Am Mittwoch, den 26.11.2014, 21:32 +0800 schrieb Andy Yan:
> 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....@rock-chips.com>
>
> ---
>
> Changes in v13: None
> Changes in v12: None
> Changes in v11: None
> Changes in v10: None
> Changes in v9: None
> Changes in v8: None
> Changes in v7: None
> Changes in v6:
> - 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
>
> 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 a53bf63..5e88c8d 100644
> --- a/drivers/gpu/drm/bridge/dw_hdmi.c
> +++ b/drivers/gpu/drm/bridge/dw_hdmi.c
> @@ -100,6 +100,11 @@ struct hdmi_data_info {
> struct hdmi_vmode video_mode;
> };
>
> +union dw_reg_ptr {
> + u32 __iomem *p32;
> + u8 __iomem *p8;
> +};
I see no need to introduce this. Just explicitly multiply the offset in
dw_hdmi_writel.
> 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;
Keep this as void __iomem *
> 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);
hdmi->regs + 4 * offset
> +}
> +
> +static u8 dw_hdmi_readl(struct dw_hdmi *hdmi, int offset)
> +{
> + return readl(hdmi->regs.p32 + offset);
same here
> +}
> +
> +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)
> @@ -1508,6 +1536,7 @@ int dw_hdmi_bind(struct device *dev, struct device
> *master,
> struct dw_hdmi *hdmi;
> struct resource *iores;
> int ret, irq;
> + u32 val = 1;
>
> hdmi = devm_kzalloc(&pdev->dev, sizeof(*hdmi), GFP_KERNEL);
> if (!hdmi)
> @@ -1520,6 +1549,22 @@ 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);
> @@ -1544,9 +1589,9 @@ int dw_hdmi_bind(struct device *dev, struct device
> *master,
> 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);
>
> /* Product and revision IDs */
> dev_info(dev,
regards
Philipp
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