linux/drivers/mfd/intel-lpss.c
Azhar Shaikh 274e43edcd mfd: intel-lpss: Do not put device in reset state on suspend
Commit 41a3da2b8e ("mfd: intel-lpss: Save register context on
suspend") saved the register context while going to suspend and
also put the device in reset state.

Due to the resetting of device, system cannot enter S3/S0ix
states when no_console_suspend flag is enabled. The system
and serial console both hang. The resetting of device is not
needed while going to suspend. Hence remove this code.

Cc: stable@vger.kernel.org
Fixes: 41a3da2b8e ("mfd: intel-lpss: Save register context on suspend")
Signed-off-by: Azhar Shaikh <azhar.shaikh@intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2016-11-16 09:50:25 +00:00

543 lines
13 KiB
C

/*
* 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/property.h>
#include <linux/seq_file.h>
#include <linux/io-64-nonatomic-lo-hi.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_PRIV_REG_COUNT (LPSS_PRIV_SIZE / 4)
#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 0x40
#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;
struct mfd_cell *cell;
struct device *dev;
void __iomem *priv;
u32 priv_ctx[LPSS_PRIV_REG_COUNT];
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)
{
const struct mfd_cell *cell;
unsigned int type;
type = lpss->caps & LPSS_PRIV_CAPS_TYPE_MASK;
type >>= LPSS_PRIV_CAPS_TYPE_SHIFT;
switch (type) {
case LPSS_DEV_I2C:
cell = &intel_lpss_i2c_cell;
break;
case LPSS_DEV_UART:
cell = &intel_lpss_uart_cell;
break;
case LPSS_DEV_SPI:
cell = &intel_lpss_spi_cell;
break;
default:
return -ENODEV;
}
lpss->cell = devm_kmemdup(lpss->dev, cell, sizeof(*cell), GFP_KERNEL);
if (!lpss->cell)
return -ENOMEM;
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;
lo_hi_writeq(addr, lpss->priv + LPSS_PRIV_REMAP_ADDR);
}
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, 0,
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;
lpss->cell->properties = info->properties;
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);
intel_lpss_unregister_clock(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)
{
struct intel_lpss *lpss = dev_get_drvdata(dev);
unsigned int i;
/* Save device context */
for (i = 0; i < LPSS_PRIV_REG_COUNT; i++)
lpss->priv_ctx[i] = readl(lpss->priv + i * 4);
return 0;
}
EXPORT_SYMBOL_GPL(intel_lpss_suspend);
int intel_lpss_resume(struct device *dev)
{
struct intel_lpss *lpss = dev_get_drvdata(dev);
unsigned int i;
intel_lpss_deassert_reset(lpss);
/* Restore device context */
for (i = 0; i < LPSS_PRIV_REG_COUNT; i++)
writel(lpss->priv_ctx[i], lpss->priv + i * 4);
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");