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Diffstat (limited to 'drivers/gpu/drm/i915/intel_i2c.c')
-rw-r--r--drivers/gpu/drm/i915/intel_i2c.c933
1 files changed, 0 insertions, 933 deletions
diff --git a/drivers/gpu/drm/i915/intel_i2c.c b/drivers/gpu/drm/i915/intel_i2c.c
deleted file mode 100644
index 422685d120e9..000000000000
--- a/drivers/gpu/drm/i915/intel_i2c.c
+++ /dev/null
@@ -1,933 +0,0 @@
-/*
- * 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/i2c.h>
-#include <linux/i2c-algo-bit.h>
-#include <linux/export.h>
-#include <drm/drm_hdcp.h>
-#include "intel_drv.h"
-#include <drm/i915_drm.h>
-#include "i915_drv.h"
-
-struct gmbus_pin {
- const char *name;
- enum i915_gpio gpio;
-};
-
-/* Map gmbus pin pairs to names and registers. */
-static const struct gmbus_pin gmbus_pins[] = {
- [GMBUS_PIN_SSC] = { "ssc", GPIOB },
- [GMBUS_PIN_VGADDC] = { "vga", GPIOA },
- [GMBUS_PIN_PANEL] = { "panel", GPIOC },
- [GMBUS_PIN_DPC] = { "dpc", GPIOD },
- [GMBUS_PIN_DPB] = { "dpb", GPIOE },
- [GMBUS_PIN_DPD] = { "dpd", GPIOF },
-};
-
-static const struct gmbus_pin gmbus_pins_bdw[] = {
- [GMBUS_PIN_VGADDC] = { "vga", GPIOA },
- [GMBUS_PIN_DPC] = { "dpc", GPIOD },
- [GMBUS_PIN_DPB] = { "dpb", GPIOE },
- [GMBUS_PIN_DPD] = { "dpd", GPIOF },
-};
-
-static const struct gmbus_pin gmbus_pins_skl[] = {
- [GMBUS_PIN_DPC] = { "dpc", GPIOD },
- [GMBUS_PIN_DPB] = { "dpb", GPIOE },
- [GMBUS_PIN_DPD] = { "dpd", GPIOF },
-};
-
-static const struct gmbus_pin gmbus_pins_bxt[] = {
- [GMBUS_PIN_1_BXT] = { "dpb", GPIOB },
- [GMBUS_PIN_2_BXT] = { "dpc", GPIOC },
- [GMBUS_PIN_3_BXT] = { "misc", GPIOD },
-};
-
-static const struct gmbus_pin gmbus_pins_cnp[] = {
- [GMBUS_PIN_1_BXT] = { "dpb", GPIOB },
- [GMBUS_PIN_2_BXT] = { "dpc", GPIOC },
- [GMBUS_PIN_3_BXT] = { "misc", GPIOD },
- [GMBUS_PIN_4_CNP] = { "dpd", GPIOE },
-};
-
-static const struct gmbus_pin gmbus_pins_icp[] = {
- [GMBUS_PIN_1_BXT] = { "dpa", GPIOB },
- [GMBUS_PIN_2_BXT] = { "dpb", GPIOC },
- [GMBUS_PIN_9_TC1_ICP] = { "tc1", GPIOJ },
- [GMBUS_PIN_10_TC2_ICP] = { "tc2", GPIOK },
- [GMBUS_PIN_11_TC3_ICP] = { "tc3", GPIOL },
- [GMBUS_PIN_12_TC4_ICP] = { "tc4", GPIOM },
-};
-
-/* pin is expected to be valid */
-static const struct gmbus_pin *get_gmbus_pin(struct drm_i915_private *dev_priv,
- unsigned int pin)
-{
- if (HAS_PCH_ICP(dev_priv))
- return &gmbus_pins_icp[pin];
- else if (HAS_PCH_CNP(dev_priv))
- return &gmbus_pins_cnp[pin];
- else if (IS_GEN9_LP(dev_priv))
- return &gmbus_pins_bxt[pin];
- else if (IS_GEN9_BC(dev_priv))
- return &gmbus_pins_skl[pin];
- else if (IS_BROADWELL(dev_priv))
- return &gmbus_pins_bdw[pin];
