2 * Copyright (c) 2006 Dave Airlie <airlied@linux.ie>
3 * Copyright © 2006-2008,2010 Intel Corporation
4 * Jesse Barnes <jesse.barnes@intel.com>
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
13 * The above copyright notice and this permission notice (including the next
14 * paragraph) shall be included in all copies or substantial portions of the
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
22 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
23 * DEALINGS IN THE SOFTWARE.
26 * Eric Anholt <eric@anholt.net>
27 * Chris Wilson <chris@chris-wilson.co.uk>
29 #include <linux/i2c.h>
30 #include <linux/i2c-algo-bit.h>
31 #include <linux/export.h>
34 #include "intel_drv.h"
43 static const struct gmbus_port gmbus_ports[] = {
52 /* Intel GPIO access functions */
54 #define I2C_RISEFALL_TIME 10
56 static inline struct intel_gmbus *
57 to_intel_gmbus(struct i2c_adapter *i2c)
59 return container_of(i2c, struct intel_gmbus, adapter);
63 intel_i2c_reset(struct drm_device *dev)
65 struct drm_i915_private *dev_priv = dev->dev_private;
66 I915_WRITE(dev_priv->gpio_mmio_base + GMBUS0, 0);
69 static void intel_i2c_quirk_set(struct drm_i915_private *dev_priv, bool enable)
73 /* When using bit bashing for I2C, this bit needs to be set to 1 */
74 if (!IS_PINEVIEW(dev_priv->dev))
77 val = I915_READ(DSPCLK_GATE_D);
79 val |= DPCUNIT_CLOCK_GATE_DISABLE;
81 val &= ~DPCUNIT_CLOCK_GATE_DISABLE;
82 I915_WRITE(DSPCLK_GATE_D, val);
85 static u32 get_reserved(struct intel_gmbus *bus)
87 struct drm_i915_private *dev_priv = bus->dev_priv;
88 struct drm_device *dev = dev_priv->dev;
91 /* On most chips, these bits must be preserved in software. */
92 if (!IS_I830(dev) && !IS_845G(dev))
93 reserved = I915_READ_NOTRACE(bus->gpio_reg) &
94 (GPIO_DATA_PULLUP_DISABLE |
95 GPIO_CLOCK_PULLUP_DISABLE);
100 static int get_clock(void *data)
102 struct intel_gmbus *bus = data;
103 struct drm_i915_private *dev_priv = bus->dev_priv;
104 u32 reserved = get_reserved(bus);
105 I915_WRITE_NOTRACE(bus->gpio_reg, reserved | GPIO_CLOCK_DIR_MASK);
106 I915_WRITE_NOTRACE(bus->gpio_reg, reserved);
107 return (I915_READ_NOTRACE(bus->gpio_reg) & GPIO_CLOCK_VAL_IN) != 0;
110 static int get_data(void *data)
112 struct intel_gmbus *bus = data;
113 struct drm_i915_private *dev_priv = bus->dev_priv;
114 u32 reserved = get_reserved(bus);
115 I915_WRITE_NOTRACE(bus->gpio_reg, reserved | GPIO_DATA_DIR_MASK);
116 I915_WRITE_NOTRACE(bus->gpio_reg, reserved);
117 return (I915_READ_NOTRACE(bus->gpio_reg) & GPIO_DATA_VAL_IN) != 0;
120 static void set_clock(void *data, int state_high)
122 struct intel_gmbus *bus = data;
123 struct drm_i915_private *dev_priv = bus->dev_priv;
124 u32 reserved = get_reserved(bus);
128 clock_bits = GPIO_CLOCK_DIR_IN | GPIO_CLOCK_DIR_MASK;
130 clock_bits = GPIO_CLOCK_DIR_OUT | GPIO_CLOCK_DIR_MASK |
133 I915_WRITE_NOTRACE(bus->gpio_reg, reserved | clock_bits);
134 POSTING_READ(bus->gpio_reg);
137 static void set_data(void *data, int state_high)
139 struct intel_gmbus *bus = data;
140 struct drm_i915_private *dev_priv = bus->dev_priv;
141 u32 reserved = get_reserved(bus);
145 data_bits = GPIO_DATA_DIR_IN | GPIO_DATA_DIR_MASK;
147 data_bits = GPIO_DATA_DIR_OUT | GPIO_DATA_DIR_MASK |
150 I915_WRITE_NOTRACE(bus->gpio_reg, reserved | data_bits);
151 POSTING_READ(bus->gpio_reg);
155 intel_gpio_pre_xfer(struct i2c_adapter *adapter)
