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author | 2018-10-30 09:15:31 -0700 | |
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committer | 2018-10-30 09:15:31 -0700 | |
commit | c2101d01826480755f2bd9f3dd5e36757be61e23 (patch) | |
tree | 3f1d29969a98cc78b84335dc185e2806cd025282 /drivers/i2c | |
parent | Merge tag 'pm-4.20-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/ra... (diff) | |
parent | ACPI / PMIC: xpower: Add depends on IOSF_MBI to Kconfig entry (diff) | |
download | linux-c2101d01826480755f2bd9f3dd5e36757be61e23.tar.gz linux-c2101d01826480755f2bd9f3dd5e36757be61e23.tar.bz2 linux-c2101d01826480755f2bd9f3dd5e36757be61e23.zip |
Merge tag 'acpi-4.20-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull more ACPI updates from Rafael Wysocki:
"Rework the handling of the P-unit semaphore on Intel Baytrail and
Cherrytrail systems to avoid race conditions and excessive overhead
related to it (Hans de Goede)"
* tag 'acpi-4.20-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
ACPI / PMIC: xpower: Add depends on IOSF_MBI to Kconfig entry
i2c: designware: Cleanup bus lock handling
ACPI / PMIC: xpower: Block P-Unit I2C access during read-modify-write
x86: baytrail/cherrytrail: Rework and move P-Unit PMIC bus semaphore code
Diffstat (limited to 'drivers/i2c')
-rw-r--r-- | drivers/i2c/busses/i2c-designware-baytrail.c | 139 | ||||
-rw-r--r-- | drivers/i2c/busses/i2c-designware-common.c | 4 | ||||
-rw-r--r-- | drivers/i2c/busses/i2c-designware-core.h | 9 | ||||
-rw-r--r-- | drivers/i2c/busses/i2c-designware-platdrv.c | 2 |
4 files changed, 6 insertions, 148 deletions
diff --git a/drivers/i2c/busses/i2c-designware-baytrail.c b/drivers/i2c/busses/i2c-designware-baytrail.c index 9ca1feaba98f..33da07d64494 100644 --- a/drivers/i2c/busses/i2c-designware-baytrail.c +++ b/drivers/i2c/busses/i2c-designware-baytrail.c @@ -3,141 +3,15 @@ * Intel BayTrail PMIC I2C bus semaphore implementaion * Copyright (c) 2014, Intel Corporation. */ -#include <linux/delay.h> #include <linux/device.h> #include <linux/acpi.h> #include <linux/i2c.h> #include <linux/interrupt.h> -#include <linux/pm_qos.h> #include <asm/iosf_mbi.h> #include "i2c-designware-core.h" -#define SEMAPHORE_TIMEOUT 500 -#define PUNIT_SEMAPHORE 0x7 -#define PUNIT_SEMAPHORE_CHT 0x10e -#define PUNIT_SEMAPHORE_BIT BIT(0) -#define PUNIT_SEMAPHORE_ACQUIRE BIT(1) - -static unsigned long acquired; - -static u32 get_sem_addr(struct dw_i2c_dev *dev) -{ - if (dev->flags & MODEL_CHERRYTRAIL) - return PUNIT_SEMAPHORE_CHT; - else - return PUNIT_SEMAPHORE; -} - -static int get_sem(struct dw_i2c_dev *dev, u32 *sem) -{ - u32 addr = get_sem_addr(dev); - u32 data; - int ret; - - ret = iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ, addr, &data); - if (ret) { - dev_err(dev->dev, "iosf failed to read punit semaphore\n"); - return ret; - } - - *sem = data & PUNIT_SEMAPHORE_BIT; - - return 0; -} - -static void reset_semaphore(struct dw_i2c_dev *dev) -{ - if (iosf_mbi_modify(BT_MBI_UNIT_PMC, MBI_REG_READ, get_sem_addr(dev), - 0, PUNIT_SEMAPHORE_BIT)) - dev_err(dev->dev, "iosf failed to reset punit semaphore during write\n"); - - pm_qos_update_request(&dev->pm_qos, PM_QOS_DEFAULT_VALUE); - - iosf_mbi_call_pmic_bus_access_notifier_chain(MBI_PMIC_BUS_ACCESS_END, - NULL); - iosf_mbi_punit_release(); -} - -static int baytrail_i2c_acquire(struct dw_i2c_dev *dev) -{ - u32 addr; - u32 sem = PUNIT_SEMAPHORE_ACQUIRE; - int ret; - unsigned long start, end; - - might_sleep(); - - if (!dev || !dev->dev) - return -ENODEV; - - if (!dev->release_lock) - return 0; - - iosf_mbi_punit_acquire(); - iosf_mbi_call_pmic_bus_access_notifier_chain(MBI_PMIC_BUS_ACCESS_BEGIN, - NULL); - - /* - * Disallow the CPU to enter C6 or C7 state, entering these states - * requires the punit to talk to the pmic and if this happens while - * we're holding the semaphore, the SoC hangs. - */ - pm_qos_update_request(&dev->pm_qos, 0); - - addr = get_sem_addr(dev); - - /* host driver writes to side band semaphore register */ - ret = iosf_mbi_write(BT_MBI_UNIT_PMC, MBI_REG_WRITE, addr, sem); - if (ret) { - dev_err(dev->dev, "iosf punit semaphore request failed\n"); - goto out; - } - - /* host driver waits for bit 0 to be set in