Re: [PATCH v13 4/5] clk: sophgo: Add SG2042 clock driver

From: Chen Wang
Date: Thu Apr 11 2024 - 08:58:28 EST



On 2024/4/11 12:11, Stephen Boyd wrote:
Quoting Chen Wang (2024-03-28 23:21:40)
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+/*
+ * Note: regarding names for mux clock, "0/1" or "div0/div1" means the
+ * first/second parent input source, not the register value.
+ * For example:
+ * "clk_div_ddr01_0" is the name of Clock divider 0 control of DDR01, and
+ * "clk_gate_ddr01_div0" is the gate clock in front of the "clk_div_ddr01_0",
+ * they are both controlled by register CLKDIVREG27;
+ * "clk_div_ddr01_1" is the name of Clock divider 1 control of DDR01, and
+ * "clk_gate_ddr01_div1" is the gate clock in front of the "clk_div_ddr01_1",
+ * they are both controlled by register CLKDIVREG28;
+ * While for register value of mux selection, use Clock Select for DDR01’s clock
+ * as example, see CLKSELREG0, bit[2].
+ * 1: Select in_dpll0_clk as clock source, correspondng to the parent input
+ * source from "clk_div_ddr01_0".
+ * 0: Select in_fpll_clk as clock source, corresponding to the parent input
+ * source from "clk_div_ddr01_1".
+ * So we need a table to define the array of register values corresponding to
+ * the parent index and tell CCF about this when registering mux clock.
+ */
+static const u32 sg2042_mux_table[] = {1, 0};
+
+static const char *const clk_mux_ddr01_p[] = {
+ "clk_div_ddr01_0", "clk_div_ddr01_1"};
+static const char *const clk_mux_ddr23_p[] = {
+ "clk_div_ddr23_0", "clk_div_ddr23_1"};
+static const char *const clk_mux_rp_cpu_normal_p[] = {
+ "clk_div_rp_cpu_normal_0", "clk_div_rp_cpu_normal_1"};
+static const char *const clk_mux_axi_ddr_p[] = {
+ "clk_div_axi_ddr_0", "clk_div_axi_ddr_1"};
+
+static struct sg2042_mux_clock sg2042_mux_clks[] = {
+ SG2042_MUX(MUX_CLK_DDR01, "clk_mux_ddr01", clk_mux_ddr01_p,
Please use struct clk_parent_data or struct clk_hw directly instead of
string names.

Hi, Stephen,

I understand that for clk_init_data, parent_names/parent_data/parent_hws are all acceptable. Why do you only suggest me to use parent_data/parent_hws here? Can you please explain?

Thank you again for your careful review

Chen

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