[PATCH 04/12] mmc: sd: add support for driver type selection

Arindam Nath
2011-02-15T09:38:01Z

This patch adds support for setting driver strength during UHS-I
initialization prcedure. Since UHS-I cards set S18A (bit 24) in
response to ACMD41, we use this as a base for UHS-I initialization.
We modify the parameter list of mmc_sd_get_cid() so that we can save
the ROCR from ACMD41 to check whether bit 24 is set.

We decide whether the Host Controller supports A, C, or D driver type
depending on the Capabilities register. We then set the appropriate
driver type for the card using CMD6 mode 1. As per Host Controller
spec v3.00, we set driver type for the host only if Preset Value Enable
in the Host Control2 register is not set. SDHCI_HOST_CONTROL has been
renamed to SDHCI_HOST_CONTROL1 to conform to the spec.

Signed-off-by: Arindam Nath <arindam.nath@amd.com>
---
drivers/mmc/core/core.c | 9 +++
drivers/mmc/core/core.h | 1 +
drivers/mmc/core/sd.c | 140 +++++++++++++++++++++++++++++++++++++---------
drivers/mmc/core/sd.h | 3 +-
drivers/mmc/core/sdio.c | 3 +-
drivers/mmc/host/sdhci.c | 48 ++++++++++++----
drivers/mmc/host/sdhci.h | 10 +++-
include/linux/mmc/card.h | 4 +
include/linux/mmc/host.h | 8 +++
9 files changed, 186 insertions(+), 40 deletions(-)

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 6625c05..daa535a 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -947,6 +947,15 @@ void mmc_set_timing(struct mmc_host *host, unsigned int timing)
}

/*
+ * Select appropriate driver type for host.
+ */
+void mmc_set_driver_type(struct mmc_host *host, unsigned int drv_type)
+{
+ host->ios.drv_type = drv_type;
+ mmc_set_ios(host);
+}
+
+/*
* Apply power to the MMC stack. This is a two-stage process.
* First, we enable power to the card without the clock running.
* We then wait a bit for the power to stabilise. Finally,
diff --git a/drivers/mmc/core/core.h b/drivers/mmc/core/core.h
index ca1fdde..6114ca5 100644
--- a/drivers/mmc/core/core.h
+++ b/drivers/mmc/core/core.h
@@ -42,6 +42,7 @@ void mmc_set_bus_width_ddr(struct mmc_host *host, unsigned int width,
unsigned int ddr);
u32 mmc_select_voltage(struct mmc_host *host, u32 ocr);
void mmc_set_timing(struct mmc_host *host, unsigned int timing);
+void mmc_set_driver_type(struct mmc_host *host, unsigned int drv_type);

static inline void mmc_delay(unsigned int ms)
{
diff --git a/drivers/mmc/core/sd.c b/drivers/mmc/core/sd.c
index 2a84396..9e4574d 100644
--- a/drivers/mmc/core/sd.c
+++ b/drivers/mmc/core/sd.c
@@ -426,6 +426,86 @@ out:
return err;
}

