[PATCH v2 1/2] clk: renesas: rzg2l: Don't assume all CPG_MOD clocks support PM

From: Prabhakar
Date: Tue Oct 25 2022 - 21:42:47 EST


From: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>

There are cases where not all CPG_MOD clocks should be assumed to support
PM. For example on the CRU block there is a particular sequence that needs
to be followed to initialize the CSI-2 D-PHY in which individual clocks
need to be turned ON/OFF, due to which Runtime PM support wasn't used by
the CRU CSI-2 driver.

This patch adds support to allow indicating if PM is not supported by the
CPG_MOD clocks. Two new members no_pm_mod_clks and num_no_pm_mod_clks are
added to struct rzg2l_cpg_info so that MOD clocks which do not support PM
can be passed by no_pm_mod_clks[] array and when the driver uses Runtime
PM support the clk ID is matched against the no_pm_mod_clks[] array to see
if the clk is needed to be included as part of Runtime PM.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@xxxxxxxxxxxxxx>
---
v1->v2
* Dropped DEF_NO_PM() macro
* Added genpd member to struct rzg2l_cpg_priv
* Added no_pm_mod_clks and num_no_pm_mod_clks members
to struct rzg2l_cpg_info
* Updated commit message

RFC->v1
* Added no_pm_mod_clks and num_no_pm_mod_clks members as part of
struct rzg2l_cpg_priv
---
drivers/clk/renesas/rzg2l-cpg.c | 37 ++++++++++++++++++++-------------
drivers/clk/renesas/rzg2l-cpg.h | 4 ++++
2 files changed, 27 insertions(+), 14 deletions(-)

diff --git a/drivers/clk/renesas/rzg2l-cpg.c b/drivers/clk/renesas/rzg2l-cpg.c
index dfd676310ce9..66b909f31c77 100644
--- a/drivers/clk/renesas/rzg2l-cpg.c
+++ b/drivers/clk/renesas/rzg2l-cpg.c
@@ -95,6 +95,7 @@ struct rzg2l_pll5_mux_dsi_div_param {
* @num_resets: Number of Module Resets in info->resets[]
* @last_dt_core_clk: ID of the last Core Clock exported to DT
* @info: Pointer to platform data
+ * @genpd: PM domain
* @mux_dsi_div_params: pll5 mux and dsi div parameters
*/
struct rzg2l_cpg_priv {
@@ -111,6 +112,8 @@ struct rzg2l_cpg_priv {

const struct rzg2l_cpg_info *info;

+ struct generic_pm_domain genpd;
+
struct rzg2l_pll5_mux_dsi_div_param mux_dsi_div_params;
};

@@ -1223,22 +1226,31 @@ static int rzg2l_cpg_reset_controller_register(struct rzg2l_cpg_priv *priv)
return devm_reset_controller_register(priv->dev, &priv->rcdev);
}

-static bool rzg2l_cpg_is_pm_clk(const struct of_phandle_args *clkspec)
+static bool rzg2l_cpg_is_pm_clk(struct rzg2l_cpg_priv *priv,
+ const struct of_phandle_args *clkspec)
{
+ const struct rzg2l_cpg_info *info = priv->info;
+ unsigned int id;
+ unsigned int i;
+
if (clkspec->args_count != 2)
return false;

- switch (clkspec->args[0]) {
- case CPG_MOD:
- return true;
-
- default:
+ if (clkspec->args[0] != CPG_MOD)
return false;
+
+ id = clkspec->args[1] + info->num_total_core_clks;
+ for (i = 0; i < info->num_no_pm_mod_clks; i++) {
+ if (info->no_pm_mod_clks[i] == id)
+ return false;
}
+
+ return true;
}

static int rzg2l_cpg_attach_dev(struct generic_pm_domain *unused, struct device *dev)
{
+ struct rzg2l_cpg_priv *priv = container_of(unused, struct rzg2l_cpg_priv, genpd);
struct device_node *np = dev->of_node;
struct of_phandle_args clkspec;
bool once = true;
@@ -1248,7 +1260,7 @@ static int rzg2l_cpg_attach_dev(struct generic_pm_domain *unused, struct device

while (!of_parse_phandle_with_args(np, "clocks", "#clock-cells", i,
&clkspec)) {
- if (rzg2l_cpg_is_pm_clk(&clkspec)) {
+ if (rzg2l_cpg_is_pm_clk(priv, &clkspec)) {
if (once) {
once = false;
error = pm_clk_create(dev);
@@ -1298,16 +1310,13 @@ static void rzg2l_cpg_genpd_remove(void *data)
pm_genpd_remove(data);
}

-static int __init rzg2l_cpg_add_clk_domain(struct device *dev)
+static int __init rzg2l_cpg_add_clk_domain(struct rzg2l_cpg_priv *priv)
{
+ struct device *dev = priv->dev;
struct device_node *np = dev->of_node;
- struct generic_pm_domain *genpd;
+ struct generic_pm_domain *genpd = &priv->genpd;
int ret;

- genpd = devm_kzalloc(dev, sizeof(*genpd), GFP_KERNEL);
- if (!genpd)
- return -ENOMEM;
-
genpd->name = np->name;
genpd->flags = GENPD_FLAG_PM_CLK | GENPD_FLAG_ALWAYS_ON |
GENPD_FLAG_ACTIVE_WAKEUP;
@@ -1377,7 +1386,7 @@ static int __init rzg2l_cpg_probe(struct platform_device *pdev)
if (error)
return error;

- error = rzg2l_cpg_add_clk_domain(dev);
+ error = rzg2l_cpg_add_clk_domain(priv);
if (error)
return error;

diff --git a/drivers/clk/renesas/rzg2l-cpg.h b/drivers/clk/renesas/rzg2l-cpg.h
index cecbdf5e4f93..eee780276a9e 100644
--- a/drivers/clk/renesas/rzg2l-cpg.h
+++ b/drivers/clk/renesas/rzg2l-cpg.h
@@ -256,6 +256,10 @@ struct rzg2l_cpg_info {
unsigned int num_mod_clks;
unsigned int num_hw_mod_clks;

+ /* No PM Module Clocks */
+ const unsigned int *no_pm_mod_clks;
+ unsigned int num_no_pm_mod_clks;
+
/* Resets */
const struct rzg2l_reset *resets;
unsigned int num_resets;
--
2.25.1