[PATCH 4/4] drm/bridge: dw-hdmi: add cec driver
Russell King
rmk+kernel at armlinux.org.uk
Tue May 30 14:23:23 UTC 2017
Add a CEC driver for the dw-hdmi hardware.
Signed-off-by: Russell King <rmk+kernel at armlinux.org.uk>
---
drivers/gpu/drm/bridge/synopsys/Kconfig | 8 +
drivers/gpu/drm/bridge/synopsys/Makefile | 1 +
drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c | 320 ++++++++++++++++++++++++++
drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.h | 19 ++
drivers/gpu/drm/bridge/synopsys/dw-hdmi.c | 40 +++-
5 files changed, 387 insertions(+), 1 deletion(-)
create mode 100644 drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c
create mode 100644 drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.h
diff --git a/drivers/gpu/drm/bridge/synopsys/Kconfig b/drivers/gpu/drm/bridge/synopsys/Kconfig
index 40d2827a6d19..bd30a0a07272 100644
--- a/drivers/gpu/drm/bridge/synopsys/Kconfig
+++ b/drivers/gpu/drm/bridge/synopsys/Kconfig
@@ -21,3 +21,11 @@ config DRM_DW_HDMI_I2S_AUDIO
help
Support the I2S Audio interface which is part of the Synopsys
Designware HDMI block.
+
+config DRM_DW_HDMI_CEC
+ tristate "Synopsis Designware CEC interface"
+ depends on DRM_DW_HDMI && MEDIA_CEC_SUPPORT
+ select MEDIA_CEC_NOTIFIER
+ help
+ Support the CE interface which is part of the Synopsis
+ Designware HDMI block.
diff --git a/drivers/gpu/drm/bridge/synopsys/Makefile b/drivers/gpu/drm/bridge/synopsys/Makefile
index 17aa7a65b57e..6fe415903668 100644
--- a/drivers/gpu/drm/bridge/synopsys/Makefile
+++ b/drivers/gpu/drm/bridge/synopsys/Makefile
@@ -3,3 +3,4 @@
obj-$(CONFIG_DRM_DW_HDMI) += dw-hdmi.o
obj-$(CONFIG_DRM_DW_HDMI_AHB_AUDIO) += dw-hdmi-ahb-audio.o
obj-$(CONFIG_DRM_DW_HDMI_I2S_AUDIO) += dw-hdmi-i2s-audio.o
+obj-$(CONFIG_DRM_DW_HDMI_CEC) += dw-hdmi-cec.o
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c
new file mode 100644
index 000000000000..761ef5ae687d
--- /dev/null
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.c
@@ -0,0 +1,320 @@
+/*
+ * Designware HDMI CEC driver
+ *
+ * Copyright (C) 2015-2017 Russell King.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+
+#include <drm/drm_edid.h>
+
+#include <media/cec.h>
+#include <media/cec-notifier.h>
+
+#include "dw-hdmi-cec.h"
+
+enum {
+ HDMI_IH_CEC_STAT0 = 0x0106,
+ HDMI_IH_MUTE_CEC_STAT0 = 0x0186,
+
+ HDMI_CEC_CTRL = 0x7d00,
+ CEC_CTRL_START = BIT(0),
+ CEC_CTRL_NORMAL = 1 << 1,
+
+ HDMI_CEC_STAT = 0x7d01,
+ CEC_STAT_DONE = BIT(0),
+ CEC_STAT_EOM = BIT(1),
+ CEC_STAT_NACK = BIT(2),
