X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=kernel%2Fdrivers%2Facpi%2Facpi_lpss.c;fp=kernel%2Fdrivers%2Facpi%2Facpi_lpss.c;h=37fb1904760396751f27778e819d90c0fd9af83b;hb=9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00;hp=0000000000000000000000000000000000000000;hpb=98260f3884f4a202f9ca5eabed40b1354c489b29;p=kvmfornfv.git diff --git a/kernel/drivers/acpi/acpi_lpss.c b/kernel/drivers/acpi/acpi_lpss.c new file mode 100644 index 000000000..37fb19047 --- /dev/null +++ b/kernel/drivers/acpi/acpi_lpss.c @@ -0,0 +1,746 @@ +/* + * ACPI support for Intel Lynxpoint LPSS. + * + * Copyright (C) 2013, Intel Corporation + * Authors: Mika Westerberg + * Rafael J. Wysocki + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "internal.h" + +ACPI_MODULE_NAME("acpi_lpss"); + +#ifdef CONFIG_X86_INTEL_LPSS + +#define LPSS_ADDR(desc) ((unsigned long)&desc) + +#define LPSS_CLK_SIZE 0x04 +#define LPSS_LTR_SIZE 0x18 + +/* Offsets relative to LPSS_PRIVATE_OFFSET */ +#define LPSS_CLK_DIVIDER_DEF_MASK (BIT(1) | BIT(16)) +#define LPSS_RESETS 0x04 +#define LPSS_RESETS_RESET_FUNC BIT(0) +#define LPSS_RESETS_RESET_APB BIT(1) +#define LPSS_GENERAL 0x08 +#define LPSS_GENERAL_LTR_MODE_SW BIT(2) +#define LPSS_GENERAL_UART_RTS_OVRD BIT(3) +#define LPSS_SW_LTR 0x10 +#define LPSS_AUTO_LTR 0x14 +#define LPSS_LTR_SNOOP_REQ BIT(15) +#define LPSS_LTR_SNOOP_MASK 0x0000FFFF +#define LPSS_LTR_SNOOP_LAT_1US 0x800 +#define LPSS_LTR_SNOOP_LAT_32US 0xC00 +#define LPSS_LTR_SNOOP_LAT_SHIFT 5 +#define LPSS_LTR_SNOOP_LAT_CUTOFF 3000 +#define LPSS_LTR_MAX_VAL 0x3FF +#define LPSS_TX_INT 0x20 +#define LPSS_TX_INT_MASK BIT(1) + +#define LPSS_PRV_REG_COUNT 9 + +/* LPSS Flags */ +#define LPSS_CLK BIT(0) +#define LPSS_CLK_GATE BIT(1) +#define LPSS_CLK_DIVIDER BIT(2) +#define LPSS_LTR BIT(3) +#define LPSS_SAVE_CTX BIT(4) + +struct lpss_private_data; + +struct lpss_device_desc { + unsigned int flags; + const char *clk_con_id; + unsigned int prv_offset; + size_t prv_size_override; + void (*setup)(struct lpss_private_data *pdata); +}; + +static struct lpss_device_desc lpss_dma_desc = { + .flags = LPSS_CLK, +}; + +struct lpss_private_data { + void __iomem *mmio_base; + resource_size_t mmio_size; + unsigned int fixed_clk_rate; + struct clk *clk; + const struct lpss_device_desc *dev_desc; + u32 prv_reg_ctx[LPSS_PRV_REG_COUNT]; +}; + +/* UART Component Parameter Register */ +#define LPSS_UART_CPR 0xF4 +#define LPSS_UART_CPR_AFCE BIT(4) + +static void lpss_uart_setup(struct lpss_private_data *pdata) +{ + unsigned int offset; + u32 val; + + offset = pdata->dev_desc->prv_offset + LPSS_TX_INT; + val = readl(pdata->mmio_base + offset); + writel(val | LPSS_TX_INT_MASK, pdata->mmio_base + offset); + + val = readl(pdata->mmio_base + LPSS_UART_CPR); + if (!(val & LPSS_UART_CPR_AFCE)) { + offset = pdata->dev_desc->prv_offset + LPSS_GENERAL; + val = readl(pdata->mmio_base + offset); + val |= LPSS_GENERAL_UART_RTS_OVRD; + writel(val, pdata->mmio_base + offset); + } +} + +static void lpss_deassert_reset(struct lpss_private_data *pdata) +{ + unsigned int offset; + u32 val; + + offset = pdata->dev_desc->prv_offset + LPSS_RESETS; + val = readl(pdata->mmio_base + offset); + val |= LPSS_RESETS_RESET_APB | LPSS_RESETS_RESET_FUNC; + writel(val, pdata->mmio_base + offset); +} + +#define LPSS_I2C_ENABLE 0x6c + +static void byt_i2c_setup(struct lpss_private_data *pdata) +{ + lpss_deassert_reset(pdata); + + if (readl(pdata->mmio_base + pdata->dev_desc->prv_offset)) + pdata->fixed_clk_rate = 133000000; + + writel(0, pdata->mmio_base + LPSS_I2C_ENABLE); +} + +static struct lpss_device_desc lpt_dev_desc = { + .flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_LTR, + .prv_offset = 0x800, +}; + +static struct lpss_device_desc lpt_i2c_dev_desc = { + .flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_LTR, + .prv_offset = 0x800, +}; + +static struct lpss_device_desc lpt_uart_dev_desc = { + .flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_LTR, + .clk_con_id = "baudclk", + .prv_offset = 0x800, + .setup = lpss_uart_setup, +}; + +static struct lpss_device_desc lpt_sdio_dev_desc = { + .flags = LPSS_LTR, + .prv_offset = 0x1000, + .prv_size_override = 0x1018, +}; + +static struct lpss_device_desc byt_pwm_dev_desc = { + .flags = LPSS_SAVE_CTX, +}; + +static struct lpss_device_desc byt_uart_dev_desc = { + .flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX, + .clk_con_id = "baudclk", + .prv_offset = 0x800, + .setup = lpss_uart_setup, +}; + +static struct lpss_device_desc byt_spi_dev_desc = { + .flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX, + .prv_offset = 0x400, +}; + +static struct lpss_device_desc byt_sdio_dev_desc = { + .flags = LPSS_CLK, +}; + +static struct lpss_device_desc byt_i2c_dev_desc = { + .flags = LPSS_CLK | LPSS_SAVE_CTX, + .prv_offset = 0x800, + .setup = byt_i2c_setup, +}; + +static struct lpss_device_desc bsw_spi_dev_desc = { + .flags = LPSS_CLK | LPSS_CLK_GATE | LPSS_CLK_DIVIDER | LPSS_SAVE_CTX, + .prv_offset = 0x400, + .setup = lpss_deassert_reset, +}; + +#else + +#define LPSS_ADDR(desc) (0UL) + +#endif /* CONFIG_X86_INTEL_LPSS */ + +static const struct acpi_device_id acpi_lpss_device_ids[] = { + /* Generic LPSS devices */ + { "INTL9C60", LPSS_ADDR(lpss_dma_desc) }, + + /* Lynxpoint LPSS devices */ + { "INT33C0", LPSS_ADDR(lpt_dev_desc) }, + { "INT33C1", LPSS_ADDR(lpt_dev_desc) }, + { "INT33C2", LPSS_ADDR(lpt_i2c_dev_desc) }, + { "INT33C3", LPSS_ADDR(lpt_i2c_dev_desc) }, + { "INT33C4", LPSS_ADDR(lpt_uart_dev_desc) }, + { "INT33C5", LPSS_ADDR(lpt_uart_dev_desc) }, + { "INT33C6", LPSS_ADDR(lpt_sdio_dev_desc) }, + { "INT33C7", }, + + /* BayTrail LPSS devices */ + { "80860F09", LPSS_ADDR(byt_pwm_dev_desc) }, + { "80860F0A", LPSS_ADDR(byt_uart_dev_desc) }, + { "80860F0E", LPSS_ADDR(byt_spi_dev_desc) }, + { "80860F14", LPSS_ADDR(byt_sdio_dev_desc) }, + { "80860F41", LPSS_ADDR(byt_i2c_dev_desc) }, + { "INT33B2", }, + { "INT33FC", }, + + /* Braswell LPSS devices */ + { "80862288", LPSS_ADDR(byt_pwm_dev_desc) }, + { "8086228A", LPSS_ADDR(byt_uart_dev_desc) }, + { "8086228E", LPSS_ADDR(bsw_spi_dev_desc) }, + { "808622C1", LPSS_ADDR(byt_i2c_dev_desc) }, + + { "INT3430", LPSS_ADDR(lpt_dev_desc) }, + { "INT3431", LPSS_ADDR(lpt_dev_desc) }, + { "INT3432", LPSS_ADDR(lpt_i2c_dev_desc) }, + { "INT3433", LPSS_ADDR(lpt_i2c_dev_desc) }, + { "INT3434", LPSS_ADDR(lpt_uart_dev_desc) }, + { "INT3435", LPSS_ADDR(lpt_uart_dev_desc) }, + { "INT3436", LPSS_ADDR(lpt_sdio_dev_desc) }, + { "INT3437", }, + + /* Wildcat Point LPSS devices */ + { "INT3438", LPSS_ADDR(lpt_dev_desc) }, + + { } +}; + +#ifdef CONFIG_X86_INTEL_LPSS + +static int is_memory(struct acpi_resource *res, void *not_used) +{ + struct resource r; + return !acpi_dev_resource_memory(res, &r); +} + +/* LPSS main clock device. */ +static struct platform_device *lpss_clk_dev; + +static inline void lpt_register_clock_device(void) +{ + lpss_clk_dev = platform_device_register_simple("clk-lpt", -1, NULL, 0); +} + +static int