@@ -55,3 +55,53 @@ 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", "active" and "idle", 2) the gpio detecting
+sdio irq in suspend and 3) compatibe section, see example below.
+The MMC driver will then toggle between active and idle 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", "active", "idle"
+ pinctrl-0 = <&mmc1_pins>;
+ pinctrl-1 = <&mmc1_pins>;
+ pinctrl-2 = <&mmc1_cirq_pin>;
+ ...
+ };
+
+ mmc1_cirq_pin: pinmux_cirq_pin {
+ pinctrl-single,pins = <
+ 0x0f8 0x3f /* GPIO2_28 */
+ >;
+ };
@@ -196,6 +196,8 @@ struct omap_hsmmc_host {
#define HSMMC_SDIO_IRQ_ENABLED (1 << 0) /* SDIO irq enabled */
#define HSMMC_SWAKEUP_QUIRK (1 << 1)
struct omap_hsmmc_next next_data;
+ struct pinctrl *pinctrl;
+ struct pinctrl_state *fixed, *active, *idle;
struct omap_mmc_platform_data *pdata;
};
@@ -452,6 +454,70 @@ static void omap_hsmmc_gpio_free(struct omap_mmc_platform_data *pdata)
gpio_free(pdata->slots[0].switch_pin);
}
+static int omap_hsmmc_pin_init(struct omap_hsmmc_host *host)
+{
+ struct pinctrl *_pinctrl;
+ int ret;
+
+ _pinctrl = devm_pinctrl_get(host->dev);
+ if (IS_ERR(_pinctrl)) {
+ /* okay, if the bootloader set it up right */
+ dev_warn(host->dev, "no pinctrl handle\n");
+ return 0;
+ }
+
+ host->fixed = pinctrl_lookup_state(_pinctrl,
+ PINCTRL_STATE_DEFAULT);
+ if (IS_ERR(host->fixed)) {
+ dev_info(host->dev,
+ "pins are not configured from the driver\n");
+ host->fixed = NULL;
+ devm_pinctrl_put(_pinctrl);
+ return 0;
+ }
+
+ ret = pinctrl_select_state(_pinctrl, host->fixed);
+ if (ret < 0) {
+ dev_warn(host->dev, "fixed pinctrl state failed %d\n", ret);
+ goto err;
+ }
+
+ /* For most cases we don't have wake-ups, and exit after this */
+ host->active = pinctrl_lookup_state(_pinctrl, "active");
+ if (IS_ERR(host->active)) {
+ ret = PTR_ERR(host->active);
+ host->active = NULL;
+ goto done;
+ }
+
+ host->idle = pinctrl_lookup_state(_pinctrl, PINCTRL_STATE_IDLE);
+ if (IS_ERR(host->idle)) {
+ ret = PTR_ERR(host->idle);
+ host->idle = NULL;
+ goto err;
+ }
+
+ /* Let's make sure the active and idle states work */
+ ret = pinctrl_select_state(_pinctrl, host->idle);
+ if (ret < 0)
+ goto err;
+
+ ret = pinctrl_select_state(_pinctrl, host->active);
+ if (ret < 0)
+ goto err;
+
+ dev_info(mmc_dev(host->mmc), "pins configured for wake-up events\n");
+
+done:
+ host->pinctrl = _pinctrl;
+ return 0;
+
+err:
+ dev_err(mmc_dev(host->mmc), "pins configuration error: %i\n", ret);
+ devm_pinctrl_put(_pinctrl);
+ return ret;
+}
+
/*
* Start clock to the card
*/
@@ -1675,8 +1741,14 @@ static int omap_hscmm_configure_wake_irq(struct omap_hsmmc_host *host)
* Some omaps don't have wake-up path from deeper idle states
* and need to remux SDIO DAT1 to GPIO for wake-up from idle.
*/
- if (host->pdata->controller_flags & OMAP_HSMMC_SWAKEUP_MISSING)
+ if (host->pdata->controller_flags & OMAP_HSMMC_SWAKEUP_MISSING) {
+ if (!host->idle) {
+ free_irq(host->wake_irq);
+ host->wake_irq = 0;
+ return -EINVAL;
+ }
host->flags |= HSMMC_SWAKEUP_QUIRK;
+ }
return 0;
}
@@ -1890,7 +1962,6 @@ static int omap_hsmmc_probe(struct platform_device *pdev)
const struct of_device_id *match;
dma_cap_mask_t mask;
unsigned tx_req, rx_req;
- struct pinctrl *pinctrl;
match = of_match_device(of_match_ptr(omap_mmc_of_match), &pdev->dev);
if (match) {
@@ -2107,10 +2178,9 @@ static int omap_hsmmc_probe(struct platform_device *pdev)
omap_hsmmc_disable_irq(host);
- pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
- if (IS_ERR(pinctrl))
- dev_warn(&pdev->dev,
- "pins are not configured from the driver\n");
+ ret = omap_hsmmc_pin_init(host);
+ if (ret)
+ goto err_pinctrl_state;
/*
* For now, only support SDIO interrupt if we have a separate
@@ -2150,7 +2220,9 @@ err_slot_name:
mmc_remove_host(mmc);
if (host->wake_irq)
free_irq(host->wake_irq, host);
- if (mmc_slot(host).card_detect_irq)
+ if (host->pinctrl)
+ devm_pinctrl_put(host->pinctrl);
+ if ((mmc_slot(host).card_detect_irq))
free_irq(mmc_slot(host).card_detect_irq, host);
err_irq_cd:
if (host->use_reg)
@@ -2205,6 +2277,8 @@ static int omap_hsmmc_remove(struct platform_device *pdev)
dma_release_channel(host->tx_chan);
if (host->rx_chan)
dma_release_channel(host->rx_chan);
+ if (host->pinctrl)
+ devm_pinctrl_put(host->pinctrl);
pm_runtime_put_sync(host->dev);
pm_runtime_disable(host->dev);
@@ -2314,6 +2388,11 @@ static int omap_hsmmc_runtime_suspend(struct device *dev)
OMAP_HSMMC_WRITE(host->base, ISE, 0);
OMAP_HSMMC_WRITE(host->base, IE, 0);
OMAP_HSMMC_WRITE(host->base, STAT, STAT_CLEAR);
+ if (host->idle) {
+ ret = pinctrl_select_state(host->pinctrl, host->idle);
+ if (ret < 0)
+ dev_warn(mmc_dev(host->mmc), "Unable to select idle pinmux\n");
+ }
hsmmc_enable_wake_irq(host);
}
@@ -2331,6 +2410,11 @@ static int omap_hsmmc_runtime_resume(struct device *dev)
if (host->mmc->caps & MMC_CAP_SDIO_IRQ) {
hsmmc_disable_wake_irq(host);
+ if (host->active) {
+ ret = pinctrl_select_state(host->pinctrl, host->active);
+ if (ret < 0)
+ dev_warn(mmc_dev(host->mmc), "Unable to select active pinmux\n");
+ }
OMAP_HSMMC_WRITE(host->base, STAT, STAT_CLEAR);
OMAP_HSMMC_WRITE(host->base, ISE, CIRQ_EN);
OMAP_HSMMC_WRITE(host->base, IE, CIRQ_EN);