summaryrefslogtreecommitdiff
path: root/drivers/mmc/core/mmc_ops.c
diff options
context:
space:
mode:
authorAries Lee <arieslee@jmicron.com>2010-12-15 10:14:24 +0300
committerChris Ball <cjb@laptop.org>2011-01-09 07:52:09 +0300
commit22113efd00491310da802f3b1a9a66cfcf415fac (patch)
tree1faf6e99a591f9b6856bab6c8318eeeacb076051 /drivers/mmc/core/mmc_ops.c
parente6f29a8dc1602e170daf955233891a9130573a55 (diff)
downloadlinux-22113efd00491310da802f3b1a9a66cfcf415fac.tar.xz
mmc: Test bus-width for old MMC devices
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] 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> Signed-off-by: Chris Ball <cjb@laptop.org>
Diffstat (limited to 'drivers/mmc/core/mmc_ops.c')
-rw-r--r--drivers/mmc/core/mmc_ops.c101
1 files changed, 101 insertions, 0 deletions
diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
index 326447c9ede8..60842f878ded 100644
--- a/drivers/mmc/core/mmc_ops.c
+++ b/drivers/mmc/core/mmc_ops.c
@@ -462,3 +462,104 @@ 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: Invalid 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. This improves chances that the 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;
+}