157 struct intel_gmbus *bus = container_of(adapter,
160 struct drm_i915_private *dev_priv = bus->dev_priv;
162 intel_i2c_reset(dev_priv->dev);
163 intel_i2c_quirk_set(dev_priv, true);
166 udelay(I2C_RISEFALL_TIME);
171 intel_gpio_post_xfer(struct i2c_adapter *adapter)
173 struct intel_gmbus *bus = container_of(adapter,
176 struct drm_i915_private *dev_priv = bus->dev_priv;
180 intel_i2c_quirk_set(dev_priv, false);
184 intel_gpio_setup(struct intel_gmbus *bus, u32 pin)
186 struct drm_i915_private *dev_priv = bus->dev_priv;
187 struct i2c_algo_bit_data *algo;
189 algo = &bus->bit_algo;
191 /* -1 to map pin pair to gmbus index */
192 bus->gpio_reg = dev_priv->gpio_mmio_base + gmbus_ports[pin - 1].reg;
194 bus->adapter.algo_data = algo;
195 algo->setsda = set_data;
196 algo->setscl = set_clock;
197 algo->getsda = get_data;
198 algo->getscl = get_clock;
199 algo->pre_xfer = intel_gpio_pre_xfer;
200 algo->post_xfer = intel_gpio_post_xfer;
201 algo->udelay = I2C_RISEFALL_TIME;
202 algo->timeout = usecs_to_jiffies(2200);
207 gmbus_xfer_read(struct drm_i915_private *dev_priv, struct i2c_msg *msg,
210 int reg_offset = dev_priv->gpio_mmio_base;
214 I915_WRITE(GMBUS1 + reg_offset,
216 (last ? GMBUS_CYCLE_STOP : 0) |
217 (len << GMBUS_BYTE_COUNT_SHIFT) |
218 (msg->addr << GMBUS_SLAVE_ADDR_SHIFT) |
219 GMBUS_SLAVE_READ | GMBUS_SW_RDY);
220 POSTING_READ(GMBUS2 + reg_offset);
224 if (wait_for(I915_READ(GMBUS2 + reg_offset) &
225 (GMBUS_SATOER | GMBUS_HW_RDY),
228 if (I915_READ(GMBUS2 + reg_offset) & GMBUS_SATOER)
231 val = I915_READ(GMBUS3 + reg_offset);
235 } while (--len && ++loop < 4);
242 gmbus_xfer_write(struct drm_i915_private *dev_priv, struct i2c_msg *msg,
245 int reg_offset = dev_priv->gpio_mmio_base;
251 while (len && loop < 4) {
252 val |= *buf++ << (8 * loop++);
256 I915_WRITE(GMBUS3 + reg_offset, val);
257 I915_WRITE(GMBUS1 + reg_offset,
259 (last ? GMBUS_CYCLE_STOP : 0) |
260 (msg->len << GMBUS_BYTE_COUNT_SHIFT) |
261 (msg->addr << GMBUS_SLAVE_ADDR_SHIFT) |
262 GMBUS_SLAVE_WRITE | GMBUS_SW_RDY);
263 POSTING_READ(GMBUS2 + reg_offset);
265 if (wait_for(I915_READ(GMBUS2 + reg_offset) &
266 (GMBUS_SATOER | GMBUS_HW_RDY),
269 if (I915_READ(GMBUS2 + reg_offset) & GMBUS_SATOER)
274 val |= *buf++ << (8 * loop);
275 } while (--len && ++loop < 4);
277 I915_WRITE(GMBUS3 + reg_offset, val);
278 POSTING_READ(GMBUS2 + reg_offset);
284 gmbus_xfer(struct i2c_adapter *adapter,
285 struct i2c_msg *msgs,
288 struct intel_gmbus *bus = container_of(adapter,
291 struct drm_i915_private *dev_priv = bus->dev_priv;
292 int i, reg_offset, ret;
294 mutex_lock(&dev_priv->gmbus_mutex);
296 if (bus->force_bit) {
297 ret = i2c_bit_algo.master_xfer(adapter, msgs, num);
301 reg_offset = dev_priv->gpio_mmio_base;
303 I915_WRITE(GMBUS0 + reg_offset, bus->reg0);
305 for (i = 0; i < num; i++) {
306 bool last = i + 1 == num;
308 if (msgs[i].flags & I2C_M_RD)
309 ret = gmbus_xfer_read(dev_priv, &msgs[i], last);
311 ret = gmbus_xfer_write(dev_priv, &msgs[i], last);
313 if (ret == -ETIMEDOUT)
319 wait_for(I915_READ(GMBUS2 + reg_offset) &
320 (GMBUS_SATOER | GMBUS_HW_WAIT_PHASE),
323 if (I915_READ(GMBUS2 + reg_offset) & GMBUS_SATOER)
330 /* Toggle the Software Clear Interrupt bit. This has the effect
331 * of resetting the GMBUS controller and so clearing the
332 * BUS_ERROR raised by the slave's NAK.
