[PATCH v4 0/2] cec: STM32 driver

[PATCH v4 0/2] cec: STM32 driver

[Benjamin Gaignard]

version 4:
- rebased on Hans cec-config branch
- rework bindings commit message
- add notifier support
- update KConfig

version 2:
- fix typo in compagnie name
- add yannick sign-off
- use cec_message instead of custom struct in cec device
- add monitor mode

I don't change the split between irq handler and irq thread because
it would had mean to handle all errors cases irq handler to keep
a correct sequence. I don't think it is critical as it is since cec is a very
slow protocol.

This serie of patches add cec driver for STM32 platforms.

This code doesn't implement cec notifier because STM32 doesn't
provide HDMI yet but it will be added later.

Those patches have been developped on top of media_tree master branch
where STM32 DCMI code has not been merged so conflict in Kconfig and Makefile
could occur depending of merge ordering.

Compliance has been tested on STM32F769.

~ # cec-ctl -p 1.0.0.0 --playback 
Driver Info:
        Driver Name                : stm32-cec
        Adapter Name               : stm32-cec
        Capabilities               : 0x0000000f
                Physical Address
                Logical Addresses
                Transmit
                Passthrough
        Driver version             : 4.11.0
        Available Logical Addresses: 1
        Physical Address           : 1.0.0.0
        Logical Address Mask       : 0x0010
        CEC Version                : 2.0
        Vendor ID                  : 0x000c03 (HDMI)
        OSD Name                   : 'Playback'
        Logical Addresses          : 1 (Allow RC Passthrough)

          Logical Address          : 4 (Playback Device 1)
            Primary Device Type    : Playback
            Logical Address Type   : Playback
            All Device Types       : Playback
            RC TV Profile          : None
            Device Features        :
                None

~ # cec-compliance -A 
cec-compliance SHA                 : 6acac5cec698de39b9398b66c4f5f4db6b2730d8

Driver Info:
        Driver Name                : stm32-cec
        Adapter Name               : stm32-cec
        Capabilities               : 0x0000000f
                Physical Address
                Logical Addresses
                Transmit
                Passthrough
        Driver version             : 4.11.0
        Available Logical Addresses: 1
        Physical Address           : 1.0.0.0
        Logical Address Mask       : 0x0010
        CEC Version                : 2.0
        Vendor ID                  : 0x000c03
        Logical Addresses          : 1 (Allow RC Passthrough)

          Logical Address          : 4
            Primary Device Type    : Playback
            Logical Address Type   : Playback
            All Device Types       : Playback
            RC TV Profile          : None
            Device Features        :
                None

Compliance test for device /dev/cec0:

    The test results mean the following:
        OK                  Supported correctly by the device.
        OK (Not Supported)  Not supported and not mandatory for the device.
        OK (Presumed)       Presumably supported.  Manually check to confirm.
        OK (Unexpected)     Supported correctly but is not expected to be supported for this device.
        OK (Refused)        Supported by the device, but was refused.
        FAIL                Failed and was expected to be supported by this device.

Find remote devices:
        Polling: OK

CEC API:
        CEC_ADAP_G_CAPS: OK
        CEC_DQEVENT: OK
        CEC_ADAP_G/S_PHYS_ADDR: OK
        CEC_ADAP_G/S_LOG_ADDRS: OK
        CEC_TRANSMIT: OK
        CEC_RECEIVE: OK
        CEC_TRANSMIT/RECEIVE (non-blocking): OK (Presumed)
        CEC_G/S_MODE: OK
        CEC_EVENT_LOST_MSGS: OK

Network topology:
        System Information for device 0 (TV) from device 4 (Playback Device 1):
                CEC Version                : 1.4
                Physical Address           : 0.0.0.0
                Primary Device Type        : TV
                Vendor ID                  : 0x00903e
                OSD Name                   : 'TV'
                Menu Language              : fre
                Power Status               : On

Total: 10, Succeeded: 10, Failed: 0, Warnings: 0


Benjamin Gaignard (2):
  dt-bindings: media: stm32 cec driver
  cec: add STM32 cec driver

 .../devicetree/bindings/media/st,stm32-cec.txt     |  22 ++
 drivers/media/platform/Kconfig                     |  13 +
 drivers/media/platform/Makefile                    |   2 +
 drivers/media/platform/stm32/Makefile              |   1 +
 drivers/media/platform/stm32/stm32-cec.c           | 392 +++++++++++++++++++++
 5 files changed, 430 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/st,stm32-cec.txt
 create mode 100644 drivers/media/platform/stm32/Makefile
 create mode 100644 drivers/media/platform/stm32/stm32-cec.c

-- 
1.9.1

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[PATCH v4 0/2] cec: STM32 driver

[Benjamin Gaignard]

version 4:
- rebased on Hans cec-config branch
- rework bindings commit message
- add notifier support
- update KConfig

version 2:
- fix typo in compagnie name
- add yannick sign-off
- use cec_message instead of custom struct in cec device
- add monitor mode

I don't change the split between irq handler and irq thread because
it would had mean to handle all errors cases irq handler to keep
a correct sequence. I don't think it is critical as it is since cec is a very
slow protocol.

This serie of patches add cec driver for STM32 platforms.

This code doesn't implement cec notifier because STM32 doesn't
provide HDMI yet but it will be added later.

Those patches have been developped on top of media_tree master branch
where STM32 DCMI code has not been merged so conflict in Kconfig and Makefile
could occur depending of merge ordering.

Compliance has been tested on STM32F769.

