[PATCH 2/2] staging: tidspbridge: use prepare/unprepare on dsp clocks

[Omar Ramirez Luna]

This solves runtime failures while trying to enable WDT3 related
functionality on firmware load, however it does affect other clocks
controlled by the driver. Seen on 3.8-rc1.

CCF provides clk_prepare and clk_unprepare for enable and disable
operations respectively, this needs to be called in the correct
order while handling clocks.

Code path to enable/disable dsp clocks can still be reached from an
atomic context, hence we can't use clk_prepare_enable and
clk_disable_unprepare yet.

Signed-off-by: Omar Ramirez Luna <omar.rami...@copitl.com>
---
 drivers/staging/tidspbridge/core/dsp-clock.c |   13 ++++++++++++-
 drivers/staging/tidspbridge/core/wdt.c       |   12 ++++++++++--
 2 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/drivers/staging/tidspbridge/core/dsp-clock.c 
b/drivers/staging/tidspbridge/core/dsp-clock.c
index b647207..2f084e18 100644
--- a/drivers/staging/tidspbridge/core/dsp-clock.c
+++ b/drivers/staging/tidspbridge/core/dsp-clock.c
@@ -121,9 +121,13 @@ void dsp_clk_exit(void)
        for (i = 0; i < DM_TIMER_CLOCKS; i++)
                omap_dm_timer_free(timer[i]);
 
+       clk_unprepare(iva2_clk);
        clk_put(iva2_clk);
+       clk_unprepare(ssi.sst_fck);
        clk_put(ssi.sst_fck);
+       clk_unprepare(ssi.ssr_fck);
        clk_put(ssi.ssr_fck);
+       clk_unprepare(ssi.ick);
        clk_put(ssi.ick);
 }
 
@@ -145,14 +149,21 @@ void dsp_clk_init(void)
        iva2_clk = clk_get(&dspbridge_device.dev, "iva2_ck");
        if (IS_ERR(iva2_clk))
                dev_err(bridge, "failed to get iva2 clock %p\n", iva2_clk);
+       else
+               clk_prepare(iva2_clk);
 
        ssi.sst_fck = clk_get(&dspbridge_device.dev, "ssi_sst_fck");
        ssi.ssr_fck = clk_get(&dspbridge_device.dev, "ssi_ssr_fck");
        ssi.ick = clk_get(&dspbridge_device.dev, "ssi_ick");
 
-       if (IS_ERR(ssi.sst_fck) || IS_ERR(ssi.ssr_fck) || IS_ERR(ssi.ick))
+       if (IS_ERR(ssi.sst_fck) || IS_ERR(ssi.ssr_fck) || IS_ERR(ssi.ick)) {
                dev_err(bridge, "failed to get ssi: sst %p, ssr %p, ick %p\n",
                                        ssi.sst_fck, ssi.ssr_fck, ssi.ick);
+       } else {
+               clk_prepare(ssi.sst_fck);
+               clk_prepare(ssi.ssr_fck);
+               clk_prepare(ssi.ick);
+       }
 }
 
 /**
diff --git a/drivers/staging/tidspbridge/core/wdt.c 
b/drivers/staging/tidspbridge/core/wdt.c
index 1dce36f..7ff0e6c 100644
--- a/drivers/staging/tidspbridge/core/wdt.c
+++ b/drivers/staging/tidspbridge/core/wdt.c
@@ -63,11 +63,15 @@ int dsp_wdt_init(void)
        dsp_wdt.fclk = clk_get(NULL, "wdt3_fck");
 
        if (!IS_ERR(dsp_wdt.fclk)) {
+               clk_prepare(dsp_wdt.fclk);
+
                dsp_wdt.iclk = clk_get(NULL, "wdt3_ick");
                if (IS_ERR(dsp_wdt.iclk)) {
                        clk_put(dsp_wdt.fclk);
                        dsp_wdt.fclk = NULL;
                        ret = -EFAULT;
+               } else {
+                       clk_prepare(dsp_wdt.iclk);
                }
        } else
                ret = -EFAULT;
@@ -95,10 +99,14 @@ void dsp_wdt_exit(void)
        free_irq(INT_34XX_WDT3_IRQ, &dsp_wdt);
        tasklet_kill(&dsp_wdt.wdt3_tasklet);
 
-       if (dsp_wdt.fclk)
+       if (dsp_wdt.fclk) {
+               clk_unprepare(dsp_wdt.fclk);
                clk_put(dsp_wdt.fclk);
-       if (dsp_wdt.iclk)
+       }
+       if (dsp_wdt.iclk) {
+               clk_unprepare(dsp_wdt.iclk);
                clk_put(dsp_wdt.iclk);
+       }
 
        dsp_wdt.fclk = NULL;
        dsp_wdt.iclk = NULL;
-- 
1.7.4.4

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