media: video: tegra: add ref count for remote clock requests

Change-Id: I824f9a27bfefe86211bc71d5f79ea798052b98b7
Signed-off-by: Dima Zavin <dima@android.com>

diff --git a/drivers/media/video/tegra/avp/avp_svc.c b/drivers/media/video/tegra/avp/avp_svc.c
index 983d602515e2348462b89fc81e76d9a916949a2e..ea593f7d3704741d64d21c1fac1f6276d27ab435 100644 (file)
--- a/drivers/media/video/tegra/avp/avp_svc.c
+++ b/drivers/media/video/tegra/avp/avp_svc.c
@@ -62,13 +62,17 @@ static struct avp_module avp_modules[] = {
 };
 #define NUM_AVP_MODULES                ARRAY_SIZE(avp_modules)
 
+struct avp_clk {
+       struct clk              *clk;
+       int                     refcnt;
+       struct avp_module       *mod;
+};
+
 struct avp_svc_info {
-       struct clk                      *clks[NUM_CLK_REQUESTS];
+       struct avp_clk                  clks[NUM_CLK_REQUESTS];
        /* used for dvfs */
        struct clk                      *sclk;
 
-       /* XXX: if # of clocks > BITS_PER_LONG, fix this */
-       unsigned long                   clk_reqs;
        struct mutex                    clk_lock;
 
        struct trpc_endpoint            *cpu_ep;
@@ -291,8 +295,7 @@ static void do_svc_module_reset(struct avp_svc_info *avp_svc,
        struct svc_module_ctrl *msg = (struct svc_module_ctrl *)_msg;
        struct svc_common_resp resp;
        struct avp_module *mod;
-
-       pr_info("avp_svc: module reset: %d\n", msg->module_id);
+       struct avp_clk *aclk;
 
        mod = find_avp_module(avp_svc, msg->module_id);
        if (!mod) {
@@ -305,10 +308,12 @@ static void do_svc_module_reset(struct avp_svc_info *avp_svc,
                resp.err = 0;
                goto send_response;
        }
+       pr_info("avp_svc: module reset: %s\n", mod->name);
 
-       tegra_periph_reset_assert(avp_svc->clks[mod->clk_req]);
+       aclk = &avp_svc->clks[mod->clk_req];
+       tegra_periph_reset_assert(aclk->clk);
        udelay(10);
-       tegra_periph_reset_deassert(avp_svc->clks[mod->clk_req]);
+       tegra_periph_reset_deassert(aclk->clk);
        resp.err = 0;
 
 send_response:
@@ -324,10 +329,8 @@ static void do_svc_module_clock(struct avp_svc_info *avp_svc,
        struct svc_module_ctrl *msg = (struct svc_module_ctrl *)_msg;
        struct svc_common_resp resp;
        struct avp_module *mod;
-       unsigned long clk_bit;
+       struct avp_clk *aclk;
 
-       pr_info("avp_svc: module clock: %d %s\n", msg->module_id,
-               msg->enable ? "on" : "off");
        mod = find_avp_module(avp_svc, msg->module_id);
        if (!mod) {
                pr_err("avp_svc: unknown module clock requested: %d\n",
@@ -335,22 +338,24 @@ static void do_svc_module_clock(struct avp_svc_info *avp_svc,
                resp.err = AVP_ERR_EINVAL;
                goto send_response;
        }
+       pr_info("avp_svc: module clock: %s %s\n", mod->name,
+               msg->enable ? "on" : "off");
 
-       clk_bit = 1 << mod->clk_req;
        mutex_lock(&avp_svc->clk_lock);
+       aclk = &avp_svc->clks[mod->clk_req];
        if (msg->enable) {
-               /* don't allow duplicate clock requests */
-               BUG_ON(avp_svc->clk_reqs & clk_bit);
-
-               clk_enable(avp_svc->sclk);
-               clk_enable(avp_svc->clks[mod->clk_req]);
-               avp_svc->clk_reqs |= clk_bit;
+               if (aclk->refcnt++ == 0) {
+                       clk_enable(avp_svc->sclk);
+                       clk_enable(aclk->clk);
+               }
        } else {
-               BUG_ON(!(avp_svc->clk_reqs & clk_bit));
-
-               avp_svc->clk_reqs &= ~clk_bit;
-               clk_disable(avp_svc->clks[mod->clk_req]);
-               clk_disable(avp_svc->sclk);
+               if (unlikely(aclk->refcnt == 0)) {
+                       pr_err("avp_svc: unbalanced clock disable for '%s'\n",
+                              aclk->mod->name);
+               } else if (--aclk->refcnt == 0) {
+                       clk_disable(aclk->clk);
+                       clk_disable(avp_svc->sclk);
+               }
        }
        mutex_unlock(&avp_svc->clk_lock);
        resp.err = 0;
@@ -612,12 +617,16 @@ void avp_svc_stop(struct avp_svc_info *avp_svc)
        avp_svc->nvmap_remote = NULL;
 
        mutex_lock(&avp_svc->clk_lock);
-       for (i = 0; i < NUM_CLK_REQUESTS; i++)
-               if (avp_svc->clk_reqs & (1 << i)) {
-                       pr_info("%s: remote left clock %d on\n", __func__, i);
-                       clk_disable(avp_svc->clks[i]);
+       for (i = 0; i < NUM_CLK_REQUESTS; i++) {
+               struct avp_clk *aclk = &avp_svc->clks[i];
+               BUG_ON(aclk->refcnt < 0);
+               if (aclk->refcnt > 0) {
+                       pr_info("%s: remote left clock '%s' on\n", __func__,
+                               aclk->mod->name);
+                       clk_disable(aclk->clk);
                }
-       avp_svc->clk_reqs = 0;
+               aclk->refcnt = 0;
+       }
        mutex_unlock(&avp_svc->clk_lock);
 }
 
@@ -653,7 +662,9 @@ struct avp_svc_info *avp_svc_init(struct platform_device *pdev,
                        pr_err("avp_svc: Couldn't get required clocks\n");
                        goto err_get_clks;
                }
-               avp_svc->clks[mod->clk_req] = clk;
+               avp_svc->clks[mod->clk_req].clk = clk;
+               avp_svc->clks[mod->clk_req].mod = mod;
+               avp_svc->clks[mod->clk_req].refcnt = 0;
        }
 
        avp_svc->sclk = clk_get(&pdev->dev, "sclk");
@@ -670,8 +681,8 @@ struct avp_svc_info *avp_svc_init(struct platform_device *pdev,
 
 err_get_clks:
        for (i = 0; i < NUM_CLK_REQUESTS; i++)
-               if (avp_svc->clks[i])
-                       clk_put(avp_svc->clks[i]);
+               if (avp_svc->clks[i].clk)
+                       clk_put(avp_svc->clks[i].clk);
        if (!IS_ERR_OR_NULL(avp_svc->sclk))
                clk_put(avp_svc->sclk);
 err_alloc:
@@ -683,7 +694,7 @@ void avp_svc_destroy(struct avp_svc_info *avp_svc)
        int i;
 
        for (i = 0; i < NUM_CLK_REQUESTS; i++)
-               clk_put(avp_svc->clks[i]);
+               clk_put(avp_svc->clks[i].clk);
        clk_put(avp_svc->sclk);
 
        kfree(avp_svc);