diff options
Diffstat (limited to 'drivers/gpu/drm/openchrome/via_i2c.c')
| -rw-r--r-- | drivers/gpu/drm/openchrome/via_i2c.c | 204 |
1 files changed, 204 insertions, 0 deletions
diff --git a/drivers/gpu/drm/openchrome/via_i2c.c b/drivers/gpu/drm/openchrome/via_i2c.c new file mode 100644 index 000000000000..96114f40b037 --- /dev/null +++ b/drivers/gpu/drm/openchrome/via_i2c.c @@ -0,0 +1,204 @@ +/* + * Copyright 2012 James Simmons <jsimmons@infradead.org> All Rights Reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License as published by the Free Software Foundation; + * either version 2, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTIES OR REPRESENTATIONS; without even + * the implied warranty of MERCHANTABILITY or FITNESS FOR + * A PARTICULAR PURPOSE.See the GNU General Public License + * for more details. + * + * This part was influenced by the via i2c code written for the viafb + * driver by VIA Technologies and S3 Graphics + */ +#include "via_drv.h" + +enum viafb_i2c_adap; + +#include <linux/via_i2c.h> + +#define SERIAL 0 +#define GPIO 1 + +static struct via_i2c_stuff via_i2c_par[5]; + +static void via_i2c_setscl(void *data, int state) +{ + struct via_i2c_stuff *i2c = data; + struct drm_device *dev = i2c_get_adapdata(&i2c->adapter); + struct via_device *dev_priv = dev->dev_private; + u8 value, mask; + + if (i2c->is_active == GPIO) { + mask = state ? BIT(7) : BIT(7) | BIT(5); + value = state ? 0x00 : BIT(7); + } else { + value = state ? BIT(5) : 0x00; + mask = BIT(5); + } + svga_wseq_mask(VGABASE, i2c->i2c_port, value, mask); +} + +static int via_i2c_getscl(void *data) +{ + struct via_i2c_stuff *i2c = data; + struct drm_device *dev = i2c_get_adapdata(&i2c->adapter); + struct via_device *dev_priv = dev->dev_private; + + return vga_rseq(VGABASE, i2c->i2c_port) & BIT(3); +} + +static int via_i2c_getsda(void *data) +{ + struct via_i2c_stuff *i2c = data; + struct drm_device *dev = i2c_get_adapdata(&i2c->adapter); + struct via_device *dev_priv = dev->dev_private; + + return vga_rseq(VGABASE, i2c->i2c_port) & BIT(2); +} + +static void via_i2c_setsda(void *data, int state) +{ + struct via_i2c_stuff *i2c = data; + struct drm_device *dev = i2c_get_adapdata(&i2c->adapter); + struct via_device *dev_priv = dev->dev_private; + u8 value, mask; + + if (i2c->is_active == GPIO) { + mask = state ? BIT(6) : BIT(6) | BIT(4); + value = state ? 0x00 : BIT(6); + } else { + value = state ? BIT(4) : 0x00; + mask = BIT(4); + } + svga_wseq_mask(VGABASE, i2c->i2c_port, value, mask); +} + +struct i2c_adapter *via_find_ddc_bus(int port) +{ + struct i2c_adapter *adapter = NULL; + int i; + + for (i = 0; i < ARRAY_SIZE(via_i2c_par); i++) { + struct via_i2c_stuff *i2c = &via_i2c_par[i]; + + if (i2c->i2c_port == port) { + adapter = &i2c->adapter; + break; + } + } + return adapter; +} + +static int +create_i2c_bus(struct drm_device *dev, struct via_i2c_stuff *i2c_par) +{ + struct i2c_adapter *adapter = &i2c_par->adapter; + struct i2c_algo_bit_data *algo = &i2c_par->algo; + + algo->setsda = via_i2c_setsda; + algo->setscl = via_i2c_setscl; + algo->getsda = via_i2c_getsda; + algo->getscl = via_i2c_getscl; + algo->udelay = 15; + algo->timeout = usecs_to_jiffies(2200); /* from VESA */ + algo->data = i2c_par; + + sprintf(adapter->name, "via i2c bit bus 0x%02x", i2c_par->i2c_port); + adapter->owner = THIS_MODULE; + adapter->class = I2C_CLASS_DDC; + adapter->algo_data = algo; + i2c_set_adapdata(adapter, dev); + + /* Raise SCL and SDA */ + via_i2c_setsda(i2c_par, 1); + via_i2c_setscl(i2c_par, 1); + udelay(20); + + return i2c_bit_add_bus(adapter); +} + +void +via_i2c_readbytes(struct i2c_adapter *adapter, + u8 slave_addr, char offset, + u8 *buffer, unsigned int size) +{ + u8 out_buf[2]; + u8 in_buf[2]; + struct i2c_msg msgs[] = { + { + .addr = slave_addr, + .flags = 0, + .len = 1, + .buf = out_buf, + }, + { + .addr = slave_addr, + .flags = I2C_M_RD, + .len = size, + .buf = in_buf, + } + }; + + out_buf[0] = offset; + out_buf[1] = 0; + + if (i2c_transfer(adapter, msgs, 2) != 2) + printk(KERN_WARNING "%s failed\n", __func__); + else + *buffer = in_buf[0]; +} + +void +via_i2c_writebytes(struct i2c_adapter *adapter, + u8 slave_addr, char offset, + u8 *data, unsigned int size) +{ + struct i2c_msg msg = { 0 }; + u8 *out_buf; + + out_buf = kzalloc(size + 1, GFP_KERNEL); + out_buf[0] = offset; + memcpy(&out_buf[1], data, size); + msg.addr = slave_addr; + msg.flags = 0; + msg.len = size + 1; + msg.buf = out_buf; + + if (i2c_transfer(adapter, &msg, 1) != 1) + printk(KERN_WARNING "%s failed\n", __func__); + + kfree(out_buf); +} + +int via_i2c_init(struct drm_device *dev) +{ + int types[] = { SERIAL, SERIAL, GPIO, GPIO, GPIO }; + int ports[] = { 0x26, 0x31, 0x25, 0x2C, 0x3D }; + int count = ARRAY_SIZE(via_i2c_par), ret, i; + struct via_i2c_stuff *i2c = via_i2c_par; + + for (i = 0; i < count; i++) { + i2c->is_active = types[i]; + i2c->i2c_port = ports[i]; + + ret = create_i2c_bus(dev, i2c); + if (ret < 0) + DRM_ERROR("cannot create i2c bus %x:%d\n", + ports[i], ret); + i2c++; + } + return 0; +} + +void via_i2c_exit(void) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(via_i2c_par); i++) + i2c_del_adapter(&via_i2c_par->adapter); +} |