- 根目录:
- drivers
- gpu
- drm
- gma500
- intel_gmbus.c
/*
* Copyright (c) 2006 Dave Airlie <airlied@linux.ie>
* Copyright © 2006-2008,2010 Intel Corporation
* Jesse Barnes <jesse.barnes@intel.com>
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
* DEALINGS IN THE SOFTWARE.
*
* Authors:
* Eric Anholt <eric@anholt.net>
* Chris Wilson <chris@chris-wilson.co.uk>
*/
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/i2c-algo-bit.h>
#include <drm/drmP.h>
#include "psb_intel_drv.h"
#include <drm/gma_drm.h>
#include "psb_drv.h"
#include "psb_intel_reg.h"
#define _wait_for(COND, MS, W) ({ \
unsigned long timeout__ = jiffies + msecs_to_jiffies(MS); \
int ret__ = 0; \
while (! (COND)) { \
if (time_after(jiffies, timeout__)) { \
ret__ = -ETIMEDOUT; \
break; \
} \
if (W && !(in_atomic() || in_dbg_master())) msleep(W); \
} \
ret__; \
})
#define wait_for(COND, MS) _wait_for(COND, MS, 1)
#define wait_for_atomic(COND, MS) _wait_for(COND, MS, 0)
#define GMBUS_REG_READ(reg) ioread32(dev_priv->gmbus_reg + (reg))
#define GMBUS_REG_WRITE(reg, val) iowrite32((val), dev_priv->gmbus_reg + (reg))
/* Intel GPIO access functions */
#define I2C_RISEFALL_TIME 20
static inline struct intel_gmbus *
to_intel_gmbus(struct i2c_adapter *i2c)
{
return container_of(i2c, struct intel_gmbus, adapter);
}
struct intel_gpio {
struct i2c_adapter adapter;
struct i2c_algo_bit_data algo;
struct drm_psb_private *dev_priv;
u32 reg;
};
void
gma_intel_i2c_reset(struct drm_device *dev)
{
struct drm_psb_private *dev_priv = dev->dev_private;
GMBUS_REG_WRITE(GMBUS0, 0);
}
static void intel_i2c_quirk_set(struct drm_psb_private *dev_priv, bool enable)
{
/* When using bit bashing for I2C, this bit needs to be set to 1 */
/* FIXME: We are never Pineview, right?
u32 val;
if (!IS_PINEVIEW(dev_priv->dev))
return;
val = REG_READ(DSPCLK_GATE_D);
if (enable)
val |= DPCUNIT_CLOCK_GATE_DISABLE;
else
val &= ~DPCUNIT_CLOCK_GATE_DISABLE;
REG_WRITE(DSPCLK_GATE_D, val);
return;
*/
}
static u32 get_reserved(struct intel_gpio *gpio)
{
struct drm_psb_private *dev_priv = gpio->dev_priv;
u32 reserved = 0;
/* On most chips, these bits must be preserved in software. */
reserved = GMBUS_REG_READ(gpio->reg) &
(GPIO_DATA_PULLUP_DISABLE |
GPIO_CLOCK_PULLUP_DISABLE);
return reserved;
}
static int get_clock(void *data)
{
struct intel_gpio *gpio = data;
struct drm_psb_private *dev_priv = gpio->dev_priv;
u32 reserved = get_reserved(gpio);
GMBUS_REG_WRITE(gpio->reg, reserved | GPIO_CLOCK_DIR_MASK);
GMBUS_REG_WRITE(gpio->reg, reserved);
return (GMBUS_REG_READ(gpio->reg) & GPIO_CLOCK_VAL_IN) != 0;