~ # cec-ctl -p 1.0.0.0 --playback 
Driver Info:
        Driver Name                : stm32-cec
        Adapter Name               : stm32-cec
        Capabilities               : 0x0000000f
                Physical Address
                Logical Addresses
                Transmit
                Passthrough
        Driver version             : 4.11.0
        Available Logical Addresses: 1
        Physical Address           : 1.0.0.0
        Logical Address Mask       : 0x0010
        CEC Version                : 2.0
        Vendor ID                  : 0x000c03 (HDMI)
        OSD Name                   : 'Playback'
        Logical Addresses          : 1 (Allow RC Passthrough)

          Logical Address          : 4 (Playback Device 1)
            Primary Device Type    : Playback
            Logical Address Type   : Playback
            All Device Types       : Playback
            RC TV Profile          : None
            Device Features        :
                None

~ # cec-compliance -A 
cec-compliance SHA                 : 6acac5cec698de39b9398b66c4f5f4db6b2730d8

Driver Info:
        Driver Name                : stm32-cec
        Adapter Name               : stm32-cec
        Capabilities               : 0x0000000f
                Physical Address
                Logical Addresses
                Transmit
                Passthrough
        Driver version             : 4.11.0
        Available Logical Addresses: 1
        Physical Address           : 1.0.0.0
        Logical Address Mask       : 0x0010
        CEC Version                : 2.0
        Vendor ID                  : 0x000c03
        Logical Addresses          : 1 (Allow RC Passthrough)

          Logical Address          : 4
            Primary Device Type    : Playback
            Logical Address Type   : Playback
            All Device Types       : Playback
            RC TV Profile          : None
            Device Features        :
                None

Compliance test for device /dev/cec0:

    The test results mean the following:
        OK                  Supported correctly by the device.
        OK (Not Supported)  Not supported and not mandatory for the device.
        OK (Presumed)       Presumably supported.  Manually check to confirm.
        OK (Unexpected)     Supported correctly but is not expected to be supported for this device.
        OK (Refused)        Supported by the device, but was refused.
        FAIL                Failed and was expected to be supported by this device.

Find remote devices:
        Polling: OK

CEC API:
        CEC_ADAP_G_CAPS: OK
        CEC_DQEVENT: OK
        CEC_ADAP_G/S_PHYS_ADDR: OK
        CEC_ADAP_G/S_LOG_ADDRS: OK
        CEC_TRANSMIT: OK
        CEC_RECEIVE: OK
        CEC_TRANSMIT/RECEIVE (non-blocking): OK (Presumed)
        CEC_G/S_MODE: OK
        CEC_EVENT_LOST_MSGS: OK

Network topology:
        System Information for device 0 (TV) from device 4 (Playback Device 1):
                CEC Version                : 1.4
                Physical Address           : 0.0.0.0
                Primary Device Type        : TV
                Vendor ID                  : 0x00903e
                OSD Name                   : 'TV'
                Menu Language              : fre
                Power Status               : On

Total: 10, Succeeded: 10, Failed: 0, Warnings: 0


Benjamin Gaignard (2):
  dt-bindings: media: stm32 cec driver
  cec: add STM32 cec driver

 .../devicetree/bindings/media/st,stm32-cec.txt     |  22 ++
 drivers/media/platform/Kconfig                     |  13 +
 drivers/media/platform/Makefile                    |   2 +
 drivers/media/platform/stm32/Makefile              |   1 +
 drivers/media/platform/stm32/stm32-cec.c           | 392 +++++++++++++++++++++
 5 files changed, 430 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/st,stm32-cec.txt
 create mode 100644 drivers/media/platform/stm32/Makefile
 create mode 100644 drivers/media/platform/stm32/stm32-cec.c

-- 
1.9.1

[PATCH v4 1/2] dt-bindings: media: stm32 cec driver

[Benjamin Gaignard]

Add bindings documentation for stm32 CEC driver.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
---
version 4:
- rework commit message
- add hdmi-phandle optional property

 .../devicetree/bindings/media/st,stm32-cec.txt     | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/media/st,stm32-cec.txt

diff --git a/Documentation/devicetree/bindings/media/st,stm32-cec.txt b/Documentation/devicetree/bindings/media/st,stm32-cec.txt
new file mode 100644
index 0000000..790d6d3
--- /dev/null
+++ b/Documentation/devicetree/bindings/media/st,stm32-cec.txt
@@ -0,0 +1,22 @@
+STMicroelectronics STM32 CEC driver
+
+Required properties:
+ - compatible : value should be "st,stm32-cec"
+ - reg : Physical base address of the IP registers and length of memory
+	 mapped region.
+ - clocks : from common clock binding: handle to CEC clocks
+ - clock-names : from common clock binding: must be "cec" and "hdmi-cec".
+ - interrupts : CEC interrupt number to the CPU.
+
+Optional properties:
+ - hdmi-phandle: Phandle to the HDMI controller
+
+Example for stm32f746:
+
+cec: cec@40006c00 {
+	compatible = "st,stm32-cec";
+	reg = <0x40006C00 0x400>;
+	interrupts = <94>;
+	clocks = <&rcc 0 STM32F7_APB1_CLOCK(CEC)>, <&rcc 1 CLK_HDMI_CEC>;
+	clock-names = "cec", "hdmi-cec";
+};
-- 
1.9.1

[PATCH v4 2/2] cec: add STM32 cec driver

[Benjamin Gaignard]

This patch add cec driver for STM32 platforms.
cec hardware block isn't not always used with hdmi so
cec notifier is not implemented. That will be done later
when STM32 DSI driver will be available.

Driver compliance has been tested with cec-ctl and cec-compliance
tools.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>
Signed-off-by: Yannick Fertre <yannick.fertre@st.com>
---
version 4:
- add cec notifier support
- rework KConfig
- rebased on Hans cec-config branch
 drivers/media/platform/Kconfig           |  13 +
 drivers/media/platform/Makefile          |   2 +
 drivers/media/platform/stm32/Makefile    |   1 +
 drivers/media/platform/stm32/stm32-cec.c | 392 +++++++++++++++++++++++++++++++
 4 files changed, 408 insertions(+)
 create mode 100644 drivers/media/platform/stm32/Makefile
 create mode 100644 drivers/media/platform/stm32/stm32-cec.c

diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig
index 041cb80..bf6dc4b 100644
--- a/drivers/media/platform/Kconfig
+++ b/drivers/media/platform/Kconfig
@@ -521,4 +521,17 @@ config VIDEO_STI_HDMI_CEC
          CEC bus is present in the HDMI connector and enables communication
          between compatible devices.
 
