[PATCH 7/8] PM / devfreq: rockchip-dfi: make RK3588 use its clocks

[Sebastian Reichel <sebastian.reichel@collabora.com>]

From: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>

So far, RK3588 doesn't have the pclks for DDRMON used in the driver, as
they weren't modelled before.

However, they are now correctly modelled, so the driver should use them
when possible.

Instead of unconditionally getting them for this SoC, add a new variant
member that specifies whether the driver should let missing clocks
slide. This is needed because we want old device trees to keep
functioning, as otherwise we'd be introducing a breaking change for
literally no functional difference here.

Fill out a clock name list for this variant as well, and hand it to it.

Signed-off-by: Nicolas Frattaroli <nicolas.frattaroli@collabora.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
---
 drivers/devfreq/event/rockchip-dfi.c | 29 +++++++++++++++++++++++++++--
 1 file changed, 27 insertions(+), 2 deletions(-)

diff --git a/drivers/devfreq/event/rockchip-dfi.c b/drivers/devfreq/event/rockchip-dfi.c
index b61ec500eaed..380361a231a2 100644
--- a/drivers/devfreq/event/rockchip-dfi.c
+++ b/drivers/devfreq/event/rockchip-dfi.c
@@ -117,6 +117,18 @@ struct rockchip_dfi {
 	const struct rockchip_dfi_variant *variant;
 };
 
+/**
+ * struct rockchip_dfi_variant
+ * @init: pointer to the variant-specific initialisation function
+ * @stride: address offset between the DDRMON per-channel instances
+ * @ctrl_single: whether only one DDRMON instance monitors multiple channels
+ * @max_channels: maximum number of memory channels for this SoC
+ * @clk_names: pointer to a constant array of constant clock name strings
+ * @num_clk: the number of elements in the @clk_names array
+ * @clocks_optional: whether not finding the clocks is non-fatal. Set if the
+ *                   DT binding for this variant didn't require clocks in the
+ *                   past, so that the driver remains compatible with old DTs.
+ */
 struct rockchip_dfi_variant {
 	int (*init)(struct rockchip_dfi *dfi);
 	int stride;
@@ -124,6 +136,7 @@ struct rockchip_dfi_variant {
 	unsigned int max_channels;
 	const char * const *clk_names;
 	unsigned int num_clks;
+	bool clocks_optional;
 };
 
 static int rockchip_dfi_ddrtype_to_ctrl(struct rockchip_dfi *dfi, u32 *ctrl)
@@ -804,6 +817,11 @@ static const char * const rk3399_clk_names[] = {
 	"pclk_ddr_mon",
 };
 
+static const char * const rk3588_clk_names[] = {
+	"pclk_ddr_mon_ch0", "pclk_ddr_mon_ch1", "pclk_ddr_mon_ch2",
+	"pclk_ddr_mon_ch3",
+};
+
 static const struct rockchip_dfi_variant rk3399_variant = {
 	.init = rk3399_dfi_init,
 	.stride = 0x14,
@@ -824,6 +842,9 @@ static const struct rockchip_dfi_variant rk3588_variant = {
 	.init = rk3588_dfi_init,
 	.stride = 0x4000,
 	.max_channels = 4,
+	.clk_names = rk3588_clk_names,
+	.num_clks = ARRAY_SIZE(rk3588_clk_names),
+	.clocks_optional = true,
 };
 
 static const struct of_device_id rockchip_dfi_id_match[] = {
@@ -883,8 +904,12 @@ static int rockchip_dfi_probe(struct platform_device *pdev)
 		for (i = 0; i < dfi->variant->num_clks; i++)
 			dfi->clocks[i].id = dfi->variant->clk_names[i];
 
-		ret = devm_clk_bulk_get(dev, dfi->variant->num_clks,
-					dfi->clocks);
+		if (dfi->variant->clocks_optional)
+			ret = devm_clk_bulk_get_optional(dev, dfi->variant->num_clks,
+							 dfi->clocks);
+		else
+			ret = devm_clk_bulk_get(dev, dfi->variant->num_clks,
+						dfi->clocks);
 		if (ret)
 			return dev_err_probe(dev, ret, "failed to get clocks\n");
 	}

-- 
2.53.0