[PATCH v3 3/4] mmc: omap_hsmmc: Remux pins to support SDIO interrupt on AM335x

From: Andreas Fenkart
Date: Sat Oct 05 2013 - 07:19:57 EST

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, while in runtime
suspend, standard detection of the module block otherwise.

Signed-off-by: Andreas Fenkart <afenkart@xxxxxxxxx>

diff --git a/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt b/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt
index 1136e6b..146f3ad 100644
--- a/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt
+++ b/Documentation/devicetree/bindings/mmc/ti-omap-hsmmc.txt
@@ -21,8 +21,11 @@ ti,non-removable: non-removable slot (like eMMC)
ti,needs-special-reset: Requires a special softreset sequence
ti,needs-special-hs-handling: HSMMC IP needs special setting for handling High Speed
ti,quirk-swakup-missing: SOC missing the swakeup line, will not detect
-SDIO irq while in suspend. Fallback to polling. Affected chips are
-am335x,
+SDIO irq while in suspend. The workaround is to reconfigure the dat1 line as a
+GPIO upon suspend. Beyond this option and the GPIO config, you also need to set
+named pinctrl states "default", "active" and "idle ", see example below. The
+MMC driver will then then toggle between default and idle during the runtime
+Affected chips are am335x,

------
| PRCM |
@@ -49,3 +52,24 @@ Example:
vmmc-supply = <&vmmc>; /* phandle to regulator node */
ti,non-removable;
};
+
+[am335x with with gpio for sdio irq]
+
+ mmc1_cirq_pin: pinmux_cirq_pin {
+ pinctrl-single,pins = <
+ 0x0f8 0x3f /* MMC0_DAT1 as GPIO2_28 */
+ >;
+ };
+
+ mmc1: mmc@48060000 {
+ ti,non-removable;
+ bus-width = <4>;
+ vmmc-supply = <&ldo2_reg>;
+ vmmc_aux-supply = <&vmmc>;
+ ti,quirk-swakeup-missing;
+ pinctrl-names = "default", "active", "idle";
+ pinctrl-0 = <&mmc1_pins>;
+ pinctrl-1 = <&mmc1_pins>;
+ pinctrl-2 = <&mmc1_cirq_pin>;
+ ti,cirq-gpio = <&gpio3 28 0>;
+ };
diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index 53beac4..a8894ee 100644
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -36,6 +36,7 @@
#include <linux/mmc/core.h>
#include <linux/mmc/mmc.h>
#include <linux/io.h>
+#include <linux/irq.h>
#include <linux/gpio.h>
#include <linux/regulator/consumer.h>
#include <linux/pinctrl/consumer.h>
@@ -214,11 +215,22 @@ struct omap_hsmmc_host {
int flags;
#define HSMMC_RUNTIME_SUSPENDED (1 << 0) /* Runtime suspended */
#define HSMMC_SDIO_IRQ_ENABLED (1 << 1) /* SDIO irq enabled */
+#define HSMMC_SWAKEUP_QUIRK (1 << 2) /* SDIO irq enabled */

struct omap_hsmmc_next next_data;
+ struct pinctrl *pinctrl;
+ struct pinctrl_state *fixed, *active, *idle;
struct omap_mmc_platform_data *pdata;
};

+static irqreturn_t omap_hsmmc_cirq(int irq, void *dev_id)
+{
+ struct omap_hsmmc_host *host = dev_id;
+
+ mmc_signal_sdio_irq(host->mmc);
+ return IRQ_HANDLED;
+}
+
static int omap_hsmmc_card_detect(struct device *dev, int slot)
{
struct omap_hsmmc_host *host = dev_get_drvdata(dev);
@@ -453,10 +465,31 @@ static int omap_hsmmc_gpio_init(struct omap_mmc_platform_data *pdata)
} else
pdata->slots[0].gpio_wp = -EINVAL;

+ if (pdata->slots[0].gpio_cirq > 0 &&
+ gpio_is_valid(pdata->slots[0].gpio_cirq)) {
+ pdata->slots[0].sdio_irq =
+ gpio_to_irq(pdata->slots[0].gpio_cirq);
+
+ ret = gpio_request(pdata->slots[0].gpio_cirq, "sdio_cirq");
+ if (ret)
+ goto err_free_ro;
+ ret = gpio_direction_input(pdata->slots[0].gpio_cirq);
+ if (ret)
+ goto err_free_cirq;
+
+ } else {
+ pdata->slots[0].gpio_cirq = -EINVAL;
+ }
+
+
return 0;

