From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: Add the rt linux 4.1.3-rt3 as base Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang --- kernel/drivers/gpu/drm/drm_dp_helper.c | 652 +++++++++++++++++++++++++++++++++ 1 file changed, 652 insertions(+) create mode 100644 kernel/drivers/gpu/drm/drm_dp_helper.c (limited to 'kernel/drivers/gpu/drm/drm_dp_helper.c') diff --git a/kernel/drivers/gpu/drm/drm_dp_helper.c b/kernel/drivers/gpu/drm/drm_dp_helper.c new file mode 100644 index 000000000..71dcbc64a --- /dev/null +++ b/kernel/drivers/gpu/drm/drm_dp_helper.c @@ -0,0 +1,652 @@ +/* + * Copyright © 2009 Keith Packard + * + * Permission to use, copy, modify, distribute, and sell this software and its + * documentation for any purpose is hereby granted without fee, provided that + * the above copyright notice appear in all copies and that both that copyright + * notice and this permission notice appear in supporting documentation, and + * that the name of the copyright holders not be used in advertising or + * publicity pertaining to distribution of the software without specific, + * written prior permission. The copyright holders make no representations + * about the suitability of this software for any purpose. It is provided "as + * is" without express or implied warranty. + * + * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, + * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO + * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR + * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, + * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER + * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE + * OF THIS SOFTWARE. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/** + * DOC: dp helpers + * + * These functions contain some common logic and helpers at various abstraction + * levels to deal with Display Port sink devices and related things like DP aux + * channel transfers, EDID reading over DP aux channels, decoding certain DPCD + * blocks, ... + */ + +/* Helpers for DP link training */ +static u8 dp_link_status(const u8 link_status[DP_LINK_STATUS_SIZE], int r) +{ + return link_status[r - DP_LANE0_1_STATUS]; +} + +static u8 dp_get_lane_status(const u8 link_status[DP_LINK_STATUS_SIZE], + int lane) +{ + int i = DP_LANE0_1_STATUS + (lane >> 1); + int s = (lane & 1) * 4; + u8 l = dp_link_status(link_status, i); + return (l >> s) & 0xf; +} + +bool drm_dp_channel_eq_ok(const u8 link_status[DP_LINK_STATUS_SIZE], + int lane_count) +{ + u8 lane_align; + u8 lane_status; + int lane; + + lane_align = dp_link_status(link_status, + DP_LANE_ALIGN_STATUS_UPDATED); + if ((lane_align & DP_INTERLANE_ALIGN_DONE) == 0) + return false; + for (lane = 0; lane < lane_count; lane++) { + lane_status = dp_get_lane_status(link_status, lane); + if ((lane_status & DP_CHANNEL_EQ_BITS) != DP_CHANNEL_EQ_BITS) + return false; + } + return true; +} +EXPORT_SYMBOL(drm_dp_channel_eq_ok); + +bool drm_dp_clock_recovery_ok(const u8 link_status[DP_LINK_STATUS_SIZE], + int lane_count) +{ + int lane; + u8 lane_status; + + for (lane = 0; lane < lane_count; lane++) { + lane_status = dp_get_lane_status(link_status, lane); + if ((lane_status & DP_LANE_CR_DONE) == 0) + return false; + } + return true; +} +EXPORT_SYMBOL(drm_dp_clock_recovery_ok); + +u8 drm_dp_get_adjust_request_voltage(const u8 link_status[DP_LINK_STATUS_SIZE], + int lane) +{ + int i = DP_ADJUST_REQUEST_LANE0_1 + (lane >> 1); + int s = ((lane & 1) ? + DP_ADJUST_VOLTAGE_SWING_LANE1_SHIFT : + DP_ADJUST_VOLTAGE_SWING_LANE0_SHIFT); + u8 l = dp_link_status(link_status, i); + + return ((l >> s) & 0x3) << DP_TRAIN_VOLTAGE_SWING_SHIFT; +} +EXPORT_SYMBOL(drm_dp_get_adjust_request_voltage); + +u8 drm_dp_get_adjust_request_pre_emphasis(const u8 