From: Hans Verkuil <hans.verkuil@cisco.com>
Date: Wed, 2 Aug 2017 10:54:06 +0200
Subject: omapdrm: hdmi4_cec: add OMAP4 HDMI CEC support
Git-commit: 8d7f934df8d87237abd5c5caa318dfbf581854aa
Patch-mainline: v4.15-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166
Add the source and header for the OMAP4 HDMI CEC support.
This code is not yet hooked up, that will happen in the next patch.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
drivers/gpu/drm/omapdrm/dss/hdmi4_cec.c | 381 ++++++++++++++++++++++++++++++++
drivers/gpu/drm/omapdrm/dss/hdmi4_cec.h | 55 ++++
2 files changed, 436 insertions(+)
--- /dev/null
+++ b/drivers/gpu/drm/omapdrm/dss/hdmi4_cec.c
@@ -0,0 +1,381 @@
+/*
+ * 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 <mythripk@ti.com>
+ *
+ * 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;
+ 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;
+ }
+}
+
+static void hdmi_cec_transmit_fifo_empty(struct hdmi_core_data *core, u32 stat1)
+{
+ if (stat1 & 2) {
+ 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);
+ } else if (stat1 & 1) {
+ cec_transmit_done(core->adap,
+ CEC_TX_STATUS_ARB_LOST |
+ CEC_TX_STATUS_MAX_RETRIES,
+ 0, 0, 0, 0);
+ } else if (stat1 == 0) {
+ cec_transmit_done(core->adap, CEC_TX_STATUS_OK,
+ 0, 0, 0, 0);
+ }
+}
+
+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 & 0x40)
+ REG_FLD_MOD(core->base, HDMI_CEC_DBG_3, 0x1, 7, 7);
+ else if (stat0 & 0x24)
+ hdmi_cec_transmit_fifo_empty(core, stat1);
+ if (stat1 & 2) {
+ 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);
+ } else if (stat1 & 1) {
+ cec_transmit_done(core->adap,
+ CEC_TX_STATUS_ARB_LOST |
+ CEC_TX_STATUS_MAX_RETRIES,
+ 0, 0, 0, 0);
+ }
+ if (stat0 & 0x02)
+ hdmi_cec_received_msg(core);
+ if (stat1 & 0x3)
+ REG_FLD_MOD(core->base, HDMI_CEC_DBG_3, 0x1, 7, 7);
+}
+
+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
+ * Transmitter FIFO Empty event
+ * Receiver FIFO Not Empty event
+ */
+ hdmi_write_reg(core->base, HDMI_CEC_INT_ENABLE_0, 0x26);
+ /*
+ * Enable CEC interrupts:
+ * RX FIFO Overrun Error event
+ * Short Pulse Detected event
+ * Frame Retransmit Count Exceeded event
+ * Start Bit Irregularity event
+ */
+ hdmi_write_reg(core->base, HDMI_CEC_INT_ENABLE_1, 0x0f);
+
+ /* 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;
+ unsigned 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);
+}
--- /dev/null
+++ b/drivers/gpu/drm/omapdrm/dss/hdmi4_cec.h
@@ -0,0 +1,55 @@
+/*
+ * HDMI header definition for OMAP4 HDMI CEC IP
+ *
+ * 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.
+ */
+
+#ifndef _HDMI4_CEC_H_
+#define _HDMI4_CEC_H_
+
+struct hdmi_core_data;
+struct hdmi_wp_data;
+struct platform_device;
+
+/* HDMI CEC funcs */
+#ifdef CONFIG_OMAP4_DSS_HDMI_CEC
+void hdmi4_cec_set_phys_addr(struct hdmi_core_data *core, u16 pa);
+void hdmi4_cec_irq(struct hdmi_core_data *core);
+int hdmi4_cec_init(struct platform_device *pdev, struct hdmi_core_data *core,
+ struct hdmi_wp_data *wp);
+void hdmi4_cec_uninit(struct hdmi_core_data *core);
+#else
+static inline void hdmi4_cec_set_phys_addr(struct hdmi_core_data *core, u16 pa)
+{
+}
+
+static inline void hdmi4_cec_irq(struct hdmi_core_data *core)
+{
+}
+
+static inline int hdmi4_cec_init(struct platform_device *pdev,
+ struct hdmi_core_data *core,
+ struct hdmi_wp_data *wp)
+{
+ return 0;
+}
+
+static inline void hdmi4_cec_uninit(struct hdmi_core_data *core)
+{
+}
+#endif
+
+#endif