From c78b0830667a7e7c1f0ca65b76b33166a84806b3 Mon Sep 17 00:00:00 2001 From: Heikki Krogerus Date: Fri, 23 May 2014 16:15:09 +0300 Subject: ACPI / LPSS: custom power domain for LPSS A power domain where we save the context of the additional LPSS registers. We need to do this or all LPSS devices are left in reset state when resuming from D3 on some Baytrails. The devices with the fractional clock divider also have zeros for N and M values after resuming unless they are reset. Li Aubrey found the root cause for the issue. The idea of using power domain for LPSS came from Mika Westerberg. Reported-by: Jin Yao Suggested-by: Li Aubrey Suggested-by: Mika Westerberg Tested-by: Mika Westerberg Signed-off-by: Heikki Krogerus [rjw: Added the .complete() callback to the PM domain, fixed build warning on 32-bit.] Signed-off-by: Rafael J. Wysocki --- drivers/acpi/acpi_lpss.c | 157 ++++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 150 insertions(+), 7 deletions(-) (limited to 'drivers/acpi') diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c index 69e29f409d4c..a01d4d1343dd 100644 --- a/drivers/acpi/acpi_lpss.c +++ b/drivers/acpi/acpi_lpss.c @@ -19,6 +19,7 @@ #include #include #include +#include #include "internal.h" @@ -43,6 +44,8 @@ ACPI_MODULE_NAME("acpi_lpss"); #define LPSS_TX_INT 0x20 #define LPSS_TX_INT_MASK BIT(1) +#define LPSS_PRV_REG_COUNT 9 + struct lpss_shared_clock { const char *name; unsigned long rate; @@ -58,6 +61,7 @@ struct lpss_device_desc { unsigned int prv_offset; size_t prv_size_override; bool clk_gate; + bool save_ctx; struct lpss_shared_clock *shared_clock; void (*setup)(struct lpss_private_data *pdata); }; @@ -72,6 +76,7 @@ struct lpss_private_data { resource_size_t mmio_size; struct clk *clk; const struct lpss_device_desc *dev_desc; + u32 prv_reg_ctx[LPSS_PRV_REG_COUNT]; }; static void lpss_uart_setup(struct lpss_private_data *pdata) @@ -116,6 +121,7 @@ static struct lpss_shared_clock pwm_clock = { static struct lpss_device_desc byt_pwm_dev_desc = { .clk_required = true, + .save_ctx = true, .shared_clock = &pwm_clock, }; @@ -128,6 +134,7 @@ static struct lpss_device_desc byt_uart_dev_desc = { .clk_required = true, .prv_offset = 0x800, .clk_gate = true, + .save_ctx = true, .shared_clock = &uart_clock, .setup = lpss_uart_setup, }; @@ -141,6 +148,7 @@ static struct lpss_device_desc byt_spi_dev_desc = { .clk_required = true, .prv_offset = 0x400, .clk_gate = true, + .save_ctx = true, .shared_clock = &spi_clock, }; @@ -156,6 +164,7 @@ static struct lpss_shared_clock i2c_clock = { static struct lpss_device_desc byt_i2c_dev_desc = { .clk_required = true, .prv_offset = 0x800, + .save_ctx = true, .shared_clock = &i2c_clock, }; @@ -449,6 +458,126 @@ static void acpi_lpss_set_ltr(struct device *dev, s32 val) } } +#ifdef CONFIG_PM +/** + * acpi_lpss_save_ctx() - Save the private registers of LPSS device + * @dev: LPSS device + * + * Most LPSS devices have private registers which may loose their context when + * the device is powered down. acpi_lpss_save_ctx() saves those registers into + * prv_reg_ctx array. + */ +static void acpi_lpss_save_ctx(struct device *dev) +{ + struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev)); + unsigned int i; + + for (i = 0; i < LPSS_PRV_REG_COUNT; i++) { + unsigned long offset = i * sizeof(u32); + + pdata->prv_reg_ctx[i] = __lpss_reg_read(pdata, offset); + dev_dbg(dev, "saving 0x%08x from LPSS reg at offset 0x%02lx\n", + pdata->prv_reg_ctx[i], offset); + } +} + +/** + * acpi_lpss_restore_ctx() - Restore the private registers of LPSS device + * @dev: LPSS device + * + * Restores the registers that were previously stored with acpi_lpss_save_ctx(). + */ +static void acpi_lpss_restore_ctx(struct device *dev) +{ + struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev)); + unsigned int i; + + /* + * The following delay is needed or the subsequent write operations may + * fail. The LPSS devices are actually PCI devices and the PCI spec + * expects 10ms delay before the device can be accessed after D3 to D0 + * transition. + */ + msleep(10); + + 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); + } +} + +#ifdef CONFIG_PM_SLEEP +static int acpi_lpss_suspend_late(struct device *dev) +{ + int ret = pm_generic_suspend_late(dev); + + if (ret) + return ret; + + acpi_lpss_save_ctx(dev); + return acpi_dev_suspend_late(dev); +} + +static int acpi_lpss_restore_early(struct device *dev) +{ + int ret = acpi_dev_resume_early(dev); + + if (ret) + return ret; + + acpi_lpss_restore_ctx(dev); + return pm_generic_resume_early(dev); +} +#endif /* CONFIG_PM_SLEEP */ + +#ifdef CONFIG_PM_RUNTIME +static int acpi_lpss_runtime_suspend(struct device *dev) +{ + int ret = pm_generic_runtime_suspend(dev); + + if (ret) + return ret; + + acpi_lpss_save_ctx(dev); + return acpi_dev_runtime_suspend(dev); +} + +static int acpi_lpss_runtime_resume(struct device *dev) +{ + int ret = acpi_dev_runtime_resume(dev); + + if (ret) + return ret; + + acpi_lpss_restore_ctx(dev); + return pm_generic_runtime_resume(dev); +} +#endif /* CONFIG_PM_RUNTIME */ +#endif /* CONFIG_PM */ + +static struct dev_pm_domain acpi_lpss_pm_domain = { + .ops = { +#ifdef CONFIG_PM_SLEEP + .suspend_late = acpi_lpss_suspend_late, + .restore_early = acpi_lpss_restore_early, + .prepare = acpi_subsys_prepare, + .complete = acpi_subsys_complete, + .suspend = acpi_subsys_suspend, + .resume_early = acpi_subsys_resume_early, + .freeze = acpi_subsys_freeze, + .poweroff = acpi_subsys_suspend, + .poweroff_late = acpi_subsys_suspend_late, +#endif +#ifdef CONFIG_PM_RUNTIME + .runtime_suspend = acpi_lpss_runtime_suspend, + .runtime_resume = acpi_lpss_runtime_resume, +#endif + }, +}; + static int acpi_lpss_platform_notify(struct notifier_block *nb, unsigned long action, void *data) { @@ -456,7 +585,6 @@ static int acpi_lpss_platform_notify(struct notifier_block *nb, struct lpss_private_data *pdata; struct acpi_device *adev; const struct acpi_device_id *id; - int ret = 0; id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev); if (!id || !id->driver_data) @@ -466,7 +594,7 @@ static int acpi_lpss_platform_notify(struct notifier_block *nb, return 0; pdata = acpi_driver_data(adev); - if (!pdata || !pdata->mmio_base || !pdata->dev_desc->ltr_required) + if (!pdata || !pdata->mmio_base) return 0; if (pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) { @@ -474,12 +602,27 @@ static int acpi_lpss_platform_notify(struct notifier_block *nb, return 0; } - if (action == BUS_NOTIFY_ADD_DEVICE) - ret = sysfs_create_group(&pdev->dev.kobj, &lpss_attr_group); - else if (action == BUS_NOTIFY_DEL_DEVICE) - sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group); + switch (action) { + case BUS_NOTIFY_BOUND_DRIVER: + if (pdata->dev_desc->save_ctx) + pdev->dev.pm_domain = &acpi_lpss_pm_domain; + break; + case BUS_NOTIFY_UNBOUND_DRIVER: + if (pdata->dev_desc->save_ctx) + pdev->dev.pm_domain = NULL; + break; + case BUS_NOTIFY_ADD_DEVICE: + if (pdata->dev_desc->ltr_required) + return sysfs_create_group(&pdev->dev.kobj, + &lpss_attr_group); + case BUS_NOTIFY_DEL_DEVICE: + if (pdata->dev_desc->ltr_required) + sysfs_remove_group(&pdev->dev.kobj, &lpss_attr_group); + default: + break; + } - return ret; + return 0; } static struct notifier_block acpi_lpss_nb = { -- cgit v1.2.3 From ed3a872e2ef62bde06e2f579d8d1458766ced078 Mon Sep 17 00:00:00 2001 From: Heikki Krogerus Date: Mon, 19 May 2014 14:42:07 +0300 Subject: ACPI / LPSS: support for fractional divider clock This creates fractional divider type clock for the ones that have it. It is needed by the UART driver as the clock rate must accommodate to the requested baud rate. Signed-off-by: Heikki Krogerus Signed-off-by: Rafael J. Wysocki --- drivers/acpi/acpi_lpss.c | 75 +++++++++++++++++++++++++++++++++--------------- 1 file changed, 52 insertions(+), 23 deletions(-) (limited to 'drivers/acpi') diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c index a01d4d1343dd..d1c9b04e29a3 100644 --- a/drivers/acpi/acpi_lpss.c +++ b/drivers/acpi/acpi_lpss.c @@ -29,6 +29,7 @@ ACPI_MODULE_NAME("acpi_lpss"); #define LPSS_LTR_SIZE 0x18 /* Offsets relative to LPSS_PRIVATE_OFFSET */ +#define LPSS_CLK_DIVIDER_DEF_MASK (BIT(1) | BIT(16)) #define LPSS_GENERAL 0x08 #define LPSS_GENERAL_LTR_MODE_SW BIT(2) #define LPSS_GENERAL_UART_RTS_OVRD BIT(3) @@ -60,6 +61,7 @@ struct lpss_device_desc { bool ltr_required; unsigned int prv_offset; size_t prv_size_override; + bool clk_divider; bool clk_gate; bool save_ctx; struct lpss_shared_clock *shared_clock; @@ -94,6 +96,14 @@ static void lpss_uart_setup(struct lpss_private_data *pdata) } static struct lpss_device_desc lpt_dev_desc = { + .clk_required = true, + .prv_offset = 0x800, + .ltr_required = true, + .clk_divider = true, + .clk_gate = true, +}; + +static struct lpss_device_desc lpt_i2c_dev_desc = { .clk_required = true, .prv_offset = 0x800, .ltr_required = true, @@ -104,6 +114,7 @@ static struct lpss_device_desc lpt_uart_dev_desc = { .clk_required = true, .prv_offset = 0x800, .ltr_required = true, + .clk_divider = true, .clk_gate = true, .setup = lpss_uart_setup, }; @@ -125,31 +136,21 @@ static struct lpss_device_desc byt_pwm_dev_desc = { .shared_clock = &pwm_clock, }; -static struct lpss_shared_clock uart_clock = { - .name = "uart_clk", - .rate = 44236800, -}; - static struct lpss_device_desc byt_uart_dev_desc = { .clk_required = true, .prv_offset = 0x800, + .clk_divider = true, .clk_gate = true, .save_ctx = true, - .shared_clock = &uart_clock, .setup = lpss_uart_setup, }; -static struct lpss_shared_clock spi_clock = { - .name = "spi_clk", - .rate = 50000000, -}; - static struct lpss_device_desc byt_spi_dev_desc = { .clk_required = true, .prv_offset = 0x400, + .clk_divider = true, .clk_gate = true, .save_ctx = true, - .shared_clock = &spi_clock, }; static struct lpss_device_desc byt_sdio_dev_desc = { @@ -175,8 +176,8 @@ static const struct acpi_device_id acpi_lpss_device_ids[] = { /* Lynxpoint LPSS devices */ { "INT33C0", (unsigned long)&lpt_dev_desc }, { "INT33C1", (unsigned long)&lpt_dev_desc }, - { "INT33C2", (unsigned long)&lpt_dev_desc }, - { "INT33C3", (unsigned long)&lpt_dev_desc }, + { "INT33C2", (unsigned long)&lpt_i2c_dev_desc }, + { "INT33C3", (unsigned long)&lpt_i2c_dev_desc }, { "INT33C4", (unsigned long)&lpt_uart_dev_desc }, { "INT33C5", (unsigned long)&lpt_uart_dev_desc }, { "INT33C6", (unsigned long)&lpt_sdio_dev_desc }, @@ -192,8 +193,8 @@ static const struct acpi_device_id acpi_lpss_device_ids[] = { { "INT3430", (unsigned long)&lpt_dev_desc }, { "INT3431", (unsigned long)&lpt_dev_desc }, - { "INT3432", (unsigned long)&lpt_dev_desc }, - { "INT3433", (unsigned long)&lpt_dev_desc }, + { "INT3432", (unsigned long)&lpt_i2c_dev_desc }, + { "INT3433", (unsigned long)&lpt_i2c_dev_desc }, { "INT3434", (unsigned long)&lpt_uart_dev_desc }, { "INT3435", (unsigned long)&lpt_uart_dev_desc }, { "INT3436", (unsigned long)&lpt_sdio_dev_desc }, @@ -221,9 +222,11 @@ static int register_device_clock(struct acpi_device *adev, { const struct lpss_device_desc *dev_desc = pdata->dev_desc; struct lpss_shared_clock *shared_clock = dev_desc->shared_clock; + const char *devname = dev_name(&adev->dev); struct clk *clk = ERR_PTR(-ENODEV); struct lpss_clk_data *clk_data; - const char *parent; + const char *parent, *clk_name; + void __iomem *prv_base; if (!lpss_clk_dev) lpt_register_clock_device(); @@ -234,7 +237,7 @@ static int register_device_clock(struct acpi_device *adev, if (dev_desc->clkdev_name) { clk_register_clkdev(clk_data->clk, dev_desc->clkdev_name, - dev_name(&adev->dev)); + devname); return 0; } @@ -243,6 +246,7 @@ static int register_device_clock(struct acpi_device *adev, return -ENODATA; parent = clk_data->name; + prv_base = pdata->mmio_base + dev_desc->prv_offset; if (shared_clock) { clk = shared_clock->clk; @@ -256,16 +260,41 @@ static int register_device_clock(struct acpi_device *adev, } if (dev_desc->clk_gate) { - clk = clk_register_gate(NULL, dev_name(&adev->dev), parent, 0, - pdata->mmio_base + dev_desc->prv_offset, - 0, 0, NULL); - pdata->clk = clk; + clk = clk_register_gate(NULL, devname, parent, 0, + prv_base, 0, 0, NULL); + parent = devname; + } + + if (dev_desc->clk_divider) { + /* Prevent division by zero */ + if (!readl(prv_base)) + writel(LPSS_CLK_DIVIDER_DEF_MASK, prv_base); + + clk_name = kasprintf(GFP_KERNEL, "%s-div", devname); + if (!clk_name) + return -ENOMEM; + clk = clk_register_fractional_divider(NULL, clk_name, parent, + 0, prv_base, + 1, 15, 16, 15, 0, NULL); + parent = clk_name; + + clk_name = kasprintf(GFP_KERNEL, "%s-update", devname); + if (!clk_name) { + kfree(parent); + return -ENOMEM; + } + clk = clk_register_gate(NULL, clk_name, parent, + CLK_SET_RATE_PARENT | CLK_SET_RATE_GATE, + prv_base, 31, 0, NULL); + kfree(parent); + kfree(clk_name); } if (IS_ERR(clk)) return PTR_ERR(clk); - clk_register_clkdev(clk, NULL, dev_name(&adev->dev)); + pdata->clk = clk; + clk_register_clkdev(clk, NULL, devname); return 0; } -- cgit v1.2.3