[PATCH] mmc: Test bus-width for old MMC devices (v2)

Takashi Iwai
2010-12-15T07:14:27Z

From: Aries Lee <arieslee@jmicron.com>

Some old MMC devices fail with the 4/8 bits the driver tries to use
exclusively. This patch adds a test for the given bus setup and falls
back to the lower bit mode (until 1-bit mode) when the test fails.

[Major rework and refactoring by tiwai]
[Quirk addition and many fixes by prakity]

v1->v2:
- Rebased to the code with DDR support, set DDR bit properly
- Return always error when bus-switching fallback failed
- Define MMC_BUS_TEST_{R|W} in linux/mmc/mmc.h
- Add quirk MMC_CAP_BUS_WIDTH_TEST -- default not used for compatibility
- Ignore errors on BUS_TEST_W -- improves chances test will work

Signed-off-by: Aries Lee <arieslee@jmicron.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Philip Rakity <prakity@marvell.com>
Tested-by: Philip Rakity <prakity@marvell.com>
---

Chris, this is a revised version of the patch. Philip merged his patch
into this version and tested. Please apply.

drivers/mmc/core/mmc.c | 76 ++++++++++++++++++++------------
drivers/mmc/core/mmc_ops.c | 102 ++++++++++++++++++++++++++++++++++++++++++++
drivers/mmc/core/mmc_ops.h | 1 +
drivers/mmc/host/sdhci.c | 7 +++-
drivers/mmc/host/sdhci.h | 1 +
include/linux/mmc/host.h | 1 +
include/linux/mmc/mmc.h | 2 +
7 files changed, 160 insertions(+), 30 deletions(-)

diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index 77f93c3..3d51949 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -534,39 +534,57 @@ static int mmc_init_card(struct mmc_host *host, u32 ocr,
*/
if ((card->csd.mmca_vsn >= CSD_SPEC_VER_4) &&
(host->caps & (MMC_CAP_4_BIT_DATA | MMC_CAP_8_BIT_DATA))) {
- unsigned ext_csd_bit, bus_width;
-
- if (host->caps & MMC_CAP_8_BIT_DATA) {
- if (ddr)
- ext_csd_bit = EXT_CSD_DDR_BUS_WIDTH_8;
- else
- ext_csd_bit = EXT_CSD_BUS_WIDTH_8;
- bus_width = MMC_BUS_WIDTH_8;
- } else {
- if (ddr)
- ext_csd_bit = EXT_CSD_DDR_BUS_WIDTH_4;
- else
- ext_csd_bit = EXT_CSD_BUS_WIDTH_4;
- bus_width = MMC_BUS_WIDTH_4;
+ 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;
+
+ 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]);
+ if (!err) {
+ /*
+ * if controller can't handle bus width test
+ * use the highest bus width to
+ * maintain compatibility with previous linux
+ */
+ if (!(host->caps & MMC_CAP_BUS_WIDTH_TEST))
+ break;
+ mmc_set_bus_width_ddr(card->host,
+ bus_width, MMC_SDR_MODE);
+ err = mmc_bus_test(card, bus_width);
+ if (!err)
+ break;
+ }
}

- err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
- EXT_CSD_BUS_WIDTH, ext_csd_bit);
-
- if (err && err != -EBADMSG)
- goto free_card;
-
+ if (!err && ddr) {
+ err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
+ EXT_CSD_BUS_WIDTH,
+ ext_csd_bits[idx][1]);
+ }
if (err) {
printk(KERN_WARNING "%s: switch to bus width %d ddr %d "
- "failed\n", mmc_hostname(card->host),
- 1 << bus_width, ddr);
- err = 0;
- } else {
- if (ddr)
- mmc_card_set_ddr_mode(card);
- else
- ddr = MMC_SDR_MODE;
-
+ "failed\n", mmc_hostname(card->host),
+ 1 << bus_width, ddr);
+ goto free_card;
+ } else if (ddr) {
+ mmc_card_set_ddr_mode(card);
mmc_set_bus_width_ddr(card->host, bus_width, ddr);
}
}
diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
index 326447c..f1bc7d8 100644
--- a/drivers/mmc/core/mmc_ops.c
+++ b/drivers/mmc/core/mmc_ops.c
@@ -462,3 +462,105 @@ int mmc_send_status(struct mmc_card *card, u32 *status)
return 0;
}

