[linux-next, 1/1] clk: imx: imx8mm-anatop: probe only on i.MX8MM platforms

[Dario Binacchi <dario.binacchi@amarulasolutions.com>]

Commit 9c1e388af87c ("clk: imx: add support for i.MX8MM anatop clock
driver") breaks boot on i.MX8M{P,N} platforms.

Here's the log for a board based on the i.MX8MP platform:

[    1.439320] i.MX clk 1: register failed with -2
[    1.441014] i.MX clk 2: register failed with -2
[    1.445610] imx8mm-anatop 30360000.clock-controller: NXP i.MX8MM anatop clock driver probed
[    1.455068] Unable to handle kernel paging request at virtual address fffffffffffffffe

...

[    1.634650] Call trace:
[    1.637102]  __clk_get_hw+0x4/0x18 (P)
[    1.640862]  imx8mp_clocks_probe+0xdc/0x2f50
[    1.645152]  platform_probe+0x68/0xc4
[    1.648827]  really_probe+0xbc/0x298
[    1.652413]  __driver_probe_device+0x78/0x12c

In the imx8mp.dtsi device tree, the anatop compatible string is:

compatible = "fsl,imx8mp-anatop", "fsl,imx8mm-anatop";

So, in configurations like arm64 defconfig, where CONFIG_CLK_IMX8MP and
CONFIG_CLK_IMX8MM as well as CONFIG_CLK_IMX8MN are enabled, the driver
for the i.MX8MM anatop is incorrectly loaded.

The patch fixes the regression by ensuring that the i.MX8MM anatop
driver only probes on i.MX8MM platforms.

Fixes: 9c1e388af87c ("clk: imx: add support for i.MX8MM anatop clock driver")
Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>

---

 drivers/clk/imx/clk-imx8mm-anatop.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/clk/imx/clk-imx8mm-anatop.c b/drivers/clk/imx/clk-imx8mm-anatop.c
index 4ac870df6370..90ff11a93fe5 100644
--- a/drivers/clk/imx/clk-imx8mm-anatop.c
+++ b/drivers/clk/imx/clk-imx8mm-anatop.c
@@ -37,6 +37,19 @@ static const char * const clkout_sels[] = {"audio_pll1_out", "audio_pll2_out", "
 static struct clk_hw_onecell_data *clk_hw_data;
 static struct clk_hw **hws;
 
+static int is_really_imx8mm(struct device_node *np)
+{
+	const char *compat;
+	struct property *p;
+
+	of_property_for_each_string(np, "compatible", p, compat) {
+		if (strcmp(compat, "fsl,imx8mm-anatop"))
+			return -EFAULT;
+	}
+
+	return 0;
+}
+
 static int imx8mm_anatop_clocks_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -44,6 +57,10 @@ static int imx8mm_anatop_clocks_probe(struct platform_device *pdev)
 	void __iomem *base;
 	int ret;
 
+	ret = is_really_imx8mm(np);
+	if (ret)
+		return ret;
+
 	base = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(base)) {
 		dev_err(dev, "failed to get base address\n");
-- 
2.43.0

base-commit: 8566fc3b96539e3235909d6bdda198e1282beaed
branch: fix-imx8mm-probing