[PATCH 4/4] drm/bridge: dw-hdmi: add cec driver
Jose Abreu
Jose.Abreu at synopsys.com
Wed May 31 17:53:21 PDT 2017
Hi Russell,
On 30-05-2017 15:23, Russell King wrote:
> 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
Synopsis -> Synopsys
> + 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),
I rather like the format HDMI_{REGISTER_NAME}_{FIELD_NAME} so
that it clearly identifies this is a internal driver register and
not a CEC core register, but I guess its up to you :)
> +
> + 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;
You can use "cec = cec_get_drvdata(adap)" here, as in the rest of
the code.
> + 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;
I think you should check first if CEC engine is in normal
operation mode, as a safety measure.
> +
> + 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");
Synopsis -> Synopsys
> +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);
Best regards,
Jose Miguel Abreu
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