Current implementation for bus speed mode selection is too
complicated. This patch is to simplify the codes and remove
some duplicate parts.
The following changes are including:
* Adds functions for each mode selection(HS, HS-DDR, HS200 and etc)
* Rearranged the mode selection sequence with supported device type
* Adds maximum speed for HS200 mode(hs200_max_dtr)
* Adds field definition for HS_TIMING of EXT_CSD
Signed-off-by: Seungwon Jeon <tgih.jun@xxxxxxxxxxx>
---
drivers/mmc/core/debugfs.c | 2 +-
drivers/mmc/core/mmc.c | 443 +++++++++++++++++++++++++-------------------
include/linux/mmc/card.h | 1 +
include/linux/mmc/mmc.h | 4 +
4 files changed, 257 insertions(+), 193 deletions(-)
diff --git a/drivers/mmc/core/debugfs.c b/drivers/mmc/core/debugfs.c
index 509229b..1f730db 100644
--- a/drivers/mmc/core/debugfs.c
+++ b/drivers/mmc/core/debugfs.c
@@ -139,7 +139,7 @@ static int mmc_ios_show(struct seq_file *s, void *data)
str = "mmc DDR52";
break;
case MMC_TIMING_MMC_HS200:
- str = "mmc high-speed SDR200";
+ str = "mmc HS200";
break;
default:
str = "invalid";
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 0d17395..aa1441a 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -242,7 +242,7 @@ static void mmc_select_card_type(struct mmc_card *card)
struct mmc_host *host = card->host;
u8 card_type = card->ext_csd.raw_card_type & EXT_CSD_CARD_TYPE_MASK;
u32 caps = host->caps, caps2 = host->caps2;
- unsigned int hs_max_dtr = 0;
+ unsigned int hs_max_dtr = 0, hs200_max_dtr = 0;
unsigned int avail_type = 0;
if (caps & MMC_CAP_MMC_HIGHSPEED &&
@@ -271,17 +271,18 @@ static void mmc_select_card_type(struct mmc_card *card)
if (caps2 & MMC_CAP2_HS200_1_8V_SDR &&
card_type & EXT_CSD_CARD_TYPE_HS200_1_8V) {
- hs_max_dtr = MMC_HS200_MAX_DTR;
+ hs200_max_dtr = MMC_HS200_MAX_DTR;
avail_type |= EXT_CSD_CARD_TYPE_HS200_1_8V;
}
if (caps2 & MMC_CAP2_HS200_1_2V_SDR &&
card_type & EXT_CSD_CARD_TYPE_HS200_1_2V) {
- hs_max_dtr = MMC_HS200_MAX_DTR;
+ hs200_max_dtr = MMC_HS200_MAX_DTR;
avail_type |= EXT_CSD_CARD_TYPE_HS200_1_2V;
}
card->ext_csd.hs_max_dtr = hs_max_dtr;
+ card->ext_csd.hs200_max_dtr = hs200_max_dtr;
card->mmc_avail_type = avail_type;
}
@@ -849,37 +850,52 @@ static int mmc_select_powerclass(struct mmc_card *card, u8 *ext_csd)
}
/*
- * Selects the desired buswidth and switch to the HS200 mode
- * if bus width set without error
+ * Set the bus speed for the selected speed mode.
*/
-static int mmc_select_hs200(struct mmc_card *card)
+static void mmc_set_bus_speed(struct mmc_card *card)
+{
+ unsigned int max_dtr = (unsigned int)-1;
+
+ BUG_ON(!card);
+
+ if (mmc_card_hs200(card) && max_dtr > card->ext_csd.hs200_max_dtr)
+ max_dtr = card->ext_csd.hs200_max_dtr;
+ else if (mmc_card_hs(card) && max_dtr > card->ext_csd.hs_max_dtr)
+ max_dtr = card->ext_csd.hs_max_dtr;
+ else if (max_dtr > card->csd.max_dtr)
+ max_dtr = card->csd.max_dtr;
+
+ mmc_set_clock(card->host, max_dtr);
+}
+
+/*
+ * Select the bus width amoung 4-bit and 8-bit(SDR).
+ * If the bus width is changed successfully, return the slected width value.
+ * Zero is returned instead of error value if the wide width is not supported.