+static int sd_select_driver_type(struct mmc_card *card, u8 *status)
+{
+ int host_set_drv_type, card_set_drv_type;
+ int err;
+
+ /*
+ * If the host doesn't support any of the Driver Types A,C or D,
+ * default Driver Type B is used.
+ */
+ if (!(card->host->caps & (MMC_CAP_DRIVER_TYPE_A | MMC_CAP_DRIVER_TYPE_C
+ | MMC_CAP_DRIVER_TYPE_D)))
+ return 0;
+
+ if (card->host->caps & MMC_CAP_DRIVER_TYPE_A) {
+ host_set_drv_type = MMC_SET_DRIVER_TYPE_A;
+ if (card->sw_caps.uhs_drv_type & SD_DRIVER_TYPE_A)
+ card_set_drv_type = MMC_SET_DRIVER_TYPE_A;
+ else if (card->sw_caps.uhs_drv_type & SD_DRIVER_TYPE_C)
+ card_set_drv_type = MMC_SET_DRIVER_TYPE_C;
+ } else if (card->host->caps & MMC_CAP_DRIVER_TYPE_C) {
+ host_set_drv_type = MMC_SET_DRIVER_TYPE_C;
+ if (card->sw_caps.uhs_drv_type & SD_DRIVER_TYPE_C)
+ card_set_drv_type = MMC_SET_DRIVER_TYPE_C;
+ }
+
+ err = mmc_sd_switch(card, 1, 2, card_set_drv_type, status);
+ if (err)
+ return err;
+
+ if ((status[15] & 0xF) != card_set_drv_type)
+ printk(KERN_WARNING "%s: Problem setting driver strength!\n",
+ mmc_hostname(card->host));
+ else
+ mmc_set_driver_type(card->host, host_set_drv_type);
+
+ return 0;
+}
+
+/*
+ * UHS-I specific initialization procedure
+ */
+static int mmc_sd_init_uhs_card(struct mmc_card *card)
+{
+ int err;
+ u8 *status;
+
+ if (!card->scr.sda_spec3)
+ return 0;
+
+ if (!(card->csd.cmdclass & CCC_SWITCH))
+ return 0;
+
+ err = -EIO;
+
+ status = kmalloc(64, GFP_KERNEL);
+ if (!status) {
+ printk(KERN_ERR "%s: could not allocate a buffer for "
+ "switch capabilities.\n", mmc_hostname(card->host));
+ return -ENOMEM;
+ }
+
+ /* Set 4-bit bus width */
+ if ((card->host->caps & MMC_CAP_4_BIT_DATA) &&
+ (card->scr.bus_widths & SD_SCR_BUS_WIDTH_4)) {
+ err = mmc_app_set_bus_width(card, MMC_BUS_WIDTH_4);
+ if (err)
+ goto out;
+
+ mmc_set_bus_width(card->host, MMC_BUS_WIDTH_4);
+ }
+
+ /* Set the driver strength for the card */
+ err = sd_select_driver_type(card, status);
+
+out:
+ kfree(status);
+
+ return err;
+}
+
MMC_DEV_ATTR(cid, "%08x%08x%08x%08x\n", card->raw_cid[0], card->raw_cid[1],
card->raw_cid[2], card->raw_cid[3]);
MMC_DEV_ATTR(csd, "%08x%08x%08x%08x\n", card->raw_csd[0], card->raw_csd[1],
@@ -474,10 +554,10 @@ struct device_type sd_type = {
/*
* Fetch CID from card.
*/
-int mmc_sd_get_cid(struct mmc_host *host, u32 ocr, u32 *cid)
+int mmc_sd_get_cid(struct mmc_host *host, u32 ocr, u32 *cid,
+ u32 *rocr)
{
int err;
- u32 rocr;

/*
* Since we're changing the OCR value, we seem to
@@ -502,7 +582,7 @@ int mmc_sd_get_cid(struct mmc_host *host, u32 ocr, u32 *cid)
MMC_CAP_SET_XPC_180))
ocr |= 1 << 28;

- err = mmc_send_app_op_cond(host, ocr, &rocr);
+ err = mmc_send_app_op_cond(host, ocr, rocr);
if (err)
return err;

@@ -510,7 +590,7 @@ int mmc_sd_get_cid(struct mmc_host *host, u32 ocr, u32 *cid)
* In case CCS and S18A in the response is set, start Signal Voltage
* Switch procedure. SPI mode doesn't support CMD11.
*/
- if (!mmc_host_is_spi(host) && (rocr & 0x41000000)) {
+ if (!mmc_host_is_spi(host) && rocr && (*rocr & 0x41000000)) {
err = mmc_start_voltage_switch(host);
if (err)
return err;
@@ -643,11 +723,12 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
struct mmc_card *card;
int err;
u32 cid[4];
+ u32 rocr;

