nv_i2c.c

  1/*
  2 * linux/drivers/video/nvidia/nvidia-i2c.c - nVidia i2c
  3 *
  4 * Copyright 2004 Antonino A. Daplas <adaplas @pol.net>
  5 *
  6 * Based on rivafb-i2c.c
  7 *
  8 * This file is subject to the terms and conditions of the GNU General Public
  9 * License.  See the file COPYING in the main directory of this archive
 10 * for more details.
 11 */
 12
 13#include <linux/module.h>
 14#include <linux/kernel.h>
 15#include <linux/delay.h>
 16#include <linux/gfp.h>
 17#include <linux/pci.h>
 18#include <linux/fb.h>
 19
 20#include <asm/io.h>
 21
 22#include "nv_type.h"
 23#include "nv_local.h"
 24#include "nv_proto.h"
 25
 26#include "../edid.h"
 27
 28static void nvidia_gpio_setscl(void *data, int state)
 29{
 30	struct nvidia_i2c_chan *chan = data;
 31	struct nvidia_par *par = chan->par;
 32	u32 val;
 33
 34	val = NVReadCrtc(par, chan->ddc_base + 1) & 0xf0;
 35
 36	if (state)
 37		val |= 0x20;
 38	else
 39		val &= ~0x20;
 40
 41	NVWriteCrtc(par, chan->ddc_base + 1, val | 0x01);
 42}
 43
 44static void nvidia_gpio_setsda(void *data, int state)
 45{
 46	struct nvidia_i2c_chan *chan = data;
 47	struct nvidia_par *par = chan->par;
 48	u32 val;
 49
 50	val = NVReadCrtc(par, chan->ddc_base + 1) & 0xf0;
 51
 52	if (state)
 53		val |= 0x10;
 54	else
 55		val &= ~0x10;
 56
 57	NVWriteCrtc(par, chan->ddc_base + 1, val | 0x01);
 58}
 59
 60static int nvidia_gpio_getscl(void *data)
 61{
 62	struct nvidia_i2c_chan *chan = data;
 63	struct nvidia_par *par = chan->par;
 64	u32 val = 0;
 65
 66	if (NVReadCrtc(par, chan->ddc_base) & 0x04)
 67		val = 1;
 68
 69	return val;
 70}
 71
 72static int nvidia_gpio_getsda(void *data)
 73{
 74	struct nvidia_i2c_chan *chan = data;
 75	struct nvidia_par *par = chan->par;
 76	u32 val = 0;
 77
 78	if (NVReadCrtc(par, chan->ddc_base) & 0x08)
 79		val = 1;
 80
 81	return val;
 82}
 83
 84static int nvidia_setup_i2c_bus(struct nvidia_i2c_chan *chan, const char *name,
 85				unsigned int i2c_class)
 86{
 87	int rc;
 88
 89	strscpy(chan->adapter.name, name, sizeof(chan->adapter.name));
 90	chan->adapter.owner = THIS_MODULE;
 91	chan->adapter.class = i2c_class;
 92	chan->adapter.algo_data = &chan->algo;
 93	chan->adapter.dev.parent = &chan->par->pci_dev->dev;
 94	chan->algo.setsda = nvidia_gpio_setsda;
 95	chan->algo.setscl = nvidia_gpio_setscl;
 96	chan->algo.getsda = nvidia_gpio_getsda;
 97	chan->algo.getscl = nvidia_gpio_getscl;
 98	chan->algo.udelay = 40;
 99	chan->algo.timeout = msecs_to_jiffies(2);
100	chan->algo.data = chan;
101
102	i2c_set_adapdata(&chan->adapter, chan);
103
104	/* Raise SCL and SDA */
105	nvidia_gpio_setsda(chan, 1);
106	nvidia_gpio_setscl(chan, 1);
107	udelay(20);
108
109	rc = i2c_bit_add_bus(&chan->adapter);
110	if (rc == 0)
111		dev_dbg(&chan->par->pci_dev->dev,
112			"I2C bus %s registered.\n", name);
113	else {
114		dev_warn(&chan->par->pci_dev->dev,
115			 "Failed to register I2C bus %s.\n", name);
116		chan->par = NULL;
117	}
118
119	return rc;
120}
121
122void nvidia_create_i2c_busses(struct nvidia_par *par)
123{
124	par->chan[0].par = par;
125	par->chan[1].par = par;
126	par->chan[2].par = par;
127
128	par->chan[0].ddc_base = (par->reverse_i2c) ? 0x36 : 0x3e;
129 	nvidia_setup_i2c_bus(&par->chan[0], "nvidia #0",
130			     (par->reverse_i2c) ? I2C_CLASS_HWMON : 0);
131
132	par->chan[1].ddc_base = (par->reverse_i2c) ? 0x3e : 0x36;
133 	nvidia_setup_i2c_bus(&par->chan[1], "nvidia #1",
134			     (par->reverse_i2c) ? 0 : I2C_CLASS_HWMON);
135
136	par->chan[2].ddc_base = 0x50;
137 	nvidia_setup_i2c_bus(&par->chan[2], "nvidia #2", 0);
138}
139
140void nvidia_delete_i2c_busses(struct nvidia_par *par)
141{
142	int i;
143
144	for (i = 0; i < 3; i++) {
145		if (!par->chan[i].par)
146			continue;
147		i2c_del_adapter(&par->chan[i].adapter);
148		par->chan[i].par = NULL;
149	}
150}
151
152int nvidia_probe_i2c_connector(struct fb_info *info, int conn, u8 **out_edid)
153{
154	struct nvidia_par *par = info->par;
155	u8 *edid = NULL;
156
157	if (par->chan[conn - 1].par)
158		edid = fb_ddc_read(&par->chan[conn - 1].adapter);
159
160	if (!edid && conn == 1) {
161		/* try to get from firmware */
162		const u8 *e = fb_firmware_edid(info->device);
163
164		if (e != NULL)
165			edid = kmemdup(e, EDID_LENGTH, GFP_KERNEL);
166	}
167
168	*out_edid = edid;
169
170	return (edid) ? 0 : 1;
171}