Hi Zabel: On 2014年11月27日 00:34, Philipp Zabel wrote:
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.yan@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.
Is there any disadvantage to do like this? The compiler can help us do the explicitly multiply by this way.
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