The HDMI blocks in the BCM2771 have an i2c controller to retrieve the EDID. This block is split into two parts, the BSC and the AUTO_I2C, lying in two separate register areas.
The AUTO_I2C block has a mailbox-like interface and will take away the BSC control from the CPU if enabled. However, the BSC is the actually the same controller than the one supported by the brcmstb driver, and the AUTO_I2C doesn't really bring any immediate benefit.
Let's use the BSC then, but let's also tie the AUTO_I2C registers with a separate compatible so that we can enable AUTO_I2C if needed in the future.
The AUTO_I2C is enabled by default at boot though, so we first need to release the BSC from the AUTO_I2C control.
Cc: Kamal Dasu kdasu.kdev@gmail.com Cc: Florian Fainelli f.fainelli@gmail.com Cc: Wolfram Sang wsa@the-dreams.de Cc: bcm-kernel-feedback-list@broadcom.com Cc: linux-i2c@vger.kernel.org Signed-off-by: Maxime Ripard maxime@cerno.tech --- drivers/i2c/busses/i2c-brcmstb.c | 33 +++++++++++++++++++++++++++++++++- 1 file changed, 33 insertions(+)
diff --git a/drivers/i2c/busses/i2c-brcmstb.c b/drivers/i2c/busses/i2c-brcmstb.c index 506991596b68..169a2836922d 100644 --- a/drivers/i2c/busses/i2c-brcmstb.c +++ b/drivers/i2c/busses/i2c-brcmstb.c @@ -580,6 +580,31 @@ static void brcmstb_i2c_set_bsc_reg_defaults(struct brcmstb_i2c_dev *dev) brcmstb_i2c_set_bus_speed(dev); }
+#define AUTOI2C_CTRL0 0x26c +#define AUTOI2C_CTRL0_RELEASE_BSC BIT(1) + +static int bcm2711_release_bsc(struct brcmstb_i2c_dev *dev) +{ + struct platform_device *pdev = to_platform_device(dev->device); + struct resource *iomem; + void __iomem *autoi2c; + + /* Map hardware registers */ + iomem = platform_get_resource_byname(pdev, IORESOURCE_MEM, "auto-i2c"); + autoi2c = devm_ioremap_resource(&pdev->dev, iomem); + if (IS_ERR(autoi2c)) + return PTR_ERR(autoi2c); + + writel(AUTOI2C_CTRL0_RELEASE_BSC, autoi2c + AUTOI2C_CTRL0); + devm_iounmap(&pdev->dev, autoi2c); + + /* We need to reset the controller after the release */ + dev->bsc_regmap->iic_enable = 0; + bsc_writel(dev, dev->bsc_regmap->iic_enable, iic_enable); + + return 0; +} + static int brcmstb_i2c_probe(struct platform_device *pdev) { int rc = 0; @@ -609,6 +634,13 @@ static int brcmstb_i2c_probe(struct platform_device *pdev) goto probe_errorout; }
+ if (of_device_is_compatible(dev->device->of_node, + "brcm,bcm2711-hdmi-i2c")) { + rc = bcm2711_release_bsc(dev); + if (rc) + goto probe_errorout; + } + rc = of_property_read_string(dev->device->of_node, "interrupt-names", &int_name); if (rc < 0) @@ -705,6 +737,7 @@ static SIMPLE_DEV_PM_OPS(brcmstb_i2c_pm, brcmstb_i2c_suspend, static const struct of_device_id brcmstb_i2c_of_match[] = { {.compatible = "brcm,brcmstb-i2c"}, {.compatible = "brcm,brcmper-i2c"}, + {.compatible = "brcm,bcm2711-hdmi-i2c"}, {}, }; MODULE_DEVICE_TABLE(of, brcmstb_i2c_of_match);