   |    2 +-
>  5 files changed, 76 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
> index d18c32b..b3f8a3c 100644
> --- a/drivers/mmc/core/sd.c
> +++ b/drivers/mmc/core/sd.c
> @@ -188,6 +188,12 @@ static int mmc_decode_scr(struct mmc_card *card)
>
>        scr->sda_vsn = UNSTUFF_BITS(resp, 56, 4);
>        scr->bus_widths = UNSTUFF_BITS(resp, 48, 4);
> +       if (scr->sda_vsn == SCR_SPEC_VER_2) {
> +               /* Check if Physical Layer Spec v3.0 is supported*/
> +               scr->sda_spec3 = UNSTUFF_BITS(resp, 47, 1);
> +               if (scr->sda_spec3)
> +                       scr->cmd_support = UNSTUFF_BITS(resp, 32, 2);
> +       }
>
>        if (UNSTUFF_BITS(resp, 55, 1))
>                card->erased_byte = 0xFF;
> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
> index 9e15f41..0b537cf 100644
> --- a/drivers/mmc/host/sdhci.c
> +++ b/drivers/mmc/host/sdhci.c
> @@ -25,6 +25,7 @@
>
>  #include <linux/mmc/mmc.h>
>  #include <linux/mmc/host.h>
> +#include <linux/mmc/card.h>
>
>  #include "sdhci.h"
>
> @@ -46,6 +47,8 @@ static void sdhci_finish_data(struct sdhci_host *);
>  static void sdhci_send_command(struct sdhci_host *, struct mmc_command *);
>  static void sdhci_finish_command(struct sdhci_host *);
>
> +static struct mmc_command *abort_cmd;
> +
>  static void sdhci_dumpregs(struct sdhci_host *host)
>  {
>        printk(KERN_DEBUG DRIVER_NAME ": =========== REGISTER DUMP (%s)===========\n",
> @@ -812,6 +815,30 @@ static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_data *data)
>        sdhci_writew(host, data->blocks, SDHCI_BLOCK_COUNT);
>  }
>
> +/*
> + * Does the Host Controller support Auto CMD23?
> + *
> + * There are four preconditions for Auto CMD23 to be supported:
> + *  1. Host Controller v3.00 or later
> + *  2. Card supports CMD23
> + *  3. If DMA is used, it should be ADMA
> + *  4. Only when CMD18 or CMD25 is issued
> + */
> +static int sdhci_host_auto_cmd23_supported(struct sdhci_host *host,
> +       struct mmc_request *mrq)
> +{
> +       struct mmc_card *card = host->mmc->card;
> +
> +       if ((host->version >= SDHCI_SPEC_300) &&
> +          card && (card->scr.cmd_support & SD_SCR_CMD23_SUPPORT) &&
> +          !(host->flags & SDHCI_USE_SDMA) &&
> +          ((mrq->cmd->opcode == MMC_READ_MULTIPLE_BLOCK) ||
> +          (mrq->cmd->opcode == MMC_WRITE_MULTIPLE_BLOCK)))
> +               return 1;
> +
> +       return 0;
> +}
> +
>  static void sdhci_set_transfer_mode(struct sdhci_host *host,
>        struct mmc_data *data)
>  {
> @@ -824,11 +851,23 @@ static void sdhci_set_transfer_mode(struct sdhci_host *host,
>
>        mode = SDHCI_TRNS_BLK_CNT_EN;
>        if (data->blocks > 1) {
> +               if (sdhci_host_auto_cmd23_supported(host, host->mrq)) {
> +                       /*
> +                        * Host Controller v3.00 can automatically send CMD23
> +                        * before CMD18 or CMD25. For that, we need to enable
> +                        * Auto CMD23 in the Transfer Mode register and
> +                        * program the block count in Argument 2 register.
> +                        */
> +                       mode |= SDHCI_TRNS_AUTO_CMD23;
> +                       sdhci_writel(host, data->blocks, SDHCI_ARGUMENT2);
> +               }
> +
>                if (host->quirks & SDHCI_QUIRK_MULTIBLOCK_READ_ACMD12)
>                        mode |= SDHCI_TRNS_MULTI | SDHCI_TRNS_ACMD12;
>                else
>                        mode |= SDHCI_TRNS_MULTI;
>        }
> +
>        if (data->flags & MMC_DATA_READ)
>                mode |= SDHCI_TRNS_READ;
>        if (host->flags & SDHCI_REQ_USE_DMA)
> @@ -1131,6 +1170,23 @@ static void sdhci_request(struct mmc_host *mmc, struct mmc_request *mrq)
>  #ifndef SDHCI_USE_LEDS_CLASS
>        sdhci_activate_led(host);
>  #endif
> +       /*
> +        * Since the block count for CMD23 has already been specified in the
> +        * Argument 2 register, we don't need CMD12 to stop multiple block
> +        * transfers.
> +        */
> +       if (sdhci_host_auto_cmd23_supported(host, mrq)) {
> +               if (mrq->stop) {
> +                       /*
> +                        * Save the stop command here to be used during
> +                        * error recovery
> +                        */
> +                       abort_cmd = mrq->data->stop;
> +                       mrq->data->stop = NULL;
> +                       mrq->stop = NULL;
> +               }
> +       }
> +
>        if (host->quirks & SDHCI_QUIRK_MULTIBLOCK_READ_ACMD12) {
>                if (mrq->stop) {
>                        mrq->data->stop = NULL;
> @@ -1396,6 +1452,7 @@ static void sdhci_timeout_timer(unsigned long data)
>
>                if (host->data) {
>                        host->data->error = -ETIMEDOUT;
> +                       host->data->stop = abort_cmd;
>                        sdhci_finish_data(host);
>                } else {
>                        if (host->cmd)
> @@ -1534,9 +1591,10 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)
>                host->data->error = -EIO;
>        }
>
> -       if (host->data->error)
> +       if (host->data->error) {
> +               host->data->stop = abort_cmd;
>                sdhci_finish_data(host);
> -       else {
> +       } else {
>                if (intmask & (SDHCI_INT_DATA_AVAIL | SDHCI_INT_SPACE_AVAIL))
>                        sdhci_transfer_pio(host);
>
> @@ -1783,8 +1841,10 @@ int sdhci_add_host(struct sdhci_host *host)
>                host->flags &= ~SDHCI_USE_SDMA;
>        }
>
> -       if ((host->version >= SDHCI_SPEC_200) && (caps & SDHCI_CAN_DO_ADMA2))
> +       if ((host->version >= SDHCI_SPEC_200) && (caps & SDHCI_CAN_DO_ADMA2)) {
> +               host->flags &= ~SDHCI_USE_SDMA;