BUG_ON(!host);
WARN_ON(!host->claimed);

- err = mmc_sd_get_cid(host, ocr, cid);
+ err = mmc_sd_get_cid(host, ocr, cid, &rocr);
if (err)
return err;

@@ -700,30 +781,37 @@ static int mmc_sd_init_card(struct mmc_host *host, u32 ocr,
if (err)
goto free_card;

- /*
- * Attempt to change to high-speed (if supported)
- */
- err = mmc_sd_switch_hs(card);
- if (err > 0)
- mmc_sd_go_highspeed(card);
- else if (err)
- goto free_card;
-
- /*
- * Set bus speed.
- */
- mmc_set_clock(host, mmc_sd_get_max_clock(card));
-
- /*
- * Switch to wider bus (if supported).
- */
- if ((host->caps & MMC_CAP_4_BIT_DATA) &&
- (card->scr.bus_widths & SD_SCR_BUS_WIDTH_4)) {
- err = mmc_app_set_bus_width(card, MMC_BUS_WIDTH_4);
+ /* Initialization sequence for UHS-I cards */
+ if (rocr & 0x01000000) {
+ err = mmc_sd_init_uhs_card(card);
if (err)
goto free_card;
+ } else {
+ /*
+ * Attempt to change to high-speed (if supported)
+ */
+ err = mmc_sd_switch_hs(card);
+ if (err > 0)
+ mmc_sd_go_highspeed(card);
+ else if (err)
+ goto free_card;
+
+ /*
+ * Set bus speed.
+ */
+ mmc_set_clock(host, mmc_sd_get_max_clock(card));

- mmc_set_bus_width(host, MMC_BUS_WIDTH_4);
+ /*
+ * Switch to wider bus (if supported).
+ */
+ if ((host->caps & MMC_CAP_4_BIT_DATA) &&
+ (card->scr.bus_widths & SD_SCR_BUS_WIDTH_4)) {
+ err = mmc_app_set_bus_width(card, MMC_BUS_WIDTH_4);
+ if (err)
+ goto free_card;
+
+ mmc_set_bus_width(host, MMC_BUS_WIDTH_4);
+ }
}

host->card = card;
diff --git a/drivers/mmc/core/sd.h b/drivers/mmc/core/sd.h
index 3d8800f..5106b44 100644
--- a/drivers/mmc/core/sd.h
+++ b/drivers/mmc/core/sd.h
@@ -5,7 +5,8 @@

extern struct device_type sd_type;

-int mmc_sd_get_cid(struct mmc_host *host, u32 ocr, u32 *cid);
+int mmc_sd_get_cid(struct mmc_host *host, u32 ocr, u32 *cid,
+ u32 *rocr);
int mmc_sd_get_csd(struct mmc_host *host, struct mmc_card *card);
void mmc_decode_cid(struct mmc_card *card);
int mmc_sd_setup_card(struct mmc_host *host, struct mmc_card *card,
diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
index 5c4a54d..6d16684 100644
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -364,7 +364,8 @@ static int mmc_sdio_init_card(struct mmc_host *host, u32 ocr,
}

if (ocr & R4_MEMORY_PRESENT
- && mmc_sd_get_cid(host, host->ocr & ocr, card->raw_cid) == 0) {
+ && mmc_sd_get_cid(host, host->ocr & ocr, card->raw_cid,
+ NULL) == 0) {
card->type = MMC_TYPE_SD_COMBO;

if (oldcard && (oldcard->type != MMC_TYPE_SD_COMBO ||
diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 6d7a276..b768839 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -65,7 +65,7 @@ static void sdhci_dumpregs(struct sdhci_host *host)
sdhci_readw(host, SDHCI_TRANSFER_MODE));
printk(KERN_DEBUG DRIVER_NAME ": Present: 0x%08x | Host ctl: 0x%08x\n",
sdhci_readl(host, SDHCI_PRESENT_STATE),
- sdhci_readb(host, SDHCI_HOST_CONTROL));
+ sdhci_readb(host, SDHCI_HOST_CONTROL1));
printk(KERN_DEBUG DRIVER_NAME ": Power: 0x%08x | Blk gap: 0x%08x\n",
sdhci_readb(host, SDHCI_POWER_CONTROL),
sdhci_readb(host, SDHCI_BLOCK_GAP_CONTROL));
@@ -218,18 +218,18 @@ static void sdhci_activate_led(struct sdhci_host *host)
{
u8 ctrl;

- ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
+ ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL1);
ctrl |= SDHCI_CTRL_LED;
- sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
+ sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL1);
}

static void sdhci_deactivate_led(struct sdhci_host *host)
{
u8 ctrl;

- ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
+ ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL1);
ctrl &= ~SDHCI_CTRL_LED;
- sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
+ sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL1);
}

#ifdef SDHCI_USE_LEDS_CLASS
@@ -788,14 +788,14 @@ static void sdhci_prepare_data(struct sdhci_host *host, struct mmc_data *data)
* is ADMA.
*/
if (host->version >= SDHCI_SPEC_200) {
- ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
+ ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL1);
ctrl &= ~SDHCI_CTRL_DMA_MASK;
if ((host->flags & SDHCI_REQ_USE_DMA) &&
(host->flags & SDHCI_USE_ADMA))
ctrl |= SDHCI_CTRL_ADMA32;
else
ctrl |= SDHCI_CTRL_SDMA;
- sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
+ sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL1);
}

if (!(host->flags & SDHCI_REQ_USE_DMA)) {
@@ -1255,7 +1255,7 @@ static void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
if (host->ops->platform_8bit_width)
host->ops->platform_8bit_width(host, ios->bus_width);
else {
- ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
+ ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL1);
if (ios->bus_width == MMC_BUS_WIDTH_8) {
ctrl &= ~SDHCI_CTRL_4BITBUS;
if (host->version >= SDHCI_SPEC_300)
@@ -1268,10 +1268,10 @@ static void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
else
ctrl &= ~SDHCI_CTRL_4BITBUS;
}
- sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
+ sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL1);
}

- ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL);
+ ctrl = sdhci_readb(host, SDHCI_HOST_CONTROL1);

if ((ios->timing == MMC_TIMING_SD_HS ||
ios->timing == MMC_TIMING_MMC_HS)
@@ -1280,7 +1280,25 @@ static void sdhci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
else
ctrl &= ~SDHCI_CTRL_HISPD;

- sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL);
+ sdhci_writeb(host, ctrl, SDHCI_HOST_CONTROL1);
+
+ if (host->version >= SDHCI_SPEC_300) {
+ u16 ctrl_2;
+
+ ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
+ if (!(ctrl_2 & SDHCI_CTRL_PRESET_VAL_ENABLE)) {
+ /*
+ * We only need to set Driver Strength if the
+ * preset value enable is not set.
+ */
+ if (ios->drv_type == MMC_SET_DRIVER_TYPE_A)
+ ctrl_2 |= SDHCI_CTRL_DRV_TYPE_A;
+ else if (ios->drv_type == MMC_SET_DRIVER_TYPE_C)
+ ctrl_2 |= SDHCI_CTRL_DRV_TYPE_C;
+
+ sdhci_writew(host, ctrl_2, SDHCI_HOST_CONTROL2);
+ }
+ }

/*
* Some (ENE) controllers go apeshit on some ios operation,
@@ -2037,6 +2055,14 @@ int sdhci_add_host(struct sdhci_host *host)
if (caps[1] & SDHCI_SUPPORT_DDR50)
mmc->caps |= MMC_CAP_UHS_DDR50;

