Linux-libre 4.5-gnu

1 files changed, 201 insertions, 15 deletions

diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c
index f9e0d09f7..0872d5fec 100644
--- a/drivers/acpi/acpi_lpss.c
+++ b/drivers/acpi/acpi_lpss.c
@@ -15,8 +15,10 @@
 #include <linux/clk-provider.h>
 #include <linux/err.h>
 #include <linux/io.h>
+#include <linux/mutex.h>
 #include <linux/platform_device.h>
 #include <linux/platform_data/clk-lpss.h>
+#include <linux/pm_domain.h>
 #include <linux/pm_runtime.h>
 #include <linux/delay.h>
 
@@ -26,6 +28,10 @@ ACPI_MODULE_NAME("acpi_lpss");
 
 #ifdef CONFIG_X86_INTEL_LPSS
 
+#include <asm/cpu_device_id.h>
+#include <asm/iosf_mbi.h>
+#include <asm/pmc_atom.h>
+
 #define LPSS_ADDR(desc) ((unsigned long)&desc)
 
 #define LPSS_CLK_SIZE	0x04
@@ -71,7 +77,7 @@ struct lpss_device_desc {
 	void (*setup)(struct lpss_private_data *pdata);
 };
 
-static struct lpss_device_desc lpss_dma_desc = {
+static const struct lpss_device_desc lpss_dma_desc = {
 	.flags = LPSS_CLK,
 };
 
@@ -84,6 +90,23 @@ struct lpss_private_data {
 	u32 prv_reg_ctx[LPSS_PRV_REG_COUNT];
 };
 
+/* LPSS run time quirks */
+static unsigned int lpss_quirks;
+
+/*
+ * LPSS_QUIRK_ALWAYS_POWER_ON: override power state for LPSS DMA device.
+ *
+ * The LPSS DMA controller has neither _PS0 nor _PS3 method. Moreover
+ * it can be powered off automatically whenever the last LPSS device goes down.
+ * In case of no power any access to the DMA controller will hang the system.
+ * The behaviour is reproduced on some HP laptops based on Intel BayTrail as
+ * well as on ASuS T100TA transformer.
+ *
+ * This quirk overrides power state of entire LPSS island to keep DMA powered
+ * on whenever we have at least one other device in use.
+ */
+#define LPSS_QUIRK_ALWAYS_POWER_ON	BIT(0)
+
 /* UART Component Parameter Register */
 #define LPSS_UART_CPR			0xF4
 #define LPSS_UART_CPR_AFCE		BIT(4)
@@ -196,13 +219,21 @@ static const struct lpss_device_desc bsw_i2c_dev_desc = {
 	.setup = byt_i2c_setup,
 };
 
-static struct lpss_device_desc bsw_spi_dev_desc = {
+static const struct lpss_device_desc bsw_spi_dev_desc = {
 	.flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX
 			| LPSS_NO_D3_DELAY,
 	.prv_offset = 0x400,
 	.setup = lpss_deassert_reset,
 };
 
+#define ICPU(model)	{ X86_VENDOR_INTEL, 6, model, X86_FEATURE_ANY, }
+
+static const struct x86_cpu_id lpss_cpu_ids[] = {
+	ICPU(0x37),	/* Valleyview, Bay Trail */
+	ICPU(0x4c),	/* Braswell, Cherry Trail */
+	{}
+};
+
 #else
 
 #define LPSS_ADDR(desc) (0UL)
@@ -574,6 +605,17 @@ static void acpi_lpss_restore_ctx(struct device *dev,
 {
 	unsigned int i;
 
+	for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
+		unsigned long offset = i * sizeof(u32);
+
+		__lpss_reg_write(pdata->prv_reg_ctx[i], pdata, offset);
+		dev_dbg(dev, "restoring 0x%08x to LPSS reg at offset 0x%02lx\n",
+			pdata->prv_reg_ctx[i], offset);
+	}
+}
+
+static void acpi_lpss_d3_to_d0_delay(struct lpss_private_data *pdata)
+{
 	/*
 	 * The following delay is needed or the subsequent write operations may
 	 * fail. The LPSS devices are actually PCI devices and the PCI spec
@@ -586,14 +628,34 @@ static void acpi_lpss_restore_ctx(struct device *dev,
 		delay = 0;
 
 	msleep(delay);
+}
 
-	for (i = 0; i < LPSS_PRV_REG_COUNT; i++) {
-		unsigned long offset = i * sizeof(u32);
+static int acpi_lpss_activate(struct device *dev)
+{
+	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
+	int ret;
 
