[RFC/RFT PATCH 1/4] drm/bridge: dw-hdmi: Switch to regmap for register access
Neil Armstrong
narmstrong at baylibre.com
Fri Jan 20 07:12:36 PST 2017
On 01/17/2017 03:39 PM, Laurent Pinchart wrote:
> Hi Neil,
>
> Thank you for the patch.
>
> On Tuesday 17 Jan 2017 13:31:31 Neil Armstrong wrote:
>> The Synopsys Designware HDMI TX Controller does not enforce register access
>> on platforms instanciating it.
>> The current driver supports two different types of memory-mapped flat
>> register access, but in order to support the Amlogic Meson SoCs integration,
>> and provide a more generic way to handle all sorts of register mapping,
>> switch the register access to use the regmap infrastructure.
>>
>> In the case of the registers are not flat memory-mapped or does not conform
>
> s/does/do/
>
>> at the actual driver implementation, a regmap struct can be given in the
>
> s/at the actual/to the current/ ?
>
>> plat_data and be used at probe or bind.
>>
>> Since the AHB audio driver only uses direct memory access, using regmap only
>> allows the I2S audio driver to be registered.
>
> This sounds a bit unclear to me, how about "[...], only allow the I2C audio
> driver to be registered if the device is directly memory-mapped." ?
>
>> Signed-off-by: Neil Armstrong <narmstrong at baylibre.com>
>> ---
>> drivers/gpu/drm/bridge/dw-hdmi.c | 105 +++++++++++++++++++-----------------
>> include/drm/bridge/dw_hdmi.h | 1 +
>> 2 files changed, 57 insertions(+), 49 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/bridge/dw-hdmi.c
>> b/drivers/gpu/drm/bridge/dw-hdmi.c index ca9d0ce..13747fe 100644
>> --- a/drivers/gpu/drm/bridge/dw-hdmi.c
>> +++ b/drivers/gpu/drm/bridge/dw-hdmi.c
>> @@ -20,6 +20,7 @@
>> #include <linux/mutex.h>
>> #include <linux/of_device.h>
>> #include <linux/spinlock.h>
>> +#include <linux/regmap.h>
>
> Could you please keep the headers alphabetically sorted ?
>
>> #include <drm/drm_of.h>
>> #include <drm/drmP.h>
>> @@ -167,8 +168,7 @@ struct dw_hdmi {
>> unsigned int audio_n;
>> bool audio_enable;
>>
>> - void (*write)(struct dw_hdmi *hdmi, u8 val, int offset);
>> - u8 (*read)(struct dw_hdmi *hdmi, int offset);
>> + struct regmap *regm;
>> };
>>
>> #define HDMI_IH_PHY_STAT0_RX_SENSE \
>> @@ -179,42 +179,23 @@ struct dw_hdmi {
>> (HDMI_PHY_RX_SENSE0 | HDMI_PHY_RX_SENSE1 | \
>> HDMI_PHY_RX_SENSE2 | HDMI_PHY_RX_SENSE3)
>>
>> -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 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)
>
> Not related to this patch, but the value, offset order of arguments to the
> write function has been making me cringe since the very first time I read the
> code. I wonder if modifying this would be accepted.
