[PATCH 7/8] ARM: OMAP: convert I2C driver to PM QoS for latency constraints
Felipe Balbi
balbi at ti.com
Tue Sep 18 04:53:16 EDT 2012
Hi,
On Tue, Sep 18, 2012 at 10:52:11AM +0200, 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 Convert the driver from the outdated omap_pm_set_max_mpu_wakeup_lat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.
>
> Signed-off-by: Jean Pihet <j-pihet at ti.com>
this needs to be rebased on top of Wolfram's i2c-next branch which has a
big series of patches on top of the i2c driver.
Also, please keep Shubhro in Cc for any i2c and spi patches ;-)
> ---
> 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
> --
> 1.7.7.6
>
> --
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--
balbi
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