From e1bfad6d936d7149a83423e2a7244dd5771f27e7 Mon Sep 17 00:00:00 2001 From: Adrian Hunter Date: Fri, 6 Feb 2015 14:13:00 +0200 Subject: [PATCH] mmc: sdhci-pci: Add support for drive strength selection for SPT Implement the select_drive_strength callback to provide drive strength selection for Intel SPT. Signed-off-by: Adrian Hunter Signed-off-by: Ulf Hansson --- drivers/mmc/host/sdhci-pci-data.c | 3 ++ drivers/mmc/host/sdhci-pci.c | 83 ++++++++++++++++++++++++++++++++++++++ drivers/mmc/host/sdhci-pci.h | 4 ++ include/linux/mmc/sdhci-pci-data.h | 2 + 4 files changed, 92 insertions(+) diff --git a/drivers/mmc/host/sdhci-pci-data.c b/drivers/mmc/host/sdhci-pci-data.c index a611217769f5..56fddc622a54 100644 --- a/drivers/mmc/host/sdhci-pci-data.c +++ b/drivers/mmc/host/sdhci-pci-data.c @@ -3,3 +3,6 @@ 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); diff --git a/drivers/mmc/host/sdhci-pci.c b/drivers/mmc/host/sdhci-pci.c index 7a3fc16d0a6c..6ecd158d8084 100644 --- a/drivers/mmc/host/sdhci-pci.c +++ b/drivers/mmc/host/sdhci-pci.c @@ -20,6 +20,7 @@ #include #include #include +#include #include #include #include @@ -266,6 +267,69 @@ 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 = 1; /* 33-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) +{ + 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; + + sdhci_pci_spt_drive_strength = 0x10 | ((val >> 12) & 0xf); +} + static int byt_emmc_probe_slot(struct sdhci_pci_slot *slot) { slot->host->mmc->caps |= MMC_CAP_8_BIT_DATA | MMC_CAP_NONREMOVABLE | @@ -276,6 +340,10 @@ 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; + } return 0; } @@ -1203,6 +1271,20 @@ static void sdhci_pci_hw_reset(struct sdhci_host *host) slot->hw_reset(host); } +static int sdhci_pci_select_drive_strength(struct sdhci_host *host, + struct mmc_card *card, + unsigned int max_dtr, int host_drv, + int card_drv, int *drv_type) +{ + struct sdhci_pci_slot *slot = sdhci_priv(host); + + if (!slot->select_drive_strength) + return 0; + + return slot->select_drive_strength(host, card, max_dtr, host_drv, + card_drv, drv_type); +} + static const struct sdhci_ops sdhci_pci_ops = { .set_clock = sdhci_set_clock, .enable_dma = sdhci_pci_enable_dma, @@ -1210,6 +1292,7 @@ static const struct sdhci_ops sdhci_pci_ops = { .reset = sdhci_reset, .set_uhs_signaling = sdhci_set_uhs_signaling, .hw_reset = sdhci_pci_hw_reset, + .select_drive_strength = sdhci_pci_select_drive_strength, }; /*****************************************************************************\ diff --git a/drivers/mmc/host/sdhci-pci.h b/drivers/mmc/host/sdhci-pci.h index 1ec684d06d54..541f1cad5247 100644 --- a/drivers/mmc/host/sdhci-pci.h +++ b/drivers/mmc/host/sdhci-pci.h @@ -72,6 +72,10 @@ struct sdhci_pci_slot { bool cd_override_level; void (*hw_reset)(struct sdhci_host *host); + int (*select_drive_strength)(struct sdhci_host *host, + struct mmc_card *card, + unsigned int max_dtr, int host_drv, + int card_drv, int *drv_type); }; struct sdhci_pci_chip { diff --git a/include/linux/mmc/sdhci-pci-data.h b/include/linux/mmc/sdhci-pci-data.h index 8959604a13d3..fda15b6d4135 100644 --- a/include/linux/mmc/sdhci-pci-data.h +++ b/include/linux/mmc/sdhci-pci-data.h @@ -15,4 +15,6 @@ struct sdhci_pci_data { extern struct sdhci_pci_data *(*sdhci_pci_get_data)(struct pci_dev *pdev, int slotno); +extern int sdhci_pci_spt_drive_strength; + #endif -- 2.11.0