i2c: designware: platdrv: Set class based on DMI

Current AMD's zen-based APUs use this core for some of its i2c-buses.

With this patch we re-enable autodetection of hwmon-alike devices, so
lm-sensors will be able to work automatically.

It does not affect the boot-time of embedded devices, as the class is
set based on the DMI information.

DMI is probed only on Qtechnology QT5222 Industrial Camera Platform.

DocLink: https://qtec.com/camera-technology-camera-platforms/
Fixes: 3eddad96c439 ("i2c: designware: reverts "i2c: designware: Add support for AMD I2C controller"")
Signed-off-by: Ricardo Ribalda <ribalda@kernel.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index c2efaaa..a71bc58 100644 (file)
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -12,6 +12,7 @@
 #include <linux/clk-provider.h>
 #include <linux/clk.h>
 #include <linux/delay.h>
+#include <linux/dmi.h>
 #include <linux/err.h>
 #include <linux/errno.h>
 #include <linux/i2c.h>
@@ -191,6 +192,17 @@ static int dw_i2c_plat_request_regs(struct dw_i2c_dev *dev)
        return ret;
 }
 
+static const struct dmi_system_id dw_i2c_hwmon_class_dmi[] = {
+       {
+               .ident = "Qtechnology QT5222",
+               .matches = {
+                       DMI_MATCH(DMI_SYS_VENDOR, "Qtechnology"),
+                       DMI_MATCH(DMI_PRODUCT_NAME, "QT5222"),
+               },
+       },
+       { } /* terminate list */
+};
+
 static int dw_i2c_plat_probe(struct platform_device *pdev)
 {
        struct dw_i2c_platform_data *pdata = dev_get_platdata(&pdev->dev);
@@ -267,7 +279,8 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
 
        adap = &dev->adapter;
        adap->owner = THIS_MODULE;
-       adap->class = I2C_CLASS_DEPRECATED;
+       adap->class = dmi_check_system(dw_i2c_hwmon_class_dmi) ?
+                                       I2C_CLASS_HWMON : I2C_CLASS_DEPRECATED;
        ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
        adap->dev.of_node = pdev->dev.of_node;
        adap->nr = -1;