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Commit 51ced59c authored by Adrian Hunter's avatar Adrian Hunter Committed by Ulf Hansson
Browse files

mmc: sdhci-pci: Use ACPI DSM to get driver strength for some Intel devices 



Make use  of an Intel ACPI _DSM that provides eMMC driver strength.

Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: default avatarUlf Hansson <ulf.hansson@linaro.org>
Tested-by: default avatarLudovic Desroches <ludovic.desroches@microchip.com>
parent c959a6b0

drivers/mmc/host/sdhci-pci-core.c

+14 −63
Original line number Diff line number Diff line
@@ -261,11 +261,13 @@ static const struct sdhci_pci_fixes sdhci_intel_pch_sdio = { 


enum {

	INTEL_DSM_FNS		=  0,

	INTEL_DSM_DRV_STRENGTH	=  9,

	INTEL_DSM_D3_RETUNE	= 10,

};



struct intel_host {

	u32	dsm_fns;

	int	drv_strength;

	bool	d3_retune;

};
@@ -326,6 +328,9 @@ static void intel_dsm_init(struct intel_host *intel_host, struct device *dev, 
	pr_debug("%s: DSM function mask %#x\n",

		 mmc_hostname(mmc), intel_host->dsm_fns);



	err = intel_dsm(intel_host, dev, INTEL_DSM_DRV_STRENGTH, &val);

	intel_host->drv_strength = err ? 0 : val;



	err = intel_dsm(intel_host, dev, INTEL_DSM_D3_RETUNE, &val);

	intel_host->d3_retune = err ? true : !!val;

}
@@ -345,67 +350,15 @@ static void sdhci_pci_int_hw_reset(struct sdhci_host *host) 
	usleep_range(300, 1000);

}



static int spt_select_drive_strength(struct sdhci_host *host,

				     struct mmc_card *card,

				     unsigned int max_dtr,

				     int host_drv, int card_drv, int *drv_type)

{

	int drive_strength;



	if (sdhci_pci_spt_drive_strength > 0)

		drive_strength = sdhci_pci_spt_drive_strength & 0xf;

	else

		drive_strength = 0; /* Default 50-ohm */



	if ((mmc_driver_type_mask(drive_strength) & card_drv) == 0)

		drive_strength = 0; /* Default 50-ohm */



	return drive_strength;

}



/* Try to read the drive strength from the card */

static void spt_read_drive_strength(struct sdhci_host *host)

static int intel_select_drive_strength(struct mmc_card *card,

				       unsigned int max_dtr, int host_drv,

				       int card_drv, int *drv_type)

{

	u32 val, i, t;

	u16 m;



	if (sdhci_pci_spt_drive_strength)

		return;



	sdhci_pci_spt_drive_strength = -1;



	m = sdhci_readw(host, SDHCI_HOST_CONTROL2) & 0x7;

	if (m != 3 && m != 5)

		return;

	val = sdhci_readl(host, SDHCI_PRESENT_STATE);

	if (val & 0x3)

		return;

	sdhci_writel(host, 0x007f0023, SDHCI_INT_ENABLE);

	sdhci_writel(host, 0, SDHCI_SIGNAL_ENABLE);

	sdhci_writew(host, 0x10, SDHCI_TRANSFER_MODE);

	sdhci_writeb(host, 0xe, SDHCI_TIMEOUT_CONTROL);

	sdhci_writew(host, 512, SDHCI_BLOCK_SIZE);

	sdhci_writew(host, 1, SDHCI_BLOCK_COUNT);

	sdhci_writel(host, 0, SDHCI_ARGUMENT);

	sdhci_writew(host, 0x83b, SDHCI_COMMAND);

	for (i = 0; i < 1000; i++) {

		val = sdhci_readl(host, SDHCI_INT_STATUS);

		if (val & 0xffff8000)

			return;

		if (val & 0x20)

			break;

		udelay(1);

	}

	val = sdhci_readl(host, SDHCI_PRESENT_STATE);

	if (!(val & 0x800))

		return;

	for (i = 0; i < 47; i++)

		val = sdhci_readl(host, SDHCI_BUFFER);

	t = val & 0xf00;

	if (t != 0x200 && t != 0x300)

		return;

	struct sdhci_host *host = mmc_priv(card->host);

	struct sdhci_pci_slot *slot = sdhci_priv(host);

	struct intel_host *intel_host = sdhci_pci_priv(slot);



	sdhci_pci_spt_drive_strength = 0x10 | ((val >> 12) & 0xf);

	return intel_host->drv_strength;

}



static int bxt_get_cd(struct mmc_host *mmc)
@@ -451,10 +404,8 @@ static int byt_emmc_probe_slot(struct sdhci_pci_slot *slot) 
	slot->hw_reset = sdhci_pci_int_hw_reset;

	if (slot->chip->pdev->device == PCI_DEVICE_ID_INTEL_BSW_EMMC)

		slot->host->timeout_clk = 1000; /* 1000 kHz i.e. 1 MHz */

	if (slot->chip->pdev->device == PCI_DEVICE_ID_INTEL_SPT_EMMC) {

		spt_read_drive_strength(slot->host);

		slot->select_drive_strength = spt_select_drive_strength;

	}

	slot->host->mmc_host_ops.select_drive_strength =

						intel_select_drive_strength;

	return 0;

}

drivers/mmc/host/sdhci-pci-data.c

+0 −3
Original line number Diff line number Diff line
@@ -3,6 +3,3 @@ 


struct sdhci_pci_data *(*sdhci_pci_get_data)(struct pci_dev *pdev, int slotno);

EXPORT_SYMBOL_GPL(sdhci_pci_get_data);
 


int sdhci_pci_spt_drive_strength;

EXPORT_SYMBOL_GPL(sdhci_pci_spt_drive_strength);