- else
- return &gmbus_pins[pin];
-}
-
-bool intel_gmbus_is_valid_pin(struct drm_i915_private *dev_priv,
- unsigned int pin)
-{
- unsigned int size;
-
- if (HAS_PCH_ICP(dev_priv))
- size = ARRAY_SIZE(gmbus_pins_icp);
- else if (HAS_PCH_CNP(dev_priv))
- size = ARRAY_SIZE(gmbus_pins_cnp);
- else if (IS_GEN9_LP(dev_priv))
- size = ARRAY_SIZE(gmbus_pins_bxt);
- else if (IS_GEN9_BC(dev_priv))
- size = ARRAY_SIZE(gmbus_pins_skl);
- else if (IS_BROADWELL(dev_priv))
- size = ARRAY_SIZE(gmbus_pins_bdw);
- else
- size = ARRAY_SIZE(gmbus_pins);
-
- return pin < size && get_gmbus_pin(dev_priv, pin)->name;
-}
-
-/* Intel GPIO access functions */
-
-#define I2C_RISEFALL_TIME 10
-
-static inline struct intel_gmbus *
-to_intel_gmbus(struct i2c_adapter *i2c)
-{
- return container_of(i2c, struct intel_gmbus, adapter);
-}
-
-void
-intel_i2c_reset(struct drm_i915_private *dev_priv)
-{
- I915_WRITE(GMBUS0, 0);
- I915_WRITE(GMBUS4, 0);
-}
-
-static void pnv_gmbus_clock_gating(struct drm_i915_private *dev_priv,
- bool enable)
-{
- u32 val;
-
- /* When using bit bashing for I2C, this bit needs to be set to 1 */
- val = I915_READ(DSPCLK_GATE_D);
- if (!enable)
- val |= PNV_GMBUSUNIT_CLOCK_GATE_DISABLE;
- else
- val &= ~PNV_GMBUSUNIT_CLOCK_GATE_DISABLE;
- I915_WRITE(DSPCLK_GATE_D, val);
-}
-
-static void pch_gmbus_clock_gating(struct drm_i915_private *dev_priv,
- bool enable)
-{
- u32 val;
-
- val = I915_READ(SOUTH_DSPCLK_GATE_D);
- if (!enable)
- val |= PCH_GMBUSUNIT_CLOCK_GATE_DISABLE;
- else
- val &= ~PCH_GMBUSUNIT_CLOCK_GATE_DISABLE;
- I915_WRITE(SOUTH_DSPCLK_GATE_D, val);
-}
-
-static void bxt_gmbus_clock_gating(struct drm_i915_private *dev_priv,
- bool enable)
-{
- u32 val;
-
- val = I915_READ(GEN9_CLKGATE_DIS_4);
- if (!enable)
- val |= BXT_GMBUS_GATING_DIS;
- else
- val &= ~BXT_GMBUS_GATING_DIS;
- I915_WRITE(GEN9_CLKGATE_DIS_4, val);
-}
-
-static u32 get_reserved(struct intel_gmbus *bus)
-{
- struct drm_i915_private *dev_priv = bus->dev_priv;
- u32 reserved = 0;
-
- /* On most chips, these bits must be preserved in software. */
- if (!IS_I830(dev_priv) && !IS_I845G(dev_priv))
- reserved = I915_READ_NOTRACE(bus->gpio_reg) &
- (GPIO_DATA_PULLUP_DISABLE |
- GPIO_CLOCK_PULLUP_DISABLE);
-
- return reserved;
-}
-
-static int get_clock(void *data)
-{
- struct intel_gmbus *bus = data;
- struct drm_i915_private *dev_priv = bus->dev_priv;
- u32 reserved = get_reserved(bus);
- I915_WRITE_NOTRACE(bus->gpio_reg, reserved | GPIO_CLOCK_DIR_MASK);
- I915_WRITE_NOTRACE(bus->gpio_reg, reserved);
- return (I915_READ_NOTRACE(bus->gpio_reg) & GPIO_CLOCK_VAL_IN) != 0;
-}
-
-static int get_data(void *data)
-{
