From 7f218065c136cc643e4773cad5e742f2c597988c Mon Sep 17 00:00:00 2001 From: Philipp Zabel Date: Thu, 12 Oct 2017 15:29:35 +0200 Subject: [PATCH] clk: imx: clk-imx6ul: allow lcdif_pre_sel to change parent rate Allowing the lcdif_pre_sel to propagate rate changes to its parent PLL allows more fine grained control over the LCDIF pixel clock rate. For example, the Innovision AT043TN24 LCD panel described in the imx6ul-14x14-evk device tree requires a 9 MHz pixel clock. Before this patch, the lcdif_pre_sel clock rate is fixed, and just setting the lcdif_pred and lcdif_podf dividers only allows to get as close as about 8.44 MHz: pll3 1 1 480000000 0 0 pll3_bypass 1 1 480000000 0 0 pll3_usb_otg 1 1 480000000 0 0 pll3_pfd1_540m 1 1 540000000 0 0 lcdif_pre_sel 1 1 540000000 0 0 lcdif_pred 1 1 67500000 0 0 lcdif_podf 1 1 8437500 0 0 lcdif_pix 1 1 8437500 0 0 Once lcdif_pre_sel is allowed to propagate rate requests to its parent, the actual pixel clock matches the requested value: pll3 1 1 480000000 0 0 pll3_bypass 1 1 480000000 0 0 pll3_usb_otg 1 1 480000000 0 0 pll3_pfd1_540m 1 1 288000000 0 0 lcdif_pre_sel 1 1 288000000 0 0 lcdif_pred 1 1 36000000 0 0 lcdif_podf 1 1 9000000 0 0 lcdif_pix 1 1 9000000 0 0 Signed-off-by: Philipp Zabel Reviewed-by: Fabio Estevam Signed-off-by: Stephen Boyd --- drivers/clk/imx/clk-imx6ul.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/clk/imx/clk-imx6ul.c b/drivers/clk/imx/clk-imx6ul.c index 5e8c18afce9a..85c118164469 100644 --- a/drivers/clk/imx/clk-imx6ul.c +++ b/drivers/clk/imx/clk-imx6ul.c @@ -267,7 +267,7 @@ static void __init imx6ul_clocks_init(struct device_node *ccm_node) clks[IMX6ULL_CLK_EPDC_SEL] = imx_clk_mux("epdc_sel", base + 0x34, 9, 3, epdc_sels, ARRAY_SIZE(epdc_sels)); } clks[IMX6UL_CLK_ECSPI_SEL] = imx_clk_mux("ecspi_sel", base + 0x38, 18, 1, ecspi_sels, ARRAY_SIZE(ecspi_sels)); - clks[IMX6UL_CLK_LCDIF_PRE_SEL] = imx_clk_mux("lcdif_pre_sel", base + 0x38, 15, 3, lcdif_pre_sels, ARRAY_SIZE(lcdif_pre_sels)); + clks[IMX6UL_CLK_LCDIF_PRE_SEL] = imx_clk_mux_flags("lcdif_pre_sel", base + 0x38, 15, 3, lcdif_pre_sels, ARRAY_SIZE(lcdif_pre_sels), CLK_SET_RATE_PARENT); clks[IMX6UL_CLK_LCDIF_SEL] = imx_clk_mux("lcdif_sel", base + 0x38, 9, 3, lcdif_sels, ARRAY_SIZE(lcdif_sels)); clks[IMX6UL_CLK_LDB_DI0_DIV_SEL] = imx_clk_mux("ldb_di0", base + 0x20, 10, 1, ldb_di0_div_sels, ARRAY_SIZE(ldb_di0_div_sels)); -- 2.17.1