+static int
+mmc_send_bus_test(struct mmc_card *card, struct mmc_host *host, u8 opcode,
+ u8 len)
+{
+ struct mmc_request mrq;
+ struct mmc_command cmd;
+ struct mmc_data data;
+ struct scatterlist sg;
+ u8 *data_buf;
+ u8 *test_buf;
+ int i, err;
+ static u8 testdata_8bit[8] = { 0x55, 0xaa, 0, 0, 0, 0, 0, 0 };
+ static u8 testdata_4bit[4] = { 0x5a, 0, 0, 0 };
+
+ /* dma onto stack is unsafe/nonportable, but callers to this
+ * routine normally provide temporary on-stack buffers ...
+ */
+ data_buf = kmalloc(len, GFP_KERNEL);
+ if (!data_buf)
+ return -ENOMEM;
+
+ if (len == 8)
+ test_buf = testdata_8bit;
+ else if (len == 4)
+ test_buf = testdata_4bit;
+ else {
+ printk(KERN_ERR "%s: Invaild bus_width %d\n",
+ mmc_hostname(host), len);
+ kfree(data_buf);
+ return -EINVAL;
+ }
+
+ if (opcode == MMC_BUS_TEST_W)
+ memcpy(data_buf, test_buf, len);
+
+ memset(&mrq, 0, sizeof(struct mmc_request));
+ memset(&cmd, 0, sizeof(struct mmc_command));
+ memset(&data, 0, sizeof(struct mmc_data));
+
+ mrq.cmd = &cmd;
+ mrq.data = &data;
+ cmd.opcode = opcode;
+ cmd.arg = 0;
+
+ /* NOTE HACK: the MMC_RSP_SPI_R1 is always correct here, but we
+ * rely on callers to never use this with "native" calls for reading
+ * CSD or CID. Native versions of those commands use the R2 type,
+ * not R1 plus a data block.
+ */
+ cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
+
+ data.blksz = len;
+ data.blocks = 1;
+ if (opcode == MMC_BUS_TEST_R)
+ data.flags = MMC_DATA_READ;
+ else
+ data.flags = MMC_DATA_WRITE;
+
+ data.sg = &sg;
+ data.sg_len = 1;
+ sg_init_one(&sg, data_buf, len);
+ mmc_wait_for_req(host, &mrq);
+ err = 0;
+ if (opcode == MMC_BUS_TEST_R) {
+ for (i = 0; i < len / 4; i++)
+ if ((test_buf[i] ^ data_buf[i]) != 0xff) {
+ err = -EIO;
+ break;
+ }
+ }
+ kfree(data_buf);
+
+ if (cmd.error)
+ return cmd.error;
+ if (data.error)
+ return data.error;
+
+ return err;
+}
+
+int mmc_bus_test(struct mmc_card *card, u8 bus_width)
+{
+ int err, width;
+
+ if (bus_width == MMC_BUS_WIDTH_8)
+ width = 8;
+ else if (bus_width == MMC_BUS_WIDTH_4)
+ width = 4;
+ else if (bus_width == MMC_BUS_WIDTH_1)
+ return 0; /* no need for test */
+ else
+ return -EINVAL;
+
+ /*
+ * ignore errors from BUS_TEST_W. BUS_TEST_R will fail
+ * if there is a problem. Improves chances test will work
+ */
+ mmc_send_bus_test(card, card->host, MMC_BUS_TEST_W, width);
+ err = mmc_send_bus_test(card, card->host, MMC_BUS_TEST_R, width);
+ return err;
+}
+
diff --git a/drivers/mmc/core/mmc_ops.h b/drivers/mmc/core/mmc_ops.h
index 653eb8e..e6d44b8 100644
--- a/drivers/mmc/core/mmc_ops.h
+++ b/drivers/mmc/core/mmc_ops.h
@@ -26,6 +26,7 @@ int mmc_send_cid(struct mmc_host *host, u32 *cid);
int mmc_spi_read_ocr(struct mmc_host *host, int highcap, u32 *ocrp);
int mmc_spi_set_crc(struct mmc_host *host, int use_crc);
int mmc_card_sleepawake(struct mmc_host *host, int sleep);
+int mmc_bus_test(struct mmc_card *card, u8 bus_width);

#endif

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index a25db42..d2673b7 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -23,6 +23,7 @@

#include <linux/leds.h>

+#include <linux/mmc/mmc.h>
#include <linux/mmc/host.h>

#include "sdhci.h"
@@ -1518,7 +1519,11 @@ static void sdhci_data_irq(struct sdhci_host *host, u32 intmask)

if (intmask & SDHCI_INT_DATA_TIMEOUT)
host->data->error = -ETIMEDOUT;
- else if (intmask & (SDHCI_INT_DATA_CRC | SDHCI_INT_DATA_END_BIT))
+ else if (intmask & SDHCI_INT_DATA_END_BIT)
+ host->data->error = -EILSEQ;
+ else if ((intmask & SDHCI_INT_DATA_CRC) &&
+ SDHCI_GET_CMD(sdhci_readw(host, SDHCI_COMMAND))
+ != MMC_BUS_TEST_R)
host->data->error = -EILSEQ;
else if (intmask & SDHCI_INT_ADMA_ERROR) {
printk(KERN_ERR "%s: ADMA error\n", mmc_hostname(host->mmc));
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index e42d7f0..5be9060 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -52,6 +52,7 @@
#define SDHCI_CMD_RESP_SHORT_BUSY 0x03

#define SDHCI_MAKE_CMD(c, f) (((c & 0xff) << 8) | (f & 0xff))
+#define SDHCI_GET_CMD(c) ((c>>8) & 0x3f)

#define SDHCI_RESPONSE 0x10

diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 30f6fad..0fc7d46 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -169,6 +169,7 @@ struct mmc_host {
#define MMC_CAP_1_2V_DDR (1 << 12) /* can support */
/* DDR mode at 1.2V */
#define MMC_CAP_POWER_OFF_CARD (1 << 13) /* Can power off after boot */
+#define MMC_CAP_BUS_WIDTH_TEST (1 << 14) /* CMD14/CMD19 bus width ok */

mmc_pm_flag_t pm_caps; /* supported pm features */

diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
index 956fbd87..612301f 100644
--- a/include/linux/mmc/mmc.h
+++ b/include/linux/mmc/mmc.h
@@ -40,7 +40,9 @@
#define MMC_READ_DAT_UNTIL_STOP 11 /* adtc [31:0] dadr R1 */
#define MMC_STOP_TRANSMISSION 12 /* ac R1b */
#define MMC_SEND_STATUS 13 /* ac [31:16] RCA R1 */
+#define MMC_BUS_TEST_R 14 /* adtc R1 */
#define MMC_GO_INACTIVE_STATE 15 /* ac [31:16] RCA */
+#define MMC_BUS_TEST_W 19 /* adtc R1 */
#define MMC_SPI_READ_OCR 58 /* spi spi_R3 */
#define MMC_SPI_CRC_ON_OFF 59 /* spi [0:0] flag spi_R1 */

--
1.7.3.1