From:   Adam Ford <aford173@gmail.com>
To:     linux-clk@vger.kernel.org
Cc:     aford@beaconembedded.com, Adam Ford <aford173@gmail.com>,
        Abel Vesa <abelvesa@kernel.org>, Peng Fan <peng.fan@nxp.com>,
        Michael Turquette <mturquette@baylibre.com>,
        Stephen Boyd <sboyd@kernel.org>,
        Shawn Guo <shawnguo@kernel.org>,
        Sascha Hauer <s.hauer@pengutronix.de>,
        Pengutronix Kernel Team <kernel@pengutronix.de>,
        Fabio Estevam <festevam@gmail.com>,
        NXP Linux Team <linux-imx@nxp.com>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH 3/3] clk: imx: Let IMX8MN_CLK_DISP_PIXEL set parent rate
Date:   Sun, 19 Mar 2023 08:21:20 -0500
Message-Id: <20230319132120.6347-4-aford173@gmail.com>
In-Reply-To: <20230319132120.6347-1-aford173@gmail.com>
References: <20230319132120.6347-1-aford173@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

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