On 2018/4/11 20:39, Ulf Hansson wrote:
On 11 April 2018 at 03:16, Shawn Lin <shawn.lin@xxxxxxxxxxxxxx> wrote:
Hi Ulf,
On 2018/4/6 4:19, Ulf Hansson wrote:
Let's implement the ->sw_reset() bus ops to allow SDIO func drivers, in
particular, to make a SW reset without doing a full power cycle of the
SDIO
card.
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
---
drivers/mmc/core/sdio.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/drivers/mmc/core/sdio.c b/drivers/mmc/core/sdio.c
index 0124e0e..088c80c 100644
--- a/drivers/mmc/core/sdio.c
+++ b/drivers/mmc/core/sdio.c
@@ -1044,6 +1044,18 @@ static int mmc_sdio_hw_reset(struct mmc_host *host)
return mmc_sdio_power_restore(host);
}
+static int mmc_sdio_sw_reset(struct mmc_host *host)
+{
+ mmc_set_clock(host, host->f_init);
This reminds me to think that why we don't fold it
into mmc_set_initial_state()? See mmc_power_up() calls
mmc_set_initial_state () and then the clock is set to host->f_init
later.
I see your point, however mmc_set_inital_state() is also called from
mmc_power_off(), which is when the clock is set to zero.
Oh, I missed that.
+ sdio_reset(host);
+ mmc_go_idle(host);
+
mmc_sdio_reinit_card() will reset I/O and memory portion internally.
So maybe we don't need these extra reset ahead?
Are you suggesting the mmc_sdio_reinit_card() should not be doing
sdio_reset() + mmc_go_idle() - or that the above calls should go away?
I don't think dropping the above calls are a good idea (at least both
of them), as changing to the initial state and initial signal voltage,
without first doing a reset may put the card in some undefined error
state. Don't you think?
Fair enough.
+ mmc_set_initial_state(host);
+ mmc_set_initial_signal_voltage(host);
+
+ return mmc_sdio_reinit_card(host, 0);
+}
+
static const struct mmc_bus_ops mmc_sdio_ops = {
.remove = mmc_sdio_remove,
.detect = mmc_sdio_detect,
@@ -1055,6 +1067,7 @@ static const struct mmc_bus_ops mmc_sdio_ops = {
.power_restore = mmc_sdio_power_restore,
.alive = mmc_sdio_alive,
.hw_reset = mmc_sdio_hw_reset,
+ .sw_reset = mmc_sdio_sw_reset,
};
Kind regards
Uffe
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