On 27 July 2016 at 06:13, Simon Horman <horms+renesas@xxxxxxxxxxxx> wrote:
> From: Ai Kyuse <ai.kyuse.uw@xxxxxxxxxxx>
>
> Add tuning support for use with SDR104 mode
>
> Signed-off-by: Ai Kyuse <ai.kyuse.uw@xxxxxxxxxxx>
> Signed-off-by: Simon Horman <horms+renesas@xxxxxxxxxxxx>
> ---
> v4 [Simon Horman]
> As suggested by Wolfram Sang:
> - Do not perform tuning if host->select_tuning is not set:
> it seems to make little sense to do so and moreover there is currently
> no such use-case
> - Do not add mrc->sbc handling from tmio_mmc_request,
> this is a hang-over from earlier versions of this patchset which
> did not use core infrastructure for retuning
> - Tidy up local variable usage
> * Correct index passed to prepare_tuning(): this seems to have
> been the last piece of resolving the timeouts during tuning puzzle
> * Further cleanups to tmio_mmc_execute_tuning():
> - Ensure tap is sized proportionally to its members
> - Remove stray '*' in comment
> - Use mmc rather than host->mmc, these are equivalent but
> the former seems tidier
> - Correct inverted logic in setting tap values
> * Re-introduce retuning support. This was removed in v3.
>
> v3 [Simon Horman]
> * As suggested by Kuninori Morimoto:
> - Do not add unused retuning callback to struct tmio_mmc_host
> - Change return type of prepare_tuning callback to void
> - Add tap_size parameter to select_tuning callback
>
> v2 [Simon Horman]
> * As suggested by Kuninori Morimoto:
> - Actually remove unnecessary TMIO_MMC_HAS_UHS_SCC define
> * As suggested by Wolfram Sang:
> - Rely on core to call tuning. This simplifies things somewhat.
> - Use mmc_send_tuning()
> - A side affect of this appears to be that we now see some recoverable
> errors logged during tuning. These are typically corrected by
> subsequent tuning. It is the logging that is the apparent side effect
> of this change.
> e.g.
> sh_mobile_sdhi ee100000.sd: timeout waiting for hardware interrupt (CMD19)
> sh_mobile_sdhi ee100000.sd: Tuning procedure failed
> * Use bool rather than unsigned long to pass test status
> to select_tuning() callback
> * Do not retune if init_tuning callback is not present or
> indicates that there are no taps present
> * Retune on hardware reset
>
> v1 [Simon Horman]
> * Omit start_signal_voltage_switch and tmio_mmc_card_busy changes which are
> already present in mainline in a different form
> * Return num from init_tuning rather than passing an extra parameter
> to hold the return value
> * Only call host->init_tuning if it is non-NULL
> * Place tmio_mmc_execute_tuning() such that no new forward declarations are
> required
> * Remove unused TMIO_MMC_HAS_UHS_SCC define
>
> v0 [Ai Kyuse]
>
> Signed-off-by: Simon Horman <horms+renesas@xxxxxxxxxxxx>
> ---
> drivers/mmc/host/tmio_mmc.h | 7 ++++
> drivers/mmc/host/tmio_mmc_pio.c | 77 +++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 84 insertions(+)
>
> diff --git a/drivers/mmc/host/tmio_mmc.h b/drivers/mmc/host/tmio_mmc.h
> index 7f63ec05bdf4..316b0c3fe745 100644
> --- a/drivers/mmc/host/tmio_mmc.h
> +++ b/drivers/mmc/host/tmio_mmc.h
> @@ -150,6 +150,7 @@ struct tmio_mmc_host {
> struct mutex ios_lock; /* protect set_ios() context */
> bool native_hotplug;
> bool sdio_irq_enabled;
> + u32 scc_tappos;
>
> int (*write16_hook)(struct tmio_mmc_host *host, int addr);
> int (*clk_enable)(struct tmio_mmc_host *host);
> @@ -160,6 +161,12 @@ struct tmio_mmc_host {
> unsigned int direction, int blk_size);
> int (*start_signal_voltage_switch)(struct mmc_host *mmc,
> struct mmc_ios *ios);
> + unsigned int (*init_tuning)(struct tmio_mmc_host *host);
> + void (*prepare_tuning)(struct tmio_mmc_host *host, unsigned long tap);
> + int (*select_tuning)(struct tmio_mmc_host *host, bool *tap,
> + int tap_size);
> + bool (*retuning)(struct tmio_mmc_host *host);
> + void (*hw_reset)(struct tmio_mmc_host *host);
Please add the HW reset support in separate patch. I guess you need it
to go in before the tuning support.