+ */
+static int mmc_select_bus_width(struct mmc_card *card)
{
- int idx, err = -EINVAL;
- struct mmc_host *host;
static unsigned ext_csd_bits[] = {
- EXT_CSD_BUS_WIDTH_4,
EXT_CSD_BUS_WIDTH_8,
+ EXT_CSD_BUS_WIDTH_4,
};
static unsigned bus_widths[] = {
- MMC_BUS_WIDTH_4,
MMC_BUS_WIDTH_8,
+ MMC_BUS_WIDTH_4,
};
+ struct mmc_host *host;
+ unsigned idx, bus_width = 0;
+ int err = 0;
BUG_ON(!card);
host = card->host;
- if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200_1_2V)
- err = __mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_120);
-
- if (err && card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200_1_8V)
- err = __mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180);
-
- /* If fails try again during next card power cycle */
- if (err)
- goto err;
+ if ((card->csd.mmca_vsn < CSD_SPEC_VER_4) &&
+ !(host->caps & (MMC_CAP_4_BIT_DATA | MMC_CAP_8_BIT_DATA)))
+ return 0;
- idx = (host->caps & MMC_CAP_8_BIT_DATA) ? 1 : 0;
+ idx = (host->caps & MMC_CAP_8_BIT_DATA) ? 0 : 1;
/*
* Unlike SD, MMC cards dont have a configuration register to notify
@@ -887,8 +903,7 @@ static int mmc_select_hs200(struct mmc_card *card)
* the supported bus width or compare the ext csd values of current
* bus width and ext csd values of 1 bit mode read earlier.
*/
- for (; idx >= 0; idx--) {
-
+ for (; idx < ARRAY_SIZE(bus_widths); idx++) {
/*
* Host is capable of 8bit transfer, then switch
* the device to work in 8bit transfer mode. If the
@@ -903,25 +918,219 @@ static int mmc_select_hs200(struct mmc_card *card)
if (err)
continue;
- mmc_set_bus_width(card->host, bus_widths[idx]);
+ bus_width = bus_widths[idx];
+ mmc_set_bus_width(host, bus_width);
+ /*
+ * If controller can't handle bus width test,
+ * compare ext_csd previously read in 1 bit mode
+ * against ext_csd at new bus width
+ */
if (!(host->caps & MMC_CAP_BUS_WIDTH_TEST))
- err = mmc_compare_ext_csds(card, bus_widths[idx]);
+ err = mmc_compare_ext_csds(card, bus_width);
else
- err = mmc_bus_test(card, bus_widths[idx]);
- if (!err)
+ err = mmc_bus_test(card, bus_width);
+
+ if (!err) {
+ err = bus_width;
break;
+ } else {
+ pr_warn("%s: switch to bus width %d failed\n",
+ mmc_hostname(card->host), ext_csd_bits[idx]);
+ }
}
- /* switch to HS200 mode if bus width set successfully */
+ return err;
+}
+
+/*
+ * Switch to the high-speed mode
+ */
+static int mmc_select_hs(struct mmc_card *card)
+{
+ int err;
+
+ BUG_ON(!card);
+
+ err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
+ EXT_CSD_HS_TIMING, EXT_CSD_TIMING_HS,
+ card->ext_csd.generic_cmd6_time);
if (!err)
+ mmc_set_timing(card->host, MMC_TIMING_MMC_HS);
+
+ return err;
+}
+
+/*
+ * Activate wide bus and DDR if supported.
+ */
+static int mmc_select_hs_ddr(struct mmc_card *card, u8 *ext_csd)
+{
+ struct mmc_host *host;
+ u32 bus_width, ext_csd_bits;
+ int err = 0, ddr;
+
+ BUG_ON(!card);
+
+ ddr = mmc_snoop_ddr(card);
+ if (!(ddr & EXT_CSD_CARD_TYPE_DDR_52))
+ return 0;
+
+ host = card->host;
+ bus_width = host->ios.bus_width;
+ if (bus_width == MMC_BUS_WIDTH_1)
+ return 0;
+
+ ext_csd_bits = (bus_width == MMC_BUS_WIDTH_8) ?
