diff mbox series

[v2,4/8] clk: qcom: apss-ipq6018: ipq5332: add safe source switch for a53pll

Message ID 000c61a028814f08a9fc6d1d5c446e8dad11a650.1697101543.git.quic_varada@quicinc.com (mailing list archive)
State Handled Elsewhere, archived
Headers show
Series Enable cpufreq for IPQ5332 & IPQ9574 | expand

Commit Message

Varadarajan Narayanan Oct. 12, 2023, 9:26 a.m. UTC 
Stromer Plus PLL found on IPQ53xx doesn't support dynamic
frequency scaling. To achieve the same, we need to park the APPS
PLL source to GPLL0, re configure the PLL and then switch the
source to APSS_PLL_EARLY.

To support this, register a clock notifier to get the PRE_RATE
and POST_RATE notification. Change the APSS PLL source to GPLL0
when PRE_RATE notification is received, then configure the PLL
and then change back the source to APSS_PLL_EARLY.

Additionally, not all SKUs of IPQ53xx support scaling. Hence,
do the above to the SKUs that support scaling.

Signed-off-by: Kathiravan T <quic_kathirav@quicinc.com>
Signed-off-by: Varadarajan Narayanan <quic_varada@quicinc.com>
---
v2:	Handle ABORT_RATE_CHANGE
	Use local variable for apcs_alias0_clk_src.clkr.hw
	Use single line comment instead of multi line style
---
 drivers/clk/qcom/apss-ipq6018.c | 53 ++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 52 insertions(+), 1 deletion(-)

Comments

Stephen Boyd Oct. 12, 2023, 8:51 p.m. UTC | #1 
Quoting Varadarajan Narayanan (2023-10-12 02:26:20)
> diff --git a/drivers/clk/qcom/apss-ipq6018.c b/drivers/clk/qcom/apss-ipq6018.c
> index 4e13a08..c05c2b2 100644
> --- a/drivers/clk/qcom/apss-ipq6018.c
> +++ b/drivers/clk/qcom/apss-ipq6018.c
> @@ -84,15 +87,63 @@ static const struct qcom_cc_desc apss_ipq6018_desc = {
>         .num_clks = ARRAY_SIZE(apss_ipq6018_clks),
>  };
>  
> +static int cpu_clk_notifier_fn(struct notifier_block *nb, unsigned long action,
> +                               void *data)
> +{
> +       struct clk_hw *hw;
> +       u8 index;
> +       int err;
> +
> +       if (action == PRE_RATE_CHANGE)
> +               index = P_GPLL0;
> +       else if ((action == POST_RATE_CHANGE) || (action == ABORT_RATE_CHANGE))

This has too many parenthesis.

> +               index = P_APSS_PLL_EARLY;
> +       else
> +               return 0;

Maybe 'return NOTIFY_OK' instead?

> +
> +       hw = &apcs_alias0_clk_src.clkr.hw;
> +       err = clk_rcg2_mux_closest_ops.set_parent(hw, index);
> +
> +       return notifier_from_errno(err);
> +}
> +
> +static struct notifier_block cpu_clk_notifier = {

Instead of a static global can this be allocated with kzalloc?

> +       .notifier_call = cpu_clk_notifier_fn,
> +};
> +
>  static int apss_ipq6018_probe(struct platform_device *pdev)
kernel test robot Oct. 19, 2023, 1:15 a.m. UTC | #2 
Hi Varadarajan,

kernel test robot noticed the following build errors:

[auto build test ERROR on linus/master]
[also build test ERROR on v6.6-rc6 next-20231018]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Varadarajan-Narayanan/clk-qcom-clk-alpha-pll-introduce-stromer-plus-ops/20231017-104355
base:   linus/master
patch link:    https://lore.kernel.org/r/000c61a028814f08a9fc6d1d5c446e8dad11a650.1697101543.git.quic_varada%40quicinc.com
patch subject: [PATCH v2 4/8] clk: qcom: apss-ipq6018: ipq5332: add safe source switch for a53pll
config: loongarch-randconfig-001-20231018 (https://download.01.org/0day-ci/archive/20231018/202310181650.g8THtfsm-lkp@intel.com/config)
compiler: loongarch64-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231018/202310181650.g8THtfsm-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <yujie.liu@intel.com>
| Closes: https://lore.kernel.org/r/202310181650.g8THtfsm-lkp@intel.com/

All errors (new ones prefixed by >>):

   loongarch64-linux-ld: drivers/clk/qcom/apss-ipq6018.o: in function `apss_ipq6018_probe':
>> apss-ipq6018.c:(.text+0xd0): undefined reference to `qcom_smem_get_soc_id'
diff mbox series

Patch

diff --git a/drivers/clk/qcom/apss-ipq6018.c b/drivers/clk/qcom/apss-ipq6018.c
index 4e13a08..c05c2b2 100644
--- a/drivers/clk/qcom/apss-ipq6018.c
+++ b/drivers/clk/qcom/apss-ipq6018.c
@@ -9,8 +9,11 @@ 
 #include <linux/clk-provider.h>
 #include <linux/regmap.h>
 #include <linux/module.h>
+#include <linux/clk.h>
+#include <linux/soc/qcom/smem.h>
 
 #include <dt-bindings/clock/qcom,apss-ipq.h>
+#include <dt-bindings/arm/qcom,ids.h>
 
 #include "common.h"
 #include "clk-regmap.h"
@@ -84,15 +87,63 @@  static const struct qcom_cc_desc apss_ipq6018_desc = {
 	.num_clks = ARRAY_SIZE(apss_ipq6018_clks),
 };
 
+static int cpu_clk_notifier_fn(struct notifier_block *nb, unsigned long action,
+				void *data)
+{
+	struct clk_hw *hw;
+	u8 index;
+	int err;
+
+	if (action == PRE_RATE_CHANGE)
+		index = P_GPLL0;
+	else if ((action == POST_RATE_CHANGE) || (action == ABORT_RATE_CHANGE))
+		index = P_APSS_PLL_EARLY;
+	else
+		return 0;
+
+	hw = &apcs_alias0_clk_src.clkr.hw;
+	err = clk_rcg2_mux_closest_ops.set_parent(hw, index);
+
+	return notifier_from_errno(err);
+}
+
+static struct notifier_block cpu_clk_notifier = {
+	.notifier_call = cpu_clk_notifier_fn,
+};
+
 static int apss_ipq6018_probe(struct platform_device *pdev)
 {
 	struct regmap *regmap;
+	u32 soc_id;
+	int ret;
+
+	ret = qcom_smem_get_soc_id(&soc_id);
+	if (ret)
+		return ret;
 
 	regmap = dev_get_regmap(pdev->dev.parent, NULL);
 	if (!regmap)
 		return -ENODEV;
 
-	return qcom_cc_really_probe(pdev, &apss_ipq6018_desc, regmap);
+	ret = qcom_cc_really_probe(pdev, &apss_ipq6018_desc, regmap);
+	if (ret)
+		return ret;
+
+	switch (soc_id) {
+	/* Only below variants of IPQ53xx support scaling */
+	case QCOM_ID_IPQ5332:
+	case QCOM_ID_IPQ5322:
+	case QCOM_ID_IPQ5300:
+		ret = clk_notifier_register(apcs_alias0_clk_src.clkr.hw.clk,
+						&cpu_clk_notifier);
+		if (ret)
+			return ret;
+		break;
+	default:
+		break;
+	}
+
+	return 0;
 }
 
 static struct platform_driver apss_ipq6018_driver = {