- struct intel_gmbus *bus = data;
- struct drm_i915_private *dev_priv = bus->dev_priv;
- u32 reserved = get_reserved(bus);
- I915_WRITE_NOTRACE(bus->gpio_reg, reserved | GPIO_DATA_DIR_MASK);
- I915_WRITE_NOTRACE(bus->gpio_reg, reserved);
- return (I915_READ_NOTRACE(bus->gpio_reg) & GPIO_DATA_VAL_IN) != 0;
-}
-
-static void set_clock(void *data, int state_high)
-{
- struct intel_gmbus *bus = data;
- struct drm_i915_private *dev_priv = bus->dev_priv;
- u32 reserved = get_reserved(bus);
- 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;
-
- I915_WRITE_NOTRACE(bus->gpio_reg, reserved | clock_bits);
- POSTING_READ(bus->gpio_reg);
-}
-
-static void set_data(void *data, int state_high)
-{
- struct intel_gmbus *bus = data;
- struct drm_i915_private *dev_priv = bus->dev_priv;
- u32 reserved = get_reserved(bus);
- 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;
-
- I915_WRITE_NOTRACE(bus->gpio_reg, reserved | data_bits);
- POSTING_READ(bus->gpio_reg);
-}
-
-static int
-intel_gpio_pre_xfer(struct i2c_adapter *adapter)
-{
- struct intel_gmbus *bus = container_of(adapter,
- struct intel_gmbus,
- adapter);
- struct drm_i915_private *dev_priv = bus->dev_priv;
-
- intel_i2c_reset(dev_priv);
-
- if (IS_PINEVIEW(dev_priv))
- pnv_gmbus_clock_gating(dev_priv, false);
-
- set_data(bus, 1);
- set_clock(bus, 1);
- udelay(I2C_RISEFALL_TIME);
- return 0;
-}
-
-static void
-intel_gpio_post_xfer(struct i2c_adapter *adapter)
-{
- struct intel_gmbus *bus = container_of(adapter,
- struct intel_gmbus,
- adapter);
- struct drm_i915_private *dev_priv = bus->dev_priv;
-
- set_data(bus, 1);
- set_clock(bus, 1);
-
- if (IS_PINEVIEW(dev_priv))
- pnv_gmbus_clock_gating(dev_priv, true);
-}
-
-static void
-intel_gpio_setup(struct intel_gmbus *bus, unsigned int pin)
-{
- struct drm_i915_private *dev_priv = bus->dev_priv;
- struct i2c_algo_bit_data *algo;
-
- algo = &bus->bit_algo;
-
- bus->gpio_reg = GPIO(get_gmbus_pin(dev_priv, pin)->gpio);
- bus->adapter.algo_data = algo;
- algo->setsda = set_data;
- algo->setscl = set_clock;
- algo->getsda = get_data;
- algo->getscl = get_clock;
- algo->pre_xfer = intel_gpio_pre_xfer;
- algo->post_xfer = intel_gpio_post_xfer;
- algo->udelay = I2C_RISEFALL_TIME;
- algo->timeout = usecs_to_jiffies(2200);
- algo->data = bus;
-}
-
-static int gmbus_wait(struct drm_i915_private *dev_priv, u32 status, u32 irq_en)
-{
- DEFINE_WAIT(wait);
- u32 gmbus2;
- int ret;
-
- /* Important: The hw handles only the first bit, so set only one! Since
- * we also need to check for NAKs besides the hw ready/idle signal, we
- * need to wake up periodically and check that ourselves.
