[PATCH 7/8] ARM: OMAP: convert I2C driver to PM QoS for latency constraints
Jean Pihet
jean.pihet at newoldbits.com
Wed Sep 19 14:34:19 EDT 2012
Hi!
On Wed, Sep 19, 2012 at 8:11 PM, Shubhrajyoti <shubhrajyoti at ti.com> wrote:
> On Tuesday 18 September 2012 02:22 PM, Jean Pihet wrote:
>> Convert the driver from the outdated omap_pm_set_max_mpu_wakeup_lat
>> API to the new PM QoS API.
>> Since the constraint is on the MPU subsystem, use the PM_QOS_CPU_DMA_LATENCY
>> class of PM QoS. The resulting MPU constraints are used by cpuidle to
>> decide the next power state of the MPU subsystem.
>>
>> The I2C device latency timing is derived from the FIFO size and the
>> clock speed and so is applicable to all OMAP SoCs.
> agree
> thanks,
The I2C patch will be rebased and submitted separately.
Thanks!
Jean
>>
>> Signed-off-by: Jean Pihet <j-pihet at ti.com>
>> ---
>> arch/arm/plat-omap/i2c.c | 21 ---------------------
>> drivers/i2c/busses/i2c-omap.c | 28 +++++++++++++++++-----------
>> include/linux/i2c-omap.h | 1 -
>> 3 files changed, 17 insertions(+), 33 deletions(-)
>>
>> diff --git a/arch/arm/plat-omap/i2c.c b/arch/arm/plat-omap/i2c.c
>> index db071bc..dba8338 100644
>> --- a/arch/arm/plat-omap/i2c.c
>> +++ b/arch/arm/plat-omap/i2c.c
>> @@ -26,7 +26,6 @@
>> #include <linux/kernel.h>
>> #include <linux/platform_device.h>
>> #include <linux/i2c.h>
>> -#include <linux/i2c-omap.h>
>> #include <linux/slab.h>
>> #include <linux/err.h>
>> #include <linux/clk.h>
>> @@ -34,7 +33,6 @@
>> #include <mach/irqs.h>
>> #include <plat/mux.h>
>> #include <plat/i2c.h>
>> -#include <plat/omap-pm.h>
>> #include <plat/omap_device.h>
>>
>> #define OMAP_I2C_SIZE 0x3f
>> @@ -129,16 +127,6 @@ static inline int omap1_i2c_add_bus(int bus_id)
>>
>>
>> #ifdef CONFIG_ARCH_OMAP2PLUS
>> -/*
>> - * XXX This function is a temporary compatibility wrapper - only
>> - * needed until the I2C driver can be converted to call
>> - * omap_pm_set_max_dev_wakeup_lat() and handle a return code.
>> - */
>> -static void omap_pm_set_max_mpu_wakeup_lat_compat(struct device *dev, long t)
>> -{
>> - omap_pm_set_max_mpu_wakeup_lat(dev, t);
>> -}
>> -
>> static inline int omap2_i2c_add_bus(int bus_id)
>> {
>> int l;
>> @@ -170,15 +158,6 @@ static inline int omap2_i2c_add_bus(int bus_id)
>> dev_attr = (struct omap_i2c_dev_attr *)oh->dev_attr;
>> pdata->flags = dev_attr->flags;
>>
>> - /*
>> - * When waiting for completion of a i2c transfer, we need to
>> - * set a wake up latency constraint for the MPU. This is to
>> - * ensure quick enough wakeup from idle, when transfer
>> - * completes.
>> - * Only omap3 has support for constraints
>> - */
>> - if (cpu_is_omap34xx())
>> - pdata->set_mpu_wkup_lat = omap_pm_set_max_mpu_wakeup_lat_compat;
>> pdev = omap_device_build(name, bus_id, oh, pdata,
>> sizeof(struct omap_i2c_bus_platform_data),
>> NULL, 0, 0);
>> diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
>> index 5d19a49..bd45cee 100644
>> --- a/drivers/i2c/busses/i2c-omap.c
>> +++ b/drivers/i2c/busses/i2c-omap.c
>> @@ -43,6 +43,7 @@
>> #include <linux/slab.h>
>> #include <linux/i2c-omap.h>
>> #include <linux/pm_runtime.h>
>> +#include <linux/pm_qos.h>
>>
>> /* I2C controller revisions */
>> #define OMAP_I2C_OMAP1_REV_2 0x20
>> @@ -183,8 +184,7 @@ struct omap_i2c_dev {
>> struct completion cmd_complete;
>> struct resource *ioarea;
>> u32 latency; /* maximum mpu wkup latency */
>> - void (*set_mpu_wkup_lat)(struct device *dev,
>> - long latency);
>> + struct pm_qos_request pm_qos_request;
>> u32 speed; /* Speed of bus in kHz */
>> u32 dtrev; /* extra revision from DT */
>> u32 flags;
>> @@ -590,8 +590,16 @@ omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
>> if (r < 0)
>> goto out;
>>
>> - if (dev->set_mpu_wkup_lat != NULL)
>> - dev->set_mpu_wkup_lat(dev->dev, dev->latency);
>> + /*
>> + * When waiting for completion of a i2c transfer, we need to
>> + * set a wake up latency constraint for the MPU. This is to
>> + * ensure quick enough wakeup from idle, when transfer
>> + * completes.
>> + */
>> + if (dev->latency)
>> + pm_qos_add_request(&dev->pm_qos_request,
>> + PM_QOS_CPU_DMA_LATENCY,
>> + dev->latency);
>>
>> for (i = 0; i < num; i++) {
>> r = omap_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)));
>> @@ -599,8 +607,8 @@ omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
>> break;
>> }
>>
>> - if (dev->set_mpu_wkup_lat != NULL)
>> - dev->set_mpu_wkup_lat(dev->dev, -1);
>> + if (dev->latency)
>> + pm_qos_remove_request(&dev->pm_qos_request);
>>
>> if (r == 0)
>> r = num;
>> @@ -989,7 +997,6 @@ omap_i2c_probe(struct platform_device *pdev)
>> } else if (pdata != NULL) {
>> dev->speed = pdata->clkrate;
>> dev->flags = pdata->flags;
>> - dev->set_mpu_wkup_lat = pdata->set_mpu_wkup_lat;
>> dev->dtrev = pdata->rev;
>> }
>>
>> @@ -1046,10 +1053,9 @@ omap_i2c_probe(struct platform_device *pdev)
>> else
>> dev->b_hw = 1; /* Enable hardware fixes */
>>
>> - /* calculate wakeup latency constraint for MPU */
>> - if (dev->set_mpu_wkup_lat != NULL)
>> - dev->latency = (1000000 * dev->fifo_size) /
>> - (1000 * dev->speed / 8);
>> + /* calculate wakeup latency constraint */
>> + dev->latency = (1000000 * dev->fifo_size) /
>> + (1000 * dev->speed / 8);
>> }
>>
>> /* reset ASAP, clearing any IRQs */
>> diff --git a/include/linux/i2c-omap.h b/include/linux/i2c-omap.h
>> index 92a0dc7..df804ba 100644
>> --- a/include/linux/i2c-omap.h
>> +++ b/include/linux/i2c-omap.h
>> @@ -34,7 +34,6 @@ struct omap_i2c_bus_platform_data {
>> u32 clkrate;
>> u32 rev;
>> u32 flags;
>> - void (*set_mpu_wkup_lat)(struct device *dev, long set);
>> };
>>
>> #endif
>
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