Re: [PATCH 10/14] clk: scmi: support SCMI multi-channel

[Sean Anderson]

On 5/13/22 2:26 AM, Etienne Carriere wrote:

Update SCMI clock driver to get its assigned SCMI channel during
initialization. This change allows SCMI clock protocol to use a
dedicated channel when defined in the DT. The reference is saved
in SCMI clock driver private data.

Cc: Lukasz Majewski <lu...@denx.de>
Cc: Sean Anderson <sean...@gmail.com>
Signed-off-by: Etienne Carriere <etienne.carri...@linaro.org>
---
  drivers/clk/clk_scmi.c | 23 +++++++++++++++++------
  1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/drivers/clk/clk_scmi.c b/drivers/clk/clk_scmi.c
index 0d0bb72eaf7..5cf7bd73df5 100644
--- a/drivers/clk/clk_scmi.c
+++ b/drivers/clk/clk_scmi.c
@@ -15,6 +15,7 @@

static int scmi_clk_get_num_clock(struct udevice *dev, size_t *num_clocks)

  {
+       struct scmi_channel **scmi_channel_ref = dev_get_priv(dev);
        struct scmi_clk_protocol_attr_out out;
        struct scmi_msg msg = {
                .protocol_id = SCMI_PROTOCOL_ID_CLOCK,
@@ -24,7 +25,7 @@ static int scmi_clk_get_num_clock(struct udevice *dev, size_t 
*num_clocks)
        };
        int ret;

- ret = devm_scmi_process_msg(dev, NULL, &msg);

+       ret = devm_scmi_process_msg(dev, *scmi_channel_ref, &msg);
        if (ret)
                return ret;

@@ -35,6 +36,7 @@ static int scmi_clk_get_num_clock(struct udevice *dev, size_t *num_clocks) static int scmi_clk_get_attibute(struct udevice *dev, int clkid, char **name)

  {
+       struct scmi_channel **scmi_channel_ref = dev_get_priv(dev);
        struct scmi_clk_attribute_in in = {
                .clock_id = clkid,
        };
@@ -49,7 +51,7 @@ static int scmi_clk_get_attibute(struct udevice *dev, int 
clkid, char **name)
        };
        int ret;

- ret = devm_scmi_process_msg(dev, NULL, &msg);

+       ret = devm_scmi_process_msg(dev, *scmi_channel_ref, &msg);
        if (ret)
                return ret;

@@ -60,6 +62,7 @@ static int scmi_clk_get_attibute(struct udevice *dev, int clkid, char **name) static int scmi_clk_gate(struct clk *clk, int enable)

  {
+       struct scmi_channel **scmi_channel_ref = dev_get_priv(clk->dev);
        struct scmi_clk_state_in in = {
                .clock_id = clk->id,
                .attributes = enable,
@@ -70,7 +73,7 @@ static int scmi_clk_gate(struct clk *clk, int enable)
                                          in, out);
        int ret;

- ret = devm_scmi_process_msg(clk->dev, NULL, &msg);

+       ret = devm_scmi_process_msg(clk->dev, *scmi_channel_ref, &msg);
        if (ret)
                return ret;

@@ -89,6 +92,7 @@ static int scmi_clk_disable(struct clk *clk) static ulong scmi_clk_get_rate(struct clk *clk)

  {
+       struct scmi_channel **scmi_channel_ref = dev_get_priv(clk->dev);
        struct scmi_clk_rate_get_in in = {
                .clock_id = clk->id,
        };
@@ -98,7 +102,7 @@ static ulong scmi_clk_get_rate(struct clk *clk)
                                          in, out);
        int ret;

- ret = devm_scmi_process_msg(clk->dev, NULL, &msg);

+       ret = devm_scmi_process_msg(clk->dev, *scmi_channel_ref, &msg);
        if (ret < 0)
                return ret;

@@ -111,6 +115,7 @@ static ulong scmi_clk_get_rate(struct clk *clk) static ulong scmi_clk_set_rate(struct clk *clk, ulong rate)

  {
+       struct scmi_channel **scmi_channel_ref = dev_get_priv(clk->dev);
        struct scmi_clk_rate_set_in in = {
                .clock_id = clk->id,
                .flags = SCMI_CLK_RATE_ROUND_CLOSEST,
@@ -123,7 +128,7 @@ static ulong scmi_clk_set_rate(struct clk *clk, ulong rate)
                                          in, out);
        int ret;

- ret = devm_scmi_process_msg(clk->dev, NULL, &msg);

+       ret = devm_scmi_process_msg(clk->dev, *scmi_channel_ref, &msg);
        if (ret < 0)
                return ret;

@@ -136,10 +141,15 @@ static ulong scmi_clk_set_rate(struct clk *clk, ulong rate) static int scmi_clk_probe(struct udevice *dev)

  {
+       struct scmi_channel **scmi_channel_ref = dev_get_priv(dev);
        struct clk *clk;
        size_t num_clocks, i;
        int ret;

+ ret = devm_scmi_of_get_channel(dev, scmi_channel_ref);

+       if (ret)
+               return ret;
+
        if (!CONFIG_IS_ENABLED(CLK_CCF))
                return 0;

@@ -186,5 +196,6 @@ U_BOOT_DRIVER(scmi_clock) = {

        .name = "scmi_clk",
        .id = UCLASS_CLK,
        .ops = &scmi_clk_ops,
-       .probe = &scmi_clk_probe,
+       .probe = scmi_clk_probe,
+       .priv_auto = sizeof(struct scmi_channel *),

Please create a priv struct to hold this. E.g.

/**
 * struct scmi_clk_priv - Private data for SCMI clocks
 * @channel: ...
 */
struct scmi_clk_priv {
        struct scmi_channel *channel;
};

This will allow for easier refactoring if it is necessary to add additional
per-device data in the future.

--Sean