- */
- if (!HAS_GMBUS_IRQ(dev_priv))
- irq_en = 0;
-
- add_wait_queue(&dev_priv->gmbus_wait_queue, &wait);
- I915_WRITE_FW(GMBUS4, irq_en);
-
- status |= GMBUS_SATOER;
- ret = wait_for_us((gmbus2 = I915_READ_FW(GMBUS2)) & status, 2);
- if (ret)
- ret = wait_for((gmbus2 = I915_READ_FW(GMBUS2)) & status, 50);
-
- I915_WRITE_FW(GMBUS4, 0);
- remove_wait_queue(&dev_priv->gmbus_wait_queue, &wait);
-
- if (gmbus2 & GMBUS_SATOER)
- return -ENXIO;
-
- return ret;
-}
-
-static int
-gmbus_wait_idle(struct drm_i915_private *dev_priv)
-{
- DEFINE_WAIT(wait);
- u32 irq_enable;
- int ret;
-
- /* Important: The hw handles only the first bit, so set only one! */
- irq_enable = 0;
- if (HAS_GMBUS_IRQ(dev_priv))
- irq_enable = GMBUS_IDLE_EN;
-
- add_wait_queue(&dev_priv->gmbus_wait_queue, &wait);
- I915_WRITE_FW(GMBUS4, irq_enable);
-
- ret = intel_wait_for_register_fw(&dev_priv->uncore,
- GMBUS2, GMBUS_ACTIVE, 0,
- 10);
-
- I915_WRITE_FW(GMBUS4, 0);
- remove_wait_queue(&dev_priv->gmbus_wait_queue, &wait);
-
- return ret;
-}
-
-static inline
-unsigned int gmbus_max_xfer_size(struct drm_i915_private *dev_priv)
-{
- return INTEL_GEN(dev_priv) >= 9 ? GEN9_GMBUS_BYTE_COUNT_MAX :
- GMBUS_BYTE_COUNT_MAX;
-}
-
-static int
-gmbus_xfer_read_chunk(struct drm_i915_private *dev_priv,
- unsigned short addr, u8 *buf, unsigned int len,
- u32 gmbus0_reg, u32 gmbus1_index)
-{
- unsigned int size = len;
- bool burst_read = len > gmbus_max_xfer_size(dev_priv);
- bool extra_byte_added = false;
-
- if (burst_read) {
- /*
- * As per HW Spec, for 512Bytes need to read extra Byte and
- * Ignore the extra byte read.
- */
- if (len == 512) {
- extra_byte_added = true;
- len++;
- }
- size = len % 256 + 256;
- I915_WRITE_FW(GMBUS0, gmbus0_reg | GMBUS_BYTE_CNT_OVERRIDE);
- }
-
- I915_WRITE_FW(GMBUS1,
- gmbus1_index |
- GMBUS_CYCLE_WAIT |
- (size << GMBUS_BYTE_COUNT_SHIFT) |
- (addr << GMBUS_SLAVE_ADDR_SHIFT) |
- GMBUS_SLAVE_READ | GMBUS_SW_RDY);
- while (len) {
- int ret;
- u32 val, loop = 0;
-
- ret = gmbus_wait(dev_priv, GMBUS_HW_RDY, GMBUS_HW_RDY_EN);
- if (ret)
- return ret;
-
- val = I915_READ_FW(GMBUS3);
- do {
- if (extra_byte_added && len == 1)
- break;
-
- *buf++ = val & 0xff;
- val >>= 8;
- } while (--len && ++loop < 4);
-
- if (burst_read && len == size - 4)
- /* Reset the override bit */
- I915_WRITE_FW(GMBUS0, gmbus0_reg);
- }
-
- return 0;
-}
-
-/*
- * HW spec says that 512Bytes in Burst read need special treatment.
- * But it doesn't talk about other multiple of 256Bytes. And couldn't locate
- * an I2C slave, which supports such a lengthy burst read too for experiments.
- *
- * So until things get clarified on HW support, to avoid the burst read length
- * in fold of 256Bytes except 512, max burst read length is fixed at 767Bytes.
