Re: [PATCH V1] mmc: sdhci-msm: Add CQHCI support for sdhci-msm

[Adrian Hunter <adrian.hunter@intel.com>]

On 10/01/20 10:56 am, Veerabhadrarao Badiganti wrote:
> 
> On 1/2/2020 5:00 PM, Veerabhadrarao Badiganti wrote:
>>
>> On 12/20/2019 7:29 PM, Adrian Hunter wrote:
>>> On 17/12/19 2:37 pm, Veerabhadrarao Badiganti wrote:
>>>> From: Ritesh Harjani<riteshh@codeaurora.org>
>>>>
>>>> This adds CQHCI support for sdhci-msm platforms.
>>>>
>>>> Signed-off-by: Ritesh Harjani<riteshh@codeaurora.org>
>>>> Signed-off-by: Veerabhadrarao Badiganti<vbadigan@codeaurora.org>
>>>>
>>>> ---
>>>> This patch is based on RFC patch
>>>> https://lkml.org/lkml/2017/8/30/313
>>>>
>>>> Changes since RFC:
>>>>     - Updated settings so that TDLBA won't get reset when
>>>>       CQE is enabled.
>>>>     - Removed new compatible string and moved to supports-cqe
>>>>       dt flag to identify CQE support.
>>>>     - Incorporated review comments.
>>>>
>>>> Tested on: qcs404, sc7180
>>>> ---
>>>>   drivers/mmc/host/sdhci-msm.c | 115
>>>> ++++++++++++++++++++++++++++++++++++++++++-
>>>>   1 file changed, 114 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
>>>> index 3d0bb5e..a4e3507 100644
>>>> --- a/drivers/mmc/host/sdhci-msm.c
>>>> +++ b/drivers/mmc/host/sdhci-msm.c
>>>> @@ -15,6 +15,7 @@
>>>>   #include <linux/regulator/consumer.h>
>>>>     #include "sdhci-pltfm.h"
>>>> +#include "cqhci.h"
>>>>     #define CORE_MCI_VERSION        0x50
>>>>   #define CORE_VERSION_MAJOR_SHIFT    28
>>>> @@ -122,6 +123,10 @@
>>>>   #define msm_host_writel(msm_host, val, host, offset) \
>>>>       msm_host->var_ops->msm_writel_relaxed(val, host, offset)
>>>>   +/* CQHCI vendor specific registers */
>>>> +#define CQHCI_VENDOR_CFG1    0xA00
>>>> +#define DISABLE_RST_ON_CMDQ_EN    (0x3 << 13)
>>>> +
>>>>   struct sdhci_msm_offset {
>>>>       u32 core_hc_mode;
>>>>       u32 core_mci_data_cnt;
>>>> @@ -1567,6 +1572,109 @@ static void sdhci_msm_set_clock(struct
>>>> sdhci_host *host, unsigned int clock)
>>>>       __sdhci_msm_set_clock(host, clock);
>>>>   }
>>>> +/*****************************************************************************\
>>>>
>>>> + * *
>>>> + * MSM Command Queue Engine
>>>> (CQE)                                            *
>>>> + * *
>>>> +\*****************************************************************************/
>>>>
>>>> +
>>>> +static u32 sdhci_msm_cqe_irq(struct sdhci_host *host, u32 intmask)
>>>> +{
>>>> +    int cmd_error = 0;
>>>> +    int data_error = 0;
>>>> +