>
>> {
>> - hdmi->write(hdmi, val, offset);
>> + regmap_write(hdmi->regm, offset, val);
>> }
>>
>> static inline u8 hdmi_readb(struct dw_hdmi *hdmi, int offset)
>> {
>> - return hdmi->read(hdmi, offset);
>> + unsigned int val = 0;
>> +
>> + regmap_read(hdmi->regm, offset, &val);
>> +
>> + return val;
>> }
>>
>> static void hdmi_modb(struct dw_hdmi *hdmi, u8 data, u8 mask, unsigned reg)
>> {
>> - u8 val = hdmi_readb(hdmi, reg) & ~mask;
>> -
>> - val |= data & mask;
>> - hdmi_writeb(hdmi, val, reg);
>> + regmap_update_bits(hdmi->regm, reg, mask, data);
>> }
>>
>> static void hdmi_mask_writeb(struct dw_hdmi *hdmi, u8 data, unsigned int
>> reg, @@ -1949,6 +1930,21 @@ static int dw_hdmi_detect_phy(struct dw_hdmi
>> *hdmi) return 0;
>> }
>>
>> +static struct regmap_config hdmi_regmap_8bit_config = {
>> + .reg_bits = 32,
>> + .val_bits = 8,
>> + .reg_stride = 1,
>> + .max_register = HDMI_I2CM_FS_SCL_LCNT_0_ADDR,
>> +};
>> +
>> +static struct regmap_config hdmi_regmap_32bit_config = {
>> + .reg_bits = 8,
>> + .pad_bits = 24,
>> + .val_bits = 32,
>> + .reg_stride = 4,
>> + .max_register = HDMI_I2CM_FS_SCL_LCNT_0_ADDR,
>> +};
>
> I believe you can make these const.
>
>> static struct dw_hdmi *
>> __dw_hdmi_probe(struct platform_device *pdev,
>> const struct dw_hdmi_plat_data *plat_data)
>> @@ -1958,7 +1954,8 @@ static int dw_hdmi_detect_phy(struct dw_hdmi *hdmi)
>> struct platform_device_info pdevinfo;
>> struct device_node *ddc_node;
>> struct dw_hdmi *hdmi;
>> - struct resource *iores;
>> + struct regmap_config *reg_config = &hdmi_regmap_8bit_config;
>
> No need to assign a value at declaration time (unless the compiler is not
> smart enough and complains, or is smarter than me and finds a problem where I
> don't).
>
>> + struct resource *iores = NULL;
>> int irq;
>> int ret;
>> u32 val = 1;
>> @@ -1982,20 +1979,21 @@ static int dw_hdmi_detect_phy(struct dw_hdmi *hdmi)
>> mutex_init(&hdmi->audio_mutex);
>> spin_lock_init(&hdmi->audio_lock);
>>
>> - 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 ERR_PTR(-EINVAL);
>> + if (plat_data->regm)
>> + hdmi->regm = plat_data->regm;
>
> You need curly braces around this statement.
>
>> + else {
>> + of_property_read_u32(np, "reg-io-width", &val);
>> + switch (val) {
>> + case 4:
>> + reg_config = &hdmi_regmap_32bit_config;
>> + break;
>> + case 1:
>> + reg_config = &hdmi_regmap_8bit_config;
>> + break;
>> + default:
>> + dev_err(dev, "reg-io-width must be 1 or 4\n");
>> + return ERR_PTR(-EINVAL);
>> + }
>> }
>>
>> ddc_node = of_parse_phandle(np, "ddc-i2c-bus", 0);
>> @@ -2011,11 +2009,20 @@ static int dw_hdmi_detect_phy(struct dw_hdmi *hdmi)
>> dev_dbg(hdmi->dev, "no ddc property found\n");
>> }
>>
>> - iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> - hdmi->regs = devm_ioremap_resource(dev, iores);
>> - if (IS_ERR(hdmi->regs)) {
>> - ret = PTR_ERR(hdmi->regs);
>> - goto err_res;
>> + if (!plat_data->regm) {
>> + iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
>> + hdmi->regs = devm_ioremap_resource(dev, iores);
>> + if (IS_ERR(hdmi->regs)) {
>> + ret = PTR_ERR(hdmi->regs);
>> + goto err_res;
>> + }
>> +
>> + hdmi->regm = devm_regmap_init_mmio(dev, hdmi->regs,
> reg_config);
>> + if (IS_ERR(hdmi->regm)) {
>> + dev_err(dev, "Failed to configure regmap\n");
>> + ret = PTR_ERR(hdmi->regm);
>> + goto err_res;
>> + }
>> }
>>
>> hdmi->isfr_clk = devm_clk_get(hdmi->dev, "isfr");
>> @@ -2123,7 +2130,7 @@ static int dw_hdmi_detect_phy(struct dw_hdmi *hdmi)
>> config0 = hdmi_readb(hdmi, HDMI_CONFIG0_ID);
>> config3 = hdmi_readb(hdmi, HDMI_CONFIG3_ID);
>>
>> - if (config3 & HDMI_CONFIG3_AHBAUDDMA) {
>> + if (iores && config3 & HDMI_CONFIG3_AHBAUDDMA) {
>
> You test !plat->regm above, and iores here. How about standardizing that ? If
> you test for !plat->regm here, you won't have to initialize iores to NULL.
