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Commit 0cd9d142 authored by Andy Yan's avatar Andy Yan Committed by Philipp Zabel
Browse files

drm: bridge/dw_hdmi: add support for multi-byte register width access 



On rockchip rk3288, only word(32-bit) accesses are
permitted for hdmi registers.  Byte width accesses (writeb,
readb) generate an imprecise external abort.

Signed-off-by: default avatarAndy Yan <andy.yan@rock-chips.com>
Tested-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
Acked-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: default avatarPhilipp Zabel <p.zabel@pengutronix.de>
parent cd152393

drivers/gpu/drm/bridge/dw_hdmi.c

+42 −2
Original line number Diff line number Diff line
@@ -128,18 +128,41 @@ struct dw_hdmi { 


	unsigned int sample_rate;

	int ratio;



	void (*write)(struct dw_hdmi *hdmi, u8 val, int offset);

	u8 (*read)(struct dw_hdmi *hdmi, int offset);

};



static inline void hdmi_writeb(struct dw_hdmi *hdmi, u8 val, int offset)

static void dw_hdmi_writel(struct dw_hdmi *hdmi, u8 val, int offset)

{

	writel(val, hdmi->regs + (offset << 2));

}



static u8 dw_hdmi_readl(struct dw_hdmi *hdmi, int offset)

{

	return readl(hdmi->regs + (offset << 2));

}



static void dw_hdmi_writeb(struct dw_hdmi *hdmi, u8 val, int offset)

{

	writeb(val, hdmi->regs + offset);

}



static inline u8 hdmi_readb(struct dw_hdmi *hdmi, int offset)

static u8 dw_hdmi_readb(struct dw_hdmi *hdmi, int offset)

{

	return readb(hdmi->regs + offset);

}



static inline void hdmi_writeb(struct dw_hdmi *hdmi, u8 val, int offset)

{

	hdmi->write(hdmi, val, offset);

}



static inline u8 hdmi_readb(struct dw_hdmi *hdmi, int offset)

{

	return hdmi->read(hdmi, offset);

}



static void hdmi_modb(struct dw_hdmi *hdmi, u8 data, u8 mask, unsigned reg)

{

	u8 val = hdmi_readb(hdmi, reg) & ~mask;
@@ -1511,6 +1534,7 @@ int dw_hdmi_bind(struct device *dev, struct device *master, 
	struct device_node *ddc_node;

	struct dw_hdmi *hdmi;

	int ret;

	u32 val = 1;



	hdmi = devm_kzalloc(dev, sizeof(*hdmi), GFP_KERNEL);

	if (!hdmi)
@@ -1523,6 +1547,22 @@ int dw_hdmi_bind(struct device *dev, struct device *master, 
	hdmi->ratio = 100;

	hdmi->encoder = encoder;



	of_property_read_u32(np, "reg-io-width", &val);



	switch (val) {

	case 4:

		hdmi->write = dw_hdmi_writel;

		hdmi->read = dw_hdmi_readl;

		break;

	case 1:

		hdmi->write = dw_hdmi_writeb;

		hdmi->read = dw_hdmi_readb;

		break;

	default:

		dev_err(dev, "reg-io-width must be 1 or 4\n");

		return -EINVAL;

	}



	ddc_node = of_parse_phandle(np, "ddc-i2c-bus", 0);

	if (ddc_node) {

		hdmi->ddc = of_find_i2c_adapter_by_node(ddc_node);