334 I915_WRITE(GMBUS1 + reg_offset, GMBUS_SW_CLR_INT);
335 I915_WRITE(GMBUS1 + reg_offset, 0);
338 /* Mark the GMBUS interface as disabled after waiting for idle.
339 * We will re-enable it at the start of the next xfer,
340 * till then let it sleep.
342 if (wait_for((I915_READ(GMBUS2 + reg_offset) & GMBUS_ACTIVE) == 0, 10))
343 DRM_INFO("GMBUS [%s] timed out waiting for idle\n",
345 I915_WRITE(GMBUS0 + reg_offset, 0);
350 DRM_INFO("GMBUS [%s] timed out, falling back to bit banging on pin %d\n",
351 bus->adapter.name, bus->reg0 & 0xff);
352 I915_WRITE(GMBUS0 + reg_offset, 0);
354 /* Hardware may not support GMBUS over these pins? Try GPIO bitbanging instead. */
355 bus->force_bit = true;
356 ret = i2c_bit_algo.master_xfer(adapter, msgs, num);
359 mutex_unlock(&dev_priv->gmbus_mutex);
363 static u32 gmbus_func(struct i2c_adapter *adapter)
365 return i2c_bit_algo.functionality(adapter) &
366 (I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL |
367 /* I2C_FUNC_10BIT_ADDR | */
368 I2C_FUNC_SMBUS_READ_BLOCK_DATA |
369 I2C_FUNC_SMBUS_BLOCK_PROC_CALL);
372 static const struct i2c_algorithm gmbus_algorithm = {
373 .master_xfer = gmbus_xfer,
374 .functionality = gmbus_func
378 * intel_gmbus_setup - instantiate all Intel i2c GMBuses
381 int intel_setup_gmbus(struct drm_device *dev)
383 struct drm_i915_private *dev_priv = dev->dev_private;
386 if (HAS_PCH_SPLIT(dev))
387 dev_priv->gpio_mmio_base = PCH_GPIOA - GPIOA;
389 dev_priv->gpio_mmio_base = 0;
391 mutex_init(&dev_priv->gmbus_mutex);
393 for (i = 0; i < GMBUS_NUM_PORTS; i++) {
394 struct intel_gmbus *bus = &dev_priv->gmbus[i];
395 u32 port = i + 1; /* +1 to map gmbus index to pin pair */
397 bus->adapter.owner = THIS_MODULE;
398 bus->adapter.class = I2C_CLASS_DDC;
399 snprintf(bus->adapter.name,
400 sizeof(bus->adapter.name),
402 gmbus_ports[i].name);
404 bus->adapter.dev.parent = &dev->pdev->dev;
405 bus->dev_priv = dev_priv;
407 bus->adapter.algo = &gmbus_algorithm;
408 ret = i2c_add_adapter(&bus->adapter);
412 /* By default use a conservative clock rate */
413 bus->reg0 = port | GMBUS_RATE_100KHZ;
415 intel_gpio_setup(bus, port);
418 intel_i2c_reset(dev_priv->dev);
424 struct intel_gmbus *bus = &dev_priv->gmbus[i];
425 i2c_del_adapter(&bus->adapter);
430 struct i2c_adapter *intel_gmbus_get_adapter(struct drm_i915_private *dev_priv,
433 WARN_ON(!intel_gmbus_is_port_valid(port));
434 /* -1 to map pin pair to gmbus index */
435 return (intel_gmbus_is_port_valid(port)) ?
436 &dev_priv->gmbus[port - 1].adapter : NULL;
439 void intel_gmbus_set_speed(struct i2c_adapter *adapter, int speed)
441 struct intel_gmbus *bus = to_intel_gmbus(adapter);
443 bus->reg0 = (bus->reg0 & ~(0x3 << 8)) | speed;
446 void intel_gmbus_force_bit(struct i2c_adapter *adapter, bool force_bit)
448 struct intel_gmbus *bus = to_intel_gmbus(adapter);
450 bus->force_bit = force_bit;
453 void intel_teardown_gmbus(struct drm_device *dev)
455 struct drm_i915_private *dev_priv = dev->dev_private;
458 if (dev_priv->gmbus == NULL)
461 for (i = 0; i < GMBUS_NUM_PORTS; i++) {
462 struct intel_gmbus *bus = &dev_priv->gmbus[i];
463 i2c_del_adapter(&bus->adapter);