+ CEC_STAT_ARBLOST = BIT(3),
+ CEC_STAT_ERROR_INIT = BIT(4),
+ CEC_STAT_ERROR_FOLL = BIT(5),
+ CEC_STAT_WAKEUP = BIT(6),
+
+ HDMI_CEC_MASK = 0x7d02,
+ HDMI_CEC_POLARITY = 0x7d03,
+ HDMI_CEC_INT = 0x7d04,
+ HDMI_CEC_ADDR_L = 0x7d05,
+ HDMI_CEC_ADDR_H = 0x7d06,
+ HDMI_CEC_TX_CNT = 0x7d07,
+ HDMI_CEC_RX_CNT = 0x7d08,
+ HDMI_CEC_TX_DATA0 = 0x7d10,
+ HDMI_CEC_RX_DATA0 = 0x7d20,
+ HDMI_CEC_LOCK = 0x7d30,
+ HDMI_CEC_WKUPCTRL = 0x7d31,
+};
+
+struct dw_hdmi_cec {
+ struct dw_hdmi *hdmi;
+ const struct dw_hdmi_cec_ops *ops;
+ u32 addresses;
+ struct cec_adapter *adap;
+ struct cec_msg rx_msg;
+ unsigned int tx_status;
+ bool tx_done;
+ bool rx_done;
+ struct cec_notifier *notify;
+ int retries;
+ int irq;
+};
+
+static void dw_hdmi_write(struct dw_hdmi_cec *cec, u8 val, int offset)
+{
+ cec->ops->write(cec->hdmi, val, offset);
+}
+
+static u8 dw_hdmi_read(struct dw_hdmi_cec *cec, int offset)
+{
+ return cec->ops->read(cec->hdmi, offset);
+}
+
+static int dw_hdmi_cec_log_addr(struct cec_adapter *adap, u8 logical_addr)
+{
+ struct dw_hdmi_cec *cec = adap->priv;
+ u32 addresses;
+
+ if (logical_addr == CEC_LOG_ADDR_INVALID)
+ addresses = cec->addresses = 0;
+ else
+ addresses = cec->addresses |= BIT(logical_addr) | BIT(15);
+
+ dw_hdmi_write(cec, addresses & 255, HDMI_CEC_ADDR_L);
+ dw_hdmi_write(cec, addresses >> 8, HDMI_CEC_ADDR_H);
+
+ return 0;
+}
+
+static int dw_hdmi_cec_transmit(struct cec_adapter *adap, u8 attempts,
+ u32 signal_free_time, struct cec_msg *msg)
+{
+ struct dw_hdmi_cec *cec = adap->priv;
+ unsigned i;
+
+ cec->retries = attempts;
+
+ for (i = 0; i < msg->len; i++)
+ dw_hdmi_write(cec, msg->msg[i], HDMI_CEC_TX_DATA0 + i);
+
+ dw_hdmi_write(cec, msg->len, HDMI_CEC_TX_CNT);
+ dw_hdmi_write(cec, CEC_CTRL_NORMAL | CEC_CTRL_START, HDMI_CEC_CTRL);
+
+ return 0;
+}
+
+static irqreturn_t dw_hdmi_cec_hardirq(int irq, void *data)
+{
+ struct cec_adapter *adap = data;
+ struct dw_hdmi_cec *cec = adap->priv;
+ unsigned stat = dw_hdmi_read(cec, HDMI_IH_CEC_STAT0);
+ irqreturn_t ret = IRQ_HANDLED;
+
+ if (stat == 0)
+ return IRQ_NONE;
+
+ dw_hdmi_write(cec, stat, HDMI_IH_CEC_STAT0);
+
+ if (stat & CEC_STAT_ERROR_INIT) {
+ if (cec->retries) {
+ unsigned v = dw_hdmi_read(cec, HDMI_CEC_CTRL);
+ dw_hdmi_write(cec, v | CEC_CTRL_START, HDMI_CEC_CTRL);
+ cec->retries -= 1;
+ } else {
+ cec->tx_status = CEC_TX_STATUS_MAX_RETRIES;
+ cec->tx_done = true;
+ ret = IRQ_WAKE_THREAD;
+ }
+ } else if (stat & CEC_STAT_DONE) {
+ cec->tx_status = CEC_TX_STATUS_OK;
