[PATCH V3] clk: imx7ulp: make it easy to change ARM core clk

From: peng . fan
Date: Mon Mar 16 2020 - 04:39:27 EST


From: Peng Fan <peng.fan@xxxxxxx>

ARM clk could only source from divcore or hsrun_divcore.

Follow what we already used on i.MX7D and i.MX8M SoCs, use
imx_clk_hw_cpu API. When ARM core is running normaly,
whether divcore or hwrun_divcore will finally source
from SPLL_PFD0. However SPLL_PFD0 is marked with CLK_SET_GATE,
so we need to disable SPLL_PFD0, when configure the rate.
So add CORE and HSRUN_CORE virtual clk to make it easy to
configure the clk using imx_clk_hw_cpu API.

Since CORE and HSRUN_CORE already marked with CLK_IS_CRITICAL, no
need to set ARM as CLK_IS_CRITICAL. And when set the rate of ARM clk,
prograting it the parent with CLK_SET_RATE_PARENT will finally set
the SPLL_PFD0 clk.

Signed-off-by: Peng Fan <peng.fan@xxxxxxx>
---

V3:
Update commit log. Make this a standalone patch from V2
V2:
https://patchwork.kernel.org/patch/11390595/
No change

drivers/clk/imx/clk-imx7ulp.c | 6 ++++--
include/dt-bindings/clock/imx7ulp-clock.h | 5 ++++-
2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/clk/imx/clk-imx7ulp.c b/drivers/clk/imx/clk-imx7ulp.c
index 3710aa0dee9b..634c0b6636b0 100644
--- a/drivers/clk/imx/clk-imx7ulp.c
+++ b/drivers/clk/imx/clk-imx7ulp.c
@@ -29,7 +29,7 @@ static const char * const ddr_sels[] = { "apll_pfd_sel", "dummy", "dummy", "dum
static const char * const nic_sels[] = { "firc", "ddr_clk", };
static const char * const periph_plat_sels[] = { "dummy", "nic1_bus_clk", "nic1_clk", "ddr_clk", "apll_pfd2", "apll_pfd1", "apll_pfd0", "upll", };
static const char * const periph_bus_sels[] = { "dummy", "sosc_bus_clk", "dummy", "firc_bus_clk", "rosc", "nic1_bus_clk", "nic1_clk", "spll_bus_clk", };
-static const char * const arm_sels[] = { "divcore", "dummy", "dummy", "hsrun_divcore", };
+static const char * const arm_sels[] = { "core", "dummy", "dummy", "hsrun_core", };

/* used by sosc/sirc/firc/ddr/spll/apll dividers */
static const struct clk_div_table ulp_div_table[] = {
@@ -121,7 +121,9 @@ static void __init imx7ulp_clk_scg1_init(struct device_node *np)
hws[IMX7ULP_CLK_DDR_SEL] = imx_clk_hw_mux_flags("ddr_sel", base + 0x30, 24, 2, ddr_sels, ARRAY_SIZE(ddr_sels), CLK_SET_RATE_PARENT | CLK_OPS_PARENT_ENABLE);

hws[IMX7ULP_CLK_CORE_DIV] = imx_clk_hw_divider_flags("divcore", "scs_sel", base + 0x14, 16, 4, CLK_SET_RATE_PARENT);
+ hws[IMX7ULP_CLK_CORE] = imx_clk_hw_cpu("core", "divcore", hws[IMX7ULP_CLK_CORE_DIV]->clk, hws[IMX7ULP_CLK_SYS_SEL]->clk, hws[IMX7ULP_CLK_SPLL_SEL]->clk, hws[IMX7ULP_CLK_FIRC]->clk);
hws[IMX7ULP_CLK_HSRUN_CORE_DIV] = imx_clk_hw_divider_flags("hsrun_divcore", "hsrun_scs_sel", base + 0x1c, 16, 4, CLK_SET_RATE_PARENT);
+ hws[IMX7ULP_CLK_HSRUN_CORE] = imx_clk_hw_cpu("hsrun_core", "hsrun_divcore", hws[IMX7ULP_CLK_HSRUN_CORE_DIV]->clk, hws[IMX7ULP_CLK_HSRUN_SYS_SEL]->clk, hws[IMX7ULP_CLK_SPLL_SEL]->clk, hws[IMX7ULP_CLK_FIRC]->clk);

hws[IMX7ULP_CLK_DDR_DIV] = imx_clk_hw_divider_gate("ddr_clk", "ddr_sel", CLK_SET_RATE_PARENT | CLK_IS_CRITICAL, base + 0x30, 0, 3,
0, ulp_div_table, &imx_ccm_lock);
@@ -270,7 +272,7 @@ static void __init imx7ulp_clk_smc1_init(struct device_node *np)
base = of_iomap(np, 0);
WARN_ON(!base);

- hws[IMX7ULP_CLK_ARM] = imx_clk_hw_mux_flags("arm", base + 0x10, 8, 2, arm_sels, ARRAY_SIZE(arm_sels), CLK_IS_CRITICAL);
+ hws[IMX7ULP_CLK_ARM] = imx_clk_hw_mux_flags("arm", base + 0x10, 8, 2, arm_sels, ARRAY_SIZE(arm_sels), CLK_SET_RATE_PARENT);

imx_check_clk_hws(hws, clk_data->num);

diff --git a/include/dt-bindings/clock/imx7ulp-clock.h b/include/dt-bindings/clock/imx7ulp-clock.h
index 38145bdcd975..b58370d146e2 100644
--- a/include/dt-bindings/clock/imx7ulp-clock.h
+++ b/include/dt-bindings/clock/imx7ulp-clock.h
@@ -58,7 +58,10 @@
#define IMX7ULP_CLK_HSRUN_SYS_SEL 44
#define IMX7ULP_CLK_HSRUN_CORE_DIV 45

-#define IMX7ULP_CLK_SCG1_END 46
+#define IMX7ULP_CLK_CORE 46
+#define IMX7ULP_CLK_HSRUN_CORE 47
+
+#define IMX7ULP_CLK_SCG1_END 48

/* PCC2 */
#define IMX7ULP_CLK_DMA1 0
--
2.16.4