170 lines · c
1/*2 * Copyright (c) 2002-2010, Intel Corporation.3 * Copyright (c) 2014 ATRON electronic GmbH4 * Author: Jan Safrata <jan.nikitenko@gmail.com>5 *6 * Permission is hereby granted, free of charge, to any person obtaining a copy7 * of this software and associated documentation files (the "Software"), to deal8 * in the Software without restriction, including without limitation the rights9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell10 * copies of the Software, and to permit persons to whom the Software is11 * furnished to do so, subject to the following conditions:12 *13 * The above copyright notice and this permission notice shall be included in14 * all copies or substantial portions of the Software.15 *16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE19 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN22 * THE SOFTWARE.23 *24 */25 26#include <linux/delay.h>27#include <linux/i2c-algo-bit.h>28#include <linux/i2c.h>29#include <linux/init.h>30#include <linux/io.h>31#include <linux/kernel.h>32#include <linux/module.h>33#include <linux/pci.h>34#include <linux/types.h>35 36#include "psb_drv.h"37#include "psb_intel_reg.h"38 39 40/*41 * LPC GPIO based I2C bus for LVDS of Atom E6xx42 */43 44/*-----------------------------------------------------------------------------45 * LPC Register Offsets. Used for LVDS GPIO Bit Bashing. Registers are part46 * Atom E6xx [D31:F0]47 ----------------------------------------------------------------------------*/48#define RGEN 0x2049#define RGIO 0x2450#define RGLVL 0x2851#define RGTPE 0x2C52#define RGTNE 0x3053#define RGGPE 0x3454#define RGSMI 0x3855#define RGTS 0x3C56 57/* The LVDS GPIO clock lines are GPIOSUS[3]58 * The LVDS GPIO data lines are GPIOSUS[4]59 */60#define GPIO_CLOCK 0x0861#define GPIO_DATA 0x1062 63#define LPC_READ_REG(chan, r) inl((chan)->reg + (r))64#define LPC_WRITE_REG(chan, r, val) outl((val), (chan)->reg + (r))65 66static int get_clock(void *data)67{68 struct gma_i2c_chan *chan = data;69 u32 val;70 71 val = LPC_READ_REG(chan, RGIO);72 val |= GPIO_CLOCK;73 LPC_WRITE_REG(chan, RGIO, val);74 LPC_READ_REG(chan, RGLVL);75 val = (LPC_READ_REG(chan, RGLVL) & GPIO_CLOCK) ? 1 : 0;76 77 return val;78}79 80static int get_data(void *data)81{82 struct gma_i2c_chan *chan = data;83 u32 val;84 85 val = LPC_READ_REG(chan, RGIO);86 val |= GPIO_DATA;87 LPC_WRITE_REG(chan, RGIO, val);88 LPC_READ_REG(chan, RGLVL);89 val = (LPC_READ_REG(chan, RGLVL) & GPIO_DATA) ? 1 : 0;90 91 return val;92}93 94static void set_clock(void *data, int state_high)95{96 struct gma_i2c_chan *chan = data;97 u32 val;98 99 if (state_high) {100 val = LPC_READ_REG(chan, RGIO);101 val |= GPIO_CLOCK;102 LPC_WRITE_REG(chan, RGIO, val);103 } else {104 val = LPC_READ_REG(chan, RGIO);105 val &= ~GPIO_CLOCK;106 LPC_WRITE_REG(chan, RGIO, val);107 val = LPC_READ_REG(chan, RGLVL);108 val &= ~GPIO_CLOCK;109 LPC_WRITE_REG(chan, RGLVL, val);110 }111}112 113static void set_data(void *data, int state_high)114{115 struct gma_i2c_chan *chan = data;116 u32 val;117 118 if (state_high) {119 val = LPC_READ_REG(chan, RGIO);120 val |= GPIO_DATA;121 LPC_WRITE_REG(chan, RGIO, val);122 } else {123 val = LPC_READ_REG(chan, RGIO);124 val &= ~GPIO_DATA;125 LPC_WRITE_REG(chan, RGIO, val);126 val = LPC_READ_REG(chan, RGLVL);127 val &= ~GPIO_DATA;128 LPC_WRITE_REG(chan, RGLVL, val);129 }130}131 132struct gma_i2c_chan *oaktrail_lvds_i2c_init(struct drm_device *dev)133{134 struct drm_psb_private *dev_priv = to_drm_psb_private(dev);135 struct gma_i2c_chan *chan;136 int ret;137 138 chan = kzalloc(sizeof(struct gma_i2c_chan), GFP_KERNEL);139 if (!chan)140 return ERR_PTR(-ENOMEM);141 142 chan->drm_dev = dev;143 chan->reg = dev_priv->lpc_gpio_base;144 strscpy(chan->base.name, "gma500 LPC", sizeof(chan->base.name));145 chan->base.owner = THIS_MODULE;146 chan->base.algo_data = &chan->algo;147 chan->base.dev.parent = dev->dev;148 chan->algo.setsda = set_data;149 chan->algo.setscl = set_clock;150 chan->algo.getsda = get_data;151 chan->algo.getscl = get_clock;152 chan->algo.udelay = 100;153 chan->algo.timeout = usecs_to_jiffies(2200);154 chan->algo.data = chan;155 156 i2c_set_adapdata(&chan->base, chan);157 158 set_data(chan, 1);159 set_clock(chan, 1);160 udelay(50);161 162 ret = i2c_bit_add_bus(&chan->base);163 if (ret < 0) {164 kfree(chan);165 return ERR_PTR(ret);166 }167 168 return chan;169}170