+ cec->tx_done = true;
+ ret = IRQ_WAKE_THREAD;
+ } else if (stat & CEC_STAT_NACK) {
+ cec->tx_status = CEC_TX_STATUS_NACK;
+ cec->tx_done = true;
+ ret = IRQ_WAKE_THREAD;
+ }
+
+ if (stat & CEC_STAT_EOM) {
+ unsigned len, i;
+
+ len = dw_hdmi_read(cec, HDMI_CEC_RX_CNT);
+ if (len > sizeof(cec->rx_msg.msg))
+ len = sizeof(cec->rx_msg.msg);
+
+ for (i = 0; i < len; i++)
+ cec->rx_msg.msg[i] =
+ dw_hdmi_read(cec, HDMI_CEC_RX_DATA0 + i);
+
+ dw_hdmi_write(cec, 0, HDMI_CEC_LOCK);
+
+ cec->rx_msg.len = len;
+ smp_wmb();
+ cec->rx_done = true;
+
+ ret = IRQ_WAKE_THREAD;
+ }
+
+ return ret;
+}
+
+static irqreturn_t dw_hdmi_cec_thread(int irq, void *data)
+{
+ struct cec_adapter *adap = data;
+ struct dw_hdmi_cec *cec = adap->priv;
+
+ if (cec->tx_done) {
+ cec->tx_done = false;
+ cec_transmit_done(adap, cec->tx_status, 0, 0, 0, 0);
+ }
+ if (cec->rx_done) {
+ cec->rx_done = false;
+ smp_rmb();
+ cec_received_msg(adap, &cec->rx_msg);
+ }
+ return IRQ_HANDLED;
+}
+
+static int dw_hdmi_cec_enable(struct cec_adapter *adap, bool enable)
+{
+ struct dw_hdmi_cec *cec = adap->priv;
+
+ if (!enable) {
+ dw_hdmi_write(cec, ~0, HDMI_CEC_MASK);
+ dw_hdmi_write(cec, ~0, HDMI_IH_MUTE_CEC_STAT0);
+ dw_hdmi_write(cec, 0, HDMI_CEC_POLARITY);
+
+ cec->ops->disable(cec->hdmi);
+ } else {
+ unsigned irqs;
+
+ dw_hdmi_write(cec, 0, HDMI_CEC_CTRL);
+ dw_hdmi_write(cec, ~0, HDMI_IH_CEC_STAT0);
+ dw_hdmi_write(cec, 0, HDMI_CEC_LOCK);
+
+ dw_hdmi_cec_log_addr(cec->adap, CEC_LOG_ADDR_INVALID);
+
+ cec->ops->enable(cec->hdmi);
+
+ irqs = CEC_STAT_ERROR_INIT | CEC_STAT_NACK | CEC_STAT_EOM |
+ CEC_STAT_DONE;
+ dw_hdmi_write(cec, irqs, HDMI_CEC_POLARITY);
+ dw_hdmi_write(cec, ~irqs, HDMI_CEC_MASK);
+ dw_hdmi_write(cec, ~irqs, HDMI_IH_MUTE_CEC_STAT0);
+ }
+ return 0;
+}
+
+static const struct cec_adap_ops dw_hdmi_cec_ops = {
+ .adap_enable = dw_hdmi_cec_enable,
+ .adap_log_addr = dw_hdmi_cec_log_addr,
+ .adap_transmit = dw_hdmi_cec_transmit,
+};
+
+static void dw_hdmi_cec_del(void *data)
+{
+ struct dw_hdmi_cec *cec = data;
+
+ cec_delete_adapter(cec->adap);
+}
+
+static int dw_hdmi_cec_probe(struct platform_device *pdev)
+{
+ struct dw_hdmi_cec_data *data = dev_get_platdata(&pdev->dev);
+ struct dw_hdmi_cec *cec;
+ int ret;
+
+ if (!data)
+ return -ENXIO;
+
+ /*
+ * Our device is just a convenience - we want to link to the real
+ * hardware device here, so that userspace can see the association
+ * between the HDMI hardware and its associated CEC chardev.