Here may have issue if controller use only support SDMA with
SDHCI_QUIRK_BROKEN_ADMA.
After this, both SDHCI_USE_SDMA and SDHCI_USE_ADMA are cleared.

>                host->flags |= SDHCI_USE_ADMA;
> +       }
>
>        if ((host->quirks & SDHCI_QUIRK_BROKEN_ADMA) &&
>                (host->flags & SDHCI_USE_ADMA)) {

> diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
> index 6e0969e..223762c 100644
> --- a/drivers/mmc/host/sdhci.h
> +++ b/drivers/mmc/host/sdhci.h
> @@ -25,6 +25,7 @@
>  */
>
>  #define SDHCI_DMA_ADDRESS      0x00
> +#define SDHCI_ARGUMENT2                SDHCI_DMA_ADDRESS
>
>  #define SDHCI_BLOCK_SIZE       0x04
>  #define  SDHCI_MAKE_BLKSZ(dma, blksz) (((dma & 0x7) << 12) | (blksz & 0xFFF))
> @@ -37,6 +38,7 @@
>  #define  SDHCI_TRNS_DMA                0x01
>  #define  SDHCI_TRNS_BLK_CNT_EN 0x02
>  #define  SDHCI_TRNS_ACMD12     0x04
> +#define  SDHCI_TRNS_AUTO_CMD23 0x08
>  #define  SDHCI_TRNS_READ       0x10
>  #define  SDHCI_TRNS_MULTI      0x20
>
> diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
> index 8ce0827..22b0335 100644
> --- a/include/linux/mmc/card.h
> +++ b/include/linux/mmc/card.h
> @@ -58,9 +58,13 @@ struct mmc_ext_csd {
>
>  struct sd_scr {
>        unsigned char           sda_vsn;
> +       unsigned char           sda_spec3;
>        unsigned char           bus_widths;
>  #define SD_SCR_BUS_WIDTH_1     (1<<0)
>  #define SD_SCR_BUS_WIDTH_4     (1<<2)
> +       unsigned char           cmd_support;
> +#define SD_SCR_CMD20_SUPPORT   (1<<0)
> +#define SD_SCR_CMD23_SUPPORT   (1<<1)
>  };
>
>  struct sd_ssr {
> diff --git a/include/linux/mmc/sd.h b/include/linux/mmc/sd.h
> index 3fd85e0..178363b 100644
> --- a/include/linux/mmc/sd.h
> +++ b/include/linux/mmc/sd.h
> @@ -59,7 +59,7 @@
>
>  #define SCR_SPEC_VER_0         0       /* Implements system specification 1.0 - 1.01 */
>  #define SCR_SPEC_VER_1         1       /* Implements system specification 1.10 */
> -#define SCR_SPEC_VER_2         2       /* Implements system specification 2.00 */
> +#define SCR_SPEC_VER_2         2       /* Implements system specification 2.00 - 3.0x */
>
>  /*
>  * SD bus widths
> --
> 1.7.1
>
> --
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