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[RFC,3/3] cpufreq: imx6q: refine clk operations

Message ID 1491969809-20154-4-git-send-email-aisheng.dong@nxp.com (mailing list archive)
State New, archived
Headers show

Commit Message

Aisheng Dong April 12, 2017, 4:03 a.m. UTC 
Use clk_bulk_get to ease the driver clocks handling.

Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@codeaurora.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Fabio Estevam <fabio.estevam@nxp.com>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Anson Huang <anson.huang@nxp.com>
Cc: Robin Gong <yibin.gong@nxp.com>
Cc: Bai Ping <ping.bai@nxp.com>
Cc: Leonard Crestez <leonard.crestez@nxp.com>
Cc: Octavian Purdila <octavian.purdila@nxp.com>
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
---
 drivers/cpufreq/imx6q-cpufreq.c | 119 ++++++++++++++++++----------------------
 1 file changed, 53 insertions(+), 66 deletions(-)

Comments

Leonard Crestez April 11, 2017, 5:48 p.m. UTC | #1 
On Wed, 2017-04-12 at 12:03 +0800, Dong Aisheng wrote:
> +static int num_clks;
> +static struct clk_bulk_data clks[] = {
> +	{ .id = "arm" },
> +	{ .id = "pll1_sys" },
> +	{ .id = "step" },
> +	{ .id = "pll1_sw" },
> +	{ .id = "pll2_pfd2_396m" },
> +	{ .id = "pll2_bus" },
> +	{ .id = "secondary_sel" },
> +};

The .id is only required for initialization, it seems strange to keep
it around runtime data. It might be better for this API to work with an
array of clk* and separate array of names (or clk_bulk_init_data if we
need flags). Variable references would be shorter and it would allow
more data to be const.

> -put_clk:
> -	if (!IS_ERR(arm_clk))
> -		clk_put(arm_clk);
> -	if (!IS_ERR(pll1_sys_clk))
> -		clk_put(pll1_sys_clk);
> -	if (!IS_ERR(pll1_sw_clk))
> -		clk_put(pll1_sw_clk);
> -	if (!IS_ERR(step_clk))
> -		clk_put(step_clk);
> -	if (!IS_ERR(pll2_pfd2_396m_clk))
> -		clk_put(pll2_pfd2_396m_clk);
> -	if (!IS_ERR(pll2_bus_clk))
> -		clk_put(pll2_bus_clk);
> -	if (!IS_ERR(secondary_sel_clk))
> -		clk_put(secondary_sel_clk);
> +
> +	clk_bulk_put(num_clks, clks);
> +put_node:
>  	of_node_put(np);
> +
>  	return ret;
>  }


My subjective opinion is that a better way to clean this up would be to
have a single imx6q_cpufreq_clean function that takes all resources and
does stuff like:

if (!IS_ERR(clk)) clk_put(clk);
clk = NULL;

That function can be called from both _remove and failed _probe without
having to keep track of which resources have been allocated until then.
Just free and NULL all clocks/regulators and simplify control flow.

--
Regards,
Leonard
Dong Aisheng April 13, 2017, 2:21 p.m. UTC | #2 
On Tue, Apr 11, 2017 at 08:48:28PM +0300, Leonard Crestez wrote:
> On Wed, 2017-04-12 at 12:03 +0800, Dong Aisheng wrote:
> > +static int num_clks;
> > +static struct clk_bulk_data clks[] = {
> > +	{ .id = "arm" },
> > +	{ .id = "pll1_sys" },
> > +	{ .id = "step" },
> > +	{ .id = "pll1_sw" },
> > +	{ .id = "pll2_pfd2_396m" },
> > +	{ .id = "pll2_bus" },
> > +	{ .id = "secondary_sel" },
> > +};
> 
> The .id is only required for initialization, it seems strange to keep
> it around runtime data.

Well, this is mainly referencing how regulator bulk does the job.

> It might be better for this API to work with an
> array of clk* and separate array of names (or clk_bulk_init_data if we
> need flags). Variable references would be shorter and it would allow
> more data to be const.

It also has side effect that we then need one more param for each API.
Is that worth?

> > -put_clk:
> > -	if (!IS_ERR(arm_clk))
> > -		clk_put(arm_clk);
> > -	if (!IS_ERR(pll1_sys_clk))
> > -		clk_put(pll1_sys_clk);
> > -	if (!IS_ERR(pll1_sw_clk))
> > -		clk_put(pll1_sw_clk);
> > -	if (!IS_ERR(step_clk))
> > -		clk_put(step_clk);
> > -	if (!IS_ERR(pll2_pfd2_396m_clk))
> > -		clk_put(pll2_pfd2_396m_clk);
> > -	if (!IS_ERR(pll2_bus_clk))
> > -		clk_put(pll2_bus_clk);
> > -	if (!IS_ERR(secondary_sel_clk))
> > -		clk_put(secondary_sel_clk);
> > +
> > +	clk_bulk_put(num_clks, clks);
> > +put_node:
> >  	of_node_put(np);
> > +
> >  	return ret;
> >  }
> 
> 
> My subjective opinion is that a better way to clean this up would be to
> have a single imx6q_cpufreq_clean function that takes all resources and
> does stuff like:
> 
> if (!IS_ERR(clk)) clk_put(clk);
> clk = NULL;
> 
> That function can be called from both _remove and failed _probe without
> having to keep track of which resources have been allocated until then.
> Just free and NULL all clocks/regulators and simplify control flow.
> 

I once thought of that way.

