Re: [PATCH RFC 5/8] mmc: sdhci: Add check_power_status host operation

Ritesh Harjani <riteshh@xxxxxxxxxxxxxx> · Fri, 5 Aug 2016 10:18:23 +0530

Hi,

Kindly drop this patch series, since recently there was another version 
of pwr_irq support added to upstream.

https://lkml.org/lkml/2016/6/24/416


Regards
Ritesh

On 6/30/2016 7:02 PM, Ritesh Harjani wrote:
Hi Adrian,


On 6/30/2016 11:30 AM, Adrian Hunter wrote:
On 29/06/16 14:20, Ritesh Harjani wrote:
From: Sahitya Tummala <stummala@xxxxxxxxxxxxxx>

MSM SDHCI doesn't control power as specified by the Standard
Host Controller 3.0 spec. Writing to power control register/
reset register/voltage bit of host control register would
trigger an IRQ with appropriate status bits set. Hence, use
host op check_power_status after writing to power control
register to check the status and wait until the IRQ is handled.

Did you consider using the SDHCI I/O Accessors for this? i.e.
CONFIG_MMC_SDHCI_IO_ACCESSORS
Thanks for the suggestion. I will check and get back.



Signed-off-by: Sahitya Tummala <stummala@xxxxxxxxxxxxxx>
Signed-off-by: Ritesh Harjani <riteshh@xxxxxxxxxxxxxx>
---
 drivers/mmc/host/sdhci.c | 24 +++++++++++++++++++++---
 drivers/mmc/host/sdhci.h |  5 +++++
 2 files changed, 26 insertions(+), 3 deletions(-)

diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c
index 0e3d7c0..12f74bd 100644
--- a/drivers/mmc/host/sdhci.c
+++ b/drivers/mmc/host/sdhci.c
@@ -176,6 +176,10 @@ void sdhci_reset(struct sdhci_host *host, u8 mask)
     /* Wait max 100 ms */
     timeout = 100;

+    if (host->ops->check_power_status && host->pwr &&
+        (mask & SDHCI_RESET_ALL))
+        host->ops->check_power_status(host, REQ_BUS_OFF);
+
     /* hw clears the bit when it's done */
     while (sdhci_readb(host, SDHCI_SOFTWARE_RESET) & mask) {
         if (timeout == 0) {
@@ -1306,6 +1310,8 @@ void sdhci_set_power(struct sdhci_host *host,
unsigned char mode,

     if (pwr == 0) {
         sdhci_writeb(host, 0, SDHCI_POWER_CONTROL);
+        if (host->ops->check_power_status)
+            host->ops->check_power_status(host, REQ_BUS_OFF);
         if (host->quirks2 & SDHCI_QUIRK2_CARD_ON_NEEDS_BUS_ON)
             sdhci_runtime_pm_bus_off(host);
     } else {
@@ -1313,20 +1319,28 @@ void sdhci_set_power(struct sdhci_host *host,
unsigned char mode,
          * Spec says that we should clear the power reg before setting
          * a new value. Some controllers don't seem to like this
though.
          */
-        if (!(host->quirks & SDHCI_QUIRK_SINGLE_POWER_WRITE))
+        if (!(host->quirks & SDHCI_QUIRK_SINGLE_POWER_WRITE)) {
             sdhci_writeb(host, 0, SDHCI_POWER_CONTROL);
-
+            if (host->ops->check_power_status)
+                host->ops->check_power_status(host,
+                            REQ_BUS_OFF);
+        }
         /*
          * At least the Marvell CaFe chip gets confused if we set the
          * voltage and set turn on power at the same time, so set the
          * voltage first.
          */
-        if (host->quirks & SDHCI_QUIRK_NO_SIMULT_VDD_AND_POWER)
+        if (host->quirks & SDHCI_QUIRK_NO_SIMULT_VDD_AND_POWER) {
             sdhci_writeb(host, pwr, SDHCI_POWER_CONTROL);
+            if (host->ops->check_power_status)
+                host->ops->check_power_status(host, REQ_BUS_ON);
+        }

         pwr |= SDHCI_POWER_ON;

         sdhci_writeb(host, pwr, SDHCI_POWER_CONTROL);
+        if (host->ops->check_power_status)
+            host->ops->check_power_status(host, REQ_BUS_ON);

         if (host->quirks2 & SDHCI_QUIRK2_CARD_ON_NEEDS_BUS_ON)
             sdhci_runtime_pm_bus_on(host);
@@ -1736,6 +1750,8 @@ static int
sdhci_start_signal_voltage_switch(struct mmc_host *mmc,
         /* Set 1.8V Signal Enable in the Host Control2 register to 0 */
         ctrl &= ~SDHCI_CTRL_VDD_180;
         sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
+        if (host->ops->check_power_status)
+            host->ops->check_power_status(host, REQ_IO_HIGH);

         if (!IS_ERR(mmc->supply.vqmmc)) {
             ret = regulator_set_voltage(mmc->supply.vqmmc, 2700000,
@@ -1775,6 +1791,8 @@ static int
sdhci_start_signal_voltage_switch(struct mmc_host *mmc,
          */
         ctrl |= SDHCI_CTRL_VDD_180;
         sdhci_writew(host, ctrl, SDHCI_HOST_CONTROL2);
+        if (host->ops->check_power_status)
+            host->ops->check_power_status(host, REQ_IO_LOW);

         /* Some controller need to do more when switching */
         if (host->ops->voltage_switch)
diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h
index 609f87c..5758cca 100644
--- a/drivers/mmc/host/sdhci.h
+++ b/drivers/mmc/host/sdhci.h
@@ -549,6 +549,11 @@ struct sdhci_ops {
                      struct mmc_card *card,
                      unsigned int max_dtr, int host_drv,
                      int card_drv, int *drv_type);
+#define REQ_BUS_OFF    BIT(0)
+#define REQ_BUS_ON    BIT(1)
+#define REQ_IO_LOW    BIT(2)
+#define REQ_IO_HIGH    BIT(3)
+    void    (*check_power_status)(struct sdhci_host *host, u32
req_type);
 };

 #ifdef CONFIG_MMC_SDHCI_IO_ACCESSORS


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