- */
-#define INTEL_GMBUS_BURST_READ_MAX_LEN 767U
-
-static int
-gmbus_xfer_read(struct drm_i915_private *dev_priv, struct i2c_msg *msg,
- u32 gmbus0_reg, u32 gmbus1_index)
-{
- u8 *buf = msg->buf;
- unsigned int rx_size = msg->len;
- unsigned int len;
- int ret;
-
- do {
- if (HAS_GMBUS_BURST_READ(dev_priv))
- len = min(rx_size, INTEL_GMBUS_BURST_READ_MAX_LEN);
- else
- len = min(rx_size, gmbus_max_xfer_size(dev_priv));
-
- ret = gmbus_xfer_read_chunk(dev_priv, msg->addr, buf, len,
- gmbus0_reg, gmbus1_index);
- if (ret)
- return ret;
-
- rx_size -= len;
- buf += len;
- } while (rx_size != 0);
-
- return 0;
-}
-
-static int
-gmbus_xfer_write_chunk(struct drm_i915_private *dev_priv,
- unsigned short addr, u8 *buf, unsigned int len,
- u32 gmbus1_index)
-{
- unsigned int chunk_size = len;
- u32 val, loop;
-
- val = loop = 0;
- while (len && loop < 4) {
- val |= *buf++ << (8 * loop++);
- len -= 1;
- }
-
- I915_WRITE_FW(GMBUS3, val);
- I915_WRITE_FW(GMBUS1,
- gmbus1_index | GMBUS_CYCLE_WAIT |
- (chunk_size << GMBUS_BYTE_COUNT_SHIFT) |
- (addr << GMBUS_SLAVE_ADDR_SHIFT) |
- GMBUS_SLAVE_WRITE | GMBUS_SW_RDY);
- while (len) {
- int ret;
-
- val = loop = 0;
- do {
- val |= *buf++ << (8 * loop);
- } while (--len && ++loop < 4);
-
- I915_WRITE_FW(GMBUS3, val);
-
- ret = gmbus_wait(dev_priv, GMBUS_HW_RDY, GMBUS_HW_RDY_EN);
- if (ret)
- return ret;
- }
-
- return 0;
-}
-
-static int
-gmbus_xfer_write(struct drm_i915_private *dev_priv, struct i2c_msg *msg,
- u32 gmbus1_index)
-{
- u8 *buf = msg->buf;
- unsigned int tx_size = msg->len;
- unsigned int len;
- int ret;
-
- do {
- len = min(tx_size, gmbus_max_xfer_size(dev_priv));
-
- ret = gmbus_xfer_write_chunk(dev_priv, msg->addr, buf, len,
- gmbus1_index);
- if (ret)
- return ret;
-
- buf += len;
- tx_size -= len;
- } while (tx_size != 0);
-
- return 0;
-}
-
-/*
- * The gmbus controller can combine a 1 or 2 byte write with another read/write
- * that immediately follows it by using an "INDEX" cycle.
- */
-static bool
-gmbus_is_index_xfer(struct i2c_msg *msgs, int i, int num)
-{
- return (i + 1 < num &&
- msgs[i].addr == msgs[i + 1].addr &&
- !(msgs[i].flags & I2C_M_RD) &&
- (msgs[i].len == 1 || msgs[i].len == 2) &&
- msgs[i + 1].len > 0);
-}
-
-static int
-gmbus_index_xfer(struct drm_i915_private *dev_priv, struct i2c_msg *msgs,
- u32 gmbus0_reg)
-{
- u32 gmbus1_index = 0;
- u32 gmbus5 = 0;
- int ret;
-
- if (msgs[0].len == 2)
- gmbus5 = GMBUS_2BYTE_INDEX_EN |
- msgs[0].buf[1] | (msgs[0].buf[0] << 8);
- if (msgs[0].len == 1)
- gmbus1_index = GMBUS_CYCLE_INDEX |
- (msgs[0].buf[0] << GMBUS_SLAVE_INDEX_SHIFT);
-
- /* GMBUS5 holds 16-bit index */
- if (gmbus5)
- I915_WRITE_FW(GMBUS5, gmbus5);
-
- if (msgs[1].flags & I2C_M_RD)
- ret = gmbus_xfer_read(dev_priv, &msgs[1], gmbus0_reg,
- gmbus1_index);
- else
- ret = gmbus_xfer_write(dev_priv, &msgs[1], gmbus1_index);
-
- /* Clear GMBUS5 after each index transfer */
- if (gmbus5)
- I915_WRITE_FW(GMBUS5, 0);
-
- return ret;
-}
-
-static int
-do_gmbus_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, int num,
- u32 gmbus0_source)
-{
- struct intel_gmbus *bus = container_of(adapter,
- struct intel_gmbus,
- adapter);
- struct drm_i915_private *dev_priv = bus->dev_priv;
- int i = 0, inc, try = 0;
- int ret = 0;
-
- /* Display WA #0868: skl,bxt,kbl,cfl,glk,cnl */