Now i'd like to remove them rather than form them into a function
which can't permanently fix the issue.

But, if Maintainers dislike it, we could do that.

Regards
Dong Aisheng
diff mbox

Patch

diff --git a/drivers/cpufreq/imx6q-cpufreq.c b/drivers/cpufreq/imx6q-cpufreq.c
index 7719b02..6158910 100644
--- a/drivers/cpufreq/imx6q-cpufreq.c
+++ b/drivers/cpufreq/imx6q-cpufreq.c
@@ -24,15 +24,29 @@  static struct regulator *arm_reg;
 static struct regulator *pu_reg;
 static struct regulator *soc_reg;
 
-static struct clk *arm_clk;
-static struct clk *pll1_sys_clk;
-static struct clk *pll1_sw_clk;
-static struct clk *step_clk;
-static struct clk *pll2_pfd2_396m_clk;
-
-/* clk used by i.MX6UL */
-static struct clk *pll2_bus_clk;
-static struct clk *secondary_sel_clk;
+enum IMX6_CPUFREQ_CLKS {
+	ARM,
+	PLL1_SYS,
+	STEP,
+	PLL1_SW,
+	PLL2_PFD2_396M,
+	/* MX6UL requires two more clks */
+	PLL2_BUS,
+	SECONDARY_SEL,
+};
+#define IMX6Q_CPUFREQ_CLK_NUM		5
+#define IMX6UL_CPUFREQ_CLK_NUM		7
+
+static int num_clks;
+static struct clk_bulk_data clks[] = {
+	{ .id = "arm" },
+	{ .id = "pll1_sys" },
+	{ .id = "step" },
+	{ .id = "pll1_sw" },
+	{ .id = "pll2_pfd2_396m" },
+	{ .id = "pll2_bus" },
+	{ .id = "secondary_sel" },
+};
 
 static struct device *cpu_dev;
 static bool free_opp;
@@ -51,7 +65,7 @@  static int imx6q_set_target(struct cpufreq_policy *policy, unsigned int index)
 
 	new_freq = freq_table[index].frequency;
 	freq_hz = new_freq * 1000;
-	old_freq = clk_get_rate(arm_clk) / 1000;
+	old_freq = clk_get_rate(clks[ARM].clk) / 1000;
 
 	opp = dev_pm_opp_find_freq_ceil(cpu_dev, &freq_hz);
 	if (IS_ERR(opp)) {
@@ -109,25 +123,27 @@  static int imx6q_set_target(struct cpufreq_policy *policy, unsigned int index)
 		 * voltage of 528MHz, so lower the CPU frequency to one
 		 * half before changing CPU frequency.
 		 */
-		clk_set_rate(arm_clk, (old_freq >> 1) * 1000);
-		clk_set_parent(pll1_sw_clk, pll1_sys_clk);
-		if (freq_hz > clk_get_rate(pll2_pfd2_396m_clk))
-			clk_set_parent(secondary_sel_clk, pll2_bus_clk);
+		clk_set_rate(clks[ARM].clk, (old_freq >> 1) * 1000);
+		clk_set_parent(clks[PLL1_SW].clk, clks[PLL1_SYS].clk);
+		if (freq_hz > clk_get_rate(clks[PLL2_PFD2_396M].clk))
+			clk_set_parent(clks[SECONDARY_SEL].clk,
+				       clks[PLL2_BUS].clk);
 		else
-			clk_set_parent(secondary_sel_clk, pll2_pfd2_396m_clk);
-		clk_set_parent(step_clk, secondary_sel_clk);
-		clk_set_parent(pll1_sw_clk, step_clk);
+			clk_set_parent(clks[SECONDARY_SEL].clk,
+				       clks[PLL2_PFD2_396M].clk);
+		clk_set_parent(clks[STEP].clk, clks[SECONDARY_SEL].clk);
+		clk_set_parent(clks[PLL1_SW].clk, clks[STEP].clk);
 	} else {
-		clk_set_parent(step_clk, pll2_pfd2_396m_clk);
-		clk_set_parent(pll1_sw_clk, step_clk);
-		if (freq_hz > clk_get_rate(pll2_pfd2_396m_clk)) {
-			clk_set_rate(pll1_sys_clk, new_freq * 1000);
-			clk_set_parent(pll1_sw_clk, pll1_sys_clk);
+		clk_set_parent(clks[STEP].clk, clks[PLL2_PFD2_396M].clk);
+		clk_set_parent(clks[PLL1_SW].clk, clks[STEP].clk);
+		if (freq_hz > clk_get_rate(clks[PLL2_PFD2_396M].clk)) {
+			clk_set_rate(clks[PLL1_SYS].clk, new_freq * 1000);
+			clk_set_parent(clks[PLL1_SW].clk, clks[PLL1_SYS].clk);
 		}
 	}
 