+ /* Driver Type(s) (A, C, D) supported by the host */
+ if (caps[1] & SDHCI_DRIVER_TYPE_A)
+ mmc->caps |= MMC_CAP_DRIVER_TYPE_A;
+ if (caps[1] & SDHCI_DRIVER_TYPE_C)
+ mmc->caps |= MMC_CAP_DRIVER_TYPE_C;
+ if (caps[1] & SDHCI_DRIVER_TYPE_D)
+ mmc->caps |= MMC_CAP_DRIVER_TYPE_D;
+
ocr_avail = 0;
/*
* According to SD Host Controller spec v3.00, if the Host System
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 95d70e6..a407b5b 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -72,7 +72,7 @@
#define SDHCI_DATA_LVL_MASK 0x00F00000
#define SDHCI_DATA_LVL_SHIFT 20

-#define SDHCI_HOST_CONTROL 0x28
+#define SDHCI_HOST_CONTROL1 0x28
#define SDHCI_CTRL_LED 0x01
#define SDHCI_CTRL_4BITBUS 0x02
#define SDHCI_CTRL_HISPD 0x04
@@ -151,6 +151,11 @@

#define SDHCI_HOST_CONTROL2 0x3E
#define SDHCI_CTRL_VDD_180 0x0008
+#define SDHCI_CTRL_DRV_TYPE_B 0x0000
+#define SDHCI_CTRL_DRV_TYPE_A 0x0010
+#define SDHCI_CTRL_DRV_TYPE_C 0x0020
+#define SDHCI_CTRL_DRV_TYPE_D 0x0030
+#define SDHCI_CTRL_PRESET_VAL_ENABLE 0x8000

#define SDHCI_CAPABILITIES 0x40
#define SDHCI_TIMEOUT_CLK_MASK 0x0000003F
@@ -174,6 +179,9 @@
#define SDHCI_SUPPORT_SDR50 0x00000001
#define SDHCI_SUPPORT_SDR104 0x00000002
#define SDHCI_SUPPORT_DDR50 0x00000004
+#define SDHCI_DRIVER_TYPE_A 0x00000010
+#define SDHCI_DRIVER_TYPE_C 0x00000020
+#define SDHCI_DRIVER_TYPE_D 0x00000040

#define SDHCI_CAPABILITIES_1 0x44

diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index 7080f22..2d7f7a3 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -77,6 +77,10 @@ struct sd_switch_caps {
unsigned int hs_max_dtr;
unsigned int uhs_bus_mode;
unsigned int uhs_drv_type;
+#define SD_DRIVER_TYPE_B 0x01
+#define SD_DRIVER_TYPE_A 0x02
+#define SD_DRIVER_TYPE_C 0x04
+#define SD_DRIVER_TYPE_D 0x08
unsigned int uhs_curr_limit;
};

diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index ec09b32..e6ae4c4 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -56,6 +56,11 @@ struct mmc_ios {
#define MMC_SDR_MODE 0
#define MMC_1_2V_DDR_MODE 1
#define MMC_1_8V_DDR_MODE 2
+
+ unsigned char drv_type; /* driver type (A, C, D) */
+
+#define MMC_SET_DRIVER_TYPE_A 1
+#define MMC_SET_DRIVER_TYPE_C 2
};

struct mmc_host_ops {
@@ -181,6 +186,9 @@ struct mmc_host {
#define MMC_CAP_SET_XPC_330 (1 << 18) /* Host supports >150mA current at 3.3V */
#define MMC_CAP_SET_XPC_300 (1 << 19) /* Host supports >150mA current at 3.0V */
#define MMC_CAP_SET_XPC_180 (1 << 20) /* Host supports >150mA current at 1.8V */
+#define MMC_CAP_DRIVER_TYPE_A (1 << 21) /* Host supports Driver Type A */
+#define MMC_CAP_DRIVER_TYPE_C (1 << 22) /* Host supports Driver Type C */
+#define MMC_CAP_DRIVER_TYPE_D (1 << 23) /* Host supports Driver Type D */

mmc_pm_flag_t pm_caps; /* supported pm features */

--
1.7.1