Input: pmic8xxx-pwrkey - support shutdown

On pm8xxx PMICs, shutdown and restart are signaled to the PMIC via a pin
called PS_HOLD. When this pin goes low, the PMIC performs a configurable
power sequence. Add a .shutdown hook so that we can properly configure this
power sequence for shutdown or restart depending on the system state.

Signed-off-by: Stephen Boyd <[e-mail]>
Reviewed-by: Bjorn Andersson <[e-mail]>
Signed-off-by: Dmitry Torokhov <[e-mail]>

drivers/input/misc/pmic8xxx-pwrkey.c

···
 #include <linux/regmap.h>
 #include <linux/log2.h>
 #include <linux/of.h>
+#include <linux/of_device.h>
 
 #define PON_CNTL_1 0x1C
 #define PON_CNTL_PULL_UP BIT(7)
 #define PON_CNTL_TRIG_DELAY_MASK (0x7)
+#define PON_CNTL_1_PULL_UP_EN			0xe0
+#define PON_CNTL_1_USB_PWR_EN			0x10
+#define PON_CNTL_1_WD_EN_RESET			0x08
+
+#define PM8058_SLEEP_CTRL			0x02b
+#define PM8921_SLEEP_CTRL			0x10a
+
+#define SLEEP_CTRL_SMPL_EN_RESET		0x04
+
+/* Regulator master enable addresses */
+#define REG_PM8058_VREG_EN_MSM			0x018
+#define REG_PM8058_VREG_EN_GRP_5_4		0x1c8
+
+/* Regulator control registers for shutdown/reset */
+#define PM8058_S0_CTRL				0x004
+#define PM8058_S1_CTRL				0x005
+#define PM8058_S3_CTRL				0x111
+#define PM8058_L21_CTRL				0x120
+#define PM8058_L22_CTRL				0x121
+
+#define PM8058_REGULATOR_ENABLE_MASK		0x80
+#define PM8058_REGULATOR_ENABLE			0x80
+#define PM8058_REGULATOR_DISABLE		0x00
+#define PM8058_REGULATOR_PULL_DOWN_MASK		0x40
+#define PM8058_REGULATOR_PULL_DOWN_EN		0x40
+
+/* Buck CTRL register */
+#define PM8058_SMPS_LEGACY_VREF_SEL		0x20
+#define PM8058_SMPS_LEGACY_VPROG_MASK		0x1f
+#define PM8058_SMPS_ADVANCED_BAND_MASK		0xC0
+#define PM8058_SMPS_ADVANCED_BAND_SHIFT		6
+#define PM8058_SMPS_ADVANCED_VPROG_MASK		0x3f
+
+/* Buck TEST2 registers for shutdown/reset */
+#define PM8058_S0_TEST2				0x084
+#define PM8058_S1_TEST2				0x085
+#define PM8058_S3_TEST2				0x11a
+
+#define PM8058_REGULATOR_BANK_WRITE		0x80
+#define PM8058_REGULATOR_BANK_MASK		0x70
+#define PM8058_REGULATOR_BANK_SHIFT		4
+#define PM8058_REGULATOR_BANK_SEL(n)	((n) << PM8058_REGULATOR_BANK_SHIFT)
+
+/* Buck TEST2 register bank 1 */
+#define PM8058_SMPS_LEGACY_VLOW_SEL		0x01
+
+/* Buck TEST2 register bank 7 */
+#define PM8058_SMPS_ADVANCED_MODE_MASK		0x02
+#define PM8058_SMPS_ADVANCED_MODE		0x02
+#define PM8058_SMPS_LEGACY_MODE			0x00
 
 /**
  * struct pmic8xxx_pwrkey - pmic8xxx pwrkey information
  * @key_press_irq: key press irq number
+ * @regmap: device regmap
+ * @shutdown_fn: shutdown configuration function
  */
 struct pmic8xxx_pwrkey {
 	int key_press_irq;
+	struct regmap *regmap;
+	int (*shutdown_fn)(struct pmic8xxx_pwrkey *, bool);
 };
 
 static irqreturn_t pwrkey_press_irq(int irq, void *_pwr)
···
 static SIMPLE_DEV_PM_OPS(pm8xxx_pwr_key_pm_ops,
 		pmic8xxx_pwrkey_suspend, pmic8xxx_pwrkey_resume);
 