}
static int get_data(void *data)
{
struct intel_gpio *gpio = data;
struct drm_psb_private *dev_priv = gpio->dev_priv;
u32 reserved = get_reserved(gpio);
GMBUS_REG_WRITE(gpio->reg, reserved | GPIO_DATA_DIR_MASK);
GMBUS_REG_WRITE(gpio->reg, reserved);
return (GMBUS_REG_READ(gpio->reg) & GPIO_DATA_VAL_IN) != 0;
}
static void set_clock(void *data, int state_high)
{
struct intel_gpio *gpio = data;
struct drm_psb_private *dev_priv = gpio->dev_priv;
u32 reserved = get_reserved(gpio);
u32 clock_bits;
if (state_high)
clock_bits = GPIO_CLOCK_DIR_IN | GPIO_CLOCK_DIR_MASK;
else
clock_bits = GPIO_CLOCK_DIR_OUT | GPIO_CLOCK_DIR_MASK |
GPIO_CLOCK_VAL_MASK;
GMBUS_REG_WRITE(gpio->reg, reserved | clock_bits);
GMBUS_REG_READ(gpio->reg); /* Posting */
}
static void set_data(void *data, int state_high)
{
struct intel_gpio *gpio = data;
struct drm_psb_private *dev_priv = gpio->dev_priv;
u32 reserved = get_reserved(gpio);
u32 data_bits;
if (state_high)
data_bits = GPIO_DATA_DIR_IN | GPIO_DATA_DIR_MASK;
else
data_bits = GPIO_DATA_DIR_OUT | GPIO_DATA_DIR_MASK |
GPIO_DATA_VAL_MASK;
GMBUS_REG_WRITE(gpio->reg, reserved | data_bits);
GMBUS_REG_READ(gpio->reg);
}
static struct i2c_adapter *
intel_gpio_create(struct drm_psb_private *dev_priv, u32 pin)
{
static const int map_pin_to_reg[] = {
0,
GPIOB,
GPIOA,
GPIOC,
GPIOD,
GPIOE,
0,
GPIOF,
};
struct intel_gpio *gpio;
if (pin >= ARRAY_SIZE(map_pin_to_reg) || !map_pin_to_reg[pin])
return NULL;
gpio = kzalloc(sizeof(struct intel_gpio), GFP_KERNEL);
if (gpio == NULL)
return NULL;
gpio->reg = map_pin_to_reg[pin];
gpio->dev_priv = dev_priv;
snprintf(gpio->adapter.name, sizeof(gpio->adapter.name),
"gma500 GPIO%c", "?BACDE?F"[pin]);
gpio->adapter.owner = THIS_MODULE;
gpio->adapter.algo_data = &gpio->algo;
gpio->adapter.dev.parent = &dev_priv->dev->pdev->dev;
gpio->algo.setsda = set_data;
gpio->algo.setscl = set_clock;
gpio->algo.getsda = get_data;
gpio->algo.getscl = get_clock;
gpio->algo.udelay = I2C_RISEFALL_TIME;
gpio->algo.timeout = usecs_to_jiffies(2200);
gpio->algo.data = gpio;
if (i2c_bit_add_bus(&gpio->adapter))
goto out_free;
return &gpio->adapter;
out_free:
kfree(gpio);
return NULL;
}
static int
intel_i2c_quirk_xfer(struct drm_psb_private *dev_priv,
struct i2c_adapter *adapter,
struct i2c_msg *msgs,
int num)
{
struct intel_gpio *gpio = container_of(adapter,
struct intel_gpio,
adapter);
int ret;
gma_intel_i2c_reset(dev_priv->dev);
intel_i2c_quirk_set(dev_priv, true);
set_data(gpio, 1);
set_clock(gpio, 1);
udelay(I2C_RISEFALL_TIME);