semaphore register */ - start = jiffies; - end = start + msecs_to_jiffies(SEMAPHORE_TIMEOUT); - do { - ret = get_sem(dev, &sem); - if (!ret && sem) { - acquired = jiffies; - dev_dbg(dev->dev, "punit semaphore acquired after %ums\n", - jiffies_to_msecs(jiffies - start)); - return 0; - } - - usleep_range(1000, 2000); - } while (time_before(jiffies, end)); - - dev_err(dev->dev, "punit semaphore timed out, resetting\n"); -out: - reset_semaphore(dev); - - ret = iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ, addr, &sem); - if (ret) - dev_err(dev->dev, "iosf failed to read punit semaphore\n"); - else - dev_err(dev->dev, "PUNIT SEM: %d\n", sem); - - WARN_ON(1); - - return -ETIMEDOUT; -} - -static void baytrail_i2c_release(struct dw_i2c_dev *dev) -{ - if (!dev || !dev->dev) - return; - - if (!dev->acquire_lock) - return; - - reset_semaphore(dev); - dev_dbg(dev->dev, "punit semaphore held for %ums\n", - jiffies_to_msecs(jiffies - acquired)); -} - int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev) { acpi_status status; @@ -162,18 +36,9 @@ int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev) return -EPROBE_DEFER; dev_info(dev->dev, "I2C bus managed by PUNIT\n"); - dev->acquire_lock = baytrail_i2c_acquire; - dev->release_lock = baytrail_i2c_release; + dev->acquire_lock = iosf_mbi_block_punit_i2c_access; + dev->release_lock = iosf_mbi_unblock_punit_i2c_access; dev->shared_with_punit = true; - pm_qos_add_request(&dev->pm_qos, PM_QOS_CPU_DMA_LATENCY, - PM_QOS_DEFAULT_VALUE); - return 0; } - -void i2c_dw_remove_lock_support(struct dw_i2c_dev *dev) -{ - if (dev->acquire_lock) - pm_qos_remove_request(&dev->pm_qos); -} diff --git a/drivers/i2c/busses/i2c-designware-common.c b/drivers/i2c/busses/i2c-designware-common.c index 36271cd75342..a4730111d290 100644 --- a/drivers/i2c/busses/i2c-designware-common.c +++ b/drivers/i2c/busses/i2c-designware-common.c @@ -269,7 +269,7 @@ int i2c_dw_acquire_lock(struct dw_i2c_dev *dev) if (!dev->acquire_lock) return 0; - ret = dev->acquire_lock(dev); + ret = dev->acquire_lock(); if (!ret) return 0; @@ -281,7 +281,7 @@ int i2c_dw_acquire_lock(struct dw_i2c_dev *dev) void i2c_dw_release_lock(struct dw_i2c_dev *dev) { if (dev->release_lock) - dev->release_lock(dev); + dev->release_lock(); } /* diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h index 9ec8394f4787..b4a0b2b99a78 100644 --- a/drivers/i2c/busses/i2c-designware-core.h +++ b/drivers/i2c/busses/i2c-designware-core.h @@ -10,7 +10,6 @@ */ #include <linux/i2c.h> -#include <linux/pm_qos.h> #define DW_IC_DEFAULT_FUNCTIONALITY (I2C_FUNC_I2C | \ I2C_FUNC_SMBUS_BYTE | \ @@ -209,7 +208,6 @@ * @fp_lcnt: fast plus LCNT value * @hs_hcnt: high speed HCNT value * @hs_lcnt: high speed LCNT value - * @pm_qos: pm_qos_request used while holding a hardware lock on the bus * @acquire_lock: function to acquire a hardware lock on the bus * @release_lock: function to release a hardware lock on the bus * @shared_with_punit: true if this bus is shared with the SoCs PUNIT @@ -263,9 +261,8 @@ struct dw_i2c_dev { u16 fp_lcnt; u16 hs_hcnt; u16 hs_lcnt; - struct pm_qos_request pm_qos; - int (*acquire_lock)(struct dw_i2c_dev *dev); - void (*release_lock)(struct dw_i2c_dev *dev); + int (*acquire_lock)(void); + void (*release_lock)(void); bool shared_with_punit; void (*disable)(struct dw_i2c_dev *dev); void (*disable_int)(struct dw_i2c_dev *dev); @@ -322,8 +319,6 @@ static inline int i2c_dw_probe_slave(struct dw_i2c_dev *dev) { return -EINVAL; } #if IS_ENABLED(CONFIG_I2C_DESIGNWARE_BAYTRAIL) extern int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev); -extern void i2c_dw_remove_lock_support(struct dw_i2c_dev *dev); #else static inline int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev) { return 0; } -static inline void i2c_dw_remove_lock_support(struct dw_i2c_dev *dev) {} #endif diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c index 997bbb3d925f..9eaac3be1f63 100644 --- a/drivers/i2c/busses/i2c-designware-platdrv.c +++ b/drivers/i2c/busses/i2c-designware-platdrv.c @@ -418,8 +418,6 @@ static int dw_i2c_plat_remove(struct platform_device *pdev) if (!IS_ERR_OR_NULL(dev->rst)) reset_control_assert(dev->rst); - i2c_dw_remove_lock_support(dev); - return 0; } |