link_status[DP_LINK_STATUS_SIZE], + int lane) +{ + int i = DP_ADJUST_REQUEST_LANE0_1 + (lane >> 1); + int s = ((lane & 1) ? + DP_ADJUST_PRE_EMPHASIS_LANE1_SHIFT : + DP_ADJUST_PRE_EMPHASIS_LANE0_SHIFT); + u8 l = dp_link_status(link_status, i); + + return ((l >> s) & 0x3) << DP_TRAIN_PRE_EMPHASIS_SHIFT; +} +EXPORT_SYMBOL(drm_dp_get_adjust_request_pre_emphasis); + +void drm_dp_link_train_clock_recovery_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) { + if (dpcd[DP_TRAINING_AUX_RD_INTERVAL] == 0) + udelay(100); + else + mdelay(dpcd[DP_TRAINING_AUX_RD_INTERVAL] * 4); +} +EXPORT_SYMBOL(drm_dp_link_train_clock_recovery_delay); + +void drm_dp_link_train_channel_eq_delay(const u8 dpcd[DP_RECEIVER_CAP_SIZE]) { + if (dpcd[DP_TRAINING_AUX_RD_INTERVAL] == 0) + udelay(400); + else + mdelay(dpcd[DP_TRAINING_AUX_RD_INTERVAL] * 4); +} +EXPORT_SYMBOL(drm_dp_link_train_channel_eq_delay); + +u8 drm_dp_link_rate_to_bw_code(int link_rate) +{ + switch (link_rate) { + case 162000: + default: + return DP_LINK_BW_1_62; + case 270000: + return DP_LINK_BW_2_7; + case 540000: + return DP_LINK_BW_5_4; + } +} +EXPORT_SYMBOL(drm_dp_link_rate_to_bw_code); + +int drm_dp_bw_code_to_link_rate(u8 link_bw) +{ + switch (link_bw) { + case DP_LINK_BW_1_62: + default: + return 162000; + case DP_LINK_BW_2_7: + return 270000; + case DP_LINK_BW_5_4: + return 540000; + } +} +EXPORT_SYMBOL(drm_dp_bw_code_to_link_rate); + +/** + * DOC: dp helpers + * + * The DisplayPort AUX channel is an abstraction to allow generic, driver- + * independent access to AUX functionality. Drivers can take advantage of + * this by filling in the fields of the drm_dp_aux structure. + * + * Transactions are described using a hardware-independent drm_dp_aux_msg + * structure, which is passed into a driver's .transfer() implementation. + * Both native and I2C-over-AUX transactions are supported. + */ + +static int drm_dp_dpcd_access(struct drm_dp_aux *aux, u8 request, + unsigned int offset, void *buffer, size_t size) +{ + struct drm_dp_aux_msg msg; + unsigned int retry; + int err; + + memset(&msg, 0, sizeof(msg)); + msg.address = offset; + msg.request = request; + msg.buffer = buffer; + msg.size = size; + + /* + * The specification doesn't give any recommendation on how often to + * retry native transactions. We used to retry 7 times like for + * aux i2c transactions but real world devices this wasn't + * sufficient, bump to 32 which makes Dell 4k monitors happier. + */ + for (retry = 0; retry < 32; retry++) { + + mutex_lock(&aux->hw_mutex); + err = aux->transfer(aux, &msg); + mutex_unlock(&aux->hw_mutex); + if (err < 0) { + if (err == -EBUSY) + continue; + + return err; + } + + + switch (msg.reply & DP_AUX_NATIVE_REPLY_MASK) { + case DP_AUX_NATIVE_REPLY_ACK: + if (err < size) + return -EPROTO; + return err; + + case DP_AUX_NATIVE_REPLY_NACK: + return -EIO; + + case DP_AUX_NATIVE_REPLY_DEFER: + usleep_range(400, 500); + break; + } + } + + DRM_DEBUG_KMS("too many retries, giving up\n"); + return -EIO; +} + +/** + * drm_dp_dpcd_read() - read a series of bytes from the DPCD + * @aux: DisplayPort AUX channel + * @offset: address of the (first) register to read + * @buffer: buffer to store the register values + * @size: number of bytes in @buffer + * + * Returns the number of bytes transferred on success, or a negative error + * code on failure. -EIO is returned if the request was NAKed by the sink or + * if the retry count was exceeded. If not all bytes were transferred, this + * function returns -EPROTO. Errors from the underlying AUX channel transfer + * function, with the exception of -EBUSY (which causes the transaction to + * be retried), are propagated to the caller. + */ +ssize_t drm_dp_dpcd_read(struct drm_dp_aux *aux, unsigned int offset, + void *buffer, size_t size) +{ + return