diff options
Diffstat (limited to 'drivers/gpu/drm/gma500/intel_gmbus.c')
-rw-r--r-- | drivers/gpu/drm/gma500/intel_gmbus.c | 493 |
1 files changed, 493 insertions, 0 deletions
diff --git a/drivers/gpu/drm/gma500/intel_gmbus.c b/drivers/gpu/drm/gma500/intel_gmbus.c new file mode 100644 index 00000000000..147584ac8d0 --- /dev/null +++ b/drivers/gpu/drm/gma500/intel_gmbus.c @@ -0,0 +1,493 @@ +/* + * 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 "drmP.h" +#include "drm.h" +#include "psb_intel_drv.h" +#include "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) + +/* 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) +{ + 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; + struct drm_device *dev = dev_priv->dev; + u32 reserved = 0; + + /* On most chips, these bits must be preserved in software. */ + reserved = 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; + struct drm_device *dev = dev_priv->dev; + u32 reserved = get_reserved(gpio); + REG_WRITE(gpio->reg, reserved | GPIO_CLOCK_DIR_MASK); + REG_WRITE(gpio->reg, reserved); + return (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; + struct drm_device *dev = dev_priv->dev; + u32 reserved = get_reserved(gpio); + REG_WRITE(gpio->reg, reserved | GPIO_DATA_DIR_MASK); + REG_WRITE(gpio->reg, reserved); + return (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; + struct drm_device *dev = dev_priv->dev; + 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; + + REG_WRITE(gpio->reg, reserved | clock_bits); + 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; + struct drm_device *dev = dev_priv->dev; + 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; + + REG_WRITE(gpio->reg, reserved | data_bits); + 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; + struct drm_device *dev = dev_priv->dev; + int i, reg_offset; + + if (bus->force_bit) + return intel_i2c_quirk_xfer(dev_priv, + bus->force_bit, msgs, num); + + reg_offset = 0; + + 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) { + 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); + REG_READ(GMBUS2+reg_offset); + do { + u32 val, loop = 0; + + if (wait_for(REG_READ(GMBUS2 + reg_offset) & (GMBUS_SATOER | GMBUS_HW_RDY), 50)) + goto timeout; + if (REG_READ(GMBUS2 + reg_offset) & GMBUS_SATOER) + goto clear_err; + + val = 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); + + REG_WRITE(GMBUS3 + reg_offset, val); + 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); + REG_READ(GMBUS2+reg_offset); + + while (len) { + if (wait_for(REG_READ(GMBUS2 + reg_offset) & (GMBUS_SATOER | GMBUS_HW_RDY), 50)) + goto timeout; + if (REG_READ(GMBUS2 + reg_offset) & GMBUS_SATOER) + goto clear_err; + + val = loop = 0; + do { + val |= *buf++ << (8 * loop); + } while (--len && ++loop < 4); + + REG_WRITE(GMBUS3 + reg_offset, val); + REG_READ(GMBUS2+reg_offset); + } + } + + if (i + 1 < num && wait_for(REG_READ(GMBUS2 + reg_offset) & (GMBUS_SATOER | GMBUS_HW_WAIT_PHASE), 50)) + goto timeout; + if (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. + */ + REG_WRITE(GMBUS1 + reg_offset, GMBUS_SW_CLR_INT); + 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. + */ + 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); + 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(sizeof(struct intel_gmbus), GMBUS_NUM_PORTS, + GFP_KERNEL); + if (dev_priv->gmbus == NULL) + return -ENOMEM; + + 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); + } + + kfree(dev_priv->gmbus); + dev_priv->gmbus = NULL; +} |