Re: [RFC][PATCH] clk: debugfs add clk_rate_fops to debugfs mux

Quoting Zhangfei Gao (2013-08-15 21:03:28)

MUX could choose parent accordingly when set_rate. Add clk_rate_fops to debug whether mux choose correct parent

Example: cat clk_summary clock enable_cnt prepare_cnt rate

---

osc24mhz 3 3 24000000 bpll 1 1 4294967295 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 1 1 4294967295 bpll_fout3 0 0 200000000

cat osc24mhz/sfc_mux/sfc/clk_rate 24000000

Signed-off-by: Zhangfei Gao zhangfei.gao@linaro.org

NACK. This patch just makes it possible to call clk_set_rate on every clock from userspace. I don't support that operation, it just leads to tons of horrible hacks where closed userspace crapplications manage hardware directly.

Also I'm not sure what this patch has to do with the description in the changelog. How does setting the rate of every clock help debug mux clocks? You can already see a mux clocks parent and rate from the existing debugs info.

Regards, Mike

---

drivers/clk/clk.c | 31 +++++++++++++++++++++++++++++-- 1 file changed, 29 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c index 373cd54..327b698 100644 --- a/drivers/clk/clk.c +++ b/drivers/clk/clk.c @@ -226,6 +226,33 @@ static const struct file_operations clk_dump_fops = { .release = single_release, }; +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");
  

/* caller must hold prepare_lock */ static int clk_debug_create_one(struct clk *clk, struct dentry *pdentry) { @@ -243,8 +270,8 @@ static int clk_debug_create_one(struct clk *clk, struct dentry *pdentry) clk->dentry = d;

•   d = debugfs_create_u32("clk_rate", S_IRUGO, clk->dentry,
  

•                   (u32 *)&clk->rate);
  

•   d = debugfs_create_file("clk_rate", S_IWUSR | S_IRUGO, clk->dentry,
  

•                           clk, &clk_rate_fops);
    if (!d)
            goto err_out;
  

1.7.9.5