+ */
+ cec = devm_kzalloc(&pdev->dev, sizeof(*cec), GFP_KERNEL);
+ if (!cec)
+ return -ENOMEM;
+
+ cec->irq = data->irq;
+ cec->ops = data->ops;
+ cec->hdmi = data->hdmi;
+
+ platform_set_drvdata(pdev, cec);
+
+ dw_hdmi_write(cec, 0, HDMI_CEC_TX_CNT);
+ dw_hdmi_write(cec, ~0, HDMI_CEC_MASK);
+ dw_hdmi_write(cec, ~0, HDMI_IH_MUTE_CEC_STAT0);
+ dw_hdmi_write(cec, 0, HDMI_CEC_POLARITY);
+
+ cec->adap = cec_allocate_adapter(&dw_hdmi_cec_ops, cec, "dw_hdmi",
+ CEC_CAP_LOG_ADDRS | CEC_CAP_TRANSMIT |
+ CEC_CAP_RC, CEC_MAX_LOG_ADDRS);
+ if (IS_ERR(cec->adap))
+ return PTR_ERR(cec->adap);
+
+ /* override the module pointer */
+ cec->adap->owner = THIS_MODULE;
+
+ ret = devm_add_action(&pdev->dev, dw_hdmi_cec_del, cec);
+ if (ret) {
+ cec_delete_adapter(cec->adap);
+ return ret;
+ }
+
+ ret = devm_request_threaded_irq(&pdev->dev, cec->irq,
+ dw_hdmi_cec_hardirq,
+ dw_hdmi_cec_thread, IRQF_SHARED,
+ "dw-hdmi-cec", cec->adap);
+ if (ret < 0)
+ return ret;
+
+ cec->notify = cec_notifier_get(pdev->dev.parent);
+ if (!cec->notify)
+ return -ENOMEM;
+
+ ret = cec_register_adapter(cec->adap, pdev->dev.parent);
+ if (ret < 0) {
+ cec_notifier_put(cec->notify);
+ return ret;
+ }
+
+ /*
+ * CEC documentation says we must not call cec_delete_adapter
+ * after a successful call to cec_register_adapter().
+ */
+ devm_remove_action(&pdev->dev, dw_hdmi_cec_del, cec);
+
+ cec_register_cec_notifier(cec->adap, cec->notify);
+
+ return 0;
+}
+
+static int dw_hdmi_cec_remove(struct platform_device *pdev)
+{
+ struct dw_hdmi_cec *cec = platform_get_drvdata(pdev);
+
+ cec_unregister_adapter(cec->adap);
+ cec_notifier_put(cec->notify);
+
+ return 0;
+}
+
+static struct platform_driver dw_hdmi_cec_driver = {
+ .probe = dw_hdmi_cec_probe,
+ .remove = dw_hdmi_cec_remove,
+ .driver = {
+ .name = "dw-hdmi-cec",
+ },
+};
+module_platform_driver(dw_hdmi_cec_driver);
+
+MODULE_AUTHOR("Russell King <rmk+kernel at armlinux.org.uk>");
+MODULE_DESCRIPTION("Synopsis Designware HDMI CEC driver for i.MX");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS(PLATFORM_MODULE_PREFIX "dw-hdmi-cec");
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.h b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.h
new file mode 100644
index 000000000000..cf4dc121a2c4
--- /dev/null
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi-cec.h
@@ -0,0 +1,19 @@
+#ifndef DW_HDMI_CEC_H
+#define DW_HDMI_CEC_H
+
+struct dw_hdmi;
+
+struct dw_hdmi_cec_ops {
+ void (*write)(struct dw_hdmi *hdmi, u8 val, int offset);
+ u8 (*read)(struct dw_hdmi *hdmi, int offset);
+ void (*enable)(struct dw_hdmi *hdmi);
+ void (*disable)(struct dw_hdmi *hdmi);
+};
+
+struct dw_hdmi_cec_data {
+ struct dw_hdmi *hdmi;
+ const struct dw_hdmi_cec_ops *ops;
+ int irq;
+};
+
+#endif