+ EXT_CSD_DDR_BUS_WIDTH_8 : EXT_CSD_DDR_BUS_WIDTH_4;
+
+ err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
+ EXT_CSD_BUS_WIDTH,
+ ext_csd_bits,
+ card->ext_csd.generic_cmd6_time);
+ if (err) {
+ pr_warn("%s: switch to bus width %d ddr failed\n",
+ mmc_hostname(host), 1 << bus_width);
+ return err;
+ }
+
+ /*
+ * eMMC cards can support 3.3V to 1.2V i/o (vccq)
+ * signaling.
+ *
+ * EXT_CSD_CARD_TYPE_DDR_1_8V means 3.3V or 1.8V vccq.
+ *
+ * 1.8V vccq at 3.3V core voltage (vcc) is not required
+ * in the JEDEC spec for DDR.
+ *
+ * Do not force change in vccq since we are obviously
+ * working and no change to vccq is needed.
+ *
+ * WARNING: eMMC rules are NOT the same as SD DDR
+ */
+ if (ddr & EXT_CSD_CARD_TYPE_DDR_1_2V) {
+ err = __mmc_set_signal_voltage(host,
+ MMC_SIGNAL_VOLTAGE_120);
+ if (err)
+ return err;
+ }
+
+ mmc_set_timing(host, MMC_TIMING_MMC_DDR52);
+
+ return err;
+}
+
+/*
+ * For device supporting HS200 mode, the following sequence
+ * should be done before executing the tuning process.
+ * 1. set the desired bus width(4-bit or 8-bit, 1-bit is not supported)
+ * 2. switch to HS200 mode
+ * 3. set the clock to > 52Mhz and <=200MHz
+ */
+static int mmc_select_hs200(struct mmc_card *card)
+{
+ int err = -EINVAL;
+ struct mmc_host *host;
+
+ BUG_ON(!card);
+
+ host = card->host;
+
+ if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200_1_2V)
+ err = __mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_120);
+
+ if (err && card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200_1_8V)
+ err = __mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180);
+
+ /* If fails try again during next card power cycle */
+ if (err)
+ goto err;
+
+ /*
+ * Set the bus width(4 or 8) with host's support and
+ * switch to HS200 mode if bus width is set successfully.
+ */
+ err = mmc_select_bus_width(card);
+ if (!IS_ERR_VALUE(err)) {
err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
- EXT_CSD_HS_TIMING, 2, 0);
+ EXT_CSD_HS_TIMING, EXT_CSD_TIMING_HS200,
+ card->ext_csd.generic_cmd6_time);
+ if (!err)
+ mmc_set_timing(host, MMC_TIMING_MMC_HS200);
+ }
err:
return err;
}
/*
+ * Activate High Speed or HS200 mode if supported.
+ */
+static int mmc_select_timing(struct mmc_card *card)
+{
+ struct mmc_host *host;
+ int err = 0;
+
+ BUG_ON(!card);
+
+ host = card->host;
+
+ if ((card->csd.mmca_vsn < CSD_SPEC_VER_4 &&
+ card->ext_csd.hs_max_dtr == 0))
+ goto bus_speed;
+
+ if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200)
+ err = mmc_select_hs200(card);
+ else if(card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS)
+ err = mmc_select_hs(card);
+
+ if (err && err != -EBADMSG)
+ return err;
+
+ if (err) {
+ pr_warn("%s: switch to %s failed\n",
+ mmc_card_hs(card) ? "high-speed" :
+ (mmc_card_hs200(card) ? "hs200" : ""),
+ mmc_hostname(card->host));
+ err = 0;
+ }
+
+bus_speed:
+ /*
+ * Set the bus speed to the selected bus timing.
+ * If timing is not selected, backward compatible is the default.
+ */
+ mmc_set_bus_speed(card);
+ return err;
+}
+
+/*
+ * Execute tuning sequence to seek the proper bus operating
+ * conditions for HS200, which sends CMD21 to the device.
+ */
+static int mmc_hs200_tuning(struct mmc_card *card)
+{
+ int err = 0;
+ struct mmc_host *host;
+
+ BUG_ON(!card);
+
+ host = card->host;
+
+ if (card->host->ops->execute_tuning) {
+ mmc_host_clk_hold(card->host);
+ err = card->host->ops->execute_tuning(card->host,
+ MMC_SEND_TUNING_BLOCK_HS200);
+ mmc_host_clk_release(card->host);
+
+ if (err)
+ pr_warn("%s: tuning execution failed\n",
+ mmc_hostname(card->host));
+ }
+
+ return err;
+}
+
+/*
* Handle the detection and initialisation of a card.
