diff options
Diffstat (limited to 'drivers/mfd/intel-lpss.c')
| -rw-r--r-- | drivers/mfd/intel-lpss.c | 524 |
1 files changed, 524 insertions, 0 deletions
diff --git a/drivers/mfd/intel-lpss.c b/drivers/mfd/intel-lpss.c new file mode 100644 index 000000000..fdf4d5c1a --- /dev/null +++ b/drivers/mfd/intel-lpss.c @@ -0,0 +1,524 @@ +/* + * Intel Sunrisepoint LPSS core support. + * + * Copyright (C) 2015, Intel Corporation + * + * Authors: Andy Shevchenko <andriy.shevchenko@linux.intel.com> + * Mika Westerberg <mika.westerberg@linux.intel.com> + * Heikki Krogerus <heikki.krogerus@linux.intel.com> + * Jarkko Nikula <jarkko.nikula@linux.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/clk.h> +#include <linux/clkdev.h> +#include <linux/clk-provider.h> +#include <linux/debugfs.h> +#include <linux/idr.h> +#include <linux/ioport.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/mfd/core.h> +#include <linux/pm_qos.h> +#include <linux/pm_runtime.h> +#include <linux/seq_file.h> + +#include "intel-lpss.h" + +#define LPSS_DEV_OFFSET 0x000 +#define LPSS_DEV_SIZE 0x200 +#define LPSS_PRIV_OFFSET 0x200 +#define LPSS_PRIV_SIZE 0x100 +#define LPSS_IDMA64_OFFSET 0x800 +#define LPSS_IDMA64_SIZE 0x800 + +/* Offsets from lpss->priv */ +#define LPSS_PRIV_RESETS 0x04 +#define LPSS_PRIV_RESETS_FUNC BIT(2) +#define LPSS_PRIV_RESETS_IDMA 0x3 + +#define LPSS_PRIV_ACTIVELTR 0x10 +#define LPSS_PRIV_IDLELTR 0x14 + +#define LPSS_PRIV_LTR_REQ BIT(15) +#define LPSS_PRIV_LTR_SCALE_MASK 0xc00 +#define LPSS_PRIV_LTR_SCALE_1US 0x800 +#define LPSS_PRIV_LTR_SCALE_32US 0xc00 +#define LPSS_PRIV_LTR_VALUE_MASK 0x3ff + +#define LPSS_PRIV_SSP_REG 0x20 +#define LPSS_PRIV_SSP_REG_DIS_DMA_FIN BIT(0) + +#define LPSS_PRIV_REMAP_ADDR_LO 0x40 +#define LPSS_PRIV_REMAP_ADDR_HI 0x44 + +#define LPSS_PRIV_CAPS 0xfc +#define LPSS_PRIV_CAPS_NO_IDMA BIT(8) +#define LPSS_PRIV_CAPS_TYPE_SHIFT 4 +#define LPSS_PRIV_CAPS_TYPE_MASK (0xf << LPSS_PRIV_CAPS_TYPE_SHIFT) + +/* This matches the type field in CAPS register */ +enum intel_lpss_dev_type { + LPSS_DEV_I2C = 0, + LPSS_DEV_UART, + LPSS_DEV_SPI, +}; + +struct intel_lpss { + const struct intel_lpss_platform_info *info; + enum intel_lpss_dev_type type; + struct clk *clk; + struct clk_lookup *clock; + const struct mfd_cell *cell; + struct device *dev; + void __iomem *priv; + int devid; + u32 caps; + u32 active_ltr; + u32 idle_ltr; + struct dentry *debugfs; +}; + +static const struct resource intel_lpss_dev_resources[] = { + DEFINE_RES_MEM_NAMED(LPSS_DEV_OFFSET, LPSS_DEV_SIZE, "lpss_dev"), + DEFINE_RES_MEM_NAMED(LPSS_PRIV_OFFSET, LPSS_PRIV_SIZE, "lpss_priv"), + DEFINE_RES_IRQ(0), +}; + +static const struct resource intel_lpss_idma64_resources[] = { + DEFINE_RES_MEM(LPSS_IDMA64_OFFSET, LPSS_IDMA64_SIZE), + DEFINE_RES_IRQ(0), +}; + +#define LPSS_IDMA64_DRIVER_NAME "idma64" + +/* + * Cells needs to be ordered so that the iDMA is created first. This is + * because we need to be sure the DMA is available when the host controller + * driver is probed. + */ +static const struct mfd_cell intel_lpss_idma64_cell = { + .name = LPSS_IDMA64_DRIVER_NAME, + .num_resources = ARRAY_SIZE(intel_lpss_idma64_resources), + .resources = intel_lpss_idma64_resources, +}; + +static const struct mfd_cell intel_lpss_i2c_cell = { + .name = "i2c_designware", + .num_resources = ARRAY_SIZE(intel_lpss_dev_resources), + .resources = intel_lpss_dev_resources, +}; + +static const struct mfd_cell intel_lpss_uart_cell = { + .name = "dw-apb-uart", + .num_resources = ARRAY_SIZE(intel_lpss_dev_resources), + .resources = intel_lpss_dev_resources, +}; + +static const struct mfd_cell intel_lpss_spi_cell = { + .name = "pxa2xx-spi", + .num_resources = ARRAY_SIZE(intel_lpss_dev_resources), + .resources = intel_lpss_dev_resources, +}; + +static DEFINE_IDA(intel_lpss_devid_ida); +static struct dentry *intel_lpss_debugfs; + +static int intel_lpss_request_dma_module(const char *name) +{ + static bool intel_lpss_dma_requested; + + if (intel_lpss_dma_requested) + return 0; + + intel_lpss_dma_requested = true; + return request_module("%s", name); +} + +static void intel_lpss_cache_ltr(struct intel_lpss *lpss) +{ + lpss->active_ltr = readl(lpss->priv + LPSS_PRIV_ACTIVELTR); + lpss->idle_ltr = readl(lpss->priv + LPSS_PRIV_IDLELTR); +} + +static int intel_lpss_debugfs_add(struct intel_lpss *lpss) +{ + struct dentry *dir; + + dir = debugfs_create_dir(dev_name(lpss->dev), intel_lpss_debugfs); + if (IS_ERR(dir)) + return PTR_ERR(dir); + + /* Cache the values into lpss structure */ + intel_lpss_cache_ltr(lpss); + + debugfs_create_x32("capabilities", S_IRUGO, dir, &lpss->caps); + debugfs_create_x32("active_ltr", S_IRUGO, dir, &lpss->active_ltr); + debugfs_create_x32("idle_ltr", S_IRUGO, dir, &lpss->idle_ltr); + + lpss->debugfs = dir; + return 0; +} + +static void intel_lpss_debugfs_remove(struct intel_lpss *lpss) +{ + debugfs_remove_recursive(lpss->debugfs); +} + +static void intel_lpss_ltr_set(struct device *dev, s32 val) +{ + struct intel_lpss *lpss = dev_get_drvdata(dev); + u32 ltr; + + /* + * Program latency tolerance (LTR) accordingly what has been asked + * by the PM QoS layer or disable it in case we were passed + * negative value or PM_QOS_LATENCY_ANY. + */ + ltr = readl(lpss->priv + LPSS_PRIV_ACTIVELTR); + + if (val == PM_QOS_LATENCY_ANY || val < 0) { + ltr &= ~LPSS_PRIV_LTR_REQ; + } else { + ltr |= LPSS_PRIV_LTR_REQ; + ltr &= ~LPSS_PRIV_LTR_SCALE_MASK; + ltr &= ~LPSS_PRIV_LTR_VALUE_MASK; + + if (val > LPSS_PRIV_LTR_VALUE_MASK) + ltr |= LPSS_PRIV_LTR_SCALE_32US | val >> 5; + else + ltr |= LPSS_PRIV_LTR_SCALE_1US | val; + } + + if (ltr == lpss->active_ltr) + return; + + writel(ltr, lpss->priv + LPSS_PRIV_ACTIVELTR); + writel(ltr, lpss->priv + LPSS_PRIV_IDLELTR); + + /* Cache the values into lpss structure */ + intel_lpss_cache_ltr(lpss); +} + +static void intel_lpss_ltr_expose(struct intel_lpss *lpss) +{ + lpss->dev->power.set_latency_tolerance = intel_lpss_ltr_set; + dev_pm_qos_expose_latency_tolerance(lpss->dev); +} + +static void intel_lpss_ltr_hide(struct intel_lpss *lpss) +{ + dev_pm_qos_hide_latency_tolerance(lpss->dev); + lpss->dev->power.set_latency_tolerance = NULL; +} + +static int intel_lpss_assign_devs(struct intel_lpss *lpss) +{ + unsigned int type; + + type = lpss->caps & LPSS_PRIV_CAPS_TYPE_MASK; + type >>= LPSS_PRIV_CAPS_TYPE_SHIFT; + + switch (type) { + case LPSS_DEV_I2C: + lpss->cell = &intel_lpss_i2c_cell; + break; + case LPSS_DEV_UART: + lpss->cell = &intel_lpss_uart_cell; + break; + case LPSS_DEV_SPI: + lpss->cell = &intel_lpss_spi_cell; + break; + default: + return -ENODEV; + } + + lpss->type = type; + + return 0; +} + +static bool intel_lpss_has_idma(const struct intel_lpss *lpss) +{ + return (lpss->caps & LPSS_PRIV_CAPS_NO_IDMA) == 0; +} + +static void intel_lpss_set_remap_addr(const struct intel_lpss *lpss) +{ + resource_size_t addr = lpss->info->mem->start; + + writel(addr, lpss->priv + LPSS_PRIV_REMAP_ADDR_LO); +#if BITS_PER_LONG > 32 + writel(addr >> 32, lpss->priv + LPSS_PRIV_REMAP_ADDR_HI); +#else + writel(0, lpss->priv + LPSS_PRIV_REMAP_ADDR_HI); +#endif +} + +static void intel_lpss_deassert_reset(const struct intel_lpss *lpss) +{ + u32 value = LPSS_PRIV_RESETS_FUNC | LPSS_PRIV_RESETS_IDMA; + + /* Bring out the device from reset */ + writel(value, lpss->priv + LPSS_PRIV_RESETS); +} + +static void intel_lpss_init_dev(const struct intel_lpss *lpss) +{ + u32 value = LPSS_PRIV_SSP_REG_DIS_DMA_FIN; + + intel_lpss_deassert_reset(lpss); + + if (!intel_lpss_has_idma(lpss)) + return; + + intel_lpss_set_remap_addr(lpss); + + /* Make sure that SPI multiblock DMA transfers are re-enabled */ + if (lpss->type == LPSS_DEV_SPI) + writel(value, lpss->priv + LPSS_PRIV_SSP_REG); +} + +static void intel_lpss_unregister_clock_tree(struct clk *clk) +{ + struct clk *parent; + + while (clk) { + parent = clk_get_parent(clk); + clk_unregister(clk); + clk = parent; + } +} + +static int intel_lpss_register_clock_divider(struct intel_lpss *lpss, + const char *devname, + struct clk **clk) +{ + char name[32]; + struct clk *tmp = *clk; + + snprintf(name, sizeof(name), "%s-enable", devname); + tmp = clk_register_gate(NULL, name, __clk_get_name(tmp), 0, + lpss->priv, 0, 0, NULL); + if (IS_ERR(tmp)) + return PTR_ERR(tmp); + + snprintf(name, sizeof(name), "%s-div", devname); + tmp = clk_register_fractional_divider(NULL, name, __clk_get_name(tmp), + 0, lpss->priv, 1, 15, 16, 15, 0, + NULL); + if (IS_ERR(tmp)) + return PTR_ERR(tmp); + *clk = tmp; + + snprintf(name, sizeof(name), "%s-update", devname); + tmp = clk_register_gate(NULL, name, __clk_get_name(tmp), + CLK_SET_RATE_PARENT, lpss->priv, 31, 0, NULL); + if (IS_ERR(tmp)) + return PTR_ERR(tmp); + *clk = tmp; + + return 0; +} + +static int intel_lpss_register_clock(struct intel_lpss *lpss) +{ + const struct mfd_cell *cell = lpss->cell; + struct clk *clk; + char devname[24]; + int ret; + + if (!lpss->info->clk_rate) + return 0; + + /* Root clock */ + clk = clk_register_fixed_rate(NULL, dev_name(lpss->dev), NULL, + CLK_IS_ROOT, lpss->info->clk_rate); + if (IS_ERR(clk)) + return PTR_ERR(clk); + + snprintf(devname, sizeof(devname), "%s.%d", cell->name, lpss->devid); + + /* + * Support for clock divider only if it has some preset value. + * Otherwise we assume that the divider is not used. + */ + if (lpss->type != LPSS_DEV_I2C) { + ret = intel_lpss_register_clock_divider(lpss, devname, &clk); + if (ret) + goto err_clk_register; + } + + ret = -ENOMEM; + + /* Clock for the host controller */ + lpss->clock = clkdev_create(clk, lpss->info->clk_con_id, "%s", devname); + if (!lpss->clock) + goto err_clk_register; + + lpss->clk = clk; + + return 0; + +err_clk_register: + intel_lpss_unregister_clock_tree(clk); + + return ret; +} + +static void intel_lpss_unregister_clock(struct intel_lpss *lpss) +{ + if (IS_ERR_OR_NULL(lpss->clk)) + return; + + clkdev_drop(lpss->clock); + intel_lpss_unregister_clock_tree(lpss->clk); +} + +int intel_lpss_probe(struct device *dev, + const struct intel_lpss_platform_info *info) +{ + struct intel_lpss *lpss; + int ret; + + if (!info || !info->mem || info->irq <= 0) + return -EINVAL; + + lpss = devm_kzalloc(dev, sizeof(*lpss), GFP_KERNEL); + if (!lpss) + return -ENOMEM; + + lpss->priv = devm_ioremap(dev, info->mem->start + LPSS_PRIV_OFFSET, + LPSS_PRIV_SIZE); + if (!lpss->priv) + return -ENOMEM; + + lpss->info = info; + lpss->dev = dev; + lpss->caps = readl(lpss->priv + LPSS_PRIV_CAPS); + + dev_set_drvdata(dev, lpss); + + ret = intel_lpss_assign_devs(lpss); + if (ret) + return ret; + + intel_lpss_init_dev(lpss); + + lpss->devid = ida_simple_get(&intel_lpss_devid_ida, 0, 0, GFP_KERNEL); + if (lpss->devid < 0) + return lpss->devid; + + ret = intel_lpss_register_clock(lpss); + if (ret) + goto err_clk_register; + + intel_lpss_ltr_expose(lpss); + + ret = intel_lpss_debugfs_add(lpss); + if (ret) + dev_warn(dev, "Failed to create debugfs entries\n"); + + if (intel_lpss_has_idma(lpss)) { + /* + * Ensure the DMA driver is loaded before the host + * controller device appears, so that the host controller + * driver can request its DMA channels as early as + * possible. + * + * If the DMA module is not there that's OK as well. + */ + intel_lpss_request_dma_module(LPSS_IDMA64_DRIVER_NAME); + + ret = mfd_add_devices(dev, lpss->devid, &intel_lpss_idma64_cell, + 1, info->mem, info->irq, NULL); + if (ret) + dev_warn(dev, "Failed to add %s, fallback to PIO\n", + LPSS_IDMA64_DRIVER_NAME); + } + + ret = mfd_add_devices(dev, lpss->devid, lpss->cell, + 1, info->mem, info->irq, NULL); + if (ret) + goto err_remove_ltr; + + return 0; + +err_remove_ltr: + intel_lpss_debugfs_remove(lpss); + intel_lpss_ltr_hide(lpss); + +err_clk_register: + ida_simple_remove(&intel_lpss_devid_ida, lpss->devid); + + return ret; +} +EXPORT_SYMBOL_GPL(intel_lpss_probe); + +void intel_lpss_remove(struct device *dev) +{ + struct intel_lpss *lpss = dev_get_drvdata(dev); + + mfd_remove_devices(dev); + intel_lpss_debugfs_remove(lpss); + intel_lpss_ltr_hide(lpss); + intel_lpss_unregister_clock(lpss); + ida_simple_remove(&intel_lpss_devid_ida, lpss->devid); +} +EXPORT_SYMBOL_GPL(intel_lpss_remove); + +static int resume_lpss_device(struct device *dev, void *data) +{ + pm_runtime_resume(dev); + return 0; +} + +int intel_lpss_prepare(struct device *dev) +{ + /* + * Resume both child devices before entering system sleep. This + * ensures that they are in proper state before they get suspended. + */ + device_for_each_child_reverse(dev, NULL, resume_lpss_device); + return 0; +} +EXPORT_SYMBOL_GPL(intel_lpss_prepare); + +int intel_lpss_suspend(struct device *dev) +{ + return 0; +} +EXPORT_SYMBOL_GPL(intel_lpss_suspend); + +int intel_lpss_resume(struct device *dev) +{ + struct intel_lpss *lpss = dev_get_drvdata(dev); + + intel_lpss_init_dev(lpss); + + return 0; +} +EXPORT_SYMBOL_GPL(intel_lpss_resume); + +static int __init intel_lpss_init(void) +{ + intel_lpss_debugfs = debugfs_create_dir("intel_lpss", NULL); + return 0; +} +module_init(intel_lpss_init); + +static void __exit intel_lpss_exit(void) +{ + debugfs_remove(intel_lpss_debugfs); +} +module_exit(intel_lpss_exit); + +MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>"); +MODULE_AUTHOR("Mika Westerberg <mika.westerberg@linux.intel.com>"); +MODULE_AUTHOR("Heikki Krogerus <heikki.krogerus@linux.intel.com>"); +MODULE_AUTHOR("Jarkko Nikula <jarkko.nikula@linux.intel.com>"); +MODULE_DESCRIPTION("Intel LPSS core driver"); +MODULE_LICENSE("GPL v2"); |