The am335x can't detect pending cirq in PM runtime suspend.
This patch reconfigures dat1 as a GPIO before going to suspend.
SDIO interrupts are detected with the GPIO, the GPIO will only wake
the module from suspend, SDIO irq detection will still happen through the
IP block.
Idea of remuxing the pins by Tony Lindgren. Code contributions from
Tony Lindgren and Balaji T K <balajitk@xxxxxx>
Signed-off-by: Andreas Fenkart <afenkart@xxxxxxxxx>
Signed-off-by: Tony Lindgren <tony@xxxxxxxxxxx>
diff --git a/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt b/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt
index ce80561..4767cd1 100644
--- a/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt
+++ b/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt
@@ -56,3 +56,54 @@ Examples:
&edma 25>;
dma-names = "tx", "rx";
};
+
+[workaround for missing swakeup on am33xx]
+
+This SOC is missing the swakeup line, it will not detect SDIO irq
+while in suspend.
+
+ ------
+ | PRCM |
+ ------
+ ^ |
+ swakeup | | fclk
+ | v
+ ------ ------- -----
+ | card | -- CIRQ --> | hsmmc | -- IRQ --> | CPU |
+ ------ ------- -----
+
+In suspend the fclk is off and the module is disfunctional. Even
+register reads will fail. A small logic in the host will request
+fclk restore, when an external event is detected. Once the clock
+is restored, the host detects the event normally. Since am33xx
+doesn't have this line it never wakes from suspend.
+
+The workaround is to reconfigure the dat1 line as a GPIO upon
+suspend. To make this work, we need to set 1) the named pinctrl
+states "default", "idle" and "gpio_dat1", 2) the gpio detecting
+sdio irq in suspend and 3) the compatibe section, see example below.
+The MMC driver will then toggle between gpio_dat1 and default during
+the runtime. If configuration is incomplete, a warning message is
+emitted "falling back to polling". Mind not every application
+needs SDIO irq, e.g. MMC cards Affected chips are am335x,
+probably others
+
+
+ mmc1: mmc@48060100 {
+ compatible = "ti,am33xx-hsmmc";
+ ...
+ interrupts-extended = <&intc 64 &gpio2 28 0>;
+ ...
+ pinctrl-names = "default", "idle", "sleep", "gpio_dat1"
+ pinctrl-0 = <&mmc1_pins>;
+ pinctrl-1 = <&mmc1_idle>;
+ pinctrl-2 = <&mmc1_sleep>;
+ pinctrl-3 = <&mmc1_cirq_pin>;
+ ...
+ };
+
+ mmc1_cirq_pin: pinmux_cirq_pin {
+ pinctrl-single,pins = <
+ 0x0f8 0x3f /* GPIO2_28 */
+ >;
+ };
diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index 9cc0d21..8661e1f 100644
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -213,7 +213,10 @@ struct omap_hsmmc_host {
#define AUTO_CMD23 (1 << 0) /* Auto CMD23 support */
#define HSMMC_SDIO_IRQ_ENABLED (1 << 1) /* SDIO irq enabled */
#define HSMMC_WAKE_IRQ_ENABLED (1 << 2)
+#define HSMMC_SWAKEUP_QUIRK (1 << 3)
struct omap_hsmmc_next next_data;
+ struct pinctrl *pinctrl;
+ struct pinctrl_state *gpio_pinmux;
struct omap_mmc_platform_data *pdata;
};
@@ -1744,8 +1747,28 @@ static int omap_hsmmc_configure_wake_irq(struct omap_hsmmc_host *host)
* and need to remux SDIO DAT1 to GPIO for wake-up from idle.
*/
if (host->pdata->controller_flags & OMAP_HSMMC_SWAKEUP_MISSING) {
- ret = -ENODEV;
- goto err;
+ if (IS_ERR(host->dev->pins->default_state)) {
+ dev_info(host->dev, "missing default pinctrl state\n");
+ ret = -EINVAL;
+ goto err;
+ }
+
+ host->pinctrl = devm_pinctrl_get(host->dev);
+ if (IS_ERR(host->pinctrl)) {
+ dev_warn(host->dev, "no pinctrl handle\n");
+ ret = -ENODEV;
+ goto err;
+ }
+
+ host->gpio_pinmux = pinctrl_lookup_state(host->pinctrl,
+ "gpio_dat1");
+ if (IS_ERR(host->gpio_pinmux)) {
+ dev_info(host->dev, "missing \"gpio_dat1\" pinctrl state\n");
+ ret = -ENODEV;
+ goto err;
+ }
+
+ host->flags |= HSMMC_SWAKEUP_QUIRK;
}
devres_remove_group(host->dev, NULL);
@@ -2438,7 +2461,10 @@ static int omap_hsmmc_runtime_suspend(struct device *dev)
goto abort;
}
- pinctrl_pm_select_idle_state(dev);
+ if (host->flags & HSMMC_SWAKEUP_QUIRK)
+ pinctrl_select_state(host->pinctrl, host->gpio_pinmux);
+ else
+ pinctrl_pm_select_idle_state(dev);
WARN_ON(host->flags & HSMMC_WAKE_IRQ_ENABLED);
enable_irq(host->wake_irq);
--
1.7.10.4
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