+config VIDEO_STM32_HDMI_CEC
+       tristate "STMicroelectronics STM32 HDMI CEC driver"
+       depends on ARCH_STM32 || COMPILE_TEST
+       select REGMAP
+       select REGMAP_MMIO
+       select CEC_CORE
+       select CEC_NOTIFIER
+       ---help---
+         This is a driver for STM32 interface. It uses the
+         generic CEC framework interface.
+         CEC bus is present in the HDMI connector and enables communication
+         between compatible devices.
+
 endif #CEC_PLATFORM_DRIVERS
diff --git a/drivers/media/platform/Makefile b/drivers/media/platform/Makefile
index 63303d6..7cd9965 100644
--- a/drivers/media/platform/Makefile
+++ b/drivers/media/platform/Makefile
@@ -44,6 +44,8 @@ obj-$(CONFIG_VIDEO_STI_HDMI_CEC) 	+= sti/cec/
 
 obj-$(CONFIG_VIDEO_STI_DELTA)		+= sti/delta/
 
+obj-$(CONFIG_VIDEO_STM32_HDMI_CEC) 	+= stm32/
+
 obj-$(CONFIG_BLACKFIN)                  += blackfin/
 
 obj-$(CONFIG_ARCH_DAVINCI)		+= davinci/
diff --git a/drivers/media/platform/stm32/Makefile b/drivers/media/platform/stm32/Makefile
new file mode 100644
index 0000000..632b04c
--- /dev/null
+++ b/drivers/media/platform/stm32/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_VIDEO_STM32_HDMI_CEC) += stm32-cec.o
diff --git a/drivers/media/platform/stm32/stm32-cec.c b/drivers/media/platform/stm32/stm32-cec.c
new file mode 100644
index 0000000..2fe8b13
--- /dev/null
+++ b/drivers/media/platform/stm32/stm32-cec.c
@@ -0,0 +1,392 @@
+/*
+ * STM32 CEC driver
+ * Copyright (C) STMicroelectronics SA 2017
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include <media/cec.h>
+#include <media/cec-notifier.h>
+
+#define CEC_NAME	"stm32-cec"
+
+/* CEC registers  */
+#define CEC_CR		0x0000 /* Control Register */
+#define CEC_CFGR	0x0004 /* ConFiGuration Register */
+#define CEC_TXDR	0x0008 /* Rx data Register */
+#define CEC_RXDR	0x000C /* Rx data Register */
+#define CEC_ISR		0x0010 /* Interrupt and status Register */
+#define CEC_IER		0x0014 /* Interrupt enable Register */
+
+#define TXEOM		BIT(2)
+#define TXSOM		BIT(1)
+#define CECEN		BIT(0)
+
+#define LSTN		BIT(31)
+#define OAR		GENMASK(30, 16)
+#define SFTOP		BIT(8)
+#define BRDNOGEN	BIT(7)
+#define LBPEGEN		BIT(6)
+#define BREGEN		BIT(5)
+#define BRESTP		BIT(4)
+#define RXTOL		BIT(3)
+#define SFT		GENMASK(2, 0)
+#define FULL_CFG	(LSTN | SFTOP | BRDNOGEN | LBPEGEN | BREGEN | BRESTP \
+			 | RXTOL | BRDNOGEN)
+
+#define TXACKE		BIT(12)
+#define TXERR		BIT(11)
+#define TXUDR		BIT(10)
+#define TXEND		BIT(9)
+#define TXBR		BIT(8)
+#define ARBLST		BIT(7)
+#define RXACKE		BIT(6)
+#define RXOVR		BIT(2)
+#define RXEND		BIT(1)
+#define RXBR		BIT(0)
+
+#define ALL_TX_IT	(TXEND | TXBR | TXACKE | TXERR | TXUDR | ARBLST)
+#define ALL_RX_IT	(RXEND | RXBR | RXACKE | RXOVR)
+
+struct stm32_cec {
+	struct cec_adapter	*adap;
+	struct device		*dev;
+	struct clk		*clk_cec;
+	struct clk		*clk_hdmi_cec;
+	struct reset_control	*rstc;
+	struct regmap		*regmap;
+	int			irq;
+	u32			irq_status;
+	struct cec_msg		rx_msg;
+	struct cec_msg		tx_msg;
+	int			tx_cnt;
+	struct cec_notifier	*notifier;
+};
+
+static void cec_hw_init(struct stm32_cec *cec)
+{
+	regmap_update_bits(cec->regmap, CEC_CR, TXEOM | TXSOM | CECEN, 0);
+
+	regmap_update_bits(cec->regmap, CEC_IER, ALL_TX_IT | ALL_RX_IT,
+			   ALL_TX_IT | ALL_RX_IT);
+
+	regmap_update_bits(cec->regmap, CEC_CFGR, FULL_CFG, FULL_CFG);
+}
+
+static void stm32_tx_done(struct stm32_cec *cec, u32 status)
+{
+	if (status & (TXERR | TXUDR)) {
+		cec_transmit_done(cec->adap, CEC_TX_STATUS_ERROR,
+				  0, 0, 0, 1);
+		return;
+	}
+
+	if (status & ARBLST) {
+		cec_transmit_done(cec->adap, CEC_TX_STATUS_ARB_LOST,
+				  1, 0, 0, 0);
+		return;
+	}
+
+	if (status & TXACKE) {
+		cec_transmit_done(cec->adap, CEC_TX_STATUS_NACK,
+				  0, 1, 0, 0);
+		return;
+	}
+
+	if (cec->irq_status & TXBR) {
+		/* send next byte */
+		if (cec->tx_cnt < cec->tx_msg.len)
+			regmap_write(cec->regmap, CEC_TXDR,
+				     cec->tx_msg.msg[cec->tx_cnt++]);
+
+		/* TXEOM is set to command transmission of the last byte */
+		if (cec->tx_cnt == cec->tx_msg.len)
+			regmap_update_bits(cec->regmap, CEC_CR, TXEOM, TXEOM);
+	}
+
+	if (cec->irq_status & TXEND)
+		cec_transmit_done(cec->adap, CEC_TX_STATUS_OK, 0, 0, 0, 0);
+}
+
+static void stm32_rx_done(struct stm32_cec *cec, u32 status)
+{
+	if (cec->irq_status & (RXACKE | RXOVR)) {
+		cec->rx_msg.len = 0;
+		return;
+	}
+
+	if (cec->irq_status & RXBR) {
+		u32 val;
+
+		regmap_read(cec->regmap, CEC_RXDR, &val);
+		cec->rx_msg.msg[cec->rx_msg.len++] = val & 0xFF;
+	}
+
+	if (cec->irq_status & RXEND) {
+		cec_received_msg(cec->adap, &cec->rx_msg);
+		cec->rx_msg.len = 0;
+	}
+}
+
+static irqreturn_t stm32_cec_irq_thread(int irq, void *arg)
+{
+	struct stm32_cec *cec = arg;
+
+	if (cec->irq_status & ALL_TX_IT)
+		stm32_tx_done(cec, cec->irq_status);
+
+	if (cec->irq_status & ALL_RX_IT)
+		stm32_rx_done(cec, cec->irq_status);
+
+	cec->irq_status = 0;
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t stm32_cec_irq_handler(int irq, void *arg)
+{
+	struct stm32_cec *cec = arg;
+
+	regmap_read(cec->regmap, CEC_ISR, &cec->irq_status);
+
+	regmap_update_bits(cec->regmap, CEC_ISR,
+			   ALL_TX_IT | ALL_RX_IT,
+			   ALL_TX_IT | ALL_RX_IT);
+
+	return IRQ_WAKE_THREAD;
+}
+
+static int stm32_cec_adap_enable(struct cec_adapter *adap, bool enable)
+{
+	struct stm32_cec *cec = adap->priv;
+	int ret = 0;
+