>>>> +    if (!sdhci_cqe_irq(host, intmask, &cmd_error, &data_error))
>>>> +        return intmask;
>>>> +
>>>> +    cqhci_irq(host->mmc, intmask, cmd_error, data_error);
>>>> +    return 0;
>>>> +}
>>>> +
>>>> +void sdhci_msm_cqe_disable(struct mmc_host *mmc, bool recovery)
>>>> +{
>>>> +    struct sdhci_host *host = mmc_priv(mmc);
>>>> +    unsigned long flags;
>>>> +    u32 ctrl;
>>>> +
>>>> +    /*
>>>> +     * When CQE is halted, the legacy SDHCI path operates only
>>>> +     * on 128bit descriptors in 64bit mode.
>>>> +     */
>>>> +    if (host->flags & SDHCI_USE_64_BIT_DMA)
>>>> +        host->desc_sz = 16;
>>> The adma_table_sz depends on desc_sz, so it cannot be changed here.
>>> If you do something like below, then you can set desc_sz before calling
>>> sdhci_setup_host()
>>>
>>> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
>>> index f4540f9892ce..f1d3b70ff769 100644
>>> --- a/drivers/mmc/host/sdhci.c
>>> +++ b/drivers/mmc/host/sdhci.c
>>> @@ -3825,9 +3825,10 @@ int sdhci_setup_host(struct sdhci_host *host)
>>>           void *buf;
>>>             if (host->flags & SDHCI_USE_64_BIT_DMA) {
>>> +            if (!host->desc_sz)
>>> +                host->desc_sz = SDHCI_ADMA2_64_DESC_SZ(host);
>>>               host->adma_table_sz = host->adma_table_cnt *
>>> -                          SDHCI_ADMA2_64_DESC_SZ(host);
>>> -            host->desc_sz = SDHCI_ADMA2_64_DESC_SZ(host);
>>> +                          host->desc_sz;
>>>           } else {
>>>               host->adma_table_sz = host->adma_table_cnt *
>>>                             SDHCI_ADMA2_32_DESC_SZ;
>>
>> Thanks Adrian for the suggestion. I will add this change.
>>
>> But even with this change, still i will have to override 'host->desc_sz'
>> variable since qcom sdhci controller expects/operates-on
>>
>> 12-byte descriptor as long was CQE is not enabled. When CQE is enabled, it
>> operates only on 16-bype descriptors (even when CQE is halted).
>>
>> If i fix "host->desc_sz" to 16 then all the data transfer commands during
>> card initialization (till CQE is enabled) would fail.
>>
>> I may have to update as below:
>>
>>     host->desc_sz = 16;
>>
>>     sdhci_add_host()  ;
>>
>>    host->desc_sz = 12;
>>
>> And then cqhci_host_ops->enable() -> host->desc_sz = 16;
>>
>> Please let me know if this is fine or if you have any other suggestion to
>> support this limitation of qcom controller w.r.t ADMA descriptors with CQE.
>>
> Hi Adrian,
> 
> Do you have any suggestions on the way to support both the descriptor sizes?

