wcnss: Add Riva 'power on lock' APIs
During SSR Riva should not be 'powered on' until all the host
drivers finish their shutdown routines. Add APIs to support
this synchronization mechanism.
Change-Id: Id211cf2deb7accd0e4bdfe8cd328e6807eac875e
Signed-off-by: Sameer Thalappil <sameert@codeaurora.org>
diff --git a/drivers/net/wireless/wcnss/wcnss_riva.c b/drivers/net/wireless/wcnss/wcnss_riva.c
index b0eac55..fe6abf2 100644
--- a/drivers/net/wireless/wcnss/wcnss_riva.c
+++ b/drivers/net/wireless/wcnss/wcnss_riva.c
@@ -19,6 +19,9 @@
#include <linux/mfd/pm8xxx/pm8921.h>
#include <linux/mfd/pm8xxx/gpio.h>
#include <linux/wcnss_wlan.h>
+#include <linux/semaphore.h>
+#include <linux/list.h>
+#include <linux/slab.h>
#include <mach/msm_xo.h>
#include <mach/msm_iomap.h>
@@ -26,6 +29,9 @@
static void __iomem *msm_riva_base;
static struct msm_xo_voter *wlan_clock;
static const char *id = "WLAN";
+static LIST_HEAD(power_on_lock_list);
+static DEFINE_MUTEX(list_lock);
+static DEFINE_SEMAPHORE(riva_power_on_lock);
#define MSM_RIVA_PHYS 0x03204000
#define RIVA_PMU_CFG (msm_riva_base + 0x28)
@@ -67,6 +73,12 @@
{"riva_vddpx", VREG_NULL_CONFIG, 1800000, 0, 1800000, 0, NULL},
};
+struct host_driver {
+ char name[20];
+ struct list_head list;
+};
+
+
static int configure_iris_xo(bool use_48mhz_xo, int on)
{
u32 reg = 0;
@@ -278,6 +290,7 @@
int rc = 0;
if (on) {
+ down(&riva_power_on_lock);
/* RIVA regulator settings */
rc = wcnss_riva_vregs_on(dev);
if (rc)
@@ -292,6 +305,7 @@
rc = configure_iris_xo(cfg->use_48mhz_xo, WCNSS_WLAN_SWITCH_ON);
if (rc)
goto fail_iris_xo;
+ up(&riva_power_on_lock);
} else {
configure_iris_xo(cfg->use_48mhz_xo, WCNSS_WLAN_SWITCH_OFF);
@@ -308,7 +322,62 @@
wcnss_riva_vregs_off();
fail_riva_on:
+ up(&riva_power_on_lock);
return rc;
}
EXPORT_SYMBOL(wcnss_wlan_power);
+/*
+ * During SSR Riva should not be 'powered on' until all the host drivers
+ * finish their shutdown routines. Host drivers use below APIs to
+ * synchronize power-on. Riva will not be 'powered on' until all the
+ * requests(to lock power-on) are freed.
+ */
+int req_riva_power_on_lock(char *driver_name)
+{
+ struct host_driver *node;
+
+ if (!driver_name)
+ goto err;
+
+ node = kmalloc(sizeof(struct host_driver), GFP_KERNEL);
+ if (!node)
+ goto err;
+ strncpy(node->name, driver_name, sizeof(node->name));
+
+ mutex_lock(&list_lock);
+ /* Lock when the first request is added */
+ if (list_empty(&power_on_lock_list))
+ down(&riva_power_on_lock);
+ list_add(&node->list, &power_on_lock_list);
+ mutex_unlock(&list_lock);
+
+ return 0;
+
+err:
+ return -EINVAL;
+}
+EXPORT_SYMBOL(req_riva_power_on_lock);
+
+int free_riva_power_on_lock(char *driver_name)
+{
+ int ret = -1;
+ struct host_driver *node;
+
+ mutex_lock(&list_lock);
+ list_for_each_entry(node, &power_on_lock_list, list) {
+ if (!strncmp(node->name, driver_name, sizeof(node->name))) {
+ list_del(&node->list);
+ kfree(node);
+ ret = 0;
+ break;
+ }
+ }
+ /* unlock when the last host driver frees the lock */
+ if (list_empty(&power_on_lock_list))
+ up(&riva_power_on_lock);
+ mutex_unlock(&list_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL(free_riva_power_on_lock);
diff --git a/include/linux/wcnss_wlan.h b/include/linux/wcnss_wlan.h
index 02c0b95..c97c664 100644
--- a/include/linux/wcnss_wlan.h
+++ b/include/linux/wcnss_wlan.h
@@ -40,7 +40,8 @@
int wcnss_wlan_power(struct device *dev,
struct wcnss_wlan_config *cfg,
enum wcnss_opcode opcode);
-
+int req_riva_power_on_lock(char *driver_name);
+int free_riva_power_on_lock(char *driver_name);
#define wcnss_wlan_get_drvdata(dev) dev_get_drvdata(dev)
#define wcnss_wlan_set_drvdata(dev, data) dev_set_drvdata((dev), (data))