Input: snvs_pwrkey - send key events for i.MX6 S, DL and Q

The first generation i.MX6 processors does not send an interrupt when the
power key is pressed. It sends a power down request interrupt if the key is
released before a hard shutdown (5 second press). This should allow
software to bring down the SoC safely.

For this driver to work as a regular power key with the older SoCs, we need
to send a keypress AND release when we get the power down request irq.

Signed-off-by: Robin van der Gracht <robin@protonic.nl>
Link: https://lore.kernel.org/r/20191125161210.8275-1-robin@protonic.nl
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/keyboard/Kconfig b/drivers/input/keyboard/Kconfig
index 61f4eb6..4706ff0 100644 (file)
--- a/drivers/input/keyboard/Kconfig
+++ b/drivers/input/keyboard/Kconfig
@@ -450,7 +450,7 @@ config KEYBOARD_SNVS_PWRKEY
        depends on OF
        help
          This is the snvs powerkey driver for the Freescale i.MX application
-         processors that are newer than i.MX6 SX.
+         processors.
 
          To compile this driver as a module, choose M here; the
          module will be called snvs_pwrkey.

diff --git a/drivers/input/keyboard/snvs_pwrkey.c b/drivers/input/keyboard/snvs_pwrkey.c
index e76b7a4..fd6f244 100644 (file)
--- a/drivers/input/keyboard/snvs_pwrkey.c
+++ b/drivers/input/keyboard/snvs_pwrkey.c
@@ -19,15 +19,16 @@
 #include <linux/mfd/syscon.h>
 #include <linux/regmap.h>
 
-#define SNVS_LPSR_REG  0x4C    /* LP Status Register */
-#define SNVS_LPCR_REG  0x38    /* LP Control Register */
-#define SNVS_HPSR_REG  0x14
-#define SNVS_HPSR_BTN  BIT(6)
-#define SNVS_LPSR_SPO  BIT(18)
-#define SNVS_LPCR_DEP_EN BIT(5)
+#define SNVS_HPVIDR1_REG       0xF8
+#define SNVS_LPSR_REG          0x4C    /* LP Status Register */
+#define SNVS_LPCR_REG          0x38    /* LP Control Register */
+#define SNVS_HPSR_REG          0x14
+#define SNVS_HPSR_BTN          BIT(6)
+#define SNVS_LPSR_SPO          BIT(18)
+#define SNVS_LPCR_DEP_EN       BIT(5)
 
-#define DEBOUNCE_TIME 30
-#define REPEAT_INTERVAL 60
+#define DEBOUNCE_TIME          30
+#define REPEAT_INTERVAL                60
 
 struct pwrkey_drv_data {
        struct regmap *snvs;
@@ -37,6 +38,7 @@ struct pwrkey_drv_data {
        int wakeup;
        struct timer_list check_timer;
        struct input_dev *input;
+       u8 minor_rev;
 };
 
 static void imx_imx_snvs_check_for_events(struct timer_list *t)
@@ -67,13 +69,29 @@ static irqreturn_t imx_snvs_pwrkey_interrupt(int irq, void *dev_id)
 {
        struct platform_device *pdev = dev_id;
        struct pwrkey_drv_data *pdata = platform_get_drvdata(pdev);
+       struct input_dev *input = pdata->input;
        u32 lp_status;
 
-       pm_wakeup_event(pdata->input->dev.parent, 0);
+       pm_wakeup_event(input->dev.parent, 0);
 
        regmap_read(pdata->snvs, SNVS_LPSR_REG, &lp_status);
-       if (lp_status & SNVS_LPSR_SPO)
-               mod_timer(&pdata->check_timer, jiffies + msecs_to_jiffies(DEBOUNCE_TIME));
+       if (lp_status & SNVS_LPSR_SPO) {
+               if (pdata->minor_rev == 0) {
+                       /*
+                        * The first generation i.MX6 SoCs only sends an
+                        * interrupt on button release. To mimic power-key
+                        * usage, we'll prepend a press event.
+                        */
+                       input_report_key(input, pdata->keycode, 1);
+                       input_sync(input);
+                       input_report_key(input, pdata->keycode, 0);
+                       input_sync(input);
+                       pm_relax(input->dev.parent);
+               } else {
+                       mod_timer(&pdata->check_timer,
+                                 jiffies + msecs_to_jiffies(DEBOUNCE_TIME));
+               }
+       }
 
        /* clear SPO status */
        regmap_write(pdata->snvs, SNVS_LPSR_REG, SNVS_LPSR_SPO);
@@ -94,6 +112,7 @@ static int imx_snvs_pwrkey_probe(struct platform_device *pdev)
        struct input_dev *input = NULL;
        struct device_node *np;
        int error;
+       u32 vid;
 
        /* Get SNVS register Page */
        np = pdev->dev.of_node;
@@ -121,6 +140,9 @@ static int imx_snvs_pwrkey_probe(struct platform_device *pdev)
        if (pdata->irq < 0)
                return -EINVAL;
 
+       regmap_read(pdata->snvs, SNVS_HPVIDR1_REG, &vid);
+       pdata->minor_rev = vid & 0xff;
+
        regmap_update_bits(pdata->snvs, SNVS_LPCR_REG, SNVS_LPCR_DEP_EN, SNVS_LPCR_DEP_EN);
 
        /* clear the unexpected interrupt before driver ready */