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mmc: sdhci-pci: add eMMC hardware reset support

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Implement eMMC hardware reset for Medfield.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Chris Ball <cjb@laptop.org>
This commit is contained in:
Adrian Hunter 2011-08-29 16:42:13 +03:00 committed by Chris Ball
parent 20758b66dc
commit 0f2016558e
1 changed files with 72 additions and 0 deletions
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72
drivers/mmc/host/sdhci-pci.c
View file

@ -21,6 +21,8 @@
#include <linux/mmc/host.h>
#include <linux/scatterlist.h>
#include <linux/io.h>
#include <linux/gpio.h>
#include <linux/sfi.h>
#include "sdhci.h"
@ -59,6 +61,7 @@ struct sdhci_pci_slot {
struct sdhci_host *host;
int pci_bar;
int rst_n_gpio;
};
struct sdhci_pci_chip {
@ -163,12 +166,63 @@ static int mrst_hc_probe(struct sdhci_pci_chip *chip)
return 0;
}
/* Medfield eMMC hardware reset GPIOs */
static int mfd_emmc0_rst_gpio = -EINVAL;
static int mfd_emmc1_rst_gpio = -EINVAL;
static int mfd_emmc_gpio_parse(struct sfi_table_header *table)
{
struct sfi_table_simple *sb = (struct sfi_table_simple *)table;
struct sfi_gpio_table_entry *entry;
int i, num;
num = SFI_GET_NUM_ENTRIES(sb, struct sfi_gpio_table_entry);
entry = (struct sfi_gpio_table_entry *)sb->pentry;
for (i = 0; i < num; i++, entry++) {
if (!strncmp(entry->pin_name, "emmc0_rst", SFI_NAME_LEN))
mfd_emmc0_rst_gpio = entry->pin_no;
else if (!strncmp(entry->pin_name, "emmc1_rst", SFI_NAME_LEN))
mfd_emmc1_rst_gpio = entry->pin_no;
}
return 0;
}
static int mfd_emmc_probe_slot(struct sdhci_pci_slot *slot)
{
const char *name = NULL;
int gpio = -EINVAL;
sfi_table_parse(SFI_SIG_GPIO, NULL, NULL, mfd_emmc_gpio_parse);
switch (slot->chip->pdev->device) {
case PCI_DEVICE_ID_INTEL_MFD_EMMC0:
gpio = mfd_emmc0_rst_gpio;
name = "eMMC0_reset";
break;
case PCI_DEVICE_ID_INTEL_MFD_EMMC1:
gpio = mfd_emmc1_rst_gpio;
name = "eMMC1_reset";
break;
}
if (!gpio_request(gpio, name)) {
gpio_direction_output(gpio, 1);
slot->rst_n_gpio = gpio;
slot->host->mmc->caps |= MMC_CAP_HW_RESET;
}
slot->host->mmc->caps |= MMC_CAP_8_BIT_DATA;
return 0;
}
static void mfd_emmc_remove_slot(struct sdhci_pci_slot *slot, int dead)
{
gpio_free(slot->rst_n_gpio);
}
static const struct sdhci_pci_fixes sdhci_intel_mrst_hc0 = {
.quirks = SDHCI_QUIRK_BROKEN_ADMA | SDHCI_QUIRK_NO_HISPD_BIT,
.probe_slot = mrst_hc_probe_slot,
@ -190,6 +244,7 @@ static const struct sdhci_pci_fixes sdhci_intel_mfd_sdio = {
static const struct sdhci_pci_fixes sdhci_intel_mfd_emmc = {
.quirks = SDHCI_QUIRK_NO_ENDATTR_IN_NOPDESC,
.probe_slot = mfd_emmc_probe_slot,
.remove_slot = mfd_emmc_remove_slot,
};
/* O2Micro extra registers */
@ -832,9 +887,25 @@ static int sdhci_pci_8bit_width(struct sdhci_host *host, int width)
return 0;
}
static void sdhci_pci_hw_reset(struct sdhci_host *host)
{
struct sdhci_pci_slot *slot = sdhci_priv(host);
int rst_n_gpio = slot->rst_n_gpio;
if (!gpio_is_valid(rst_n_gpio))
return;
gpio_set_value_cansleep(rst_n_gpio, 0);
/* For eMMC, minimum is 1us but give it 10us for good measure */
udelay(10);
gpio_set_value_cansleep(rst_n_gpio, 1);
/* For eMMC, minimum is 200us but give it 300us for good measure */
usleep_range(300, 1000);
}
static struct sdhci_ops sdhci_pci_ops = {
.enable_dma = sdhci_pci_enable_dma,
.platform_8bit_width = sdhci_pci_8bit_width,
.hw_reset = sdhci_pci_hw_reset,
};
/*****************************************************************************\
@ -988,6 +1059,7 @@ static struct sdhci_pci_slot * __devinit sdhci_pci_probe_slot(
slot->chip = chip;
slot->host = host;
slot->pci_bar = bar;
slot->rst_n_gpio = -EINVAL;
host->hw_name = "PCI";
host->ops = &sdhci_pci_ops;