+	if (enable) {
+		ret = clk_enable(cec->clk_cec);
+		if (ret)
+			dev_err(cec->dev, "fail to enable cec clock\n");
+
+		clk_enable(cec->clk_hdmi_cec);
+		regmap_update_bits(cec->regmap, CEC_CR, CECEN, CECEN);
+	} else {
+		clk_disable(cec->clk_cec);
+		clk_disable(cec->clk_hdmi_cec);
+		regmap_update_bits(cec->regmap, CEC_CR, CECEN, 0);
+	}
+
+	return ret;
+}
+
+static int stm32_cec_adap_log_addr(struct cec_adapter *adap, u8 logical_addr)
+{
+	struct stm32_cec *cec = adap->priv;
+	u32 oar = (1 << logical_addr) << 16;
+
+	regmap_update_bits(cec->regmap, CEC_CR, CECEN, 0);
+
+	if (logical_addr == CEC_LOG_ADDR_INVALID)
+		regmap_update_bits(cec->regmap, CEC_CFGR, OAR, 0);
+	else
+		regmap_update_bits(cec->regmap, CEC_CFGR, oar, oar);
+
+	regmap_update_bits(cec->regmap, CEC_CR, CECEN, CECEN);
+
+	return 0;
+}
+
+static int stm32_cec_adap_transmit(struct cec_adapter *adap, u8 attempts,
+				   u32 signal_free_time, struct cec_msg *msg)
+{
+	struct stm32_cec *cec = adap->priv;
+
+	/* Copy message */
+	cec->tx_msg = *msg;
+	cec->tx_cnt = 0;
+
+	/*
+	 * If the CEC message consists of only one byte,
+	 * TXEOM must be set before of TXSOM.
+	 */
+	if (cec->tx_msg.len == 1)
+		regmap_update_bits(cec->regmap, CEC_CR, TXEOM, TXEOM);
+
+	/* TXSOM is set to command transmission of the first byte */
+	regmap_update_bits(cec->regmap, CEC_CR, TXSOM, TXSOM);
+
+	/* Write the header (first byte of message) */
+	regmap_write(cec->regmap, CEC_TXDR, cec->tx_msg.msg[0]);
+	cec->tx_cnt++;
+
+	return 0;
+}
+
+static const struct cec_adap_ops stm32_cec_adap_ops = {
+	.adap_enable = stm32_cec_adap_enable,
+	.adap_log_addr = stm32_cec_adap_log_addr,
+	.adap_transmit = stm32_cec_adap_transmit,
+};
+
+static const struct regmap_config stm32_cec_regmap_cfg = {
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = sizeof(u32),
+	.max_register = 0x14,
+	.fast_io = true,
+};
+
+static int stm32_cec_probe(struct platform_device *pdev)
+{
+	struct resource *res;
+	struct stm32_cec *cec;
+	void __iomem *mmio;
+	struct device_node *np;
+	int ret;
+	u32 caps = CEC_CAP_LOG_ADDRS | CEC_CAP_PASSTHROUGH |
+		   CEC_CAP_TRANSMIT | CEC_CAP_RC;
+
+	cec = devm_kzalloc(&pdev->dev, sizeof(*cec), GFP_KERNEL);
+	if (!cec)
+		return -ENOMEM;
+
+	/*
+	 * getting an hdmi device is optional but if the phanlde exists
+	 * all must be good to use it
+	 */
+	np = of_parse_phandle(pdev->dev.of_node, "hdmi-phandle", 0);
+	if (np) {
+		struct platform_device *hdmi_dev;
+
+		hdmi_dev = of_find_device_by_node(np);
+		if (!hdmi_dev)
+			return -EPROBE_DEFER;
+
+		cec->notifier = cec_notifier_get(&hdmi_dev->dev);
+		if (!cec->notifier)
+			return -ENOMEM;
+	} else {
+		/*
+		 * no hdmi notifier so physical address need to be set by
+		 * userland
+		 */
+		caps |= CEC_CAP_PHYS_ADDR;
+	}
+
+	cec->dev = &pdev->dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	mmio = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(mmio))
+		return PTR_ERR(mmio);
+
+	cec->regmap = devm_regmap_init_mmio_clk(&pdev->dev, "cec", mmio,
+						&stm32_cec_regmap_cfg);
+
+	if (IS_ERR(cec->regmap))
+		return PTR_ERR(cec->regmap);
+
+	cec->irq = platform_get_irq(pdev, 0);
+	if (cec->irq < 0)
+		return cec->irq;
+
+	ret = devm_request_threaded_irq(&pdev->dev, cec->irq,
+					stm32_cec_irq_handler,
+					stm32_cec_irq_thread,
+					0,
+					pdev->name, cec);
+	if (ret)
+		return ret;
+
+	cec->clk_cec = devm_clk_get(&pdev->dev, "cec");
+	if (IS_ERR(cec->clk_cec)) {
+		dev_err(&pdev->dev, "Cannot get cec clock\n");
+		return PTR_ERR(cec->clk_cec);
+	}
+
+	ret = clk_prepare(cec->clk_cec);
+	if (ret) {
+		dev_err(&pdev->dev, "Unable to prepare cec clock\n");
+		return ret;
+	}
+
+	cec->clk_hdmi_cec = devm_clk_get(&pdev->dev, "hdmi-cec");
+	if (!IS_ERR(cec->clk_hdmi_cec)) {
+		ret = clk_prepare(cec->clk_hdmi_cec);
+		if (ret) {
+			dev_err(&pdev->dev, "Unable to prepare hdmi-cec clock\n");
+			return ret;
+		}
+	}
+
+	/*
+	 * CEC_CAP_PHYS_ADDR could be removed when a cec notifier is available
+	 */
+	cec->adap = cec_allocate_adapter(&stm32_cec_adap_ops, cec,
+			CEC_NAME, caps,	CEC_MAX_LOG_ADDRS);
+	ret = PTR_ERR_OR_ZERO(cec->adap);
+	if (ret)
+		return ret;
+
+	ret = cec_register_adapter(cec->adap, &pdev->dev);
+	if (ret) {
+		cec_delete_adapter(cec->adap);
+		return ret;
+	}
+
+	if (cec->notifier)
+		cec_register_cec_notifier(cec->adap, cec->notifier);
+
+	cec_hw_init(cec);
+
+	platform_set_drvdata(pdev, cec);
+
+	return 0;
+}
+
+static int stm32_cec_remove(struct platform_device *pdev)
+{
+	struct stm32_cec *cec = platform_get_drvdata(pdev);
+
+	clk_unprepare(cec->clk_cec);
+	clk_unprepare(cec->clk_hdmi_cec);
+
+	cec_unregister_adapter(cec->adap);
+
+	if (cec->notifier)
+		cec_notifier_put(cec->notifier);
+
+	return 0;
+}
+
+static const struct of_device_id stm32_cec_of_match[] = {
+	{ .compatible = "st,stm32-cec" },
+	{ /* end node */ }
+};
+MODULE_DEVICE_TABLE(of, stm32_cec_of_match);
+
+static struct platform_driver stm32_cec_driver = {
+	.probe  = stm32_cec_probe,
+	.remove = stm32_cec_remove,
+	.driver = {
+		.name		= CEC_NAME,
+		.of_match_table = stm32_cec_of_match,
+	},
+};
+
+module_platform_driver(stm32_cec_driver);
+
+MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@st.com>");
+MODULE_AUTHOR("Yannick Fertre <yannick.fertre@st.com>");
+MODULE_DESCRIPTION("STMicroelectronics STM32 Consumer Electronics Control");
+MODULE_LICENSE("GPL v2");
-- 
1.9.1

