Re: [PATCH V2 2/2] mmc: sdhci-msm: Add CQHCI support for sdhci-msm

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

On 16/01/20 7:03 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>

Acked-by: Adrian Hunter <adrian.hunter@intel.com>

> ---
>  drivers/mmc/host/Kconfig     |   1 +
>  drivers/mmc/host/sdhci-msm.c | 133 ++++++++++++++++++++++++++++++++++++++++++-
>  2 files changed, 133 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/mmc/host/Kconfig b/drivers/mmc/host/Kconfig
> index d06b2df..7f2ae59 100644
> --- a/drivers/mmc/host/Kconfig
> +++ b/drivers/mmc/host/Kconfig
> @@ -501,6 +501,7 @@ config MMC_SDHCI_MSM
>  	depends on ARCH_QCOM || (ARM && COMPILE_TEST)
>  	depends on MMC_SDHCI_PLTFM
>  	select MMC_SDHCI_IO_ACCESSORS
> +	select MMC_CQHCI
>  	help
>  	  This selects the Secure Digital Host Controller Interface (SDHCI)
>  	  support present in Qualcomm SOCs. The controller supports
> diff --git a/drivers/mmc/host/sdhci-msm.c b/drivers/mmc/host/sdhci-msm.c
> index 3d0bb5e..0b4d01f 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 CQHCI_VENDOR_DIS_RST_ON_CQ_EN	(0x3 << 13)
> +
>  struct sdhci_msm_offset {
>  	u32 core_hc_mode;
>  	u32 core_mci_data_cnt;
> @@ -1567,6 +1572,127 @@ 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 16-byte descriptors in 64bit mode.
> +	 */
> +	if (host->flags & SDHCI_USE_64_BIT_DMA)
> +		host->desc_sz = 16;
> +
> +	spin_lock_irqsave(&host->lock, flags);
> +
> +	/*
> +	 * During CQE command transfers, command complete bit gets latched.
> +	 * So s/w should clear command complete interrupt status when CQE is
> +	 * either halted or disabled. Otherwise unexpected SDCHI legacy
> +	 * interrupt gets triggered when CQE is halted/disabled.
> +	 */
> +	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;
> +	u32 cqcfg;
> +	int ret;
> +
> +	/*
> +	 * When CQE is halted, SDHC operates only on 16byte ADMA descriptors.
> +	 * So ensure ADMA table is allocated for 16byte descriptors.
> +	 */
> +	if (host->caps & SDHCI_CAN_64BIT)
> +		host->alloc_desc_sz = 16;
> +
> +	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 */
> +	cqcfg = cqhci_readl(cq_host, CQHCI_VENDOR_CFG1);
> +	cqcfg |= CQHCI_VENDOR_DIS_RST_ON_CQ_EN;
> +	cqhci_writel(cq_host, cqcfg, CQHCI_VENDOR_CFG1);
> +
> +	/*
> +	 * SDHC expects 12byte ADMA descriptors till CQE is enabled.
> +	 * So limit desc_sz to 12 so that the data commands that are sent
> +	 * during card initialization (before CQE gets enabled) would
> +	 * get executed without any issues.
> +	 */
> +	if (host->flags & SDHCI_USE_64_BIT_DMA)
> +		host->desc_sz = 12;
> +
> +	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 +1857,7 @@ 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 +1881,7 @@ 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 +2080,10 @@ 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);
>