Some devices need some time between asserting reset-gpios before can
receive sdio commands.
This commits adds a pre-power-on-delay-ms devicetree property to
mmc-pwrseq-simple for use with such devices.
Cc: Tony Lindgren <tony@xxxxxxxxxxx>
Cc: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Signed-off-by: Matt Ranostay <matt@ranostay.consulting>
---
Documentation/devicetree/bindings/mmc/mmc-pwrseq-simple.txt | 2 ++
drivers/mmc/core/pwrseq_simple.c | 7 +++++++
2 files changed, 9 insertions(+)
diff --git a/Documentation/devicetree/bindings/mmc/mmc-pwrseq-simple.txt b/Documentation/devicetree/bindings/mmc/mmc-pwrseq-simple.txt
index e25436861867..88826f7d1d38 100644
--- a/Documentation/devicetree/bindings/mmc/mmc-pwrseq-simple.txt
+++ b/Documentation/devicetree/bindings/mmc/mmc-pwrseq-simple.txt
@@ -16,6 +16,8 @@ Optional properties:
See ../clocks/clock-bindings.txt for details.
- clock-names : Must include the following entry:
"ext_clock" (External clock provided to the card).
+- pre-power-on-delay-ms : Delay in ms before powering the card which
+ the reset-gpios (if any) are asserted
- post-power-on-delay-ms : Delay in ms after powering the card and
de-asserting the reset-gpios (if any)
diff --git a/drivers/mmc/core/pwrseq_simple.c b/drivers/mmc/core/pwrseq_simple.c
index 1304160de168..cb2ba7b11383 100644
--- a/drivers/mmc/core/pwrseq_simple.c
+++ b/drivers/mmc/core/pwrseq_simple.c
@@ -26,6 +26,7 @@
struct mmc_pwrseq_simple {
struct mmc_pwrseq pwrseq;
bool clk_enabled;
+ u32 pre_power_on_delay_ms;
u32 post_power_on_delay_ms;
struct clk *ext_clk;
struct gpio_descs *reset_gpios;
@@ -60,6 +61,9 @@ static void mmc_pwrseq_simple_pre_power_on(struct mmc_host *host)
}
mmc_pwrseq_simple_set_gpios_value(pwrseq, 1);
+
+ if (pwrseq->pre_power_on_delay_ms)
+ msleep(pwrseq->pre_power_on_delay_ms);
}
static void mmc_pwrseq_simple_post_power_on(struct mmc_host *host)
@@ -117,6 +121,9 @@ static int mmc_pwrseq_simple_probe(struct platform_device *pdev)
return PTR_ERR(pwrseq->reset_gpios);
}
+ device_property_read_u32(dev, "pre-power-on-delay-ms",
+ &pwrseq->pre_power_on_delay_ms);
+
device_property_read_u32(dev, "post-power-on-delay-ms",
&pwrseq->post_power_on_delay_ms);
--
2.7.4
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