> };
>
> struct tmio_mmc_host *tmio_mmc_host_alloc(struct platform_device *pdev);
> diff --git a/drivers/mmc/host/tmio_mmc_pio.c b/drivers/mmc/host/tmio_mmc_pio.c
> index a9d07b5f3c63..83b5148a2684 100644
> --- a/drivers/mmc/host/tmio_mmc_pio.c
> +++ b/drivers/mmc/host/tmio_mmc_pio.c
> @@ -36,6 +36,7 @@
> #include <linux/io.h>
> #include <linux/irq.h>
> #include <linux/mfd/tmio.h>
> +#include <linux/mmc/card.h>
> #include <linux/mmc/host.h>
> #include <linux/mmc/mmc.h>
> #include <linux/mmc/slot-gpio.h>
> @@ -298,6 +299,15 @@ static void tmio_mmc_finish_request(struct tmio_mmc_host *host)
> if (mrq->cmd->error || (mrq->data && mrq->data->error))
> tmio_mmc_abort_dma(host);
>
> + if (host->retuning) {
> + int result = host->retuning(host);
This looks like you need to re-tune between each an every request. :-)
Although I guess what really are doing here is that you check if the
auto-retuning has failed, correct?
Perhaps one could update the naming of the new tmio callbacks for
tuning as to make those more self-explained.
> +
> + if (result || (mrq->cmd->error == -EILSEQ)) {
> + mmc_retune_timer_stop(host->mmc);
> + mmc_retune_needed(host->mmc);
The mmc core already deals with re-tuning when it get an -EILSEQ error
from a request, so you shouldn't need to manage that here as well.
> + }
> + }
> +
> mmc_request_done(host->mmc, mrq);
> }
>
> @@ -756,6 +766,68 @@ static int tmio_mmc_start_data(struct tmio_mmc_host *host,
> return 0;
> }
>
> +static void tmio_mmc_hw_reset(struct mmc_host *mmc)
As stated earlier, please add the HW reset in a separate patch.
> +{
> + struct tmio_mmc_host *host = mmc_priv(mmc);
> +
> + if (host->hw_reset)
> + host->hw_reset(host);
> +
> + mmc_retune_timer_stop(host->mmc);
> + mmc_retune_needed(host->mmc);
This looks like it belongs in the mmc core when it invokes a HW reset
sequence. Please try to move it into there (unless it already covers
this).
> +}
> +
> +static int tmio_mmc_execute_tuning(struct mmc_host *mmc, u32 opcode)
> +{
> + struct tmio_mmc_host *host = mmc_priv(mmc);
> + unsigned int num;
> + int i, ret = 0;
> + bool *tap;
> +
> + if (!host->init_tuning || !host->select_tuning)
When defining these callbacks, it would be nice to know which ones are
optional and which ones are required.
> + /* Tuning is not supported */
> + goto out;
> +
> + num = host->init_tuning(host);
> + if (!num)
> + /* Tuning is not supported */
> + goto out;
> +
> + tap = kmalloc(num * 2 * sizeof(*tap), GFP_KERNEL);
> + if (!tap) {
> + ret = -ENOMEM;
> + goto out;
> + }
> +
> + /* Issue CMD19 twice for each tap */
> + for (i = 0; i < 2 * num; i++) {
> + if (host->prepare_tuning)
> + host->prepare_tuning(host, i % num);
> +
> + ret = mmc_send_tuning(mmc, opcode, NULL);
> + if (ret && ret != -EILSEQ)
> + goto err_free;
> + tap[i] = (ret != 0);
> +
> + mdelay(1);
> + }
> +
> + ret = host->select_tuning(host, tap, num * 2);
> +
> +err_free:
> + kfree(tap);
> +out:
> + if (ret < 0) {
> + dev_warn(&host->pdev->dev, "Tuning procedure failed\n");
> + tmio_mmc_hw_reset(mmc);
> + } else {
> + host->mmc->retune_period = 0;
> + }
> +
> + return ret;
> +
> +}
> +
> /* Process requests from the MMC layer */
> static void tmio_mmc_request(struct mmc_host *mmc, struct mmc_request *mrq)
> {
> @@ -978,6 +1050,8 @@ static struct mmc_host_ops tmio_mmc_ops = {
> .enable_sdio_irq = tmio_mmc_enable_sdio_irq,
> .card_busy = tmio_mmc_card_busy,
> .multi_io_quirk = tmio_multi_io_quirk,
> + .execute_tuning = tmio_mmc_execute_tuning,
> + .hw_reset = tmio_mmc_hw_reset,
> };
>
> static int tmio_mmc_init_ocr(struct tmio_mmc_host *host)
> @@ -1202,6 +1276,9 @@ int tmio_mmc_host_runtime_suspend(struct device *dev)
> struct mmc_host *mmc = dev_get_drvdata(dev);
> struct tmio_mmc_host *host = mmc_priv(mmc);
>
> + mmc_retune_timer_stop(host->mmc);
> + mmc_retune_needed(host->mmc);
I am wondering whether it would it be possible to keep a cache of the
currently used tuning values and then restore these values at
runtime_resume?
In that way you wouldn't need to force new re-tuning cycle here.
> +
> tmio_mmc_disable_mmc_irqs(host, TMIO_MASK_ALL);
>
> if (host->clk_cache)
> --
> 2.7.0.rc3.207.g0ac5344
>
Kind regards
Uffe