-		__lpss_reg_write(pdata->prv_reg_ctx[i], pdata, offset);
-		dev_dbg(dev, "restoring 0x%08x to LPSS reg at offset 0x%02lx\n",
-			pdata->prv_reg_ctx[i], offset);
-	}
+	ret = acpi_dev_runtime_resume(dev);
+	if (ret)
+		return ret;
+
+	acpi_lpss_d3_to_d0_delay(pdata);
+
+	/*
+	 * This is called only on ->probe() stage where a device is either in
+	 * known state defined by BIOS or most likely powered off. Due to this
+	 * we have to deassert reset line to be sure that ->probe() will
+	 * recognize the device.
+	 */
+	if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
+		lpss_deassert_reset(pdata);
+
+	return 0;
+}
+
+static void acpi_lpss_dismiss(struct device *dev)
+{
+	acpi_dev_runtime_suspend(dev);
 }
 
 #ifdef CONFIG_PM_SLEEP
@@ -621,6 +683,8 @@ static int acpi_lpss_resume_early(struct device *dev)
 	if (ret)
 		return ret;
 
+	acpi_lpss_d3_to_d0_delay(pdata);
+
 	if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
 		acpi_lpss_restore_ctx(dev, pdata);
 
@@ -628,6 +692,89 @@ static int acpi_lpss_resume_early(struct device *dev)
 }
 #endif /* CONFIG_PM_SLEEP */
 
+/* IOSF SB for LPSS island */
+#define LPSS_IOSF_UNIT_LPIOEP		0xA0
+#define LPSS_IOSF_UNIT_LPIO1		0xAB
+#define LPSS_IOSF_UNIT_LPIO2		0xAC
+
+#define LPSS_IOSF_PMCSR			0x84
+#define LPSS_PMCSR_D0			0
+#define LPSS_PMCSR_D3hot		3
+#define LPSS_PMCSR_Dx_MASK		GENMASK(1, 0)
+
+#define LPSS_IOSF_GPIODEF0		0x154
+#define LPSS_GPIODEF0_DMA1_D3		BIT(2)
+#define LPSS_GPIODEF0_DMA2_D3		BIT(3)
+#define LPSS_GPIODEF0_DMA_D3_MASK	GENMASK(3, 2)
+
+static DEFINE_MUTEX(lpss_iosf_mutex);
+
+static void lpss_iosf_enter_d3_state(void)
+{
+	u32 value1 = 0;
+	u32 mask1 = LPSS_GPIODEF0_DMA_D3_MASK;
+	u32 value2 = LPSS_PMCSR_D3hot;
+	u32 mask2 = LPSS_PMCSR_Dx_MASK;
+	/*
+	 * PMC provides an information about actual status of the LPSS devices.
+	 * Here we read the values related to LPSS power island, i.e. LPSS
+	 * devices, excluding both LPSS DMA controllers, along with SCC domain.
+	 */
+	u32 func_dis, d3_sts_0, pmc_status, pmc_mask = 0xfe000ffe;
+	int ret;
+
+	ret = pmc_atom_read(PMC_FUNC_DIS, &func_dis);
+	if (ret)
+		return;
+
+	mutex_lock(&lpss_iosf_mutex);
+
+	ret = pmc_atom_read(PMC_D3_STS_0, &d3_sts_0);
+	if (ret)
+		goto exit;
+
+	/*
+	 * Get the status of entire LPSS power island per device basis.
+	 * Shutdown both LPSS DMA controllers if and only if all other devices
+	 * are already in D3hot.
+	 */
+	pmc_status = (~(d3_sts_0 | func_dis)) & pmc_mask;
+	if (pmc_status)
+		goto exit;
+
+	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO1, MBI_CFG_WRITE,
+			LPSS_IOSF_PMCSR, value2, mask2);
+
+	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO2, MBI_CFG_WRITE,
+			LPSS_IOSF_PMCSR, value2, mask2);
+
+	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIOEP, MBI_CR_WRITE,
+			LPSS_IOSF_GPIODEF0, value1, mask1);
+exit:
+	mutex_unlock(&lpss_iosf_mutex);
+}
+
+static void lpss_iosf_exit_d3_state(void)
+{
+	u32 value1 = LPSS_GPIODEF0_DMA1_D3 | LPSS_GPIODEF0_DMA2_D3;
+	u32 mask1 = LPSS_GPIODEF0_DMA_D3_MASK;
+	u32 value2 = LPSS_PMCSR_D0;
+	u32 mask2 = LPSS_PMCSR_Dx_MASK;
+
+	mutex_lock(&lpss_iosf_mutex);
+
+	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIOEP, MBI_CR_WRITE,
+			LPSS_IOSF_GPIODEF0, value1, mask1);
+
+	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO2, MBI_CFG_WRITE,
+			LPSS_IOSF_PMCSR, value2, mask2);
+
+	iosf_mbi_modify(LPSS_IOSF_UNIT_LPIO1, MBI_CFG_WRITE,
+			LPSS_IOSF_PMCSR, value2, mask2);
+
+	mutex_unlock(&lpss_iosf_mutex);
+}
+
 static int acpi_lpss_runtime_suspend(struct device *dev)
 {
 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
@@ -640,7 +787,17 @@ static int acpi_lpss_runtime_suspend(struct device *dev)
 	if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
 		acpi_lpss_save_ctx(dev, pdata);
 
