Re: [PATCH drm/hisilicon 1/3] drm/hisilicon: Support i2c driver algorithms for bit-shift adapters

[Thomas Zimmermann]

Hi

Am 21.09.20 um 05:25 schrieb Tian Tao:
> Adding driver implementation to support i2c driver algorithms for
> bit-shift adapters, so hibmc will using the interface provided by
> drm to read edid.
> 
> Signed-off-by: Tian Tao <tiantao6@xxxxxxxxxxxxx>
> ---
>  drivers/gpu/drm/hisilicon/hibmc/Makefile        |  2 +-
>  drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h | 21 +++++-
>  drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_i2c.c | 98 +++++++++++++++++++++++++
>  3 files changed, 119 insertions(+), 2 deletions(-)
>  create mode 100644 drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_i2c.c
> 
> diff --git a/drivers/gpu/drm/hisilicon/hibmc/Makefile b/drivers/gpu/drm/hisilicon/hibmc/Makefile
> index f991327..684ef79 100644
> --- a/drivers/gpu/drm/hisilicon/hibmc/Makefile
> +++ b/drivers/gpu/drm/hisilicon/hibmc/Makefile
> @@ -1,4 +1,4 @@
>  # SPDX-License-Identifier: GPL-2.0-only
> -hibmc-drm-y := hibmc_drm_drv.o hibmc_drm_de.o hibmc_drm_vdac.o hibmc_ttm.o
> +hibmc-drm-y := hibmc_drm_drv.o hibmc_drm_de.o hibmc_drm_vdac.o hibmc_ttm.o hibmc_drm_i2c.o
>  
>  obj-$(CONFIG_DRM_HISI_HIBMC) += hibmc-drm.o
> diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h
> index 197485e..1b2edb3 100644
> --- a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h
> +++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_drv.h
> @@ -14,11 +14,24 @@
>  #ifndef HIBMC_DRM_DRV_H
>  #define HIBMC_DRM_DRV_H
>  
> +#include <linux/gpio/consumer.h>
> +#include <linux/i2c-algo-bit.h>
> +#include <linux/i2c.h>
> +
> +#include <drm/drm_edid.h>
>  #include <drm/drm_fb_helper.h>
>  #include <drm/drm_framebuffer.h>
>  
>  struct drm_device;
>  
> +struct hibmc_connector {
> +	struct drm_connector base;
> +	struct drm_device  *dev;

dev is not required. There's already a dev field under base.

> +
> +	struct i2c_adapter adapter;
> +	struct i2c_algo_bit_data bit_data;
> +};
> +
>  struct hibmc_drm_private {
>  	/* hw */
>  	void __iomem   *mmio;
> @@ -31,10 +44,15 @@ struct hibmc_drm_private {
>  	struct drm_plane primary_plane;
>  	struct drm_crtc crtc;
>  	struct drm_encoder encoder;
> -	struct drm_connector connector;
> +	struct hibmc_connector connector;
>  	bool mode_config_initialized;
>  };
>  
> +static inline struct hibmc_connector *to_hibmc_connector(struct drm_connector *connector)
> +{
> +	return container_of(connector, struct hibmc_connector, base);
> +}
> +
>  void hibmc_set_power_mode(struct hibmc_drm_private *priv,
>  			  unsigned int power_mode);
>  void hibmc_set_current_gate(struct hibmc_drm_private *priv,
> @@ -47,6 +65,7 @@ int hibmc_mm_init(struct hibmc_drm_private *hibmc);
>  void hibmc_mm_fini(struct hibmc_drm_private *hibmc);
>  int hibmc_dumb_create(struct drm_file *file, struct drm_device *dev,
>  		      struct drm_mode_create_dumb *args);
> +int hibmc_ddc_create(struct hibmc_connector *connector);
>  
>  extern const struct drm_mode_config_funcs hibmc_mode_funcs;
>  
> diff --git a/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_i2c.c b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_i2c.c
> new file mode 100644
> index 0000000..0506846
> --- /dev/null
> +++ b/drivers/gpu/drm/hisilicon/hibmc/hibmc_drm_i2c.c
> @@ -0,0 +1,98 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/* Hisilicon Hibmc SoC drm driver
> + *
> + * Based on the bochs drm driver.
> + *
> + * Copyright (c) 2016 Huawei Limited.
> + *
> + * Author:
> + *      Tian Tao <tiantao6@xxxxxxxxxxxxx>
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/pci.h>
> +
> +#include <drm/drm_atomic_helper.h>
> +#include <drm/drm_probe_helper.h>
> +
> +#include "hibmc_drm_drv.h"
> +
> +#define GPIO_DATA		0x0802A0
> +#define GPIO_DATA_DIRECTION	0x0802A4
> +
> +#define GPIO_SCL_MASK 0x1
> +#define GPIO_SDA_MASK  0x2

Weird indention.

