[PATCH 3/3] clk: imx: Let IMX8MN_CLK_DISP_PIXEL set parent rate

Adam Ford
2023-03-19T13:21:51Z

By default the display pixel clock needs to be evenly divide
down from the video_pll_out clock which rules out a significant
number of resolution and refresh rates.

The current clock tree looks something like:

video_pll 594000000
video_pll_bypass 594000000
video_pll_out 594000000
disp_pixel 148500000
disp_pixel_clk 148500000

Now that composite-8m supports determine_rate, we can allow
disp_pixel to set the parent rate which then switches
every clock in the chain to a new frequency when disp_pixel
cannot evenly divide from video_pll_out.

Signed-off-by: Adam Ford <aford173@gmail.com>

diff --git a/drivers/clk/imx/clk-imx8mn.c b/drivers/clk/imx/clk-imx8mn.c
index a042ed3a9d6c..4b23a4648600 100644
--- a/drivers/clk/imx/clk-imx8mn.c
+++ b/drivers/clk/imx/clk-imx8mn.c
@@ -470,7 +470,7 @@ static int imx8mn_clocks_probe(struct platform_device *pdev)
hws[IMX8MN_CLK_DRAM_ALT] = imx8m_clk_hw_fw_managed_composite("dram_alt", imx8mn_dram_alt_sels, base + 0xa000);
hws[IMX8MN_CLK_DRAM_APB] = imx8m_clk_hw_fw_managed_composite_critical("dram_apb", imx8mn_dram_apb_sels, base + 0xa080);

- hws[IMX8MN_CLK_DISP_PIXEL] = imx8m_clk_hw_composite("disp_pixel", imx8mn_disp_pixel_sels, base + 0xa500);
+ hws[IMX8MN_CLK_DISP_PIXEL] = imx8m_clk_hw_composite_flags("disp_pixel", imx8mn_disp_pixel_sels, base + 0xa500, CLK_SET_RATE_PARENT);
hws[IMX8MN_CLK_SAI2] = imx8m_clk_hw_composite("sai2", imx8mn_sai2_sels, base + 0xa600);
hws[IMX8MN_CLK_SAI3] = imx8m_clk_hw_composite("sai3", imx8mn_sai3_sels, base + 0xa680);
hws[IMX8MN_CLK_SAI5] = imx8m_clk_hw_composite("sai5", imx8mn_sai5_sels, base + 0xa780);
diff --git a/drivers/clk/imx/clk.h b/drivers/clk/imx/clk.h
index 3d94722bbf99..621b0e84ef27 100644
--- a/drivers/clk/imx/clk.h
+++ b/drivers/clk/imx/clk.h
@@ -417,6 +417,10 @@ struct clk_hw *__imx8m_clk_hw_composite(const char *name,
_imx8m_clk_hw_composite(name, parent_names, reg, \
0, IMX_COMPOSITE_CLK_FLAGS_DEFAULT)

+#define imx8m_clk_hw_composite_flags(name, parent_names, reg, flags) \
+ _imx8m_clk_hw_composite(name, parent_names, reg, \
+ 0, IMX_COMPOSITE_CLK_FLAGS_DEFAULT | flags)
+
#define imx8m_clk_hw_composite_critical(name, parent_names, reg) \
_imx8m_clk_hw_composite(name, parent_names, reg, \
0, IMX_COMPOSITE_CLK_FLAGS_CRITICAL)
--
2.34.1