ret = adapter->algo->master_xfer(adapter, msgs, num);
set_data(gpio, 1);
set_clock(gpio, 1);
intel_i2c_quirk_set(dev_priv, false);
return ret;
}
static int
gmbus_xfer(struct i2c_adapter *adapter,
struct i2c_msg *msgs,
int num)
{
struct intel_gmbus *bus = container_of(adapter,
struct intel_gmbus,
adapter);
struct drm_psb_private *dev_priv = adapter->algo_data;
int i, reg_offset;
if (bus->force_bit)
return intel_i2c_quirk_xfer(dev_priv,
bus->force_bit, msgs, num);
reg_offset = 0;
GMBUS_REG_WRITE(GMBUS0 + reg_offset, bus->reg0);
for (i = 0; i < num; i++) {
u16 len = msgs[i].len;
u8 *buf = msgs[i].buf;
if (msgs[i].flags & I2C_M_RD) {
GMBUS_REG_WRITE(GMBUS1 + reg_offset,
GMBUS_CYCLE_WAIT |
(i + 1 == num ? GMBUS_CYCLE_STOP : 0) |
(len << GMBUS_BYTE_COUNT_SHIFT) |
(msgs[i].addr << GMBUS_SLAVE_ADDR_SHIFT) |
GMBUS_SLAVE_READ | GMBUS_SW_RDY);
GMBUS_REG_READ(GMBUS2+reg_offset);
do {
u32 val, loop = 0;
if (wait_for(GMBUS_REG_READ(GMBUS2 + reg_offset) &
(GMBUS_SATOER | GMBUS_HW_RDY), 50))
goto timeout;
if (GMBUS_REG_READ(GMBUS2 + reg_offset) & GMBUS_SATOER)
goto clear_err;
val = GMBUS_REG_READ(GMBUS3 + reg_offset);
do {
*buf++ = val & 0xff;
val >>= 8;
} while (--len && ++loop < 4);
} while (len);
} else {
u32 val, loop;
val = loop = 0;
do {
val |= *buf++ << (8 * loop);
} while (--len && ++loop < 4);
GMBUS_REG_WRITE(GMBUS3 + reg_offset, val);
GMBUS_REG_WRITE(GMBUS1 + reg_offset,
(i + 1 == num ? GMBUS_CYCLE_STOP : GMBUS_CYCLE_WAIT) |
(msgs[i].len << GMBUS_BYTE_COUNT_SHIFT) |
(msgs[i].addr << GMBUS_SLAVE_ADDR_SHIFT) |
GMBUS_SLAVE_WRITE | GMBUS_SW_RDY);
GMBUS_REG_READ(GMBUS2+reg_offset);
while (len) {
if (wait_for(GMBUS_REG_READ(GMBUS2 + reg_offset) &
(GMBUS_SATOER | GMBUS_HW_RDY), 50))
goto timeout;
if (GMBUS_REG_READ(GMBUS2 + reg_offset) &
GMBUS_SATOER)
goto clear_err;
val = loop = 0;
do {
val |= *buf++ << (8 * loop);
} while (--len && ++loop < 4);
GMBUS_REG_WRITE(GMBUS3 + reg_offset, val);
GMBUS_REG_READ(GMBUS2+reg_offset);
}
}
if (i + 1 < num && wait_for(GMBUS_REG_READ(GMBUS2 + reg_offset) & (GMBUS_SATOER | GMBUS_HW_WAIT_PHASE), 50))
goto timeout;
if (GMBUS_REG_READ(GMBUS2 + reg_offset) & GMBUS_SATOER)
goto clear_err;
}
goto done;
clear_err:
/* Toggle the Software Clear Interrupt bit. This has the effect
* of resetting the GMBUS controller and so clearing the
* BUS_ERROR raised by the slave's NAK.
*/
GMBUS_REG_WRITE(GMBUS1 + reg_offset, GMBUS_SW_CLR_INT);
GMBUS_REG_WRITE(GMBUS1 + reg_offset, 0);
done:
/* Mark the GMBUS interface as disabled. We will re-enable it at the
* start of the next xfer, till then let it sleep.
