100 lines
2.6 KiB
C
100 lines
2.6 KiB
C
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// 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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#include <linux/delay.h>
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#include <linux/pci.h>
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#include <drm/drm_atomic_helper.h>
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#include <drm/drm_probe_helper.h>
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#include "hibmc_drm_drv.h"
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#define GPIO_DATA 0x0802A0
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#define GPIO_DATA_DIRECTION 0x0802A4
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#define I2C_SCL_MASK BIT(0)
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#define I2C_SDA_MASK BIT(1)
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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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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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tmp_data &= ~mask;
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writel(tmp_data, priv->mmio + GPIO_DATA);
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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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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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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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return (readl(priv->mmio + GPIO_DATA) & mask) ? 1 : 0;
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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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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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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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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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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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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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return i2c_bit_add_bus(&connector->adapter);
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}
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