Re: [PATCH v4 0/2] cec: STM32 driver

[Hans Verkuil]

Hi Benjamin,

On 05/29/2017 10:34 AM, Benjamin Gaignard wrote:
> version 4:
> - rebased on Hans cec-config branch
> - rework bindings commit message
> - add notifier support

I really don't like this change. This forced me to think about this a bit more,
and I think this requires another change as well.

The problem you have is that the drm driver for this platform isn't ready yet,
so this CEC driver needs userspace to provide a physical address since it can't
use a notifier.

Trying to support both is a bad idea since this runs the risk that we will forget
to remove the CAP_PHYS_ADDR path later.

Instead, just drop the notifier support. And move this driver to staging, just
as we did with the st-cec driver. Once the drm driver arrives this cec driver
can switch to using the notifier and be moved out of staging.

Add a TODO file explaining that this is waiting for the drm driver so the
CEC_CAP_PHYS_ADDR capability can be removed after switching to using CEC_NOTIFIER.

I should have realized this when reviewing v2, sorry about that.

The reason why I don't want CEC drivers using CEC_CAP_PHYS_ADDR in mainline (except
if it is obviously required such as for the usb CEC dongles) is that it puts a
major burden on the application to discover the physical address from the EDID. It
should only be used if there is no other way. In this case this is just a
temporary situation, so staging is the right place.

BTW, if the stm32 drm driver is going to be accepted for 4.13, then that would
change things, but I don't think that's the case.

Regards,

	Hans

> - update KConfig
> 
> version 2:
> - fix typo in compagnie name
> - add yannick sign-off
> - use cec_message instead of custom struct in cec device
> - add monitor mode
> 
> I don't change the split between irq handler and irq thread because
> it would had mean to handle all errors cases irq handler to keep
> a correct sequence. I don't think it is critical as it is since cec is a very
> slow protocol.
> 
> This serie of patches add cec driver for STM32 platforms.
> 
> This code doesn't implement cec notifier because STM32 doesn't
> provide HDMI yet but it will be added later.
> 
> Those patches have been developped on top of media_tree master branch
> where STM32 DCMI code has not been merged so conflict in Kconfig and Makefile
> could occur depending of merge ordering.
> 
> Compliance has been tested on STM32F769.
> 
> ~ # cec-ctl -p 1.0.0.0 --playback
> Driver Info:
>          Driver Name                : stm32-cec
>          Adapter Name               : stm32-cec
>          Capabilities               : 0x0000000f
>                  Physical Address
>                  Logical Addresses
>                  Transmit
>                  Passthrough
>          Driver version             : 4.11.0
>          Available Logical Addresses: 1
>          Physical Address           : 1.0.0.0
>          Logical Address Mask       : 0x0010
>          CEC Version                : 2.0
>          Vendor ID                  : 0x000c03 (HDMI)
>          OSD Name                   : 'Playback'
>          Logical Addresses          : 1 (Allow RC Passthrough)
> 
>            Logical Address          : 4 (Playback Device 1)
>              Primary Device Type    : Playback
>              Logical Address Type   : Playback
>              All Device Types       : Playback
>              RC TV Profile          : None
>              Device Features        :
>                  None
> 
> ~ # cec-compliance -A
> cec-compliance SHA                 : 6acac5cec698de39b9398b66c4f5f4db6b2730d8
> 
> Driver Info:
>          Driver Name                : stm32-cec
>          Adapter Name               : stm32-cec
>          Capabilities               : 0x0000000f
>                  Physical Address
>                  Logical Addresses
>                  Transmit
>                  Passthrough
>          Driver version             : 4.11.0
>          Available Logical Addresses: 1
>          Physical Address           : 1.0.0.0
>          Logical Address Mask       : 0x0010
>          CEC Version                : 2.0
>          Vendor ID                  : 0x000c03
>          Logical Addresses          : 1 (Allow RC Passthrough)
> 
>            Logical Address          : 4
>              Primary Device Type    : Playback
>              Logical Address Type   : Playback
>              All Device Types       : Playback
>              RC TV Profile          : None
>              Device Features        :
>                  None
> 
> Compliance test for device /dev/cec0:
> 
>      The test results mean the following:
>          OK                  Supported correctly by the device.
>          OK (Not Supported)  Not supported and not mandatory for the device.
>          OK (Presumed)       Presumably supported.  Manually check to confirm.
>          OK (Unexpected)     Supported correctly but is not expected to be supported for this device.
>          OK (Refused)        Supported by the device, but was refused.
>          FAIL                Failed and was expected to be supported by this device.
> 
> Find remote devices:
>          Polling: OK
> 
> CEC API:
>          CEC_ADAP_G_CAPS: OK
>          CEC_DQEVENT: OK
>          CEC_ADAP_G/S_PHYS_ADDR: OK
>          CEC_ADAP_G/S_LOG_ADDRS: OK
>          CEC_TRANSMIT: OK
>          CEC_RECEIVE: OK
>          CEC_TRANSMIT/RECEIVE (non-blocking): OK (Presumed)
>          CEC_G/S_MODE: OK
>          CEC_EVENT_LOST_MSGS: OK
> 
> Network topology:
>          System Information for device 0 (TV) from device 4 (Playback Device 1):
>                  CEC Version                : 1.4
>                  Physical Address           : 0.0.0.0
>                  Primary Device Type        : TV
>                  Vendor ID                  : 0x00903e
>                  OSD Name                   : 'TV'
>                  Menu Language              : fre
>                  Power Status               : On
> 
> Total: 10, Succeeded: 10, Failed: 0, Warnings: 0
> 
> 
> Benjamin Gaignard (2):
>    dt-bindings: media: stm32 cec driver
>    cec: add STM32 cec driver
> 
>   .../devicetree/bindings/media/st,stm32-cec.txt     |  22 ++
>   drivers/media/platform/Kconfig                     |  13 +
>   drivers/media/platform/Makefile                    |   2 +
>   drivers/media/platform/stm32/Makefile              |   1 +
>   drivers/media/platform/stm32/stm32-cec.c           | 392 +++++++++++++++++++++
>   5 files changed, 430 insertions(+)
>   create mode 100644 Documentation/devicetree/bindings/media/st,stm32-cec.txt
>   create mode 100644 drivers/media/platform/stm32/Makefile
>   create mode 100644 drivers/media/platform/stm32/stm32-cec.c
> 