>
> Apart from these small issues the patch looks good to me.
>
>> struct dw_hdmi_audio_data audio;
>>
>> audio.phys = iores->start;
>> diff --git a/include/drm/bridge/dw_hdmi.h b/include/drm/bridge/dw_hdmi.h
>> index 735a8ab..163842d 100644
>> --- a/include/drm/bridge/dw_hdmi.h
>> +++ b/include/drm/bridge/dw_hdmi.h
>> @@ -60,6 +60,7 @@ struct dw_hdmi_plat_data {
>> unsigned long mpixelclock);
>> enum drm_mode_status (*mode_valid)(struct drm_connector *connector,
>> struct drm_display_mode *mode);
>> + struct regmap *regm;
>> };
>>
>> int dw_hdmi_probe(struct platform_device *pdev,
>
Hi All,
The actual 4bytes regmap config actually fails on rk3288 because regmap bypasses
all modification of the reg address because of the regmap_mmio implementation.
The only remaining way is to keep a reg_shift in in the hdmi context, see the
patch below.
With such change, on rk3288 :
Tested-by: Neil Armstrong <narmstrong at baylibre.com>
"
[ 10.400294] dwhdmi-rockchip ff980000.hdmi: Detected HDMI TX controller v2.00a with HDCP (DWC MHL PHY)
"
Neil
-><------------------
diff --git a/drivers/gpu/drm/bridge/dw-hdmi.c b/drivers/gpu/drm/bridge/dw-hdmi.c
index 8b35df5..563647f 100644
--- a/drivers/gpu/drm/bridge/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/dw-hdmi.c
@@ -168,6 +168,7 @@ struct dw_hdmi {
unsigned int audio_n;
bool audio_enable;
+ unsigned int reg_shift;
struct regmap *regm;
};
@@ -181,21 +182,21 @@ struct dw_hdmi {
static inline void hdmi_writeb(struct dw_hdmi *hdmi, u8 val, int offset)
{
- regmap_write(hdmi->regm, offset, val);
+ regmap_write(hdmi->regm, offset << hdmi->reg_shift, val);
}
static inline u8 hdmi_readb(struct dw_hdmi *hdmi, int offset)
{
unsigned int val = 0;
- regmap_read(hdmi->regm, offset, &val);
+ regmap_read(hdmi->regm, offset << hdmi->reg_shift, &val);
return val;
}
static void hdmi_modb(struct dw_hdmi *hdmi, u8 data, u8 mask, unsigned reg)
{
- regmap_update_bits(hdmi->regm, reg, mask, data);
+ regmap_update_bits(hdmi->regm, reg << hdmi->reg_shift, mask, data);
}
static void hdmi_mask_writeb(struct dw_hdmi *hdmi, u8 data, unsigned int reg,
@@ -1984,11 +1985,10 @@ static const struct regmap_config hdmi_regmap_8bit_config = {
};
static const struct regmap_config hdmi_regmap_32bit_config = {
- .reg_bits = 8,
- .pad_bits = 24,
+ .reg_bits = 32,
.val_bits = 32,
.reg_stride = 4,
- .max_register = HDMI_I2CM_FS_SCL_LCNT_0_ADDR,
+ .max_register = HDMI_I2CM_FS_SCL_LCNT_0_ADDR << 2,
};
static struct dw_hdmi *
@@ -2044,6 +2044,7 @@ __dw_hdmi_probe(struct platform_device *pdev,
switch (val) {
case 4:
reg_config = &hdmi_regmap_32bit_config;
+ hdmi->reg_shift = 2;
break;
case 1:
reg_config = &hdmi_regmap_8bit_config;
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