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Commit c9faff6c authored by Adrian Hunter's avatar Adrian Hunter Committed by Chris Ball
Browse files

mmc: sdhci-pci: add support for eMMC hardware reset for BYT eMMC. 



Add support for eMMC hardware reset for BYT eMMC.

Signed-off-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
Signed-off-by: default avatarChris Ball <cjb@laptop.org>
parent eede2111

drivers/mmc/host/sdhci-pci.c

+30 −2
Original line number Diff line number Diff line
@@ -77,6 +77,8 @@ struct sdhci_pci_slot { 
	int			rst_n_gpio;

	int			cd_gpio;

	int			cd_irq;



	void (*hw_reset)(struct sdhci_host *host);

};



struct sdhci_pci_chip {
@@ -307,10 +309,27 @@ static const struct sdhci_pci_fixes sdhci_intel_pch_sdio = { 
	.probe_slot	= pch_hc_probe_slot,

};



static void sdhci_pci_int_hw_reset(struct sdhci_host *host)

{

	u8 reg;



	reg = sdhci_readb(host, SDHCI_POWER_CONTROL);

	reg |= 0x10;

	sdhci_writeb(host, reg, SDHCI_POWER_CONTROL);

	/* For eMMC, minimum is 1us but give it 9us for good measure */

	udelay(9);

	reg &= ~0x10;

	sdhci_writeb(host, reg, SDHCI_POWER_CONTROL);

	/* For eMMC, minimum is 200us but give it 300us for good measure */

	usleep_range(300, 1000);

}



static int byt_emmc_probe_slot(struct sdhci_pci_slot *slot)

{

	slot->host->mmc->caps |= MMC_CAP_8_BIT_DATA | MMC_CAP_NONREMOVABLE;

	slot->host->mmc->caps |= MMC_CAP_8_BIT_DATA | MMC_CAP_NONREMOVABLE |

				 MMC_CAP_HW_RESET;

	slot->host->mmc->caps2 |= MMC_CAP2_HC_ERASE_SZ;

	slot->hw_reset = sdhci_pci_int_hw_reset;

	return 0;

}
@@ -1016,7 +1035,7 @@ static int sdhci_pci_bus_width(struct sdhci_host *host, int width) 
	return 0;

}



static void sdhci_pci_hw_reset(struct sdhci_host *host)

static void sdhci_pci_gpio_hw_reset(struct sdhci_host *host)

{

	struct sdhci_pci_slot *slot = sdhci_priv(host);

	int rst_n_gpio = slot->rst_n_gpio;
@@ -1031,6 +1050,14 @@ static void sdhci_pci_hw_reset(struct sdhci_host *host) 
	usleep_range(300, 1000);

}



static void sdhci_pci_hw_reset(struct sdhci_host *host)

{

	struct sdhci_pci_slot *slot = sdhci_priv(host);



	if (slot->hw_reset)

		slot->hw_reset(host);

}



static const struct sdhci_ops sdhci_pci_ops = {

	.enable_dma	= sdhci_pci_enable_dma,

	.platform_bus_width	= sdhci_pci_bus_width,
@@ -1328,6 +1355,7 @@ static struct sdhci_pci_slot *sdhci_pci_probe_slot( 
		if (!gpio_request(slot->rst_n_gpio, "eMMC_reset")) {

			gpio_direction_output(slot->rst_n_gpio, 1);

			slot->host->mmc->caps |= MMC_CAP_HW_RESET;

			slot->hw_reset = sdhci_pci_gpio_hw_reset;

		} else {

			dev_warn(&pdev->dev, "failed to request rst_n_gpio\n");

			slot->rst_n_gpio = -EINVAL;