register_device_clock(struct acpi_device *adev, + struct lpss_private_data *pdata) +{ + const struct lpss_device_desc *dev_desc = pdata->dev_desc; + const char *devname = dev_name(&adev->dev); + struct clk *clk = ERR_PTR(-ENODEV); + struct lpss_clk_data *clk_data; + const char *parent, *clk_name; + void __iomem *prv_base; + + if (!lpss_clk_dev) + lpt_register_clock_device(); + + clk_data = platform_get_drvdata(lpss_clk_dev); + if (!clk_data) + return -ENODEV; + clk = clk_data->clk; + + if (!pdata->mmio_base + || pdata->mmio_size < dev_desc->prv_offset + LPSS_CLK_SIZE) + return -ENODATA; + + parent = clk_data->name; + prv_base = pdata->mmio_base + dev_desc->prv_offset; + + if (pdata->fixed_clk_rate) { + clk = clk_register_fixed_rate(NULL, devname, parent, 0, + pdata->fixed_clk_rate); + goto out; + } + + if (dev_desc->flags & LPSS_CLK_GATE) { + clk = clk_register_gate(NULL, devname, parent, 0, + prv_base, 0, 0, NULL); + parent = devname; + } + + if (dev_desc->flags & LPSS_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); + } +out: + if (IS_ERR(clk)) + return PTR_ERR(clk); + + pdata->clk = clk; + clk_register_clkdev(clk, dev_desc->clk_con_id, devname); + return 0; +} + +static int acpi_lpss_create_device(struct acpi_device *adev, + const struct acpi_device_id *id) +{ + struct lpss_device_desc *dev_desc; + struct lpss_private_data *pdata; + struct resource_entry *rentry; + struct list_head resource_list; + struct platform_device *pdev; + int ret; + + dev_desc = (struct lpss_device_desc *)id->driver_data; + if (!dev_desc) { + pdev = acpi_create_platform_device(adev); + return IS_ERR_OR_NULL(pdev) ? PTR_ERR(pdev) : 1; + } + pdata = kzalloc(sizeof(*pdata), GFP_KERNEL); + if (!pdata) + return -ENOMEM; + + INIT_LIST_HEAD(&resource_list); + ret = acpi_dev_get_resources(adev, &resource_list, is_memory, NULL); + if (ret < 0) + goto err_out; + + list_for_each_entry(rentry, &resource_list, node) + if (resource_type(rentry->res) == IORESOURCE_MEM) { + if (dev_desc->prv_size_override) + pdata->mmio_size = dev_desc->prv_size_override; + else + pdata->mmio_size = resource_size(rentry->res); + pdata->mmio_base = ioremap(rentry->res->start, + pdata->mmio_size); + if (!pdata->mmio_base) + goto err_out; + break; + } + + acpi_dev_free_resource_list(&resource_list); + + pdata->dev_desc = dev_desc; + + if (dev_desc->setup) + dev_desc->setup(pdata); + + if (dev_desc->flags & LPSS_CLK) { + ret = register_device_clock(adev, pdata); + if (ret) { + /* Skip the device, but continue the namespace scan. */ + ret = 0; + goto err_out; + } + } + + /* + * This works around a known issue in ACPI tables where LPSS devices + * have _PS0 and _PS3 without _PSC (and no power resources), so + * acpi_bus_init_power() will assume that the BIOS has put them into D0. + */ + ret = acpi_device_fix_up_power(adev); + if (ret) { + /* Skip the device, but continue the namespace scan. */ + ret = 0; + goto err_out; + } + + adev->driver_data = pdata; + pdev = acpi_create_platform_device(adev); + if (!IS_ERR_OR_NULL(pdev)) { + return 1; + } + + ret = PTR_ERR(pdev); + adev->driver_data = NULL; + + err_out: + kfree(pdata); + return ret; +} + +static u32 __lpss_reg_read(struct lpss_private_data *pdata, unsigned int reg) +{ + return readl(pdata->mmio_base + pdata->dev_desc->prv_offset + reg); +} + +static void __lpss_reg_write(u32 val, struct lpss_private_data *pdata, + unsigned int reg) +{ + writel(val, pdata->mmio_base + pdata->dev_desc->prv_offset + reg); +} + +static