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Re: [PATCH v4 0/2] cec: STM32 driver

[Hans Verkuil]

Hi Benjamin,

On 05/29/2017 10:34 AM, Benjamin Gaignard wrote:
> version 4:
> - rebased on Hans cec-config branch
> - rework bindings commit message
> - add notifier support

I really don't like this change. This forced me to think about this a bit more,
and I think this requires another change as well.

The problem you have is that the drm driver for this platform isn't ready yet,
so this CEC driver needs userspace to provide a physical address since it can't
use a notifier.

Trying to support both is a bad idea since this runs the risk that we will forget
to remove the CAP_PHYS_ADDR path later.

Instead, just drop the notifier support. And move this driver to staging, just
as we did with the st-cec driver. Once the drm driver arrives this cec driver
can switch to using the notifier and be moved out of staging.

Add a TODO file explaining that this is waiting for the drm driver so the
CEC_CAP_PHYS_ADDR capability can be removed after switching to using CEC_NOTIFIER.

I should have realized this when reviewing v2, sorry about that.

The reason why I don't want CEC drivers using CEC_CAP_PHYS_ADDR in mainline (except
if it is obviously required such as for the usb CEC dongles) is that it puts a
major burden on the application to discover the physical address from the EDID. It
should only be used if there is no other way. In this case this is just a
temporary situation, so staging is the right place.

BTW, if the stm32 drm driver is going to be accepted for 4.13, then that would
change things, but I don't think that's the case.

Regards,

	Hans

> - update KConfig
> 
> version 2:
> - fix typo in compagnie name
> - add yannick sign-off
> - use cec_message instead of custom struct in cec device
> - add monitor mode
> 
> I don't change the split between irq handler and irq thread because
> it would had mean to handle all errors cases irq handler to keep
> a correct sequence. I don't think it is critical as it is since cec is a very
> slow protocol.
> 
> This serie of patches add cec driver for STM32 platforms.
> 
> This code doesn't implement cec notifier because STM32 doesn't
> provide HDMI yet but it will be added later.
> 
> Those patches have been developped on top of media_tree master branch
> where STM32 DCMI code has not been merged so conflict in Kconfig and Makefile
> could occur depending of merge ordering.
> 
> Compliance has been tested on STM32F769.
> 
> ~ # cec-ctl -p 1.0.0.0 --playback
> Driver Info:
>          Driver Name                : stm32-cec
>          Adapter Name               : stm32-cec
>          Capabilities               : 0x0000000f
>                  Physical Address
>                  Logical Addresses
>                  Transmit
>                  Passthrough
>          Driver version             : 4.11.0
>          Available Logical Addresses: 1
>          Physical Address           : 1.0.0.0
>          Logical Address Mask       : 0x0010
>          CEC Version                : 2.0
>          Vendor ID                  : 0x000c03 (HDMI)
>          OSD Name                   : 'Playback'
>          Logical Addresses          : 1 (Allow RC Passthrough)
> 
>            Logical Address          : 4 (Playback Device 1)
>              Primary Device Type    : Playback
>              Logical Address Type   : Playback
>              All Device Types       : Playback
>              RC TV Profile          : None
>              Device Features        :
>                  None
> 
> ~ # cec-compliance -A
> cec-compliance SHA                 : 6acac5cec698de39b9398b66c4f5f4db6b2730d8
> 
> Driver Info:
>          Driver Name                : stm32-cec
>          Adapter Name               : stm32-cec
>          Capabilities               : 0x0000000f
>                  Physical Address
>                  Logical Addresses
>                  Transmit
>                  Passthrough
>          Driver version             : 4.11.0
>          Available Logical Addresses: 1
>          Physical Address           : 1.0.0.0
>          Logical Address Mask       : 0x0010
>          CEC Version                : 2.0
>          Vendor ID                  : 0x000c03
>          Logical Addresses          : 1 (Allow RC Passthrough)
> 
>            Logical Address          : 4
>              Primary Device Type    : Playback
>              Logical Address Type   : Playback
>              All Device Types       : Playback
>              RC TV Profile          : None
>              Device Features        :
>                  None
> 
> Compliance test for device /dev/cec0:
> 
>      The test results mean the following:
>          OK                  Supported correctly by the device.
>          OK (Not Supported)  Not supported and not mandatory for the device.
>          OK (Presumed)       Presumably supported.  Manually check to confirm.
>          OK (Unexpected)     Supported correctly but is not expected to be supported for this device.
>          OK (Refused)        Supported by the device, but was refused.
>          FAIL                Failed and was expected to be supported by this device.
> 
> Find remote devices:
>          Polling: OK
> 
> CEC API:
>          CEC_ADAP_G_CAPS: OK
>          CEC_DQEVENT: OK
>          CEC_ADAP_G/S_PHYS_ADDR: OK
>          CEC_ADAP_G/S_LOG_ADDRS: OK
>          CEC_TRANSMIT: OK
>          CEC_RECEIVE: OK
>          CEC_TRANSMIT/RECEIVE (non-blocking): OK (Presumed)
>          CEC_G/S_MODE: OK
>          CEC_EVENT_LOST_MSGS: OK
> 
> Network topology:
>          System Information for device 0 (TV) from device 4 (Playback Device 1):
>                  CEC Version                : 1.4
>                  Physical Address           : 0.0.0.0
>                  Primary Device Type        : TV
>                  Vendor ID                  : 0x00903e
>                  OSD Name                   : 'TV'
>                  Menu Language              : fre
>                  Power Status               : On
> 
> Total: 10, Succeeded: 10, Failed: 0, Warnings: 0
> 
> 
> Benjamin Gaignard (2):
>    dt-bindings: media: stm32 cec driver
>    cec: add STM32 cec driver
> 
>   .../devicetree/bindings/media/st,stm32-cec.txt     |  22 ++
>   drivers/media/platform/Kconfig                     |  13 +
>   drivers/media/platform/Makefile                    |   2 +
>   drivers/media/platform/stm32/Makefile              |   1 +
>   drivers/media/platform/stm32/stm32-cec.c           | 392 +++++++++++++++++++++
>   5 files changed, 430 insertions(+)
>   create mode 100644 Documentation/devicetree/bindings/media/st,stm32-cec.txt
>   create mode 100644 drivers/media/platform/stm32/Makefile
>   create mode 100644 drivers/media/platform/stm32/stm32-cec.c
> 

