diff options
author | Dave Airlie <airlied@redhat.com> | 2011-09-20 09:35:22 +0100 |
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committer | Dave Airlie <airlied@redhat.com> | 2011-09-20 09:35:22 +0100 |
commit | b2d108ba333cdff80d9e7645d7697cbb6bb0fc29 (patch) | |
tree | f62b2464a35e4676b5e3e9ef340758a17d0b80f8 /drivers/clocksource/sh_cmt.c | |
parent | fcf4de5acf09889e3f0c131ebe385c983006d71b (diff) | |
parent | a0d9a8feb928465f3cb525a19e5fafd06ef66ced (diff) |
Merge branch 'drm-nouveau-next' of git://git.freedesktop.org/git/nouveau/linux-2.6 into drm-next
* 'drm-nouveau-next' of git://git.freedesktop.org/git/nouveau/linux-2.6: (353 commits)
drm/nouveau: remove allocations from gart populate() hook
drm/nvc0/fb: slightly improve PMFB intr handling, move out of nvc0_graph.c
drm/nvc0/fifo: avoid touching missing subfifos
drm/nvd9/disp: bail out of mode_set_base if no fb bound to crtc
drm/nvd9/disp: stub some more api hooks so we don't oops on resume
drm/nouveau: fix printk typo in ioremap failure path
drm/nvc0/pm: minor clock readback fixes
drm/nv40/pm: execute memory reset script from vbios
drm/nv50/gr: refactor initialisation
drm/nouveau: if requested, try harder at disabling sysmem pushbufs
drm/nv50/gr: enable ctxprog xfer only when we need it to save power
drm/nouveau/dp: add support for displayport table 0x30
drm/nouveau/dp: return master dp table pointer too when looking up encoder
drm/nouveau/bios: simplify U/d table hash matching func to just match
drm/nouveau/dp: preserve non-pattern bits in DP_TRAINING_PATTERN_SET
drm/nvc0/gr: remove MODULE_FIRMWARE() lines
drm/nouveau/dp: use alternate lane mask for nvaf
drm/nouveau/dp: link rate scripts are selected with a comparison table
drm/nv40/pm: write nv40-specific reclocking routines
drm/nv40/pm: parse geometric delta clock from vbios
...
Diffstat (limited to 'drivers/clocksource/sh_cmt.c')
-rw-r--r-- | drivers/clocksource/sh_cmt.c | 34 |
1 files changed, 32 insertions, 2 deletions
diff --git a/drivers/clocksource/sh_cmt.c b/drivers/clocksource/sh_cmt.c index dc7c033ef58..32a77becc09 100644 --- a/drivers/clocksource/sh_cmt.c +++ b/drivers/clocksource/sh_cmt.c @@ -26,6 +26,7 @@ #include <linux/clk.h> #include <linux/irq.h> #include <linux/err.h> +#include <linux/delay.h> #include <linux/clocksource.h> #include <linux/clockchips.h> #include <linux/sh_timer.h> @@ -150,13 +151,13 @@ static void sh_cmt_start_stop_ch(struct sh_cmt_priv *p, int start) static int sh_cmt_enable(struct sh_cmt_priv *p, unsigned long *rate) { - int ret; + int k, ret; /* enable clock */ ret = clk_enable(p->clk); if (ret) { dev_err(&p->pdev->dev, "cannot enable clock\n"); - return ret; + goto err0; } /* make sure channel is disabled */ @@ -174,9 +175,38 @@ static int sh_cmt_enable(struct sh_cmt_priv *p, unsigned long *rate) sh_cmt_write(p, CMCOR, 0xffffffff); sh_cmt_write(p, CMCNT, 0); + /* + * According to the sh73a0 user's manual, as CMCNT can be operated + * only by the RCLK (Pseudo 32 KHz), there's one restriction on + * modifying CMCNT register; two RCLK cycles are necessary before + * this register is either read or any modification of the value + * it holds is reflected in the LSI's actual operation. + * + * While at it, we're supposed to clear out the CMCNT as of this + * moment, so make sure it's processed properly here. This will + * take RCLKx2 at maximum. + */ + for (k = 0; k < 100; k++) { + if (!sh_cmt_read(p, CMCNT)) + break; + udelay(1); + } + + if (sh_cmt_read(p, CMCNT)) { + dev_err(&p->pdev->dev, "cannot clear CMCNT\n"); + ret = -ETIMEDOUT; + goto err1; + } + /* enable channel */ sh_cmt_start_stop_ch(p, 1); return 0; + err1: + /* stop clock */ + clk_disable(p->clk); + + err0: + return ret; } static void sh_cmt_disable(struct sh_cmt_priv *p) |