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: Andy Yan andy.yan@rock-chips.com
---
Changes in v10: None Changes in v9: None Changes in v8: None Changes in v7: None Changes in v6: - move some modification to patch#6 - refactor register access without reg_shift
Changes in v5: - refactor reg-io-width
Changes in v4: None Changes in v3: - split multi register access to one indepent patch
Changes in v2: None
drivers/gpu/drm/bridge/dw_hdmi.c | 57 +++++++++++++++++++++++++++++++++++----- 1 file changed, 51 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/bridge/dw_hdmi.c b/drivers/gpu/drm/bridge/dw_hdmi.c index 4f9a5c0..d7bf46d 100644 --- a/drivers/gpu/drm/bridge/dw_hdmi.c +++ b/drivers/gpu/drm/bridge/dw_hdmi.c @@ -101,6 +101,11 @@ struct hdmi_data_info { struct hdmi_vmode video_mode; };
+union dw_reg_ptr { + u32 __iomem *p32; + u8 __iomem *p8; +}; + struct dw_hdmi { struct drm_connector connector; struct drm_encoder encoder; @@ -121,20 +126,43 @@ struct dw_hdmi {
struct regmap *regmap; struct i2c_adapter *ddc; - void __iomem *regs; + union dw_reg_ptr regs;
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 void dw_hdmi_writel(struct dw_hdmi *hdmi, u8 val, int offset) +{ + writel(val, hdmi->regs.p32 + offset); +} + +static u8 dw_hdmi_readl(struct dw_hdmi *hdmi, int offset) +{ + return readl(hdmi->regs.p32 + offset); +} + +static void dw_hdmi_writeb(struct dw_hdmi *hdmi, u8 val, int offset) +{ + writeb(val, hdmi->regs.p8 + offset); +} + +static u8 dw_hdmi_readb(struct dw_hdmi *hdmi, int offset) +{ + return readb(hdmi->regs.p8 + offset); +} + static inline void hdmi_writeb(struct dw_hdmi *hdmi, u8 val, int offset) { - writeb(val, hdmi->regs + offset); + hdmi->write(hdmi, val, offset); }
static inline u8 hdmi_readb(struct dw_hdmi *hdmi, int offset) { - return readb(hdmi->regs + offset); + return hdmi->read(hdmi, offset); }
static void hdmi_modb(struct dw_hdmi *hdmi, u8 data, u8 mask, unsigned reg) @@ -1528,6 +1556,23 @@ static int dw_hdmi_bind(struct device *dev, struct device *master, void *data) struct device_node *ddc_node; struct resource *iores; int ret, irq; + u32 val = 1; + + 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) { @@ -1554,9 +1599,9 @@ static int dw_hdmi_bind(struct device *dev, struct device *master, void *data) return ret;
iores = platform_get_resource(pdev, IORESOURCE_MEM, 0); - hdmi->regs = devm_ioremap_resource(dev, iores); - if (IS_ERR(hdmi->regs)) - return PTR_ERR(hdmi->regs); + hdmi->regs.p32 = devm_ioremap_resource(dev, iores); + if (IS_ERR(hdmi->regs.p32)) + return PTR_ERR(hdmi->regs.p32);
if (hdmi->plat_data->setup) hdmi->priv = hdmi->plat_data->setup(pdev);