From: Aries Lee <arieslee@xxxxxxxxxxx>
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]
Signed-off-by: Aries Lee <arieslee@xxxxxxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
---
drivers/mmc/core/mmc.c | 49 ++++++++++++---------
drivers/mmc/core/mmc_ops.c | 102 ++++++++++++++++++++++++++++++++++++++++++++
drivers/mmc/core/mmc_ops.h | 1 +
3 files changed, 131 insertions(+), 21 deletions(-)
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index e81e6fe..5d8b4b2 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -507,29 +507,36 @@ 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) {
- ext_csd_bit = EXT_CSD_BUS_WIDTH_8;
- bus_width = MMC_BUS_WIDTH_8;
- } else {
- ext_csd_bit = EXT_CSD_BUS_WIDTH_4;
- bus_width = MMC_BUS_WIDTH_4;
+ static unsigned ext_csd_bits[] = {
+ EXT_CSD_BUS_WIDTH_8,
+ EXT_CSD_BUS_WIDTH_4,
+ EXT_CSD_BUS_WIDTH_1
+ };
+ static unsigned bus_widths[] = {
+ MMC_BUS_WIDTH_8,
+ MMC_BUS_WIDTH_4,
+ MMC_BUS_WIDTH_1
+ };
+ unsigned idx;
+
+ if (host->caps & MMC_CAP_8_BIT_DATA)
+ idx = 0;
+ else
+ idx = 1;
+ for (; idx < ARRAY_SIZE(bus_widths); idx++) {
+ err = mmc_switch(card, EXT_CSD_CMD_SET_NORMAL,
+ EXT_CSD_BUS_WIDTH, ext_csd_bits[idx]);
+ if (!err) {
+ mmc_set_bus_width(card->host, bus_widths[idx]);
+ err = mmc_bus_test(card, bus_widths[idx]);
+ 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) {
- printk(KERN_WARNING "%s: switch to bus width %d "
- "failed\n", mmc_hostname(card->host),
- 1 << bus_width);
- err = 0;
- } else {
- mmc_set_bus_width(card->host, bus_width);
+ printk(KERN_WARNING "%s: switch to bus width failed\n",
+ mmc_hostname(card->host));
+ goto free_card;
}
}
diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
index 326447c..f8f47f9 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;
}
+#define MMC_CMD_BUS_TEST_W 19
+#define MMC_CMD_BUS_TEST_R 14
+
+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);
+ return -EINVAL;
+ }
+
+ if (opcode == MMC_CMD_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_CMD_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_CMD_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;
+ err = mmc_send_bus_test(card, card->host, MMC_CMD_BUS_TEST_W, width);
+ if (err < 0)
+ return err;
+ err = mmc_send_bus_test(card, card->host, MMC_CMD_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
--
1.7.3.1
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