drm_dp_dpcd_access(aux, DP_AUX_NATIVE_READ, offset, buffer, + size); +} +EXPORT_SYMBOL(drm_dp_dpcd_read); + +/** + * drm_dp_dpcd_write() - write a series of bytes to the DPCD + * @aux: DisplayPort AUX channel + * @offset: address of the (first) register to write + * @buffer: buffer containing the values to write + * @size: number of bytes in @buffer + * + * Returns the number of bytes transferred on success, or a negative error + * code on failure. -EIO is returned if the request was NAKed by the sink or + * if the retry count was exceeded. If not all bytes were transferred, this + * function returns -EPROTO. Errors from the underlying AUX channel transfer + * function, with the exception of -EBUSY (which causes the transaction to + * be retried), are propagated to the caller. + */ +ssize_t drm_dp_dpcd_write(struct drm_dp_aux *aux, unsigned int offset, + void *buffer, size_t size) +{ + return drm_dp_dpcd_access(aux, DP_AUX_NATIVE_WRITE, offset, buffer, + size); +} +EXPORT_SYMBOL(drm_dp_dpcd_write); + +/** + * drm_dp_dpcd_read_link_status() - read DPCD link status (bytes 0x202-0x207) + * @aux: DisplayPort AUX channel + * @status: buffer to store the link status in (must be at least 6 bytes) + * + * Returns the number of bytes transferred on success or a negative error + * code on failure. + */ +int drm_dp_dpcd_read_link_status(struct drm_dp_aux *aux, + u8 status[DP_LINK_STATUS_SIZE]) +{ + return drm_dp_dpcd_read(aux, DP_LANE0_1_STATUS, status, + DP_LINK_STATUS_SIZE); +} +EXPORT_SYMBOL(drm_dp_dpcd_read_link_status); + +/** + * drm_dp_link_probe() - probe a DisplayPort link for capabilities + * @aux: DisplayPort AUX channel + * @link: pointer to structure in which to return link capabilities + * + * The structure filled in by this function can usually be passed directly + * into drm_dp_link_power_up() and drm_dp_link_configure() to power up and + * configure the link based on the link's capabilities. + * + * Returns 0 on success or a negative error code on failure. + */ +int drm_dp_link_probe(struct drm_dp_aux *aux, struct drm_dp_link *link) +{ + u8 values[3]; + int err; + + memset(link, 0, sizeof(*link)); + + err = drm_dp_dpcd_read(aux, DP_DPCD_REV, values, sizeof(values)); + if (err < 0) + return err; + + link->revision = values[0]; + link->rate = drm_dp_bw_code_to_link_rate(values[1]); + link->num_lanes = values[2] & DP_MAX_LANE_COUNT_MASK; + + if (values[2] & DP_ENHANCED_FRAME_CAP) + link->capabilities |= DP_LINK_CAP_ENHANCED_FRAMING; + + return 0; +} +EXPORT_SYMBOL(drm_dp_link_probe); + +/** + * drm_dp_link_power_up() - power up a DisplayPort link + * @aux: DisplayPort AUX channel + * @link: pointer to a structure containing the link configuration + * + * Returns 0 on success or a negative error code on failure. + */ +int drm_dp_link_power_up(struct drm_dp_aux *aux, struct drm_dp_link *link) +{ + u8 value; + int err; + + /* DP_SET_POWER register is only available on DPCD v1.1 and later */ + if (link->revision < 0x11) + return 0; + + err = drm_dp_dpcd_readb(aux, DP_SET_POWER, &value); + if (err < 0) + return err; + + value &= ~DP_SET_POWER_MASK; + value |= DP_SET_POWER_D0; + + err = drm_dp_dpcd_writeb(aux, DP_SET_POWER, value); + if (err < 0) + return err; + + /* + * According to the DP 1.1 specification, a "Sink Device must exit the + * power saving state within 1 ms" (Section 2.5.3.1, Table 5-52, "Sink + * Control Field" (register 0x600). + */ + usleep_range(1000, 2000); + + return 0; +} +EXPORT_SYMBOL(drm_dp_link_power_up); + +/** + * drm_dp_link_power_down() - power down a DisplayPort link + * @aux: DisplayPort AUX channel + * @link: pointer to a structure containing the link configuration + * + * Returns 0 on success or a negative error code on failure. + */ +int drm_dp_link_power_down(struct drm_dp_aux *aux, struct drm_dp_link *link) +{ + u8 value; + int err; + + /* DP_SET_POWER register is only available on DPCD v1.1 and later */ + if (link->revision < 0x11) + return 0; + + err = drm_dp_dpcd_readb(aux, DP_SET_POWER, &value); + if (err < 0) + return err; + + value &= ~DP_SET_POWER_MASK; + value |= DP_SET_POWER_D3; + + err = drm_dp_dpcd_writeb(aux, DP_SET_POWER, value); + if (err < 0) + return err; + + return 0; +} +EXPORT_SYMBOL(drm_dp_link_power_down); + +/** + * drm_dp_link_configure() - configure a DisplayPort link + * @aux: DisplayPort AUX channel + * @link: pointer to a structure containing the link configuration + * + * Returns 0 on success or a negative error code on failure. + */ +int drm_dp_link_configure(struct drm_dp_aux *aux, struct drm_dp_link *link) +{ + u8 values[2]; + int err; + + values[0] = drm_dp_link_rate_to_bw_code(link->rate); + values[1] = link->num_lanes; + + if (link->capabilities & DP_LINK_CAP_ENHANCED_FRAMING) + values[1] |= DP_LANE_COUNT_ENHANCED_FRAME_EN; + + err = drm_dp_dpcd_write(aux, DP_LINK_BW_SET, values, sizeof(values)); + if (err < 0) + return err; + + return 0; +} +EXPORT_SYMBOL(drm_dp_link_configure); + +/* + * I2C-over-AUX implementation + */ + +static u32 drm_dp_i2c_functionality(struct i2c_adapter *adapter) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | + I2C_FUNC_SMBUS_READ_BLOCK_DATA | + I2C_FUNC_SMBUS_BLOCK_PROC_CALL | + I2C_FUNC_10BIT_ADDR; +} + +/* + * Transfer a single I2C-over-AUX message and handle various error conditions, + * retrying the transaction as appropriate. It is assumed that the + * aux->transfer function does not modify anything in the msg other than the + * reply field. + * + * Returns bytes transferred on success, or a negative error code on failure. + */ +static int drm_dp_i2c_do_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *msg) +{ + unsigned int retry; + int ret; + + /* + * DP1.2 sections 2.7.7.1.5.6.1 and 2.7.7.1.6.6.1: A DP Source device + * is required to retry at least seven times upon receiving AUX_DEFER + * before giving up the AUX transaction. + */ + for (retry = 0; retry < 7; retry++) { + mutex_lock(&aux->hw_mutex); + ret = aux->transfer(aux, msg); + mutex_unlock(&aux->hw_mutex); + if (ret < 0) { + if (ret == -EBUSY) + continue; + + DRM_DEBUG_KMS("transaction failed: %d\n", ret); + return ret; + } + + + switch (msg->reply & DP_AUX_NATIVE_REPLY_MASK) { + case DP_AUX_NATIVE_REPLY_ACK: + /* + * For I2C-over-AUX transactions this isn't enough, we + * need to check for the I2C ACK reply. + */ + break; + + case DP_AUX_NATIVE_REPLY_NACK: + DRM_DEBUG_KMS("native nack (result=%d, size=%zu)\n", ret, msg->size); + return -EREMOTEIO; + + case DP_AUX_NATIVE_REPLY_DEFER: + DRM_DEBUG_KMS("native defer"); + /* + * We could check for I2C bit rate capabilities and if + * available adjust this interval. We could also be + * more careful with DP-to-legacy adapters where a + * long legacy cable may force very low I2C bit rates. + * + * For now just defer for long enough to hopefully be + * safe for all use-cases. + */ + usleep_range(500, 600); + continue; + + default: + DRM_ERROR("invalid native reply %#04x\n", msg->reply); + return -EREMOTEIO; + } + + switch (msg->reply & DP_AUX_I2C_REPLY_MASK) { + case DP_AUX_I2C_REPLY_ACK: + /* + * Both native ACK and I2C ACK replies received. We + * can assume the transfer was successful. + */ + return ret; + + case DP_AUX_I2C_REPLY_NACK: + DRM_DEBUG_KMS("I2C nack (result=%d, size=%zu\n", ret, msg->size); + aux->i2c_nack_count++; + return -EREMOTEIO; + + case DP_AUX_I2C_REPLY_DEFER: + DRM_DEBUG_KMS("I2C defer\n"); + aux->i2c_defer_count++; + usleep_range(400, 500); + continue; + + default: + DRM_ERROR("invalid I2C reply %#04x\n", msg->reply); + return -EREMOTEIO; + } + } + + DRM_DEBUG_KMS("too