diff options
Diffstat (limited to 'drivers/acpi/acpi_lpss.c')
| -rw-r--r-- | drivers/acpi/acpi_lpss.c | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c new file mode 100644 index 00000000000..823df46a3de --- /dev/null +++ b/drivers/acpi/acpi_lpss.c @@ -0,0 +1,163 @@ +/* + * ACPI support for Intel Lynxpoint LPSS. + * + * Copyright (C) 2013, Intel Corporation + * Authors: Mika Westerberg <mika.westerberg@linux.intel.com> + * Rafael J. Wysocki <rafael.j.wysocki@intel.com> + * + * 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 <linux/acpi.h> +#include <linux/clk.h> +#include <linux/clkdev.h> +#include <linux/clk-provider.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/platform_device.h> +#include <linux/platform_data/clk-lpss.h> + +#include "internal.h" + +ACPI_MODULE_NAME("acpi_lpss"); + +#define LPSS_CLK_OFFSET 0x800 +#define LPSS_CLK_SIZE 0x04 + +struct lpss_device_desc { + bool clk_required; + const char *clk_parent; +}; + +struct lpss_private_data { + void __iomem *mmio_base; + resource_size_t mmio_size; + struct clk *clk; + const struct lpss_device_desc *dev_desc; +}; + +static struct lpss_device_desc lpt_dev_desc = { + .clk_required = true, + .clk_parent = "lpss_clk", +}; + +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 }, + { "INT33C4", (unsigned long)&lpt_dev_desc }, + { "INT33C5", (unsigned long)&lpt_dev_desc }, + { "INT33C6", }, + { "INT33C7", }, + + { } +}; + +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; + + if (!lpss_clk_dev) + lpt_register_clock_device(); + + if (!dev_desc->clk_parent || !pdata->mmio_base + || pdata->mmio_size < LPSS_CLK_OFFSET + LPSS_CLK_SIZE) + return -ENODATA; + + pdata->clk = clk_register_gate(NULL, dev_name(&adev->dev), + dev_desc->clk_parent, 0, + pdata->mmio_base + LPSS_CLK_OFFSET, + 0, 0, NULL); + if (IS_ERR(pdata->clk)) + return PTR_ERR(pdata->clk); + + clk_register_clkdev(pdata->clk, NULL, dev_name(&adev->dev)); + 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_list_entry *rentry; + struct list_head resource_list; + int ret; + + dev_desc = (struct lpss_device_desc *)id->driver_data; + if (!dev_desc) + return acpi_create_platform_device(adev, id); + + 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) { + pdata->mmio_size = resource_size(&rentry->res); + pdata->mmio_base = ioremap(rentry->res.start, + pdata->mmio_size); + pdata->dev_desc = dev_desc; + break; + } + + acpi_dev_free_resource_list(&resource_list); + + if (dev_desc->clk_required) { + ret = register_device_clock(adev, pdata); + if (ret) { + /* + * Skip the device, but don't terminate the namespace + * scan. + */ + ret = 0; + goto err_out; + } + } + + adev->driver_data = pdata; + ret = acpi_create_platform_device(adev, id); + if (ret > 0) + return ret; + + adev->driver_data = NULL; + + err_out: + kfree(pdata); + return ret; +} + +static struct acpi_scan_handler lpss_handler = { + .ids = acpi_lpss_device_ids, + .attach = acpi_lpss_create_device, +}; + +void __init acpi_lpss_init(void) +{ + if (!lpt_clk_init()) + acpi_scan_add_handler(&lpss_handler); +} |