> +
> +static void hibmc_set_i2c_signal(void *data, u32 mask, int value)
> +{
> +	struct hibmc_connector *hibmc_connector = data;
> +	struct hibmc_drm_private *priv = hibmc_connector->dev->dev_private;

Oh, hibmc is still using dev_private. dev_private is on it's way out.

The least thing to do is to make little function that wraps the
conversion from struct drm_device to hibmc_drm_private. And then convert
over all uses of dev_private over to the function. That's for another
patchset.


That's all just nits, so

Reviewed-by: Thomas Zimmermann <tzimmermann@xxxxxxx>

Best regards
Thomas

> +	u32 tmp_dir = readl(priv->mmio + GPIO_DATA_DIRECTION);
> +
> +	if (value) {
> +		tmp_dir &= ~mask;
> +		writel(tmp_dir, priv->mmio + GPIO_DATA_DIRECTION);
> +	} else {
> +		u32 tmp_data = readl(priv->mmio + GPIO_DATA);
> +
> +		tmp_data &= ~mask;
> +		writel(tmp_data, priv->mmio + GPIO_DATA);
> +
> +		tmp_dir |= mask;
> +		writel(tmp_dir, priv->mmio + GPIO_DATA_DIRECTION);
> +	}
> +}
> +
> +static int hibmc_get_i2c_signal(void *data, u32 mask)
> +{
> +	struct hibmc_connector *hibmc_connector = data;
> +	struct hibmc_drm_private *priv = hibmc_connector->dev->dev_private;
> +	u32 tmp_dir = readl(priv->mmio + GPIO_DATA_DIRECTION);
> +
> +	if ((tmp_dir & mask) != mask) {
> +		tmp_dir &= ~mask;
> +		writel(tmp_dir, priv->mmio + GPIO_DATA_DIRECTION);
> +	}
> +
> +	return (readl(priv->mmio + GPIO_DATA) & mask) ? 1 : 0;
> +}
> +
> +static void hibmc_ddc_setsda(void *data, int state)
> +{
> +	hibmc_set_i2c_signal(data, GPIO_SDA_MASK, state);
> +}
> +
> +static void hibmc_ddc_setscl(void *data, int state)
> +{
> +	hibmc_set_i2c_signal(data, GPIO_SCL_MASK, state);
> +}
> +
> +static int hibmc_ddc_getsda(void *data)
> +{
> +	return hibmc_get_i2c_signal(data, GPIO_SDA_MASK);
> +}
> +
> +static int hibmc_ddc_getscl(void *data)
> +{
> +	return hibmc_get_i2c_signal(data, GPIO_SCL_MASK);
> +}
> +
> +int hibmc_ddc_create(struct hibmc_connector *connector)
> +{
> +	connector->adapter.owner = THIS_MODULE;
> +	connector->adapter.class = I2C_CLASS_DDC;
> +	snprintf(connector->adapter.name, I2C_NAME_SIZE, "HIS i2c bit bus");
> +	connector->adapter.dev.parent = &connector->dev->pdev->dev;
> +	i2c_set_adapdata(&connector->adapter, connector);
> +	connector->adapter.algo_data = &connector->bit_data;
> +
> +	connector->bit_data.udelay = 20;
> +	connector->bit_data.timeout = usecs_to_jiffies(2000);
> +	connector->bit_data.data = connector;
> +	connector->bit_data.setsda = hibmc_ddc_setsda;
> +	connector->bit_data.setscl = hibmc_ddc_setscl;
> +	connector->bit_data.getsda = hibmc_ddc_getsda;
> +	connector->bit_data.getscl = hibmc_ddc_getscl;
> +
> +	return i2c_bit_add_bus(&connector->adapter);
> +}
> 

-- 
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Maxfeldstr. 5, 90409 Nürnberg, Germany
(HRB 36809, AG Nürnberg)
Geschäftsführer: Felix Imendörffer

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