- if (IS_GEN9_LP(dev_priv))
- bxt_gmbus_clock_gating(dev_priv, false);
- else if (HAS_PCH_SPT(dev_priv) ||
- HAS_PCH_KBP(dev_priv) || HAS_PCH_CNP(dev_priv))
- pch_gmbus_clock_gating(dev_priv, false);
-
-retry:
- I915_WRITE_FW(GMBUS0, gmbus0_source | bus->reg0);
-
- for (; i < num; i += inc) {
- inc = 1;
- if (gmbus_is_index_xfer(msgs, i, num)) {
- ret = gmbus_index_xfer(dev_priv, &msgs[i],
- gmbus0_source | bus->reg0);
- inc = 2; /* an index transmission is two msgs */
- } else if (msgs[i].flags & I2C_M_RD) {
- ret = gmbus_xfer_read(dev_priv, &msgs[i],
- gmbus0_source | bus->reg0, 0);
- } else {
- ret = gmbus_xfer_write(dev_priv, &msgs[i], 0);
- }
-
- if (!ret)
- ret = gmbus_wait(dev_priv,
- GMBUS_HW_WAIT_PHASE, GMBUS_HW_WAIT_EN);
- if (ret == -ETIMEDOUT)
- goto timeout;
- else if (ret)
- goto clear_err;
- }
-
- /* Generate a STOP condition on the bus. Note that gmbus can't generata
- * a STOP on the very first cycle. To simplify the code we
- * unconditionally generate the STOP condition with an additional gmbus
- * cycle. */
- I915_WRITE_FW(GMBUS1, GMBUS_CYCLE_STOP | GMBUS_SW_RDY);
-
- /* Mark the GMBUS interface as disabled after waiting for idle.
- * We will re-enable it at the start of the next xfer,
- * till then let it sleep.
- */
- if (gmbus_wait_idle(dev_priv)) {
- DRM_DEBUG_KMS("GMBUS [%s] timed out waiting for idle\n",
- adapter->name);
- ret = -ETIMEDOUT;
- }
- I915_WRITE_FW(GMBUS0, 0);
- ret = ret ?: i;
- goto out;
-
-clear_err:
- /*
- * Wait for bus to IDLE before clearing NAK.
- * If we clear the NAK while bus is still active, then it will stay
- * active and the next transaction may fail.
- *
- * If no ACK is received during the address phase of a transaction, the
- * adapter must report -ENXIO. It is not clear what to return if no ACK
- * is received at other times. But we have to be careful to not return
- * spurious -ENXIO because that will prevent i2c and drm edid functions
- * from retrying. So return -ENXIO only when gmbus properly quiescents -
- * timing out seems to happen when there _is_ a ddc chip present, but
- * it's slow responding and only answers on the 2nd retry.
- */
- ret = -ENXIO;
- if (gmbus_wait_idle(dev_priv)) {
- DRM_DEBUG_KMS("GMBUS [%s] timed out after NAK\n",
- adapter->name);
- ret = -ETIMEDOUT;
- }
-
- /* 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.
- */
- I915_WRITE_FW(GMBUS1, GMBUS_SW_CLR_INT);
- I915_WRITE_FW(GMBUS1, 0);
- I915_WRITE_FW(GMBUS0, 0);
-
- DRM_DEBUG_KMS("GMBUS [%s] NAK for addr: %04x %c(%d)\n",
- adapter->name, msgs[i].addr,
- (msgs[i].flags & I2C_M_RD) ? 'r' : 'w', msgs[i].len);
-
- /*
- * Passive adapters sometimes NAK the first probe. Retry the first
- * message once on -ENXIO for GMBUS transfers; the bit banging algorithm
- * has retries internally. See also the retry loop in
- * drm_do_probe_ddc_edid, which bails out on the first -ENXIO.
- */
- if (ret == -ENXIO && i == 0 && try++ == 0) {
- DRM_DEBUG_KMS("GMBUS [%s] NAK on first message, retry\n",
- adapter->name);
- goto retry;
- }
-
- goto out;
-
-timeout:
- DRM_DEBUG_KMS("GMBUS [%s] timed out, falling back to bit banging on pin %d\n",
- bus->adapter.name, bus->reg0 & 0xff);
- I915_WRITE_FW(GMBUS0, 0);
-
- /*
- * Hardware may not support GMBUS over these pins? Try GPIO bitbanging
- * instead. Use EAGAIN to have i2c core retry.
