diff options
Diffstat (limited to 'drivers/mmc/core/mmc_ops.c')
| -rw-r--r-- | drivers/mmc/core/mmc_ops.c | 101 |
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; +} |