+static void pmic8xxx_pwrkey_shutdown(struct platform_device *pdev)
+{
+	struct pmic8xxx_pwrkey *pwrkey = platform_get_drvdata(pdev);
+	int error;
+	u8 mask, val;
+	bool reset = system_state == SYSTEM_RESTART;
+
+	if (pwrkey->shutdown_fn) {
+		error = pwrkey->shutdown_fn(pwrkey, reset);
+		if (error)
+			return;
+	}
+
+	/*
+	 * Select action to perform (reset or shutdown) when PS_HOLD goes low.
+	 * Also ensure that KPD, CBL0, and CBL1 pull ups are enabled and that
+	 * USB charging is enabled.
+	 */
+	mask = PON_CNTL_1_PULL_UP_EN | PON_CNTL_1_USB_PWR_EN;
+	mask |= PON_CNTL_1_WD_EN_RESET;
+	val = mask;
+	if (!reset)
+		val &= ~PON_CNTL_1_WD_EN_RESET;
+
+	regmap_update_bits(pwrkey->regmap, PON_CNTL_1, mask, val);
+}
+
+/*
+ * Set an SMPS regulator to be disabled in its CTRL register, but enabled
+ * in the master enable register.  Also set it's pull down enable bit.
+ * Take care to make sure that the output voltage doesn't change if switching
+ * from advanced mode to legacy mode.
+ */
+static int pm8058_disable_smps_locally_set_pull_down(struct regmap *regmap,
+	u16 ctrl_addr, u16 test2_addr, u16 master_enable_addr,
+	u8 master_enable_bit)
+{
+	int error;
+	u8 vref_sel, vlow_sel, band, vprog, bank;
+	unsigned int reg;
+
+	bank = PM8058_REGULATOR_BANK_SEL(7);
+	error = regmap_write(regmap, test2_addr, bank);
+	if (error)
+		return error;
+
+	error = regmap_read(regmap, test2_addr, &reg);
+	if (error)
+		return error;
+
+	reg &= PM8058_SMPS_ADVANCED_MODE_MASK;
+	/* Check if in advanced mode. */
+	if (reg == PM8058_SMPS_ADVANCED_MODE) {
+		/* Determine current output voltage. */
+		error = regmap_read(regmap, ctrl_addr, &reg);
+		if (error)
+			return error;
+
+		band = reg & PM8058_SMPS_ADVANCED_BAND_MASK;
+		band >>= PM8058_SMPS_ADVANCED_BAND_SHIFT;
+		switch (band) {
+		case 3:
+			vref_sel = 0;
+			vlow_sel = 0;
+			break;
+		case 2:
+			vref_sel = PM8058_SMPS_LEGACY_VREF_SEL;
+			vlow_sel = 0;
+			break;
+		case 1:
+			vref_sel = PM8058_SMPS_LEGACY_VREF_SEL;
+			vlow_sel = PM8058_SMPS_LEGACY_VLOW_SEL;
+			break;
+		default:
+			pr_err("%s: regulator already disabled\n", __func__);
+			return -EPERM;
+		}
+		vprog = reg & PM8058_SMPS_ADVANCED_VPROG_MASK;
+		/* Round up if fine step is in use. */
+		vprog = (vprog + 1) >> 1;
+		if (vprog > PM8058_SMPS_LEGACY_VPROG_MASK)
+			vprog = PM8058_SMPS_LEGACY_VPROG_MASK;
+
+		/* Set VLOW_SEL bit. */
+		bank = PM8058_REGULATOR_BANK_SEL(1);
+		error = regmap_write(regmap, test2_addr, bank);
+		if (error)
+			return error;
+
+		error = regmap_update_bits(regmap, test2_addr,
+			PM8058_REGULATOR_BANK_WRITE | PM8058_REGULATOR_BANK_MASK
+				| PM8058_SMPS_LEGACY_VLOW_SEL,
+			PM8058_REGULATOR_BANK_WRITE |
+			PM8058_REGULATOR_BANK_SEL(1) | vlow_sel);
+		if (error)
+			return error;
+
+		/* Switch to legacy mode */
+		bank = PM8058_REGULATOR_BANK_SEL(7);
+		error = regmap_write(regmap, test2_addr, bank);
+		if (error)
+			return error;
+
+		error = regmap_update_bits(regmap, test2_addr,
+				PM8058_REGULATOR_BANK_WRITE |
+				PM8058_REGULATOR_BANK_MASK |
+				PM8058_SMPS_ADVANCED_MODE_MASK,
+				PM8058_REGULATOR_BANK_WRITE |
+				PM8058_REGULATOR_BANK_SEL(7) |
+				PM8058_SMPS_LEGACY_MODE);
+		if (error)
+			return error;
+
+		/* Enable locally, enable pull down, keep voltage the same. */
+		error = regmap_update_bits(regmap, ctrl_addr,
+			PM8058_REGULATOR_ENABLE_MASK |
+			PM8058_REGULATOR_PULL_DOWN_MASK |
+			PM8058_SMPS_LEGACY_VREF_SEL |
+			PM8058_SMPS_LEGACY_VPROG_MASK,
+			PM8058_REGULATOR_ENABLE | PM8058_REGULATOR_PULL_DOWN_EN
+				| vref_sel | vprog);
+		if (error)