Re: [PATCH v4 0/2] cec: STM32 driver

[Benjamin Gaignard]

2017-05-29 10:54 GMT+02:00 Hans Verkuil <hverkuil@xs4all.nl>:
> Hi Benjamin,
>
> On 05/29/2017 10:34 AM, Benjamin Gaignard wrote:
>>
>> version 4:
>> - rebased on Hans cec-config branch
>> - rework bindings commit message
>> - add notifier support
>
>
> I really don't like this change. This forced me to think about this a bit
> more,
> and I think this requires another change as well.
>
> The problem you have is that the drm driver for this platform isn't ready
> yet,
> so this CEC driver needs userspace to provide a physical address since it
> can't
> use a notifier.
>
> Trying to support both is a bad idea since this runs the risk that we will
> forget
> to remove the CAP_PHYS_ADDR path later.

I would like stm32 cec driver to be able to work with or without
notifier support.
stm32 are small platforms and not everybody will use hdmi because of memory
consomption but cec can be used anyway.

>
> Instead, just drop the notifier support. And move this driver to staging,
> just
> as we did with the st-cec driver. Once the drm driver arrives this cec
> driver
> can switch to using the notifier and be moved out of staging.
>
> Add a TODO file explaining that this is waiting for the drm driver so the
> CEC_CAP_PHYS_ADDR capability can be removed after switching to using
> CEC_NOTIFIER.
>
> I should have realized this when reviewing v2, sorry about that.
>
> The reason why I don't want CEC drivers using CEC_CAP_PHYS_ADDR in mainline
> (except
> if it is obviously required such as for the usb CEC dongles) is that it puts
> a
> major burden on the application to discover the physical address from the
> EDID. It
> should only be used if there is no other way. In this case this is just a
> temporary situation, so staging is the right place.
>
> BTW, if the stm32 drm driver is going to be accepted for 4.13, then that
> would
> change things, but I don't think that's the case.
>
> Regards,
>
>         Hans
>
>
>> - update KConfig
>>
>> version 2:
>> - fix typo in compagnie name
>> - add yannick sign-off
>> - use cec_message instead of custom struct in cec device
>> - add monitor mode
>>
>> I don't change the split between irq handler and irq thread because
>> it would had mean to handle all errors cases irq handler to keep
>> a correct sequence. I don't think it is critical as it is since cec is a
>> very
>> slow protocol.
>>
>> This serie of patches add cec driver for STM32 platforms.
>>
>> This code doesn't implement cec notifier because STM32 doesn't
>> provide HDMI yet but it will be added later.
>>
>> Those patches have been developped on top of media_tree master branch
>> where STM32 DCMI code has not been merged so conflict in Kconfig and
>> Makefile
>> could occur depending of merge ordering.
>>
>> Compliance has been tested on STM32F769.
>>
>> ~ # cec-ctl -p 1.0.0.0 --playback
>> Driver Info:
>>          Driver Name                : stm32-cec
>>          Adapter Name               : stm32-cec
>>          Capabilities               : 0x0000000f
>>                  Physical Address
>>                  Logical Addresses
>>                  Transmit
>>                  Passthrough
>>          Driver version             : 4.11.0
>>          Available Logical Addresses: 1
>>          Physical Address           : 1.0.0.0
>>          Logical Address Mask       : 0x0010
>>          CEC Version                : 2.0
>>          Vendor ID                  : 0x000c03 (HDMI)
>>          OSD Name                   : 'Playback'
>>          Logical Addresses          : 1 (Allow RC Passthrough)
>>
>>            Logical Address          : 4 (Playback Device 1)
>>              Primary Device Type    : Playback
>>              Logical Address Type   : Playback
>>              All Device Types       : Playback
>>              RC TV Profile          : None
>>              Device Features        :
>>                  None
>>
>> ~ # cec-compliance -A
>> cec-compliance SHA                 :
>> 6acac5cec698de39b9398b66c4f5f4db6b2730d8
>>
>> Driver Info:
>>          Driver Name                : stm32-cec
>>          Adapter Name               : stm32-cec
>>          Capabilities               : 0x0000000f
>>                  Physical Address
>>                  Logical Addresses
>>                  Transmit
>>                  Passthrough
>>          Driver version             : 4.11.0
>>          Available Logical Addresses: 1
>>          Physical Address           : 1.0.0.0
>>          Logical Address Mask       : 0x0010
>>          CEC Version                : 2.0
>>          Vendor ID                  : 0x000c03
>>          Logical Addresses          : 1 (Allow RC Passthrough)
>>
>>            Logical Address          : 4
>>              Primary Device Type    : Playback
>>              Logical Address Type   : Playback
>>              All Device Types       : Playback
>>              RC TV Profile          : None
>>              Device Features        :
>>                  None
>>
>> Compliance test for device /dev/cec0:
>>
>>      The test results mean the following:
>>          OK                  Supported correctly by the device.
>>          OK (Not Supported)  Not supported and not mandatory for the
>> device.
>>          OK (Presumed)       Presumably supported.  Manually check to
>> confirm.
>>          OK (Unexpected)     Supported correctly but is not expected to be
>> supported for this device.
>>          OK (Refused)        Supported by the device, but was refused.
>>          FAIL                Failed and was expected to be supported by
>> this device.
>>
>> Find remote devices:
>>          Polling: OK
>>
>> CEC API:
>>          CEC_ADAP_G_CAPS: OK
>>          CEC_DQEVENT: OK
>>          CEC_ADAP_G/S_PHYS_ADDR: OK
>>          CEC_ADAP_G/S_LOG_ADDRS: OK
>>          CEC_TRANSMIT: OK
>>          CEC_RECEIVE: OK
>>          CEC_TRANSMIT/RECEIVE (non-blocking): OK (Presumed)
>>          CEC_G/S_MODE: OK
>>          CEC_EVENT_LOST_MSGS: OK
>>
>> Network topology:
>>          System Information for device 0 (TV) from device 4 (Playback
>> Device 1):
>>                  CEC Version                : 1.4
>>                  Physical Address           : 0.0.0.0
>>                  Primary Device Type        : TV
>>                  Vendor ID                  : 0x00903e
>>                  OSD Name                   : 'TV'
>>                  Menu Language              : fre
>>                  Power Status               : On
>>
>> Total: 10, Succeeded: 10, Failed: 0, Warnings: 0
>>
>>
>> Benjamin Gaignard (2):
>>    dt-bindings: media: stm32 cec driver
>>    cec: add STM32 cec driver
>>
>>   .../devicetree/bindings/media/st,stm32-cec.txt     |  22 ++
>>   drivers/media/platform/Kconfig                     |  13 +
>>   drivers/media/platform/Makefile                    |   2 +
>>   drivers/media/platform/stm32/Makefile              |   1 +
>>   drivers/media/platform/stm32/stm32-cec.c           | 392
>> +++++++++++++++++++++
>>   5 files changed, 430 insertions(+)
>>   create mode 100644
>> Documentation/devicetree/bindings/media/st,stm32-cec.txt
>>   create mode 100644 drivers/media/platform/stm32/Makefile
>>   create mode 100644 drivers/media/platform/stm32/stm32-cec.c
>>
>