int lpss_reg_read(struct device *dev, unsigned int reg, u32 *val) +{ + struct acpi_device *adev; + struct lpss_private_data *pdata; + unsigned long flags; + int ret; + + ret = acpi_bus_get_device(ACPI_HANDLE(dev), &adev); + if (WARN_ON(ret)) + return ret; + + spin_lock_irqsave(&dev->power.lock, flags); + if (pm_runtime_suspended(dev)) { + ret = -EAGAIN; + goto out; + } + pdata = acpi_driver_data(adev); + if (WARN_ON(!pdata || !pdata->mmio_base)) { + ret = -ENODEV; + goto out; + } + *val = __lpss_reg_read(pdata, reg); + + out: + spin_unlock_irqrestore(&dev->power.lock, flags); + return ret; +} + +static ssize_t lpss_ltr_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + u32 ltr_value = 0; + unsigned int reg; + int ret; + + reg = strcmp(attr->attr.name, "auto_ltr") ? LPSS_SW_LTR : LPSS_AUTO_LTR; + ret = lpss_reg_read(dev, reg, <r_value); + if (ret) + return ret; + + return snprintf(buf, PAGE_SIZE, "%08x\n", ltr_value); +} + +static ssize_t lpss_ltr_mode_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + u32 ltr_mode = 0; + char *outstr; + int ret; + + ret = lpss_reg_read(dev, LPSS_GENERAL, <r_mode); + if (ret) + return ret; + + outstr = (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) ? "sw" : "auto"; + return sprintf(buf, "%s\n", outstr); +} + +static DEVICE_ATTR(auto_ltr, S_IRUSR, lpss_ltr_show, NULL); +static DEVICE_ATTR(sw_ltr, S_IRUSR, lpss_ltr_show, NULL); +static DEVICE_ATTR(ltr_mode, S_IRUSR, lpss_ltr_mode_show, NULL); + +static struct attribute *lpss_attrs[] = { + &dev_attr_auto_ltr.attr, + &dev_attr_sw_ltr.attr, + &dev_attr_ltr_mode.attr, + NULL, +}; + +static struct attribute_group lpss_attr_group = { + .attrs = lpss_attrs, + .name = "lpss_ltr", +}; + +static void acpi_lpss_set_ltr(struct device *dev, s32 val) +{ + struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev)); + u32 ltr_mode, ltr_val; + + ltr_mode = __lpss_reg_read(pdata, LPSS_GENERAL); + if (val < 0) { + if (ltr_mode & LPSS_GENERAL_LTR_MODE_SW) { + ltr_mode &= ~LPSS_GENERAL_LTR_MODE_SW; + __lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL); + } + return; + } + ltr_val = __lpss_reg_read(pdata, LPSS_SW_LTR) & ~LPSS_LTR_SNOOP_MASK; + if (val >= LPSS_LTR_SNOOP_LAT_CUTOFF) { + ltr_val |= LPSS_LTR_SNOOP_LAT_32US; + val = LPSS_LTR_MAX_VAL; + } else if (val > LPSS_LTR_MAX_VAL) { + ltr_val |= LPSS_LTR_SNOOP_LAT_32US | LPSS_LTR_SNOOP_REQ; + val >>= LPSS_LTR_SNOOP_LAT_SHIFT; + } else { + ltr_val |= LPSS_LTR_SNOOP_LAT_1US | LPSS_LTR_SNOOP_REQ; + } + ltr_val |= val; + __lpss_reg_write(ltr_val, pdata, LPSS_SW_LTR); + if (!(ltr_mode & LPSS_GENERAL_LTR_MODE_SW)) { + ltr_mode |= LPSS_GENERAL_LTR_MODE_SW; + __lpss_reg_write(ltr_mode, pdata, LPSS_GENERAL); + } +} + +#ifdef CONFIG_PM +/** + * acpi_lpss_save_ctx() - Save the private registers of LPSS device + * @dev: LPSS device + * @pdata: pointer to the private data of the 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) +{ + 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 + * @pdata: pointer to the private data of the 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) +{ + 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) +{ + struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev)); + int ret; + + ret = pm_generic_suspend_late(dev); + if (ret) + return ret; + + if (pdata->dev_desc->flags & LPSS_SAVE_CTX) + acpi_lpss_save_ctx(dev, pdata); + + return acpi_dev_suspend_late(dev); +} + +static int acpi_lpss_resume_early(struct device *dev) +{ + struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev)); + int ret; + + ret = acpi_dev_resume_early(dev); + if (ret) + return ret; + + if (pdata->dev_desc->flags & LPSS_SAVE_CTX) + acpi_lpss_restore_ctx(dev, pdata); + + return pm_generic_resume_early(dev); +} +#endif /* CONFIG_PM_SLEEP */ + +static int acpi_lpss_runtime_suspend(struct device *dev) +{ + struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev)); + int ret; + + ret = pm_generic_runtime_suspend(dev); + if (ret) + return ret; + + if (pdata->dev_desc->flags & LPSS_SAVE_CTX) + acpi_lpss_save_ctx(dev, pdata); + + return acpi_dev_runtime_suspend(dev); +} + +static int acpi_lpss_runtime_resume(struct device *dev) +{ + struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev)); + int ret; + + ret = acpi_dev_runtime_resume(dev); + if (ret) + return ret; + + if (pdata->dev_desc->flags & LPSS_SAVE_CTX) + acpi_lpss_restore_ctx(dev, pdata); + + return pm_generic_runtime_resume(dev); +} +#endif /* CONFIG_PM */ + +static struct dev_pm_domain acpi_lpss_pm_domain = { + .ops = { +#ifdef CONFIG_PM +#ifdef CONFIG_PM_SLEEP + .prepare = acpi_subsys_prepare, + .complete = acpi_subsys_complete, + .suspend = acpi_subsys_suspend, + .suspend_late = acpi_lpss_suspend_late, + .resume_early = acpi_lpss_resume_early, + .freeze = acpi_subsys_freeze, + .poweroff = acpi_subsys_suspend, + .poweroff_late = acpi_lpss_suspend_late, + .restore_early = acpi_lpss_resume_early, +#endif + .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) +{ + struct platform_device *pdev = to_platform_device(data); + struct lpss_private_data *pdata; + struct acpi_device *adev; + const struct acpi_device_id *id; + + id = acpi_match_device(acpi_lpss_device_ids, &pdev->dev); + if (!id || !id->driver_data) + return 0; + + if (acpi_bus_get_device(ACPI_HANDLE(&pdev->dev), &adev)) + return 0; + + pdata = acpi_driver_data(adev); + if (!pdata) + return 0; + + if (pdata->mmio_base && + pdata->mmio_size < pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) { + dev_err(&pdev->dev, "MMIO size insufficient to access LTR\n"); + return 0; + } + + switch (action) { + case BUS_NOTIFY_ADD_DEVICE: + pdev->dev.pm_domain = &acpi_lpss_pm_domain; + if (pdata->dev_desc->flags & LPSS_LTR) + return sysfs_create_group(&pdev->dev.kobj, + &lpss_attr_group); + break; + 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; + break; + default: + break; + } + + return 0; +} + +static struct notifier_block acpi_lpss_nb = { + .notifier_call = acpi_lpss_platform_notify, +}; + +static void acpi_lpss_bind(struct device *dev) +{ + struct lpss_private_data *pdata = acpi_driver_data(ACPI_COMPANION(dev)); + + if (!pdata || !pdata->mmio_base || !(pdata->dev_desc->flags & LPSS_LTR)) + return; + + if (pdata->mmio_size >= pdata->dev_desc->prv_offset + LPSS_LTR_SIZE) + dev->power.set_latency_tolerance = acpi_lpss_set_ltr; + else + dev_err(dev, "MMIO size insufficient to access LTR\n"); +} + +static void acpi_lpss_unbind(struct device *dev) +{ + dev->power.set_latency_tolerance = NULL; +} + +static struct acpi_scan_handler lpss_handler = { + .ids = acpi_lpss_device_ids, + .attach = acpi_lpss_create_device, + .bind = acpi_lpss_bind, + .unbind = acpi_lpss_unbind, +}; + +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); + } +} + +#else + +static struct acpi_scan_handler lpss_handler = { + .ids = acpi_lpss_device_ids, +}; + +void __init acpi_lpss_init(void) +{ + acpi_scan_add_handler(&lpss_handler); +} + +#endif /* CONFIG_X86_INTEL_LPSS */