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1// SPDX-License-Identifier: GPL-2.0-or-later2/* Hisilicon Hibmc SoC drm driver3 *4 * Based on the bochs drm driver.5 *6 * Copyright (c) 2016 Huawei Limited.7 *8 * Author:9 * Tian Tao <tiantao6@hisilicon.com>10 */11 12#include <linux/delay.h>13#include <linux/pci.h>14 15#include <drm/drm_atomic_helper.h>16#include <drm/drm_probe_helper.h>17 18#include "hibmc_drm_drv.h"19 20#define GPIO_DATA 0x0802A021#define GPIO_DATA_DIRECTION 0x0802A422 23#define I2C_SCL_MASK BIT(0)24#define I2C_SDA_MASK BIT(1)25 26static void hibmc_set_i2c_signal(void *data, u32 mask, int value)27{28 struct hibmc_connector *hibmc_connector = data;29 struct hibmc_drm_private *priv = to_hibmc_drm_private(hibmc_connector->base.dev);30 u32 tmp_dir = readl(priv->mmio + GPIO_DATA_DIRECTION);31 32 if (value) {33 tmp_dir &= ~mask;34 writel(tmp_dir, priv->mmio + GPIO_DATA_DIRECTION);35 } else {36 u32 tmp_data = readl(priv->mmio + GPIO_DATA);37 38 tmp_data &= ~mask;39 writel(tmp_data, priv->mmio + GPIO_DATA);40 41 tmp_dir |= mask;42 writel(tmp_dir, priv->mmio + GPIO_DATA_DIRECTION);43 }44}45 46static int hibmc_get_i2c_signal(void *data, u32 mask)47{48 struct hibmc_connector *hibmc_connector = data;49 struct hibmc_drm_private *priv = to_hibmc_drm_private(hibmc_connector->base.dev);50 u32 tmp_dir = readl(priv->mmio + GPIO_DATA_DIRECTION);51 52 if ((tmp_dir & mask) != mask) {53 tmp_dir &= ~mask;54 writel(tmp_dir, priv->mmio + GPIO_DATA_DIRECTION);55 }56 57 return (readl(priv->mmio + GPIO_DATA) & mask) ? 1 : 0;58}59 60static void hibmc_ddc_setsda(void *data, int state)61{62 hibmc_set_i2c_signal(data, I2C_SDA_MASK, state);63}64 65static void hibmc_ddc_setscl(void *data, int state)66{67 hibmc_set_i2c_signal(data, I2C_SCL_MASK, state);68}69 70static int hibmc_ddc_getsda(void *data)71{72 return hibmc_get_i2c_signal(data, I2C_SDA_MASK);73}74 75static int hibmc_ddc_getscl(void *data)76{77 return hibmc_get_i2c_signal(data, I2C_SCL_MASK);78}79 80int hibmc_ddc_create(struct drm_device *drm_dev,81 struct hibmc_connector *connector)82{83 connector->adapter.owner = THIS_MODULE;84 snprintf(connector->adapter.name, I2C_NAME_SIZE, "HIS i2c bit bus");85 connector->adapter.dev.parent = drm_dev->dev;86 i2c_set_adapdata(&connector->adapter, connector);87 connector->adapter.algo_data = &connector->bit_data;88 89 connector->bit_data.udelay = 20;90 connector->bit_data.timeout = usecs_to_jiffies(2000);91 connector->bit_data.data = connector;92 connector->bit_data.setsda = hibmc_ddc_setsda;93 connector->bit_data.setscl = hibmc_ddc_setscl;94 connector->bit_data.getsda = hibmc_ddc_getsda;95 connector->bit_data.getscl = hibmc_ddc_getscl;96 97 return i2c_bit_add_bus(&connector->adapter);98}99