Re: [PATCH v4 0/2] cec: STM32 driver

[Hans Verkuil]

On 05/29/2017 11:07 AM, Benjamin Gaignard wrote:
> 2017-05-29 10:54 GMT+02:00 Hans Verkuil <hverkuil-qWit8jRvyhVmR6Xm/wNWPw@public.gmane.org>:
>> Hi Benjamin,
>>
>> On 05/29/2017 10:34 AM, Benjamin Gaignard wrote:
>>>
>>> version 4:
>>> - rebased on Hans cec-config branch
>>> - rework bindings commit message
>>> - add notifier support
>>
>>
>> I really don't like this change. This forced me to think about this a bit
>> more,
>> and I think this requires another change as well.
>>
>> The problem you have is that the drm driver for this platform isn't ready
>> yet,
>> so this CEC driver needs userspace to provide a physical address since it
>> can't
>> use a notifier.
>>
>> Trying to support both is a bad idea since this runs the risk that we will
>> forget
>> to remove the CAP_PHYS_ADDR path later.
> 
> I would like stm32 cec driver to be able to work with or without
> notifier support.
> stm32 are small platforms and not everybody will use hdmi because of memory
> consomption but cec can be used anyway.

Ah, that's a good point.

So drop the notifier and add a comment where you describe that once the drm
driver becomes available notifier support will be added, but that CAP_PHYS_ADDR
remains allowed in cases where the drm driver isn't enabled due to the small
size of the platform.

With that comment it can stay in mainline.

When the drm driver arrives the notifier should probably be automatically
selected when the drm driver is enabled. I want to avoid the combination of
CAP_PHYS_ADDR and a drm driver, that shouldn't happen.

Regards,

	Hans
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Re: [PATCH v4 0/2] cec: STM32 driver

[Hans Verkuil]

On 05/29/2017 11:07 AM, Benjamin Gaignard wrote:
> 2017-05-29 10:54 GMT+02:00 Hans Verkuil <hverkuil@xs4all.nl>:
>> Hi Benjamin,
>>
>> On 05/29/2017 10:34 AM, Benjamin Gaignard wrote:
>>>
>>> version 4:
>>> - rebased on Hans cec-config branch
>>> - rework bindings commit message
>>> - add notifier support
>>
>>
>> I really don't like this change. This forced me to think about this a bit
>> more,
>> and I think this requires another change as well.
>>
>> The problem you have is that the drm driver for this platform isn't ready
>> yet,
>> so this CEC driver needs userspace to provide a physical address since it
>> can't
>> use a notifier.
>>
>> Trying to support both is a bad idea since this runs the risk that we will
>> forget
>> to remove the CAP_PHYS_ADDR path later.
> 
> I would like stm32 cec driver to be able to work with or without
> notifier support.
> stm32 are small platforms and not everybody will use hdmi because of memory
> consomption but cec can be used anyway.

Ah, that's a good point.

So drop the notifier and add a comment where you describe that once the drm
driver becomes available notifier support will be added, but that CAP_PHYS_ADDR
remains allowed in cases where the drm driver isn't enabled due to the small
size of the platform.

With that comment it can stay in mainline.

When the drm driver arrives the notifier should probably be automatically
selected when the drm driver is enabled. I want to avoid the combination of
CAP_PHYS_ADDR and a drm driver, that shouldn't happen.

Regards,

	Hans