> This patch adds support to set the RTC information in
> the eMMC device. This is based on the JEDEC specification.
>
> There is no way however, to read the RTC time from the
> device. Hence we rely on the response of the CMD49 to
> confirm the completion of the operation.
>
> This patch has been tested successfully with the ioctl
> interface. This patch has also been tested suceessfully
> with all the three RTC_INFO_TYPEs.
If this is triggered from user-space via ioctl anyway,
Why do we need this command to be implemented in the kernel?
Why not just add this to mmc-utils?
Thanks,
Avri
>
> Signed-off-by: Nishad Kamdar <nishadkamdar@xxxxxxxxx>
> ---
> drivers/mmc/core/mmc_ops.c | 59
> ++++++++++++++++++++++++++++++++++++++
> drivers/mmc/core/mmc_ops.h | 2 ++
> include/linux/mmc/mmc.h | 1 +
> 3 files changed, 62 insertions(+)
>
> diff --git a/drivers/mmc/core/mmc_ops.c b/drivers/mmc/core/mmc_ops.c
> index d63d1c735335..490372341b3b 100644
> --- a/drivers/mmc/core/mmc_ops.c
> +++ b/drivers/mmc/core/mmc_ops.c
> @@ -1063,3 +1063,62 @@ int mmc_sanitize(struct mmc_card *card,
> unsigned int timeout_ms)
> return err;
> }
> EXPORT_SYMBOL_GPL(mmc_sanitize);
> +
> +int mmc_set_time(struct mmc_card *card, struct mmc_host *host,
> + u8 rtc_info_type, u64 seconds)
> +{
> + struct mmc_request mrq = {};
> + struct mmc_command cmd = {};
> + struct mmc_data data = {};
> + struct scatterlist sg;
> + int err = 0;
> + u8 *data_buf;
> +
> + data_buf = kzalloc(512, GFP_KERNEL);
> + if (!data_buf)
> + return -ENOMEM;
> +
> + if (rtc_info_type == 0x01 || rtc_info_type == 0x02 ||
> + rtc_info_type == 0x03) {
> + data_buf[0] = 0x01;
> + data_buf[1] = rtc_info_type;
> + memcpy(&data_buf[2], &seconds, sizeof(u64));
> + } else {
> + pr_err("%s: invalid rtc_info_type %d\n",
> + mmc_hostname(host), rtc_info_type);
> + kfree(data_buf);
> + return -EINVAL;
> + }
> +
> + mrq.cmd = &cmd;
> + mrq.data = &data;
> +
> + cmd.opcode = MMC_SET_TIME;
> + cmd.arg = 0;
> + cmd.flags = MMC_RSP_SPI_R1 | MMC_RSP_R1 | MMC_CMD_ADTC;
> +
> + data.blksz = 512;
> + data.blocks = 1;
> + data.flags = MMC_DATA_WRITE;
> + data.sg = &sg;
> + data.sg_len = 1;
> + sg_init_one(&sg, data_buf, 512);
> +
> + mmc_set_data_timeout(&data, card);
> +
> + mmc_wait_for_req(host, &mrq);
> +
> + if (cmd.error) {
> + err = cmd.error;
> + goto out;
> + }
> +
> + if (data.error) {
> + err = data.error;
> + goto out;
> + }
> +out:
> + kfree(data_buf);
> + return err;
> +}
> +EXPORT_SYMBOL_GPL(mmc_set_time);
> diff --git a/drivers/mmc/core/mmc_ops.h b/drivers/mmc/core/mmc_ops.h
> index 9c813b851d0b..0c8695d1b363 100644
> --- a/drivers/mmc/core/mmc_ops.h
> +++ b/drivers/mmc/core/mmc_ops.h
> @@ -55,6 +55,8 @@ void mmc_run_bkops(struct mmc_card *card);
> int mmc_cmdq_enable(struct mmc_card *card);
> int mmc_cmdq_disable(struct mmc_card *card);
> int mmc_sanitize(struct mmc_card *card, unsigned int timeout_ms);
> +int mmc_set_time(struct mmc_card *card, struct mmc_host *host,
> + u8 rtc_info_type, u64 seconds);
>
> #endif
>
> diff --git a/include/linux/mmc/mmc.h b/include/linux/mmc/mmc.h
> index d9a65c6a8816..52a3bf873d50 100644
> --- a/include/linux/mmc/mmc.h
> +++ b/include/linux/mmc/mmc.h
> @@ -64,6 +64,7 @@
> #define MMC_WRITE_MULTIPLE_BLOCK 25 /* adtc R1 */
> #define MMC_PROGRAM_CID 26 /* adtc R1 */
> #define MMC_PROGRAM_CSD 27 /* adtc R1 */
> +#define MMC_SET_TIME 49 /* adtc R1 */
>
> /* class 6 */
> #define MMC_SET_WRITE_PROT 28 /* ac [31:0] data addr R1b */
> --
> 2.17.1