How about we have 2 variables: alloc_desc_sz and desc_sz
Then, in sdhci_setup_host():

	host->alloc_desc_sz = SDHCI_ADMA2_64/32_DESC_SZ(host);
	host->desc_sz = host->alloc_desc_sz;

Then desc_sz can be changed (in between requests) so long as desc_sz <
alloc_desc_sz.


> 
>>>> +
>>>> +    spin_lock_irqsave(&host->lock, flags);
>>>> +
>>>> +    /*
>>>> +     * During CQE operation command complete bit gets latched.
>>>> +     * So s/w should clear command complete interrupt status when CQE is
>>>> +     * halted. Otherwise unexpected SDCHI legacy interrupt gets
>>>> +     * triggered when CQE is halted.
>>>> +     */
>>>> +    ctrl = sdhci_readl(host, SDHCI_INT_ENABLE);
>>>> +    ctrl |= SDHCI_INT_RESPONSE;
>>>> +    sdhci_writel(host,  ctrl, SDHCI_INT_ENABLE);
>>>> +    sdhci_writel(host, SDHCI_INT_RESPONSE, SDHCI_INT_STATUS);
>>>> +
>>>> +    spin_unlock_irqrestore(&host->lock, flags);
>>>> +
>>>> +    sdhci_cqe_disable(mmc, recovery);
>>>> +}
>>>> +
>>>> +static const struct cqhci_host_ops sdhci_msm_cqhci_ops = {
>>>> +    .enable        = sdhci_cqe_enable,
>>>> +    .disable    = sdhci_msm_cqe_disable,
>>>> +};
>>>> +
>>>> +static int sdhci_msm_cqe_add_host(struct sdhci_host *host,
>>>> +                struct platform_device *pdev)
>>>> +{
>>>> +    struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
>>>> +    struct sdhci_msm_host *msm_host = sdhci_pltfm_priv(pltfm_host);
>>>> +    struct cqhci_host *cq_host;
>>>> +    bool dma64;
>>>> +    int ret;
>>>> +
>>>> +    ret = sdhci_setup_host(host);
>>>> +    if (ret)
>>>> +        return ret;
>>>> +
>>>> +    cq_host = cqhci_pltfm_init(pdev);
>>>> +    if (IS_ERR(cq_host)) {
>>>> +        ret = PTR_ERR(cq_host);
>>>> +        dev_err(&pdev->dev, "cqhci-pltfm init: failed: %d\n", ret);
>>>> +        goto cleanup;
>>>> +    }
>>>> +
>>>> +    msm_host->mmc->caps2 |= MMC_CAP2_CQE | MMC_CAP2_CQE_DCMD;
>>>> +    cq_host->ops = &sdhci_msm_cqhci_ops;
>>>> +
>>>> +    dma64 = host->flags & SDHCI_USE_64_BIT_DMA;
>>>> +
>>>> +    ret = cqhci_init(cq_host, host->mmc, dma64);
>>>> +    if (ret) {
>>>> +        dev_err(&pdev->dev, "%s: CQE init: failed (%d)\n",
>>>> +                mmc_hostname(host->mmc), ret);
>>>> +        goto cleanup;
>>>> +    }
>>>> +
>>>> +    /* Disable cqe reset due to cqe enable signal */
>>>> +    cqhci_writel(cq_host, cqhci_readl(cq_host, CQHCI_VENDOR_CFG1) |
>>>> +               DISABLE_RST_ON_CMDQ_EN, CQHCI_VENDOR_CFG1);
>>>> +
>>>> +    ret = __sdhci_add_host(host);
>>>> +    if (ret)
>>>> +        goto cleanup;
>>>> +
>>>> +    dev_info(&pdev->dev, "%s: CQE init: success\n",
>>>> +            mmc_hostname(host->mmc));
>>>> +    return ret;
>>>> +
>>>> +cleanup:
>>>> +    sdhci_cleanup_host(host);
>>>> +    return ret;
>>>> +}
>>>> +
>>>>   /*
>>>>    * Platform specific register write functions. This is so that, if any
>>>>    * register write needs to be followed up by platform specific actions,
>>>> @@ -1731,6 +1839,7 @@ static void sdhci_msm_set_regulator_caps(struct
>>>> sdhci_msm_host *msm_host)
>>>>       .set_uhs_signaling = sdhci_msm_set_uhs_signaling,
>>>>       .write_w = sdhci_msm_writew,
>>>>       .write_b = sdhci_msm_writeb,
>>>> +    .irq    = sdhci_msm_cqe_irq,
>>>>   };
>>>>     static const struct sdhci_pltfm_data sdhci_msm_pdata = {
>>>> @@ -1754,6 +1863,7 @@ static int sdhci_msm_probe(struct platform_device
>>>> *pdev)
>>>>       u8 core_major;
>>>>       const struct sdhci_msm_offset *msm_offset;
>>>>       const struct sdhci_msm_variant_info *var_info;
>>>> +    struct device_node *node = pdev->dev.of_node;
>>>>         host = sdhci_pltfm_init(pdev, &sdhci_msm_pdata, sizeof(*msm_host));
>>>>       if (IS_ERR(host))
>>>> @@ -1952,7 +2062,10 @@ static int sdhci_msm_probe(struct platform_device
>>>> *pdev)
>>>>       pm_runtime_use_autosuspend(&pdev->dev);
>>>>         host->mmc_host_ops.execute_tuning = sdhci_msm_execute_tuning;
>>>> -    ret = sdhci_add_host(host);
>>>> +    if (of_property_read_bool(node, "supports-cqe"))
>>>> +        ret = sdhci_msm_cqe_add_host(host, pdev);
>>>> +    else
>>>> +        ret = sdhci_add_host(host);
>>>>       if (ret)
>>>>           goto pm_runtime_disable;
>>>>       sdhci_msm_set_regulator_caps(msm_host);
>>>>
> Thanks
> 
> Veera