From mboxrd@z Thu Jan 1 00:00:00 1970 From: jean.pihet@newoldbits.com Subject: [PATCH 1/2] OMAP: convert I2C driver to PM QoS for latency constraints Date: Wed, 19 Oct 2011 16:28:50 +0200 Message-ID: <1319034531-22964-2-git-send-email-j-pihet@ti.com> References: <1319034531-22964-1-git-send-email-j-pihet@ti.com> Return-path: Received: from mail-ww0-f42.google.com ([74.125.82.42]:35760 "EHLO mail-ww0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755214Ab1JSO3K (ORCPT ); Wed, 19 Oct 2011 10:29:10 -0400 Received: by wwn22 with SMTP id 22so6438519wwn.1 for ; Wed, 19 Oct 2011 07:29:09 -0700 (PDT) In-Reply-To: <1319034531-22964-1-git-send-email-j-pihet@ti.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Kevin Hilman , Linux PM mailing list , linux-omap@vger.kernel.org, "Rafael J. Wysocki" , Paul Walmsley Cc: Jean Pihet From: Jean Pihet Convert the driver from the outdated omap_pm_set_max_mpu_wakeup_lat API to the new PM QoS API.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 --- arch/arm/plat-omap/i2c.c | 20 -------------------- drivers/i2c/busses/i2c-omap.c | 30 +++++++++++++++--------------- include/linux/i2c-omap.h | 1 - 3 files changed, 15 insertions(+), 36 deletions(-) diff --git a/arch/arm/plat-omap/i2c.c b/arch/arm/plat-omap/i2c.c index 3341ca4..e1e2502 100644 --- a/arch/arm/plat-omap/i2c.c +++ b/arch/arm/plat-omap/i2c.c @@ -34,7 +34,6 @@ #include #include #include -#include #include #define OMAP_I2C_SIZE 0x3f @@ -113,16 +112,6 @@ 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 struct omap_device_pm_latency omap_i2c_latency[] = { [0] = { .deactivate_func = omap_device_idle_hwmods, @@ -151,15 +140,6 @@ static inline int omap2_i2c_add_bus(int bus_id) } pdata = &i2c_pdata[bus_id - 1]; - /* - * 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; od = omap_device_build(name, bus_id, oh, pdata, sizeof(struct omap_i2c_bus_platform_data), omap_i2c_latency, ARRAY_SIZE(omap_i2c_latency), 0); diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c index 1a766cf..95e5205 100644 --- a/drivers/i2c/busses/i2c-omap.c +++ b/drivers/i2c/busses/i2c-omap.c @@ -40,6 +40,7 @@ #include #include #include +#include /* I2C controller revisions */ #define OMAP_I2C_REV_2 0x20 @@ -179,8 +180,7 @@ 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 */ u16 cmd_err; u8 *buf; @@ -648,8 +648,14 @@ 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. + */ + 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))); @@ -657,8 +663,7 @@ 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); + pm_qos_remove_request(&dev->pm_qos_request); if (r == 0) r = num; @@ -1007,13 +1012,10 @@ omap_i2c_probe(struct platform_device *pdev) goto err_release_region; } - if (pdata != NULL) { + if (pdata != NULL) speed = pdata->clkrate; - dev->set_mpu_wkup_lat = pdata->set_mpu_wkup_lat; - } else { + else speed = 100; /* Default speed */ - dev->set_mpu_wkup_lat = NULL; - } dev->speed = speed; dev->idle = 1; @@ -1066,10 +1068,8 @@ omap_i2c_probe(struct platform_device *pdev) dev->fifo_size = (dev->fifo_size / 2); 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 * speed / 8); + /* calculate wakeup latency constraint */ + dev->latency = (1000000 * dev->fifo_size) / (1000 * speed / 8); } /* reset ASAP, clearing any IRQs */ diff --git a/include/linux/i2c-omap.h b/include/linux/i2c-omap.h index 0aa0cbd..d06a8aa 100644 --- a/include/linux/i2c-omap.h +++ b/include/linux/i2c-omap.h @@ -32,7 +32,6 @@ struct omap_i2c_bus_platform_data { u32 clkrate; - void (*set_mpu_wkup_lat)(struct device *dev, long set); int (*device_enable) (struct platform_device *pdev); int (*device_shutdown) (struct platform_device *pdev); int (*device_idle) (struct platform_device *pdev); -- 1.7.4.1