omapdrm: hdmi4_cec: add OMAP4 HDMI CEC support
authorHans Verkuil <hans.verkuil@cisco.com>
Wed, 2 Aug 2017 08:54:06 +0000 (10:54 +0200)
committerTomi Valkeinen <tomi.valkeinen@ti.com>
Thu, 12 Oct 2017 07:49:14 +0000 (10:49 +0300)
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>
drivers/gpu/drm/omapdrm/dss/hdmi4_cec.c [new file with mode: 0644]
drivers/gpu/drm/omapdrm/dss/hdmi4_cec.h [new file with mode: 0644]

diff --git a/drivers/gpu/drm/omapdrm/dss/hdmi4_cec.c b/drivers/gpu/drm/omapdrm/dss/hdmi4_cec.c
new file mode 100644 (file)
index 0000000..d86873f
--- /dev/null
@@ -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);
+}
diff --git a/drivers/gpu/drm/omapdrm/dss/hdmi4_cec.h b/drivers/gpu/drm/omapdrm/dss/hdmi4_cec.h
new file mode 100644 (file)
index 0000000..0292337
--- /dev/null
@@ -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