+			return error;
+	}
+
+	/* Enable in master control register. */
+	error = regmap_update_bits(regmap, master_enable_addr,
+			master_enable_bit, master_enable_bit);
+	if (error)
+		return error;
+
+	/* Disable locally and enable pull down. */
+	return regmap_update_bits(regmap, ctrl_addr,
+		PM8058_REGULATOR_ENABLE_MASK | PM8058_REGULATOR_PULL_DOWN_MASK,
+		PM8058_REGULATOR_DISABLE | PM8058_REGULATOR_PULL_DOWN_EN);
+}
+
+static int pm8058_disable_ldo_locally_set_pull_down(struct regmap *regmap,
+		u16 ctrl_addr, u16 master_enable_addr, u8 master_enable_bit)
+{
+	int error;
+
+	/* Enable LDO in master control register. */
+	error = regmap_update_bits(regmap, master_enable_addr,
+			master_enable_bit, master_enable_bit);
+	if (error)
+		return error;
+
+	/* Disable LDO in CTRL register and set pull down */
+	return regmap_update_bits(regmap, ctrl_addr,
+		PM8058_REGULATOR_ENABLE_MASK | PM8058_REGULATOR_PULL_DOWN_MASK,
+		PM8058_REGULATOR_DISABLE | PM8058_REGULATOR_PULL_DOWN_EN);
+}
+
+static int pm8058_pwrkey_shutdown(struct pmic8xxx_pwrkey *pwrkey, bool reset)
+{
+	int error;
+	struct regmap *regmap = pwrkey->regmap;
+	u8 mask, val;
+
+	/* When shutting down, enable active pulldowns on important rails. */
+	if (!reset) {
+		/* Disable SMPS's 0,1,3 locally and set pulldown enable bits. */
+		pm8058_disable_smps_locally_set_pull_down(regmap,
+			PM8058_S0_CTRL, PM8058_S0_TEST2,
+			REG_PM8058_VREG_EN_MSM, BIT(7));
+		pm8058_disable_smps_locally_set_pull_down(regmap,
+			PM8058_S1_CTRL, PM8058_S1_TEST2,
+			REG_PM8058_VREG_EN_MSM, BIT(6));
+		pm8058_disable_smps_locally_set_pull_down(regmap,
+			PM8058_S3_CTRL, PM8058_S3_TEST2,
+			REG_PM8058_VREG_EN_GRP_5_4, BIT(7) | BIT(4));
+		/* Disable LDO 21 locally and set pulldown enable bit. */
+		pm8058_disable_ldo_locally_set_pull_down(regmap,
+			PM8058_L21_CTRL, REG_PM8058_VREG_EN_GRP_5_4,
+			BIT(1));
+	}
+
+	/*
+	 * Fix-up: Set regulator LDO22 to 1.225 V in high power mode. Leave its
+	 * pull-down state intact. This ensures a safe shutdown.
+	 */
+	error = regmap_update_bits(regmap, PM8058_L22_CTRL, 0xbf, 0x93);
+	if (error)
+		return error;
+
+	/* Enable SMPL if resetting is desired */
+	mask = SLEEP_CTRL_SMPL_EN_RESET;
+	val = 0;
+	if (reset)
+		val = mask;
+	return regmap_update_bits(regmap, PM8058_SLEEP_CTRL, mask, val);
+}
+
+static int pm8921_pwrkey_shutdown(struct pmic8xxx_pwrkey *pwrkey, bool reset)
+{
+	struct regmap *regmap = pwrkey->regmap;
+	u8 mask = SLEEP_CTRL_SMPL_EN_RESET;
+	u8 val = 0;
+
+	/* Enable SMPL if resetting is desired */
+	if (reset)
+		val = mask;
+	return regmap_update_bits(regmap, PM8921_SLEEP_CTRL, mask, val);
+}
+
 static int pmic8xxx_pwrkey_probe(struct platform_device *pdev)
 {
 	struct input_dev *pwr;
···
 	if (!pwrkey)
 		return -ENOMEM;
 
+	pwrkey->shutdown_fn = of_device_get_match_data(&pdev->dev);
+	pwrkey->regmap = regmap;
 	pwrkey->key_press_irq = key_press_irq;
 
 	pwr = devm_input_allocate_device(&pdev->dev);
···
 }
 
 static const struct of_device_id pm8xxx_pwr_key_id_table[] = {
-	{ .compatible = "qcom,pm8058-pwrkey" },
-	{ .compatible = "qcom,pm8921-pwrkey" },
+	{ .compatible = "qcom,pm8058-pwrkey", .data = &pm8058_pwrkey_shutdown },
+	{ .compatible = "qcom,pm8921-pwrkey", .data = &pm8921_pwrkey_shutdown },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, pm8xxx_pwr_key_id_table);
···
 static struct platform_driver pmic8xxx_pwrkey_driver = {
 	.probe		= pmic8xxx_pwrkey_probe,
 	.remove		= pmic8xxx_pwrkey_remove,
+	.shutdown	= pmic8xxx_pwrkey_shutdown,
 	.driver		= {
 		.name	= "pm8xxx-pwrkey",
 		.pm	= &pm8xxx_pwr_key_pm_ops,