+err_free_cirq:
+ gpio_free(pdata->slots[0].gpio_cirq);
+err_free_ro:
+ if (gpio_is_valid(pdata->slots[0].gpio_wp))
err_free_wp:
- gpio_free(pdata->slots[0].gpio_wp);
+ gpio_free(pdata->slots[0].gpio_wp);
err_free_cd:
if (gpio_is_valid(pdata->slots[0].switch_pin))
err_free_sp:
@@ -470,6 +503,68 @@ static void omap_hsmmc_gpio_free(struct omap_mmc_platform_data *pdata)
gpio_free(pdata->slots[0].gpio_wp);
if (gpio_is_valid(pdata->slots[0].switch_pin))
gpio_free(pdata->slots[0].switch_pin);
+ if (gpio_is_valid(pdata->slots[0].gpio_cirq))
+ gpio_free(pdata->slots[0].gpio_cirq);
+}
+
+static int omap_hsmmc_pin_init(struct omap_hsmmc_host *host)
+{
+ int ret;
+
+ host->pinctrl = devm_pinctrl_get(host->dev);
+ if (IS_ERR(host->pinctrl)) {
+ dev_dbg(host->dev, "no pinctrl handle\n");
+ ret = 0;
+ goto out;
+ }
+
+ host->fixed = pinctrl_lookup_state(host->pinctrl,
+ PINCTRL_STATE_DEFAULT);
+ if (IS_ERR(host->fixed)) {
+ dev_dbg(host->dev, "pins are not configured from the driver\n");
+ host->fixed = NULL;
+ ret = 0;
+ goto out;
+ }
+
+ ret = pinctrl_select_state(host->pinctrl, host->fixed);
+ if (ret < 0)
+ goto err;
+
+ /* For most cases we don't have wake-ups, and exit after this */
+ host->active = pinctrl_lookup_state(host->pinctrl, "active");
+ if (IS_ERR(host->active)) {
+ ret = PTR_ERR(host->active);
+ host->active = NULL;
+ return 0;
+ }
+
+ host->idle = pinctrl_lookup_state(host->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(host->pinctrl, host->idle);
+ if (ret < 0)
+ goto err;
+
+ ret = pinctrl_select_state(host->pinctrl, host->active);
+ if (ret < 0)
+ goto err;
+
+ dev_info(mmc_dev(host->mmc), "pins configured for wake-up events\n");
+
+ return 0;
+
+err:
+ dev_err(mmc_dev(host->mmc), "pins configuration error: %i\n", ret);
+
+out:
+ return ret;
}

/*
@@ -1613,13 +1708,18 @@ static void omap_hsmmc_enable_sdio_irq(struct mmc_host *mmc, int enable)

spin_lock_irqsave(&host->irq_lock, flags);

+ if (!enable == !(host->flags & HSMMC_SDIO_IRQ_ENABLED)) {
+ /* sdio_irq is refcounted, keep in sync */
+ goto out;
+ }
+
if (enable)
host->flags |= HSMMC_SDIO_IRQ_ENABLED;
else
host->flags &= ~HSMMC_SDIO_IRQ_ENABLED;

- /* if statement here with followup patch */
- {
+ if (!(host->flags & HSMMC_RUNTIME_SUSPENDED)) {
+ /* SIGBUS without without fclk */
irq_mask = OMAP_HSMMC_READ(host->base, ISE);
if (enable)
irq_mask |= CIRQ_EN;
@@ -1638,6 +1738,16 @@ static void omap_hsmmc_enable_sdio_irq(struct mmc_host *mmc, int enable)
OMAP_HSMMC_READ(host->base, IE);
}

+ if (host->flags & HSMMC_SWAKEUP_QUIRK) {
+ if (enable) {
+ enable_irq(mmc_slot(host).sdio_irq);
+ } else {
+ /* _nosync, see mmc_signal_sdio_irq */
+ disable_irq_nosync(mmc_slot(host).sdio_irq);
+ }
+ }
+
+out:
spin_unlock_irqrestore(&host->irq_lock, flags);
}

