diff options
Diffstat (limited to 'drivers/gpu/drm/omapdrm/dss/hdmi4_cec.c')
| -rw-r--r-- | drivers/gpu/drm/omapdrm/dss/hdmi4_cec.c | 353 |
1 files changed, 353 insertions, 0 deletions
diff --git a/drivers/gpu/drm/omapdrm/dss/hdmi4_cec.c b/drivers/gpu/drm/omapdrm/dss/hdmi4_cec.c new file mode 100644 index 000000000000..23db74ae1826 --- /dev/null +++ b/drivers/gpu/drm/omapdrm/dss/hdmi4_cec.c @@ -0,0 +1,353 @@ +/* + * HDMI CEC + * + * Based on the CEC code from hdmi_ti_4xxx_ip.c from Android. + * + * Copyright (C) 2010-2011 Texas Instruments Incorporated - http://www.ti.com/ + * Authors: Yong Zhi + * Mythri pk <[email protected]> + * + * Heavily modified to use the linux CEC framework: + * + * Copyright 2016-2017 Cisco Systems, Inc. and/or its affiliates. All rights reserved. + * + * This program is free software; you may redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; version 2 of the License. + * + * 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. + */ + +#include <linux/kernel.h> +#include <linux/err.h> +#include <linux/io.h> +#include <linux/platform_device.h> +#include <linux/slab.h> + +#include "dss.h" +#include "hdmi.h" +#include "hdmi4_core.h" +#include "hdmi4_cec.h" + +/* HDMI CEC */ +#define HDMI_CEC_DEV_ID 0x900 +#define HDMI_CEC_SPEC 0x904 + +/* Not really a debug register, more a low-level control register */ +#define HDMI_CEC_DBG_3 0x91C +#define HDMI_CEC_TX_INIT 0x920 +#define HDMI_CEC_TX_DEST 0x924 +#define HDMI_CEC_SETUP 0x938 +#define HDMI_CEC_TX_COMMAND 0x93C +#define HDMI_CEC_TX_OPERAND 0x940 +#define HDMI_CEC_TRANSMIT_DATA 0x97C +#define HDMI_CEC_CA_7_0 0x988 +#define HDMI_CEC_CA_15_8 0x98C +#define HDMI_CEC_INT_STATUS_0 0x998 +#define HDMI_CEC_INT_STATUS_1 0x99C +#define HDMI_CEC_INT_ENABLE_0 0x990 +#define HDMI_CEC_INT_ENABLE_1 0x994 +#define HDMI_CEC_RX_CONTROL 0x9B0 +#define HDMI_CEC_RX_COUNT 0x9B4 +#define HDMI_CEC_RX_CMD_HEADER 0x9B8 +#define HDMI_CEC_RX_COMMAND 0x9BC +#define HDMI_CEC_RX_OPERAND 0x9C0 + +#define HDMI_CEC_TX_FIFO_INT_MASK 0x64 +#define HDMI_CEC_RETRANSMIT_CNT_INT_MASK 0x2 + +#define HDMI_CORE_CEC_RETRY 200 + +static void hdmi_cec_received_msg(struct hdmi_core_data *core) +{ + u32 cnt = hdmi_read_reg(core->base, HDMI_CEC_RX_COUNT) & 0xff; + + /* While there are CEC frames in the FIFO */ + while (cnt & 0x70) { + /* and the frame doesn't have an error */ + if (!(cnt & 0x80)) { + struct cec_msg msg = {}; + unsigned int i; + + /* then read the message */ + msg.len = cnt & 0xf; + if (msg.len > CEC_MAX_MSG_SIZE - 2) + msg.len = CEC_MAX_MSG_SIZE - 2; + msg.msg[0] = hdmi_read_reg(core->base, + HDMI_CEC_RX_CMD_HEADER); + msg.msg[1] = hdmi_read_reg(core->base, + HDMI_CEC_RX_COMMAND); + for (i = 0; i < msg.len; i++) { + unsigned int reg = HDMI_CEC_RX_OPERAND + i * 4; + + msg.msg[2 + i] = + hdmi_read_reg(core->base, reg); + } + msg.len += 2; + cec_received_msg(core->adap, &msg); + } + /* Clear the current frame from the FIFO */ + hdmi_write_reg(core->base, HDMI_CEC_RX_CONTROL, 1); + /* Wait until the current frame is cleared */ + while (hdmi_read_reg(core->base, HDMI_CEC_RX_CONTROL) & 1) + udelay(1); + /* + * Re-read the count register and loop to see if there are + * more messages in the FIFO. + */ + cnt = hdmi_read_reg(core->base, HDMI_CEC_RX_COUNT) & 0xff; + } +} + +void hdmi4_cec_irq(struct hdmi_core_data *core) +{ + u32 stat0 = hdmi_read_reg(core->base, HDMI_CEC_INT_STATUS_0); + u32 stat1 = hdmi_read_reg(core->base, HDMI_CEC_INT_STATUS_1); + + hdmi_write_reg(core->base, HDMI_CEC_INT_STATUS_0, stat0); + hdmi_write_reg(core->base, HDMI_CEC_INT_STATUS_1, stat1); + + if (stat0 & 0x20) { + cec_transmit_done(core->adap, CEC_TX_STATUS_OK, + 0, 0, 0, 0); + REG_FLD_MOD(core->base, HDMI_CEC_DBG_3, 0x1, 7, 7); + } else if (stat1 & 0x02) { + u32 dbg3 = hdmi_read_reg(core->base, HDMI_CEC_DBG_3); + + cec_transmit_done(core->adap, + CEC_TX_STATUS_NACK | + CEC_TX_STATUS_MAX_RETRIES, + 0, (dbg3 >> 4) & 7, 0, 0); + REG_FLD_MOD(core->base, HDMI_CEC_DBG_3, 0x1, 7, 7); + } + if (stat0 & 0x02) + hdmi_cec_received_msg(core); +} + +static bool hdmi_cec_clear_tx_fifo(struct cec_adapter *adap) +{ + struct hdmi_core_data *core = cec_get_drvdata(adap); + int retry = HDMI_CORE_CEC_RETRY; + int temp; + + REG_FLD_MOD(core->base, HDMI_CEC_DBG_3, 0x1, 7, 7); + while (retry) { + temp = hdmi_read_reg(core->base, HDMI_CEC_DBG_3); + if (FLD_GET(temp, 7, 7) == 0) + break; + retry--; + } + return retry != 0; +} + +static bool hdmi_cec_clear_rx_fifo(struct cec_adapter *adap) +{ + struct hdmi_core_data *core = cec_get_drvdata(adap); + int retry = HDMI_CORE_CEC_RETRY; + int temp; + + hdmi_write_reg(core->base, HDMI_CEC_RX_CONTROL, 0x3); + retry = HDMI_CORE_CEC_RETRY; + while (retry) { + temp = hdmi_read_reg(core->base, HDMI_CEC_RX_CONTROL); + if (FLD_GET(temp, 1, 0) == 0) + break; + retry--; + } + return retry != 0; +} + +static int hdmi_cec_adap_enable(struct cec_adapter *adap, bool enable) +{ + struct hdmi_core_data *core = cec_get_drvdata(adap); + int temp, err; + + if (!enable) { + hdmi_write_reg(core->base, HDMI_CEC_INT_ENABLE_0, 0); + hdmi_write_reg(core->base, HDMI_CEC_INT_ENABLE_1, 0); + REG_FLD_MOD(core->base, HDMI_CORE_SYS_INTR_UNMASK4, 0, 3, 3); + hdmi_wp_clear_irqenable(core->wp, HDMI_IRQ_CORE); + hdmi_wp_set_irqstatus(core->wp, HDMI_IRQ_CORE); + hdmi4_core_disable(NULL); + return 0; + } + err = hdmi4_core_enable(NULL); + if (err) + return err; + + /* Clear TX FIFO */ + if (!hdmi_cec_clear_tx_fifo(adap)) { + pr_err("cec-%s: could not clear TX FIFO\n", adap->name); + return -EIO; + } + + /* Clear RX FIFO */ + if (!hdmi_cec_clear_rx_fifo(adap)) { + pr_err("cec-%s: could not clear RX FIFO\n", adap->name); + return -EIO; + } + + /* Clear CEC interrupts */ + hdmi_write_reg(core->base, HDMI_CEC_INT_STATUS_1, + hdmi_read_reg(core->base, HDMI_CEC_INT_STATUS_1)); + hdmi_write_reg(core->base, HDMI_CEC_INT_STATUS_0, + hdmi_read_reg(core->base, HDMI_CEC_INT_STATUS_0)); + + /* Enable HDMI core interrupts */ + hdmi_wp_set_irqenable(core->wp, HDMI_IRQ_CORE); + /* Unmask CEC interrupt */ + REG_FLD_MOD(core->base, HDMI_CORE_SYS_INTR_UNMASK4, 0x1, 3, 3); + /* + * Enable CEC interrupts: + * Transmit Buffer Full/Empty Change event + * Receiver FIFO Not Empty event + */ + hdmi_write_reg(core->base, HDMI_CEC_INT_ENABLE_0, 0x22); + /* + * Enable CEC interrupts: + * Frame Retransmit Count Exceeded event + */ + hdmi_write_reg(core->base, HDMI_CEC_INT_ENABLE_1, 0x02); + + /* cec calibration enable (self clearing) */ + hdmi_write_reg(core->base, HDMI_CEC_SETUP, 0x03); + msleep(20); + hdmi_write_reg(core->base, HDMI_CEC_SETUP, 0x04); + + temp = hdmi_read_reg(core->base, HDMI_CEC_SETUP); + if (FLD_GET(temp, 4, 4) != 0) { + temp = FLD_MOD(temp, 0, 4, 4); + hdmi_write_reg(core->base, HDMI_CEC_SETUP, temp); + + /* + * If