Revert "ARM: OMAP: convert I2C driver to PM QoS for MPU latency constraints"

This reverts commit 3db11feffc1ad2ab9dea27789e6b5b3032827adc
(ARM: OMAP: convert I2C driver to PM QoS for MPU latency constraints).
This commit causes I2C timeouts to appear on several OMAP3430/3530-based
boards:

  http://marc.info/?l=linux-arm-kernel&m=135071372426971&w=2
  http://marc.info/?l=linux-arm-kernel&m=135067558415214&w=2
  http://marc.info/?l=linux-arm-kernel&m=135216013608196&w=2

and appears to have been sent for merging before one of its prerequisites
was merged:

  http://marc.info/?l=linux-arm-kernel&m=135219411617621&w=2

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Acked-by: Jean Pihet <j-pihet@ti.com>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>

1 files changed, 21 insertions, 0 deletions

diff --git a/arch/arm/plat-omap/i2c.c b/arch/arm/plat-omap/i2c.c
index a5683a84c6ee..6013831a043e 100644
--- a/arch/arm/plat-omap/i2c.c
+++ b/arch/arm/plat-omap/i2c.c
@@ -26,12 +26,14 @@
 #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>
 
 #include <mach/irqs.h>
 #include <plat/i2c.h>
+#include <plat/omap-pm.h>
 #include <plat/omap_device.h>
 
 #define OMAP_I2C_SIZE           0x3f
@@ -127,6 +129,16 @@ 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;
@@ -158,6 +170,15 @@ 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);