*
* In the case of a resume, "oldcard" will contain the card
@@ -931,9 +1140,8 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
struct mmc_card *oldcard)
{
struct mmc_card *card;
- int err, ddr = 0;
+ int err;
u32 cid[4];
- unsigned int max_dtr;
u32 rocr;
u8 *ext_csd = NULL;
@@ -1125,172 +1333,23 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
}
/*
- * Activate high speed (if supported)
+ * Select timing interface
*/
- if (card->ext_csd.hs_max_dtr != 0) {
- err = 0;
- if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200)
- err = mmc_select_hs200(card);
- else if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS)
- err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
- EXT_CSD_HS_TIMING, 1,
- card->ext_csd.generic_cmd6_time);
-
- if (err && err != -EBADMSG)
- goto free_card;
-
- if (err) {
- pr_warning("%s: switch to highspeed failed\n",
- mmc_hostname(card->host));
- err = 0;
- } else {
- if (card->mmc_avail_type & EXT_CSD_CARD_TYPE_HS200)
- mmc_set_timing(card->host,
- MMC_TIMING_MMC_HS200);
- else
- mmc_set_timing(card->host, MMC_TIMING_MMC_HS);
- }
- }
-
- /*
- * Compute bus speed.
- */
- max_dtr = (unsigned int)-1;
-
- if (mmc_card_hs(card) || mmc_card_hs200(card)) {
- if (max_dtr > card->ext_csd.hs_max_dtr)
- max_dtr = card->ext_csd.hs_max_dtr;
- if (mmc_card_hs(card) && (max_dtr > 52000000))
- max_dtr = 52000000;
- } else if (max_dtr > card->csd.max_dtr) {
- max_dtr = card->csd.max_dtr;
- }
-
- mmc_set_clock(host, max_dtr);
-
- /*
- * Indicate DDR mode (if supported).
- */
- if (mmc_card_hs(card))
- ddr = mmc_snoop_ddr(card);
+ err = mmc_select_timing(card);
+ if (err)
+ goto free_card;
- /*
- * Indicate HS200 SDR mode (if supported).
- */
if (mmc_card_hs200(card)) {
- u32 ext_csd_bits;
- u32 bus_width = card->host->ios.bus_width;
-
- /*
- * For devices supporting HS200 mode, the bus width has
- * to be set before executing the tuning function. If
- * set before tuning, then device will respond with CRC
- * errors for responses on CMD line. So for HS200 the
- * sequence will be
- * 1. set bus width 4bit / 8 bit (1 bit not supported)
- * 2. switch to HS200 mode
- * 3. set the clock to > 52Mhz <=200MHz and
- * 4. execute tuning for HS200
- */
- if (card->host->ops->execute_tuning) {
- mmc_host_clk_hold(card->host);
- err = card->host->ops->execute_tuning(card->host,
- MMC_SEND_TUNING_BLOCK_HS200);
- mmc_host_clk_release(card->host);
- }
- if (err) {
- pr_warning("%s: tuning execution failed\n",
- mmc_hostname(card->host));
+ err = mmc_hs200_tuning(card);
+ if (err)
goto err;
- }
-
- ext_csd_bits = (bus_width == MMC_BUS_WIDTH_8) ?
- EXT_CSD_BUS_WIDTH_8 : EXT_CSD_BUS_WIDTH_4;
- }
-
- /*
- * Activate wide bus and DDR (if supported).