we enabled CEC in middle of a CEC message on the bus, + * we could have start bit irregularity and/or short + * pulse event. Clear them now. + */ + temp = hdmi_read_reg(core->base, HDMI_CEC_INT_STATUS_1); + temp = FLD_MOD(0x0, 0x5, 2, 0); + hdmi_write_reg(core->base, HDMI_CEC_INT_STATUS_1, temp); + } + return 0; +} + +static int hdmi_cec_adap_log_addr(struct cec_adapter *adap, u8 log_addr) +{ + struct hdmi_core_data *core = cec_get_drvdata(adap); + u32 v; + + if (log_addr == CEC_LOG_ADDR_INVALID) { + hdmi_write_reg(core->base, HDMI_CEC_CA_7_0, 0); + hdmi_write_reg(core->base, HDMI_CEC_CA_15_8, 0); + return 0; + } + if (log_addr <= 7) { + v = hdmi_read_reg(core->base, HDMI_CEC_CA_7_0); + v |= 1 << log_addr; + hdmi_write_reg(core->base, HDMI_CEC_CA_7_0, v); + } else { + v = hdmi_read_reg(core->base, HDMI_CEC_CA_15_8); + v |= 1 << (log_addr - 8); + hdmi_write_reg(core->base, HDMI_CEC_CA_15_8, v); + } + return 0; +} + +static int hdmi_cec_adap_transmit(struct cec_adapter *adap, u8 attempts, + u32 signal_free_time, struct cec_msg *msg) +{ + struct hdmi_core_data *core = cec_get_drvdata(adap); + int temp; + u32 i; + + /* Clear TX FIFO */ + if (!hdmi_cec_clear_tx_fifo(adap)) { + pr_err("cec-%s: could not clear TX FIFO for transmit\n", + adap->name); + return -EIO; + } + + /* Clear TX interrupts */ + hdmi_write_reg(core->base, HDMI_CEC_INT_STATUS_0, + HDMI_CEC_TX_FIFO_INT_MASK); + + hdmi_write_reg(core->base, HDMI_CEC_INT_STATUS_1, + HDMI_CEC_RETRANSMIT_CNT_INT_MASK); + + /* Set the retry count */ + REG_FLD_MOD(core->base, HDMI_CEC_DBG_3, attempts - 1, 6, 4); + + /* Set the initiator addresses */ + hdmi_write_reg(core->base, HDMI_CEC_TX_INIT, cec_msg_initiator(msg)); + + /* Set destination id */ + temp = cec_msg_destination(msg); + if (msg->len == 1) + temp |= 0x80; + hdmi_write_reg(core->base, HDMI_CEC_TX_DEST, temp); + if (msg->len == 1) + return 0; + + /* Setup command and arguments for the command */ + hdmi_write_reg(core->base, HDMI_CEC_TX_COMMAND, msg->msg[1]); + + for (i = 0; i < msg->len - 2; i++) + hdmi_write_reg(core->base, HDMI_CEC_TX_OPERAND + i * 4, + msg->msg[2 + i]); + + /* Operand count */ + hdmi_write_reg(core->base, HDMI_CEC_TRANSMIT_DATA, + (msg->len - 2) | 0x10); + return 0; +} + +static const struct cec_adap_ops hdmi_cec_adap_ops = { + .adap_enable = hdmi_cec_adap_enable, + .adap_log_addr = hdmi_cec_adap_log_addr, + .adap_transmit = hdmi_cec_adap_transmit, +}; + +void hdmi4_cec_set_phys_addr(struct hdmi_core_data *core, u16 pa) +{ + cec_s_phys_addr(core->adap, pa, false); +} + +int hdmi4_cec_init(struct platform_device *pdev, struct hdmi_core_data *core, + struct hdmi_wp_data *wp) +{ + const u32 caps = CEC_CAP_TRANSMIT | CEC_CAP_LOG_ADDRS | + CEC_CAP_PASSTHROUGH | CEC_CAP_RC; + int ret; + + core->adap = cec_allocate_adapter(&hdmi_cec_adap_ops, core, + "omap4", caps, CEC_MAX_LOG_ADDRS); + ret = PTR_ERR_OR_ZERO(core->adap); + if (ret < 0) + return ret; + core->wp = wp; + + /* + * Initialize CEC clock divider: CEC needs 2MHz clock hence + * set the devider to 24 to get 48/24=2MHz clock + */ + REG_FLD_MOD(core->wp->base, HDMI_WP_CLK, 0x18, 5, 0); + + ret = cec_register_adapter(core->adap, &pdev->dev); + if (ret < 0) { + cec_delete_adapter(core->adap); + return ret; + } + return 0; +} + +void hdmi4_cec_uninit(struct hdmi_core_data *core) +{ + cec_unregister_adapter(core->adap); +} |