 	/* Ensure the arm clock divider is what we expect */
-	ret = clk_set_rate(arm_clk, new_freq * 1000);
+	ret = clk_set_rate(clks[ARM].clk, new_freq * 1000);
 	if (ret) {
 		dev_err(cpu_dev, "failed to set clock rate: %d\n", ret);
 		regulator_set_voltage_tol(arm_reg, volt_old, 0);
@@ -161,7 +177,7 @@  static int imx6q_set_target(struct cpufreq_policy *policy, unsigned int index)
 
 static int imx6q_cpufreq_init(struct cpufreq_policy *policy)
 {
-	policy->clk = arm_clk;
+	policy->clk = clks[ARM].clk;
 	return cpufreq_generic_init(policy, freq_table, transition_latency);
 }
 
@@ -197,27 +213,14 @@  static int imx6q_cpufreq_probe(struct platform_device *pdev)
 		return -ENOENT;
 	}
 
-	arm_clk = clk_get(cpu_dev, "arm");
-	pll1_sys_clk = clk_get(cpu_dev, "pll1_sys");
-	pll1_sw_clk = clk_get(cpu_dev, "pll1_sw");
-	step_clk = clk_get(cpu_dev, "step");
-	pll2_pfd2_396m_clk = clk_get(cpu_dev, "pll2_pfd2_396m");
-	if (IS_ERR(arm_clk) || IS_ERR(pll1_sys_clk) || IS_ERR(pll1_sw_clk) ||
-	    IS_ERR(step_clk) || IS_ERR(pll2_pfd2_396m_clk)) {
-		dev_err(cpu_dev, "failed to get clocks\n");
-		ret = -ENOENT;
-		goto put_clk;
-	}
+	if (of_machine_is_compatible("fsl,imx6ul"))
+		num_clks = IMX6UL_CPUFREQ_CLK_NUM;
+	else
+		num_clks = IMX6Q_CPUFREQ_CLK_NUM;
 
-	if (of_machine_is_compatible("fsl,imx6ul")) {
-		pll2_bus_clk = clk_get(cpu_dev, "pll2_bus");
-		secondary_sel_clk = clk_get(cpu_dev, "secondary_sel");
-		if (IS_ERR(pll2_bus_clk) || IS_ERR(secondary_sel_clk)) {
-			dev_err(cpu_dev, "failed to get clocks specific to imx6ul\n");
-			ret = -ENOENT;
-			goto put_clk;
-		}
-	}
+	ret = clk_bulk_get(cpu_dev, num_clks, clks);
+	if (ret)
+		goto put_node;
 
 	arm_reg = regulator_get(cpu_dev, "arm");
 	pu_reg = regulator_get_optional(cpu_dev, "pu");
@@ -354,22 +357,11 @@  static int imx6q_cpufreq_probe(struct platform_device *pdev)
 		regulator_put(pu_reg);
 	if (!IS_ERR(soc_reg))
 		regulator_put(soc_reg);
-put_clk:
-	if (!IS_ERR(arm_clk))
-		clk_put(arm_clk);
-	if (!IS_ERR(pll1_sys_clk))
-		clk_put(pll1_sys_clk);
-	if (!IS_ERR(pll1_sw_clk))
-		clk_put(pll1_sw_clk);
-	if (!IS_ERR(step_clk))
-		clk_put(step_clk);
-	if (!IS_ERR(pll2_pfd2_396m_clk))
-		clk_put(pll2_pfd2_396m_clk);
-	if (!IS_ERR(pll2_bus_clk))
-		clk_put(pll2_bus_clk);
-	if (!IS_ERR(secondary_sel_clk))
-		clk_put(secondary_sel_clk);
+
+	clk_bulk_put(num_clks, clks);
+put_node:
 	of_node_put(np);
+
 	return ret;
 }
 
@@ -383,13 +375,8 @@  static int imx6q_cpufreq_remove(struct platform_device *pdev)
 	if (!IS_ERR(pu_reg))
 		regulator_put(pu_reg);
 	regulator_put(soc_reg);
-	clk_put(arm_clk);
-	clk_put(pll1_sys_clk);
-	clk_put(pll1_sw_clk);
-	clk_put(step_clk);
-	clk_put(pll2_pfd2_396m_clk);
-	clk_put(pll2_bus_clk);
-	clk_put(secondary_sel_clk);
+
+	clk_bulk_put(num_clks, clks);
 
 	return 0;
 }