@@ -1797,6 +1907,7 @@ static struct omap_mmc_platform_data *of_get_hsmmc_pdata(struct device *dev)
pdata->nr_slots = 1;
pdata->slots[0].switch_pin = cd_gpio;
pdata->slots[0].gpio_wp = wp_gpio;
+ pdata->slots[0].gpio_cirq = of_get_named_gpio(np, "ti,cirq-gpio", 0);

if (of_find_property(np, "ti,non-removable", NULL)) {
pdata->slots[0].nonremovable = true;
@@ -1837,7 +1948,6 @@ 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) {
@@ -2075,12 +2185,35 @@ static int omap_hsmmc_probe(struct platform_device *pdev)
pdata->resume = omap_hsmmc_resume_cdirq;
}

- omap_hsmmc_disable_irq(host);
+ if ((mmc_slot(host).sdio_irq)) {
+ /* prevent auto-enabling of IRQ */
+ irq_set_status_flags(mmc_slot(host).sdio_irq, IRQ_NOAUTOEN);
+ ret = request_irq(mmc_slot(host).sdio_irq, omap_hsmmc_cirq,
+ IRQF_TRIGGER_LOW | IRQF_ONESHOT,
+ mmc_hostname(mmc), host);
+ if (ret) {
+ dev_dbg(mmc_dev(host->mmc),
+ "Unable to grab MMC SDIO IRQ\n");
+ goto err_irq_sdio;
+ }

- pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
- if (IS_ERR(pinctrl))
- dev_warn(&pdev->dev,
- "pins are not configured from the driver\n");
+ /*
+ * sdio_irq is managed with ref count
+ * - start with initial value of 2
+ * - omap_hsmmc_enable_sdio_irq enable/disable will -1/+1
+ * - pm_suspend/pm_resume will -1/+1
+ *
+ * if sdio irq are enabled AND runtime suspend on, only then
+ * the ref count drops to zero and the gpio irq is armed
+ */
+ disable_irq(mmc_slot(host).sdio_irq); /* -> ref cnt == 2 */
+ }
+
+ ret = omap_hsmmc_pin_init(host);
+ if (ret)
+ goto err_pinctrl_state;
+
+ omap_hsmmc_disable_irq(host);

/*
* For now, only support SDIO interrupt if we are booted with
@@ -2093,8 +2226,14 @@ static int omap_hsmmc_probe(struct platform_device *pdev)
mmc->caps |= MMC_CAP_SDIO_IRQ;
if (of_find_property(host->dev->of_node,
"ti,quirk-swakeup-missing", NULL)) {
- /* no wakeup from deeper power states, use polling */
- mmc->caps &= ~MMC_CAP_SDIO_IRQ;
+ /* no wakeup from deeper power states, use GPIO */
+ if (!host->idle || !mmc_slot(host).sdio_irq) {
+ dev_err(mmc_dev(host->mmc),
+ "Missing GPIO config or pinctrl idle state\n");
+ goto err_pinctrl_state;
+ }
+
+ host->flags |= HSMMC_SWAKEUP_QUIRK;
}
}

@@ -2122,7 +2261,13 @@ static int omap_hsmmc_probe(struct platform_device *pdev)

err_slot_name:
mmc_remove_host(mmc);
- free_irq(mmc_slot(host).card_detect_irq, host);
+err_pinctrl_state:
+ devm_pinctrl_put(host->pinctrl);
+ if ((mmc_slot(host).sdio_irq))
+ free_irq(mmc_slot(host).sdio_irq, host);
+err_irq_sdio:
+ if ((mmc_slot(host).card_detect_irq))
+ free_irq(mmc_slot(host).card_detect_irq, host);
err_irq_cd:
if (host->use_reg)
omap_hsmmc_reg_put(host);
@@ -2167,13 +2312,15 @@ static int omap_hsmmc_remove(struct platform_device *pdev)
if (host->pdata->cleanup)
host->pdata->cleanup(&pdev->dev);
free_irq(host->irq, host);
+ if ((mmc_slot(host).sdio_irq))
+ free_irq(mmc_slot(host).sdio_irq, host);
if (mmc_slot(host).card_detect_irq)
free_irq(mmc_slot(host).card_detect_irq, host);
-
if (host->tx_chan)
dma_release_channel(host->tx_chan);
if (host->rx_chan)
dma_release_channel(host->rx_chan);
+ devm_pinctrl_put(host->pinctrl);

pm_runtime_put_sync(host->dev);
pm_runtime_disable(host->dev);
@@ -2293,23 +2440,66 @@ static int omap_hsmmc_resume(struct device *dev)
static int omap_hsmmc_runtime_suspend(struct device *dev)
{
struct omap_hsmmc_host *host;
+ unsigned long flags;
+ int ret = 0;

host = platform_get_drvdata(to_platform_device(dev));
omap_hsmmc_context_save(host);
dev_dbg(dev, "disabled\n");

