100 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			100 lines
		
	
	
		
			2.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| // SPDX-License-Identifier: GPL-2.0-or-later
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| /* Hisilicon Hibmc SoC drm driver
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|  *
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|  * Based on the bochs drm driver.
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|  *
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|  * Copyright (c) 2016 Huawei Limited.
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|  *
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|  * Author:
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|  *      Tian Tao <tiantao6@hisilicon.com>
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|  */
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| 
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| #include <linux/delay.h>
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| #include <linux/pci.h>
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| 
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| #include <drm/drm_atomic_helper.h>
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| #include <drm/drm_probe_helper.h>
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| 
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| #include "hibmc_drm_drv.h"
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| 
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| #define GPIO_DATA		0x0802A0
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| #define GPIO_DATA_DIRECTION	0x0802A4
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| 
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| #define I2C_SCL_MASK		BIT(0)
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| #define I2C_SDA_MASK		BIT(1)
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| 
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| static void hibmc_set_i2c_signal(void *data, u32 mask, int value)
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| {
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| 	struct hibmc_connector *hibmc_connector = data;
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| 	struct hibmc_drm_private *priv = to_hibmc_drm_private(hibmc_connector->base.dev);
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| 	u32 tmp_dir = readl(priv->mmio + GPIO_DATA_DIRECTION);
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| 
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| 	if (value) {
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| 		tmp_dir &= ~mask;
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| 		writel(tmp_dir, priv->mmio + GPIO_DATA_DIRECTION);
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| 	} else {
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| 		u32 tmp_data = readl(priv->mmio + GPIO_DATA);
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| 
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| 		tmp_data &= ~mask;
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| 		writel(tmp_data, priv->mmio + GPIO_DATA);
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| 
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| 		tmp_dir |= mask;
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| 		writel(tmp_dir, priv->mmio + GPIO_DATA_DIRECTION);
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| 	}
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| }
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| 
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| static int hibmc_get_i2c_signal(void *data, u32 mask)
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| {
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| 	struct hibmc_connector *hibmc_connector = data;
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| 	struct hibmc_drm_private *priv = to_hibmc_drm_private(hibmc_connector->base.dev);
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| 	u32 tmp_dir = readl(priv->mmio + GPIO_DATA_DIRECTION);
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| 
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| 	if ((tmp_dir & mask) != mask) {
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| 		tmp_dir &= ~mask;
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| 		writel(tmp_dir, priv->mmio + GPIO_DATA_DIRECTION);
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| 	}
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| 
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| 	return (readl(priv->mmio + GPIO_DATA) & mask) ? 1 : 0;
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| }
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| 
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| static void hibmc_ddc_setsda(void *data, int state)
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| {
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| 	hibmc_set_i2c_signal(data, I2C_SDA_MASK, state);
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| }
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| 
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| static void hibmc_ddc_setscl(void *data, int state)
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| {
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| 	hibmc_set_i2c_signal(data, I2C_SCL_MASK, state);
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| }
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| 
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| static int hibmc_ddc_getsda(void *data)
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| {
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| 	return hibmc_get_i2c_signal(data, I2C_SDA_MASK);
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| }
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| 
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| static int hibmc_ddc_getscl(void *data)
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| {
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| 	return hibmc_get_i2c_signal(data, I2C_SCL_MASK);
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| }
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| 
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| int hibmc_ddc_create(struct drm_device *drm_dev,
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| 		     struct hibmc_connector *connector)
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| {
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| 	connector->adapter.owner = THIS_MODULE;
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| 	connector->adapter.class = I2C_CLASS_DDC;
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| 	snprintf(connector->adapter.name, I2C_NAME_SIZE, "HIS i2c bit bus");
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| 	connector->adapter.dev.parent = drm_dev->dev;
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| 	i2c_set_adapdata(&connector->adapter, connector);
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| 	connector->adapter.algo_data = &connector->bit_data;
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| 
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| 	connector->bit_data.udelay = 20;
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| 	connector->bit_data.timeout = usecs_to_jiffies(2000);
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| 	connector->bit_data.data = connector;
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| 	connector->bit_data.setsda = hibmc_ddc_setsda;
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| 	connector->bit_data.setscl = hibmc_ddc_setscl;
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| 	connector->bit_data.getsda = hibmc_ddc_getsda;
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| 	connector->bit_data.getscl = hibmc_ddc_getscl;
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| 
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| 	return i2c_bit_add_bus(&connector->adapter);
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| }
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