*/
GMBUS_REG_WRITE(GMBUS0 + reg_offset, 0);
return i;
timeout:
DRM_INFO("GMBUS timed out, falling back to bit banging on pin %d [%s]\n",
bus->reg0 & 0xff, bus->adapter.name);
GMBUS_REG_WRITE(GMBUS0 + reg_offset, 0);
/* Hardware may not support GMBUS over these pins? Try GPIO bitbanging instead. */
bus->force_bit = intel_gpio_create(dev_priv, bus->reg0 & 0xff);
if (!bus->force_bit)
return -ENOMEM;
return intel_i2c_quirk_xfer(dev_priv, bus->force_bit, msgs, num);
}
static u32 gmbus_func(struct i2c_adapter *adapter)
{
struct intel_gmbus *bus = container_of(adapter,
struct intel_gmbus,
adapter);
if (bus->force_bit)
bus->force_bit->algo->functionality(bus->force_bit);
return (I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
/* I2C_FUNC_10BIT_ADDR | */
I2C_FUNC_SMBUS_READ_BLOCK_DATA |
I2C_FUNC_SMBUS_BLOCK_PROC_CALL);
}
static const struct i2c_algorithm gmbus_algorithm = {
.master_xfer = gmbus_xfer,
.functionality = gmbus_func
};
/**
* intel_gmbus_setup - instantiate all Intel i2c GMBuses
* @dev: DRM device
*/
int gma_intel_setup_gmbus(struct drm_device *dev)
{
static const char *names[GMBUS_NUM_PORTS] = {
"disabled",
"ssc",
"vga",
"panel",
"dpc",
"dpb",
"reserved",
"dpd",
};
struct drm_psb_private *dev_priv = dev->dev_private;
int ret, i;
dev_priv->gmbus = kcalloc(GMBUS_NUM_PORTS, sizeof(struct intel_gmbus),
GFP_KERNEL);
if (dev_priv->gmbus == NULL)
return -ENOMEM;
if (IS_MRST(dev))
dev_priv->gmbus_reg = dev_priv->aux_reg;
else
dev_priv->gmbus_reg = dev_priv->vdc_reg;
for (i = 0; i < GMBUS_NUM_PORTS; i++) {
struct intel_gmbus *bus = &dev_priv->gmbus[i];
bus->adapter.owner = THIS_MODULE;
bus->adapter.class = I2C_CLASS_DDC;
snprintf(bus->adapter.name,
sizeof(bus->adapter.name),
"gma500 gmbus %s",
names[i]);
bus->adapter.dev.parent = &dev->pdev->dev;
bus->adapter.algo_data = dev_priv;
bus->adapter.algo = &gmbus_algorithm;
ret = i2c_add_adapter(&bus->adapter);
if (ret)
goto err;
/* By default use a conservative clock rate */
bus->reg0 = i | GMBUS_RATE_100KHZ;
/* XXX force bit banging until GMBUS is fully debugged */
bus->force_bit = intel_gpio_create(dev_priv, i);
}
gma_intel_i2c_reset(dev_priv->dev);
return 0;
err:
while (--i) {
struct intel_gmbus *bus = &dev_priv->gmbus[i];
i2c_del_adapter(&bus->adapter);
}
kfree(dev_priv->gmbus);
dev_priv->gmbus = NULL;
return ret;
}
void gma_intel_gmbus_set_speed(struct i2c_adapter *adapter, int speed)
{
struct intel_gmbus *bus = to_intel_gmbus(adapter);
/* speed:
* 0x0 = 100 KHz
* 0x1 = 50 KHz
* 0x2 = 400 KHz
* 0x3 = 1000 Khz
*/
bus->reg0 = (bus->reg0 & ~(0x3 << 8)) | (speed << 8);
}
void gma_intel_gmbus_force_bit(struct i2c_adapter *adapter, bool force_bit)
{
struct intel_gmbus *bus = to_intel_gmbus(adapter);
if (force_bit) {
if (bus->force_bit == NULL) {
struct drm_psb_private *dev_priv = adapter->algo_data;
bus->force_bit = intel_gpio_create(dev_priv,
bus->reg0 & 0xff);
}
} else {
if (bus->force_bit) {
i2c_del_adapter(bus->force_bit);
kfree(bus->force_bit);
bus->force_bit = NULL;
}
}
}
void gma_intel_teardown_gmbus(struct drm_device *dev)
{
struct drm_psb_private *dev_priv = dev->dev_private;
int i;
if (dev_priv->gmbus == NULL)
return;
for (i = 0; i < GMBUS_NUM_PORTS; i++) {
struct intel_gmbus *bus = &dev_priv->gmbus[i];
if (bus->force_bit) {
i2c_del_adapter(bus->force_bit);
kfree(bus->force_bit);
}
i2c_del_adapter(&bus->adapter);
}
dev_priv->gmbus_reg = NULL; /* iounmap is done in driver_unload */
kfree(dev_priv->gmbus);
dev_priv->gmbus = NULL;
}