- */
- if (!mmc_card_hs200(card) &&
- (card->csd.mmca_vsn >= CSD_SPEC_VER_4) &&
- (host->caps & (MMC_CAP_4_BIT_DATA | MMC_CAP_8_BIT_DATA))) {
- static unsigned ext_csd_bits[][2] = {
- { EXT_CSD_BUS_WIDTH_8, EXT_CSD_DDR_BUS_WIDTH_8 },
- { EXT_CSD_BUS_WIDTH_4, EXT_CSD_DDR_BUS_WIDTH_4 },
- { EXT_CSD_BUS_WIDTH_1, EXT_CSD_BUS_WIDTH_1 },
- };
- static unsigned bus_widths[] = {
- MMC_BUS_WIDTH_8,
- MMC_BUS_WIDTH_4,
- MMC_BUS_WIDTH_1
- };
- unsigned idx, bus_width = 0;
-
- if (host->caps & MMC_CAP_8_BIT_DATA)
- idx = 0;
- else
- idx = 1;
- for (; idx < ARRAY_SIZE(bus_widths); idx++) {
- bus_width = bus_widths[idx];
- if (bus_width == MMC_BUS_WIDTH_1)
- ddr = 0; /* no DDR for 1-bit width */
-
- err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
- EXT_CSD_BUS_WIDTH,
- ext_csd_bits[idx][0],
- card->ext_csd.generic_cmd6_time);
- if (!err) {
- mmc_set_bus_width(card->host, bus_width);
-
- /*
- * If controller can't handle bus width test,
- * compare ext_csd previously read in 1 bit mode
- * against ext_csd at new bus width
- */
- if (!(host->caps & MMC_CAP_BUS_WIDTH_TEST))
- err = mmc_compare_ext_csds(card,
- bus_width);
- else
- err = mmc_bus_test(card, bus_width);
- if (!err)
- break;
- }
- }
-
- if (!err && ddr) {
- err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
- EXT_CSD_BUS_WIDTH,
- ext_csd_bits[idx][1],
- card->ext_csd.generic_cmd6_time);
- }
- if (err) {
- pr_warning("%s: switch to bus width %d ddr %d "
- "failed\n", mmc_hostname(card->host),
- 1 << bus_width, ddr);
- goto free_card;
- } else if (ddr) {
- /*
- * eMMC cards can support 3.3V to 1.2V i/o (vccq)
- * signaling.
- *
- * EXT_CSD_CARD_TYPE_DDR_1_8V means 3.3V or 1.8V vccq.
- *
- * 1.8V vccq at 3.3V core voltage (vcc) is not required
- * in the JEDEC spec for DDR.
- *
- * Do not force change in vccq since we are obviously
- * working and no change to vccq is needed.
- *
- * WARNING: eMMC rules are NOT the same as SD DDR
- */
- if (ddr & EXT_CSD_CARD_TYPE_DDR_1_2V) {
- err = __mmc_set_signal_voltage(host,
- MMC_SIGNAL_VOLTAGE_120);
- if (err)
- goto err;
- }
- mmc_set_timing(card->host, MMC_TIMING_MMC_DDR52);
- mmc_set_bus_width(card->host, bus_width);
+ } else if (mmc_card_hs(card)) {
+ /* Select the desired bus width optionally */
+ err = mmc_select_bus_width(card);
+ if (!IS_ERR_VALUE(err)) {
+ err = mmc_select_hs_ddr(card, ext_csd);
+ if (err)
+ goto err;
}
}
diff --git a/include/linux/mmc/card.h b/include/linux/mmc/card.h
index c1ded09..974da1e 100644
--- a/include/linux/mmc/card.h
+++ b/include/linux/mmc/card.h
@@ -63,6 +63,7 @@ struct mmc_ext_csd {
unsigned int power_off_longtime; /* Units: ms */
u8 power_off_notification; /* state */
unsigned int hs_max_dtr;
+ unsigned int hs200_max_dtr;
#define MMC_HIGH_26_MAX_DTR 26000000
#define MMC_HIGH_52_MAX_DTR 52000000
#define MMC_HIGH_DDR_MAX_DTR 52000000
diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
index f734c0c..f429f13 100644
--- a/include/linux/mmc/mmc.h
+++ b/include/linux/mmc/mmc.h
@@ -377,6 +377,10 @@ struct _mmc_csd {
#define EXT_CSD_DDR_BUS_WIDTH_4 5 /* Card is in 4 bit DDR mode */
#define EXT_CSD_DDR_BUS_WIDTH_8 6 /* Card is in 8 bit DDR mode */
+#define EXT_CSD_TIMING_BC 0 /* Backwards compatility */
+#define EXT_CSD_TIMING_HS 1 /* High speed */
+#define EXT_CSD_TIMING_HS200 2 /* HS200 */
+
#define EXT_CSD_SEC_ER_EN BIT(0)
#define EXT_CSD_SEC_BD_BLK_EN BIT(2)
#define EXT_CSD_SEC_GB_CL_EN BIT(4)
--
1.7.0.4
--
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