- */
- ret = -EAGAIN;
-
-out:
- /* Display WA #0868: skl,bxt,kbl,cfl,glk,cnl */
- if (IS_GEN9_LP(dev_priv))
- bxt_gmbus_clock_gating(dev_priv, true);
- else if (HAS_PCH_SPT(dev_priv) ||
- HAS_PCH_KBP(dev_priv) || HAS_PCH_CNP(dev_priv))
- pch_gmbus_clock_gating(dev_priv, true);
-
- 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_i915_private *dev_priv = bus->dev_priv;
- intel_wakeref_t wakeref;
- int ret;
-
- wakeref = intel_display_power_get(dev_priv, POWER_DOMAIN_GMBUS);
-
- if (bus->force_bit) {
- ret = i2c_bit_algo.master_xfer(adapter, msgs, num);
- if (ret < 0)
- bus->force_bit &= ~GMBUS_FORCE_BIT_RETRY;
- } else {
- ret = do_gmbus_xfer(adapter, msgs, num, 0);
- if (ret == -EAGAIN)
- bus->force_bit |= GMBUS_FORCE_BIT_RETRY;
- }
-
- intel_display_power_put(dev_priv, POWER_DOMAIN_GMBUS, wakeref);
-
- return ret;
-}
-
-int intel_gmbus_output_aksv(struct i2c_adapter *adapter)
-{
- struct intel_gmbus *bus =
- container_of(adapter, struct intel_gmbus, adapter);
- struct drm_i915_private *dev_priv = bus->dev_priv;
- u8 cmd = DRM_HDCP_DDC_AKSV;
- u8 buf[DRM_HDCP_KSV_LEN] = { 0 };
- struct i2c_msg msgs[] = {
- {
- .addr = DRM_HDCP_DDC_ADDR,
- .flags = 0,
- .len = sizeof(cmd),
- .buf = &cmd,
- },
- {
- .addr = DRM_HDCP_DDC_ADDR,
- .flags = 0,
- .len = sizeof(buf),
- .buf = buf,
- }
- };
- intel_wakeref_t wakeref;
- int ret;
-
- wakeref = intel_display_power_get(dev_priv, POWER_DOMAIN_GMBUS);
- mutex_lock(&dev_priv->gmbus_mutex);
-
- /*
- * In order to output Aksv to the receiver, use an indexed write to
- * pass the i2c command, and tell GMBUS to use the HW-provided value
- * instead of sourcing GMBUS3 for the data.
- */
- ret = do_gmbus_xfer(adapter, msgs, ARRAY_SIZE(msgs), GMBUS_AKSV_SELECT);
-
- mutex_unlock(&dev_priv->gmbus_mutex);
- intel_display_power_put(dev_priv, POWER_DOMAIN_GMBUS, wakeref);
-
- return ret;
-}
-
-static u32 gmbus_func(struct i2c_adapter *adapter)
-{
- return i2c_bit_algo.functionality(adapter) &
- (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
-};
-
-static void gmbus_lock_bus(struct i2c_adapter *adapter,
- unsigned int flags)
-{
- struct intel_gmbus *bus = to_intel_gmbus(adapter);
- struct drm_i915_private *dev_priv = bus->dev_priv;
-
- mutex_lock(&dev_priv->gmbus_mutex);
-}
-
-static int gmbus_trylock_bus(struct i2c_adapter *adapter,
- unsigned int flags)
-{
- struct intel_gmbus *bus = to_intel_gmbus(adapter);
- struct drm_i915_private *dev_priv = bus->dev_priv;
-
- return mutex_trylock(&dev_priv->gmbus_mutex);
-}
-
-static void gmbus_unlock_bus(struct i2c_adapter *adapter,
- unsigned int flags)
-{
- struct intel_gmbus *bus = to_intel_gmbus(adapter);
- struct drm_i915_private *dev_priv = bus->dev_priv;
-
- mutex_unlock(&dev_priv->gmbus_mutex);
-}
-
-static const struct i2c_lock_operations gmbus_lock_ops = {
- .lock_bus = gmbus_lock_bus,
- .trylock_bus = gmbus_trylock_bus,
- .unlock_bus = gmbus_unlock_bus,
-};
-
-/**
- * intel_gmbus_setup - instantiate all Intel i2c GMBuses
- * @dev_priv: i915 device private
- */
-int intel_setup_gmbus(struct drm_i915_private *dev_priv)
-{
- struct pci_dev *pdev = dev_priv->drm.pdev;
- struct intel_gmbus *bus;
- unsigned int pin;
- int ret;
-
- if (!HAS_DISPLAY(dev_priv))
- return 0;
-
- if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
- dev_priv->gpio_mmio_base = VLV_DISPLAY_BASE;
- else if (!HAS_GMCH(dev_priv))
- /*
- * Broxton uses the same PCH offsets for South Display Engine,
- * even though it doesn't have a PCH.