- return 0;
+ if (host->flags & HSMMC_SWAKEUP_QUIRK) {
+ spin_lock_irqsave(&host->irq_lock, flags);
+ OMAP_HSMMC_WRITE(host->base, ISE, 0);
+ OMAP_HSMMC_WRITE(host->base, IE, 0);
+ OMAP_HSMMC_WRITE(host->base, STAT, STAT_CLEAR);
+ spin_unlock_irqrestore(&host->irq_lock, flags);
+
+ ret = pinctrl_select_state(host->pinctrl, host->idle);
+ if (ret < 0)
+ dev_warn(mmc_dev(host->mmc), "Unable to select idle pinmux\n");
+
+ enable_irq(mmc_slot(host).sdio_irq);
+ }
+
+ spin_lock_irqsave(&host->irq_lock, flags);
+ /* infinite loop, if irq not cleared in omap_hsmmc_enable_sdio_irq */
+ host->flags |= HSMMC_RUNTIME_SUSPENDED;
+ spin_unlock_irqrestore(&host->irq_lock, flags);
+
+ return ret;
}

static int omap_hsmmc_runtime_resume(struct device *dev)
{
struct omap_hsmmc_host *host;
+ unsigned long flags;
+ int ret = 0;

host = platform_get_drvdata(to_platform_device(dev));
omap_hsmmc_context_restore(host);
dev_dbg(dev, "enabled\n");

- return 0;
+ spin_lock_irqsave(&host->irq_lock, flags);
+ /* infinite loop, if irq not cleared in omap_hsmmc_enable_sdio_irq */
+ host->flags &= ~HSMMC_RUNTIME_SUSPENDED;
+ spin_unlock_irqrestore(&host->irq_lock, flags);
+
+ if (host->flags & HSMMC_SWAKEUP_QUIRK) {
+ disable_irq(mmc_slot(host).sdio_irq);
+
+ ret = pinctrl_select_state(host->pinctrl, host->active);
+ if (ret < 0)
+ dev_warn(mmc_dev(host->mmc), "Unable to select active pinmux\n");
+
+ spin_lock_irqsave(&host->irq_lock, flags);
+ if (host->flags & HSMMC_SDIO_IRQ_ENABLED) {
+ OMAP_HSMMC_WRITE(host->base, STAT, STAT_CLEAR);
+ OMAP_HSMMC_WRITE(host->base, ISE, CIRQ_EN);
+ OMAP_HSMMC_WRITE(host->base, IE, CIRQ_EN);
+ }
+ spin_unlock_irqrestore(&host->irq_lock, flags);
+ }
+ return ret;
}

static struct dev_pm_ops omap_hsmmc_dev_pm_ops = {
diff --git a/include/linux/platform_data/mmc-omap.h b/include/linux/platform_data/mmc-omap.h
index 2bf1b30..fd5fff5 100644
--- a/include/linux/platform_data/mmc-omap.h
+++ b/include/linux/platform_data/mmc-omap.h
@@ -115,6 +115,7 @@ struct omap_mmc_platform_data {

int switch_pin; /* gpio (card detect) */
int gpio_wp; /* gpio (write protect) */
+ int gpio_cirq; /* gpio (card irq) */

int (*set_bus_mode)(struct device *dev, int slot, int bus_mode);
int (*set_power)(struct device *dev, int slot,
@@ -145,6 +146,9 @@ struct omap_mmc_platform_data {
int card_detect_irq;
int (*card_detect)(struct device *dev, int slot);

+ /* SDIO IRQs */
+ int sdio_irq;
+
unsigned int ban_openended:1;

} slots[OMAP_MMC_MAX_SLOTS];
--
1.7.10.4

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