many retries, giving up\n"); + return -EREMOTEIO; +} + +/* + * Keep retrying drm_dp_i2c_do_msg until all data has been transferred. + * + * Returns an error code on failure, or a recommended transfer size on success. + */ +static int drm_dp_i2c_drain_msg(struct drm_dp_aux *aux, struct drm_dp_aux_msg *orig_msg) +{ + int err, ret = orig_msg->size; + struct drm_dp_aux_msg msg = *orig_msg; + + while (msg.size > 0) { + err = drm_dp_i2c_do_msg(aux, &msg); + if (err <= 0) + return err == 0 ? -EPROTO : err; + + if (err < msg.size && err < ret) { + DRM_DEBUG_KMS("Partial I2C reply: requested %zu bytes got %d bytes\n", + msg.size, err); + ret = err; + } + + msg.size -= err; + msg.buffer += err; + } + + return ret; +} + +/* + * Bizlink designed DP->DVI-D Dual Link adapters require the I2C over AUX + * packets to be as large as possible. If not, the I2C transactions never + * succeed. Hence the default is maximum. + */ +static int dp_aux_i2c_transfer_size __read_mostly = DP_AUX_MAX_PAYLOAD_BYTES; +module_param_unsafe(dp_aux_i2c_transfer_size, int, 0644); +MODULE_PARM_DESC(dp_aux_i2c_transfer_size, + "Number of bytes to transfer in a single I2C over DP AUX CH message, (1-16, default 16)"); + +static int drm_dp_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg *msgs, + int num) +{ + struct drm_dp_aux *aux = adapter->algo_data; + unsigned int i, j; + unsigned transfer_size; + struct drm_dp_aux_msg msg; + int err = 0; + + dp_aux_i2c_transfer_size = clamp(dp_aux_i2c_transfer_size, 1, DP_AUX_MAX_PAYLOAD_BYTES); + + memset(&msg, 0, sizeof(msg)); + + for (i = 0; i < num; i++) { + msg.address = msgs[i].addr; + msg.request = (msgs[i].flags & I2C_M_RD) ? + DP_AUX_I2C_READ : + DP_AUX_I2C_WRITE; + msg.request |= DP_AUX_I2C_MOT; + /* Send a bare address packet to start the transaction. + * Zero sized messages specify an address only (bare + * address) transaction. + */ + msg.buffer = NULL; + msg.size = 0; + err = drm_dp_i2c_do_msg(aux, &msg); + if (err < 0) + break; + /* We want each transaction to be as large as possible, but + * we'll go to smaller sizes if the hardware gives us a + * short reply. + */ + transfer_size = dp_aux_i2c_transfer_size; + for (j = 0; j < msgs[i].len; j += msg.size) { + msg.buffer = msgs[i].buf + j; + msg.size = min(transfer_size, msgs[i].len - j); + + err = drm_dp_i2c_drain_msg(aux, &msg); + if (err < 0) + break; + transfer_size = err; + } + if (err < 0) + break; + } + if (err >= 0) + err = num; + /* Send a bare address packet to close out the transaction. + * Zero sized messages specify an address only (bare + * address) transaction. + */ + msg.request &= ~DP_AUX_I2C_MOT; + msg.buffer = NULL; + msg.size = 0; + (void)drm_dp_i2c_do_msg(aux, &msg); + + return err; +} + +static const struct i2c_algorithm drm_dp_i2c_algo = { + .functionality = drm_dp_i2c_functionality, + .master_xfer = drm_dp_i2c_xfer, +}; + +/** + * drm_dp_aux_register() - initialise and register aux channel + * @aux: DisplayPort AUX channel + * + * Returns 0 on success or a negative error code on failure. + */ +int drm_dp_aux_register(struct drm_dp_aux *aux) +{ + mutex_init(&aux->hw_mutex); + + aux->ddc.algo = &drm_dp_i2c_algo; + aux->ddc.algo_data = aux; + aux->ddc.retries = 3; + + aux->ddc.class = I2C_CLASS_DDC; + aux->ddc.owner = THIS_MODULE; + aux->ddc.dev.parent = aux->dev; + aux->ddc.dev.of_node = aux->dev->of_node; + + strlcpy(aux->ddc.name, aux->name ? aux->name : dev_name(aux->dev), + sizeof(aux->ddc.name)); + + return i2c_add_adapter(&aux->ddc); +} +EXPORT_SYMBOL(drm_dp_aux_register); + +/** + * drm_dp_aux_unregister() - unregister an AUX adapter + * @aux: DisplayPort AUX channel + */ +void drm_dp_aux_unregister(struct drm_dp_aux *aux) +{ + i2c_del_adapter(&aux->ddc); +} +EXPORT_SYMBOL(drm_dp_aux_unregister); -- cgit 1.2.3-korg