| Message ID | 1376890457-17871-1-git-send-email-zhangfei.gao@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Quoting Zhangfei Gao (2013-08-18 22:34:17) > clk_rate_fops is added to debug > 1. set_rate (e.g. PLL) > 2. Choose mux parent, since mux could choose parent accordingly when set_rate. > > Causion: set_rate can be called directly from user space > > Example: > sfc_mux have two parents: 24M and 200M > > cat clk_summary > clock enable_cnt prepare_cnt rate > --------------------------------------------------------------------- > osc24mhz 3 3 24000000 > bpll_fout3 0 0 200000000 > sfc_mux 0 0 200000000 > sfc 0 0 200000000 > > cat osc24mhz/bpll/bpll_fout3/sfc_mux/sfc/clk_rate > 200000000 > > echo 24000000 > osc24mhz/bpll/bpll_fout3/sfc_mux/sfc/clk_rate > cat clk_summary > clock enable_cnt prepare_cnt rate > --------------------------------------------------------------------- > osc24mhz 3 3 24000000 > sfc_mux 0 0 24000000 > sfc 0 0 24000000 > bpll_fout3 0 0 200000000 > > cat osc24mhz/sfc_mux/sfc/clk_rate > 24000000 > > Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org> Thanks for the patch. It is trivial enough where I think we can leave it on the list and let developers apply it if they need it for debug. I don't want to merge it since it exposes hardware control to userspace and could be abused in a way that could damage a device. Regards, Mike > --- > drivers/clk/clk.c | 34 ++++++++++++++++++++++++++++++++++ > 1 file changed, 34 insertions(+) > > diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c > index 373cd54..6b582f7 100644 > --- a/drivers/clk/clk.c > +++ b/drivers/clk/clk.c > @@ -226,6 +226,35 @@ static const struct file_operations clk_dump_fops = { > .release = single_release, > }; > > +#ifdef DEBUG > +static int clk_rate_fops_get(void *data, u64 *rate) > +{ > + struct clk *clk = data; > + > + *rate = clk->rate; > + > + return 0; > +}; > + > +static int clk_rate_fops_set(void *data, u64 rate) > +{ > + struct clk *clk = data; > + int ret = 0; > + > + ret = clk_prepare_enable(clk); > + if (ret) > + goto out; > + clk_set_rate(clk, rate); > + clk_disable_unprepare(clk); > + > +out: > + return ret; > +}; > + > +DEFINE_SIMPLE_ATTRIBUTE(clk_rate_fops, clk_rate_fops_get, > + clk_rate_fops_set, "%llu\n"); > +#endif > + > /* caller must hold prepare_lock */ > static int clk_debug_create_one(struct clk *clk, struct dentry *pdentry) > { > @@ -243,8 +272,13 @@ static int clk_debug_create_one(struct clk *clk, struct dentry *pdentry) > > clk->dentry = d; > > +#ifdef DEBUG > + d = debugfs_create_file("clk_rate", S_IWUSR | S_IRUGO, clk->dentry, > + clk, &clk_rate_fops); > +#else > d = debugfs_create_u32("clk_rate", S_IRUGO, clk->dentry, > (u32 *)&clk->rate); > +#endif > if (!d) > goto err_out; > > -- > 1.7.9.5
On Tue, Oct 8, 2013 at 5:29 AM, Mike Turquette <mturquette@linaro.org> wrote: > Quoting Zhangfei Gao (2013-08-18 22:34:17) >> clk_rate_fops is added to debug >> 1. set_rate (e.g. PLL) >> 2. Choose mux parent, since mux could choose parent accordingly when set_rate. >> >> Causion: set_rate can be called directly from user space >> >> Example: >> sfc_mux have two parents: 24M and 200M >> >> cat clk_summary >> clock enable_cnt prepare_cnt rate >> --------------------------------------------------------------------- >> osc24mhz 3 3 24000000 >> bpll_fout3 0 0 200000000 >> sfc_mux 0 0 200000000 >> sfc 0 0 200000000 >> >> cat osc24mhz/bpll/bpll_fout3/sfc_mux/sfc/clk_rate >> 200000000 >> >> echo 24000000 > osc24mhz/bpll/bpll_fout3/sfc_mux/sfc/clk_rate >> cat clk_summary >> clock enable_cnt prepare_cnt rate >> --------------------------------------------------------------------- >> osc24mhz 3 3 24000000 >> sfc_mux 0 0 24000000 >> sfc 0 0 24000000 >> bpll_fout3 0 0 200000000 >> >> cat osc24mhz/sfc_mux/sfc/clk_rate >> 24000000 >> >> Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org> > > Thanks for the patch. It is trivial enough where I think we can leave it > on the list and let developers apply it if they need it for debug. I > don't want to merge it since it exposes hardware control to userspace > and could be abused in a way that could damage a device. > > Regards, > Mike > Thanks Mike Understand the risk, it is fine. Thanks
diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 373cd54..6b582f7 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -226,6 +226,35 @@ static const struct file_operations clk_dump_fops = { .release = single_release, }; +#ifdef DEBUG +static int clk_rate_fops_get(void *data, u64 *rate) +{ + struct clk *clk = data; + + *rate = clk->rate; + + return 0; +}; + +static int clk_rate_fops_set(void *data, u64 rate) +{ + struct clk *clk = data; + int ret = 0; + + ret = clk_prepare_enable(clk); + if (ret) + goto out; + clk_set_rate(clk, rate); + clk_disable_unprepare(clk); + +out: + return ret; +}; + +DEFINE_SIMPLE_ATTRIBUTE(clk_rate_fops, clk_rate_fops_get, + clk_rate_fops_set, "%llu\n"); +#endif + /* caller must hold prepare_lock */ static int clk_debug_create_one(struct clk *clk, struct dentry *pdentry) { @@ -243,8 +272,13 @@ static int clk_debug_create_one(struct clk *clk, struct dentry *pdentry) clk->dentry = d; +#ifdef DEBUG + d = debugfs_create_file("clk_rate", S_IWUSR | S_IRUGO, clk->dentry, + clk, &clk_rate_fops); +#else d = debugfs_create_u32("clk_rate", S_IRUGO, clk->dentry, (u32 *)&clk->rate); +#endif if (!d) goto err_out;
clk_rate_fops is added to debug 1. set_rate (e.g. PLL) 2. Choose mux parent, since mux could choose parent accordingly when set_rate. Causion: set_rate can be called directly from user space Example: sfc_mux have two parents: 24M and 200M cat clk_summary clock enable_cnt prepare_cnt rate --------------------------------------------------------------------- osc24mhz 3 3 24000000 bpll_fout3 0 0 200000000 sfc_mux 0 0 200000000 sfc 0 0 200000000 cat osc24mhz/bpll/bpll_fout3/sfc_mux/sfc/clk_rate 200000000 echo 24000000 > osc24mhz/bpll/bpll_fout3/sfc_mux/sfc/clk_rate cat clk_summary clock enable_cnt prepare_cnt rate --------------------------------------------------------------------- osc24mhz 3 3 24000000 sfc_mux 0 0 24000000 sfc 0 0 24000000 bpll_fout3 0 0 200000000 cat osc24mhz/sfc_mux/sfc/clk_rate 24000000 Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org> --- drivers/clk/clk.c | 34 ++++++++++++++++++++++++++++++++++ 1 file changed, 34 insertions(+)