clk: rockchip: allow additional mux options for cpu-clock frequency changes

In order to improve the main frequency of CPU, the clock path of CPU is
simplified as follows:
                         |--\
                         |   \            |--\
 --apll--|\              |    \           |   \
         | |--apll_core--|     \          |    \
 --24M---|/              |mux1 |--[gate]--|mux2|---clk_core
                         |     /          |    /
 --gpll--|\              |    /    |------|   /
         | |--gpll_core--|   /     |      |--/
 --24M---|/              |--/      |
                                   |
 -------apll_directly--------------|

When the CPU requests high frequency, we want to use MUX2 select the
"apll_directly".
At low frequencies use MUX1 to select “apll_core" and then MUX2 to
select "apll_core_gate".

However, in this way, the CPU frequency conversion needs to be
in the following order:
1. MUX2 select to "apll_core_gate", MUX1 select "gpll_core"
2. Apll sets slow_mode, sets APLL parameters, locks APLL, and then APLL
sets normal_mode
3. MUX1 select "apll_core", MUX2 select "apll_directly"

So add pre_mux and post_mux options to cover this special requirements.

Signed-off-by: Elaine Zhang <zhangqing@rock-chips.com>
[rebase]
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Link: https://lore.kernel.org/r/20221018151407.63395-7-sebastian.reichel@collabora.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

diff --git a/drivers/clk/rockchip/clk-cpu.c b/drivers/clk/rockchip/clk-cpu.c
index 11aa225..6ea7fba 100644 (file)
--- a/drivers/clk/rockchip/clk-cpu.c
+++ b/drivers/clk/rockchip/clk-cpu.c
@@ -113,6 +113,42 @@ static void rockchip_cpuclk_set_dividers(struct rockchip_cpuclk *cpuclk,
        }
 }
 
+static void rockchip_cpuclk_set_pre_muxs(struct rockchip_cpuclk *cpuclk,
+                                        const struct rockchip_cpuclk_rate_table *rate)
+{
+       int i;
+
+       /* alternate parent is active now. set the pre_muxs */
+       for (i = 0; i < ARRAY_SIZE(rate->pre_muxs); i++) {
+               const struct rockchip_cpuclk_clksel *clksel = &rate->pre_muxs[i];
+
+               if (!clksel->reg)
+                       break;
+
+               pr_debug("%s: setting reg 0x%x to 0x%x\n",
+                        __func__, clksel->reg, clksel->val);
+               writel(clksel->val, cpuclk->reg_base + clksel->reg);
+       }
+}
+
+static void rockchip_cpuclk_set_post_muxs(struct rockchip_cpuclk *cpuclk,
+                                         const struct rockchip_cpuclk_rate_table *rate)
+{
+       int i;
+
+       /* alternate parent is active now. set the muxs */
+       for (i = 0; i < ARRAY_SIZE(rate->post_muxs); i++) {
+               const struct rockchip_cpuclk_clksel *clksel = &rate->post_muxs[i];
+
+               if (!clksel->reg)
+                       break;
+
+               pr_debug("%s: setting reg 0x%x to 0x%x\n",
+                        __func__, clksel->reg, clksel->val);
+               writel(clksel->val, cpuclk->reg_base + clksel->reg);
+       }
+}
+
 static int rockchip_cpuclk_pre_rate_change(struct rockchip_cpuclk *cpuclk,
                                           struct clk_notifier_data *ndata)
 {
@@ -165,6 +201,9 @@ static int rockchip_cpuclk_pre_rate_change(struct rockchip_cpuclk *cpuclk,
                               cpuclk->reg_base + reg_data->core_reg[i]);
                }
        }
+
+       rockchip_cpuclk_set_pre_muxs(cpuclk, rate);
+
        /* select alternate parent */
        if (reg_data->mux_core_reg)
                writel(HIWORD_UPDATE(reg_data->mux_core_alt,
@@ -219,6 +258,8 @@ static int rockchip_cpuclk_post_rate_change(struct rockchip_cpuclk *cpuclk,
                                     reg_data->mux_core_shift),
                       cpuclk->reg_base + reg_data->core_reg[0]);
 
+       rockchip_cpuclk_set_post_muxs(cpuclk, rate);
+
        /* remove dividers */
        for (i = 0; i < reg_data->num_cores; i++) {
                writel(HIWORD_UPDATE(0, reg_data->div_core_mask[i],

diff --git a/drivers/clk/rockchip/clk.h b/drivers/clk/rockchip/clk.h
index 6eb31d3..24d3e56 100644 (file)
--- a/drivers/clk/rockchip/clk.h
+++ b/drivers/clk/rockchip/clk.h
@@ -399,6 +399,8 @@ struct rockchip_cpuclk_clksel {
 struct rockchip_cpuclk_rate_table {
        unsigned long prate;
        struct rockchip_cpuclk_clksel divs[ROCKCHIP_CPUCLK_NUM_DIVIDERS];
+       struct rockchip_cpuclk_clksel pre_muxs[ROCKCHIP_CPUCLK_NUM_DIVIDERS];
+       struct rockchip_cpuclk_clksel post_muxs[ROCKCHIP_CPUCLK_NUM_DIVIDERS];
 };
 
 /**