-	return acpi_dev_runtime_suspend(dev);
+	ret = acpi_dev_runtime_suspend(dev);
+
+	/*
+	 * This call must be last in the sequence, otherwise PMC will return
+	 * wrong status for devices being about to be powered off. See
+	 * lpss_iosf_enter_d3_state() for further information.
+	 */
+	if (lpss_quirks & LPSS_QUIRK_ALWAYS_POWER_ON && iosf_mbi_available())
+		lpss_iosf_enter_d3_state();
+
+	return ret;
 }
 
 static int acpi_lpss_runtime_resume(struct device *dev)
@@ -648,10 +805,19 @@ static int acpi_lpss_runtime_resume(struct device *dev)
 	struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev));
 	int ret;
 
+	/*
+	 * This call is kept first to be in symmetry with
+	 * acpi_lpss_runtime_suspend() one.
+	 */
+	if (lpss_quirks & LPSS_QUIRK_ALWAYS_POWER_ON && iosf_mbi_available())
+		lpss_iosf_exit_d3_state();
+
 	ret = acpi_dev_runtime_resume(dev);
 	if (ret)
 		return ret;
 
+	acpi_lpss_d3_to_d0_delay(pdata);
+
 	if (pdata->dev_desc->flags & LPSS_SAVE_CTX)
 		acpi_lpss_restore_ctx(dev, pdata);
 
@@ -660,6 +826,10 @@ static int acpi_lpss_runtime_resume(struct device *dev)
 #endif /* CONFIG_PM */
 
 static struct dev_pm_domain acpi_lpss_pm_domain = {
+#ifdef CONFIG_PM
+	.activate = acpi_lpss_activate,
+	.dismiss = acpi_lpss_dismiss,
+#endif
 	.ops = {
 #ifdef CONFIG_PM
 #ifdef CONFIG_PM_SLEEP
@@ -705,8 +875,15 @@ static int acpi_lpss_platform_notify(struct notifier_block *nb,
 	}
 
 	switch (action) {
+	case BUS_NOTIFY_BIND_DRIVER:
+		dev_pm_domain_set(&pdev->dev, &acpi_lpss_pm_domain);
+		break;
+	case BUS_NOTIFY_DRIVER_NOT_BOUND:
+	case BUS_NOTIFY_UNBOUND_DRIVER:
+		dev_pm_domain_set(&pdev->dev, NULL);
+		break;
 	case BUS_NOTIFY_ADD_DEVICE:
-		pdev->dev.pm_domain = &acpi_lpss_pm_domain;
+		dev_pm_domain_set(&pdev->dev, &acpi_lpss_pm_domain);
 		if (pdata->dev_desc->flags & LPSS_LTR)
 			return sysfs_create_group(&pdev->dev.kobj,
 						  &lpss_attr_group);
@@ -714,7 +891,7 @@ static int acpi_lpss_platform_notify(struct notifier_block *nb,
 	case BUS_NOTIFY_DEL_DEVICE:
 		if (pdata->dev_desc->flags & LPSS_LTR)
 			sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group);
-		pdev->dev.pm_domain = NULL;
+		dev_pm_domain_set(&pdev->dev, NULL);
 		break;
 	default:
 		break;
@@ -754,10 +931,19 @@ static struct acpi_scan_handler lpss_handler = {
 
 void __init acpi_lpss_init(void)
 {
-	if (!lpt_clk_init()) {
-		bus_register_notifier(&platform_bus_type, &acpi_lpss_nb);
-		acpi_scan_add_handler(&lpss_handler);
-	}
+	const struct x86_cpu_id *id;
+	int ret;
+
+	ret = lpt_clk_init();
+	if (ret)
+		return;
+
+	id = x86_match_cpu(lpss_cpu_ids);
+	if (id)
+		lpss_quirks |= LPSS_QUIRK_ALWAYS_POWER_ON;
+
+	bus_register_notifier(&platform_bus_type, &acpi_lpss_nb);
+	acpi_scan_add_handler(&lpss_handler);
 }
 
 #else