- */
- dev_priv->gpio_mmio_base = PCH_DISPLAY_BASE;
-
- mutex_init(&dev_priv->gmbus_mutex);
- init_waitqueue_head(&dev_priv->gmbus_wait_queue);
-
- for (pin = 0; pin < ARRAY_SIZE(dev_priv->gmbus); pin++) {
- if (!intel_gmbus_is_valid_pin(dev_priv, pin))
- continue;
-
- bus = &dev_priv->gmbus[pin];
-
- bus->adapter.owner = THIS_MODULE;
- bus->adapter.class = I2C_CLASS_DDC;
- snprintf(bus->adapter.name,
- sizeof(bus->adapter.name),
- "i915 gmbus %s",
- get_gmbus_pin(dev_priv, pin)->name);
-
- bus->adapter.dev.parent = &pdev->dev;
- bus->dev_priv = dev_priv;
-
- bus->adapter.algo = &gmbus_algorithm;
- bus->adapter.lock_ops = &gmbus_lock_ops;
-
- /*
- * We wish to retry with bit banging
- * after a timed out GMBUS attempt.
- */
- bus->adapter.retries = 1;
-
- /* By default use a conservative clock rate */
- bus->reg0 = pin | GMBUS_RATE_100KHZ;
-
- /* gmbus seems to be broken on i830 */
- if (IS_I830(dev_priv))
- bus->force_bit = 1;
-
- intel_gpio_setup(bus, pin);
-
- ret = i2c_add_adapter(&bus->adapter);
- if (ret)
- goto err;
- }
-
- intel_i2c_reset(dev_priv);
-
- return 0;
-
-err:
- while (pin--) {
- if (!intel_gmbus_is_valid_pin(dev_priv, pin))
- continue;
-
- bus = &dev_priv->gmbus[pin];
- i2c_del_adapter(&bus->adapter);
- }
- return ret;
-}
-
-struct i2c_adapter *intel_gmbus_get_adapter(struct drm_i915_private *dev_priv,
- unsigned int pin)
-{
- if (WARN_ON(!intel_gmbus_is_valid_pin(dev_priv, pin)))
- return NULL;
-
- return &dev_priv->gmbus[pin].adapter;
-}
-
-void intel_gmbus_set_speed(struct i2c_adapter *adapter, int speed)
-{
- struct intel_gmbus *bus = to_intel_gmbus(adapter);
-
- bus->reg0 = (bus->reg0 & ~(0x3 << 8)) | speed;
-}
-
-void intel_gmbus_force_bit(struct i2c_adapter *adapter, bool force_bit)
-{
- struct intel_gmbus *bus = to_intel_gmbus(adapter);
- struct drm_i915_private *dev_priv = bus->dev_priv;
-
- mutex_lock(&dev_priv->gmbus_mutex);
-
- bus->force_bit += force_bit ? 1 : -1;
- DRM_DEBUG_KMS("%sabling bit-banging on %s. force bit now %d\n",
- force_bit ? "en" : "dis", adapter->name,
- bus->force_bit);
-
- mutex_unlock(&dev_priv->gmbus_mutex);
-}
-
-void intel_teardown_gmbus(struct drm_i915_private *dev_priv)
-{
- struct intel_gmbus *bus;
- unsigned int pin;
-
- for (pin = 0; pin < ARRAY_SIZE(dev_priv->gmbus); pin++) {
- if (!intel_gmbus_is_valid_pin(dev_priv, pin))
- continue;
-
- bus = &dev_priv->gmbus[pin];
- i2c_del_adapter(&bus->adapter);
- }
-}
generated by cgit v1.2.3 (git 2.39.1) at 2025-04-08 08:41:21 +0000