diff --git a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
index 58781d4c1034..5a389f1f58d9 100644
--- a/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-hdmi.c
@@ -35,6 +35,7 @@
#include "dw-hdmi.h"
#include "dw-hdmi-audio.h"
+#include "dw-hdmi-cec.h"
#include <media/cec-notifier.h>
@@ -133,6 +134,7 @@ struct dw_hdmi {
unsigned int version;
struct platform_device *audio;
+ struct platform_device *cec;
struct device *dev;
struct clk *isfr_clk;
struct clk *iahb_clk;
@@ -1766,7 +1768,6 @@ static void initialize_hdmi_ih_mutes(struct dw_hdmi *hdmi)
hdmi_writeb(hdmi, 0xff, HDMI_AUD_HBR_MASK);
hdmi_writeb(hdmi, 0xff, HDMI_GP_MASK);
hdmi_writeb(hdmi, 0xff, HDMI_A_APIINTMSK);
- hdmi_writeb(hdmi, 0xff, HDMI_CEC_MASK);
hdmi_writeb(hdmi, 0xff, HDMI_I2CM_INT);
hdmi_writeb(hdmi, 0xff, HDMI_I2CM_CTLINT);
@@ -2223,6 +2224,29 @@ static int dw_hdmi_detect_phy(struct dw_hdmi *hdmi)
return -ENODEV;
}
+static void dw_hdmi_cec_enable(struct dw_hdmi *hdmi)
+{
+ mutex_lock(&hdmi->mutex);
+ hdmi->mc_clkdis &= ~HDMI_MC_CLKDIS_CECCLK_DISABLE;
+ hdmi_writeb(hdmi, hdmi->mc_clkdis, HDMI_MC_CLKDIS);
+ mutex_unlock(&hdmi->mutex);
+}
+
+static void dw_hdmi_cec_disable(struct dw_hdmi *hdmi)
+{
+ mutex_lock(&hdmi->mutex);
+ hdmi->mc_clkdis |= HDMI_MC_CLKDIS_CECCLK_DISABLE;
+ hdmi_writeb(hdmi, hdmi->mc_clkdis, HDMI_MC_CLKDIS);
+ mutex_unlock(&hdmi->mutex);
+}
+
+static const struct dw_hdmi_cec_ops dw_hdmi_cec_ops = {
+ .write = hdmi_writeb,
+ .read = hdmi_readb,
+ .enable = dw_hdmi_cec_enable,
+ .disable = dw_hdmi_cec_disable,
+};
+
static const struct regmap_config hdmi_regmap_8bit_config = {
.reg_bits = 32,
.val_bits = 8,
@@ -2245,6 +2269,7 @@ __dw_hdmi_probe(struct platform_device *pdev,
struct device_node *np = dev->of_node;
struct platform_device_info pdevinfo;
struct device_node *ddc_node;
+ struct dw_hdmi_cec_data cec;
struct dw_hdmi *hdmi;
struct resource *iores = NULL;
int irq;
@@ -2445,6 +2470,17 @@ __dw_hdmi_probe(struct platform_device *pdev,
hdmi->audio = platform_device_register_full(&pdevinfo);
}
+ cec.hdmi = hdmi;
+ cec.ops = &dw_hdmi_cec_ops;
+ cec.irq = irq;
+
+ pdevinfo.name = "dw-hdmi-cec";
+ pdevinfo.data = &cec;
+ pdevinfo.size_data = sizeof(cec);
+ pdevinfo.dma_mask = 0;
+
+ hdmi->cec = platform_device_register_full(&pdevinfo);
+
/* Reset HDMI DDC I2C master controller and mute I2CM interrupts */
if (hdmi->i2c)
dw_hdmi_i2c_init(hdmi);
@@ -2475,6 +2511,8 @@ static void __dw_hdmi_remove(struct dw_hdmi *hdmi)
{
if (hdmi->audio && !IS_ERR(hdmi->audio))
platform_device_unregister(hdmi->audio);
+ if (!IS_ERR(hdmi->cec))
+ platform_device_unregister(hdmi->cec);
/* Disable all interrupts */
hdmi_writeb(hdmi, ~0, HDMI_IH_MUTE_PHY_STAT0);
--
2.7.4
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