[v2,2/3] stih-cec: add HPD notifier support

Message ID 1483455297-2286-3-git-send-email-benjamin.gaignard@linaro.org
State New
Headers show

Commit Message

Benjamin Gaignard Jan. 3, 2017, 2:54 p.m.
By using the HPD notifier framework there is no longer any reason
to manually set the physical address. This was the one blocking
issue that prevented this driver from going out of staging, so do
this move as well.

Update the bindings documentation the new hdmi phandle.

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>

---
version 2:
- use HPD notifier
- move stih-cec out of staging
- split driver code and devicetree change in two patches
---
 .../devicetree/bindings/media/stih-cec.txt         |   2 +
 drivers/media/platform/Kconfig                     |  10 +
 drivers/media/platform/Makefile                    |   1 +
 drivers/media/platform/sti/cec/Makefile            |   1 +
 drivers/media/platform/sti/cec/stih-cec.c          | 404 +++++++++++++++++++++
 drivers/staging/media/Kconfig                      |   2 -
 drivers/staging/media/Makefile                     |   1 -
 drivers/staging/media/st-cec/Kconfig               |   8 -
 drivers/staging/media/st-cec/Makefile              |   1 -
 drivers/staging/media/st-cec/TODO                  |   7 -
 drivers/staging/media/st-cec/stih-cec.c            | 379 -------------------
 11 files changed, 418 insertions(+), 398 deletions(-)
 create mode 100644 drivers/media/platform/sti/cec/Makefile
 create mode 100644 drivers/media/platform/sti/cec/stih-cec.c
 delete mode 100644 drivers/staging/media/st-cec/Kconfig
 delete mode 100644 drivers/staging/media/st-cec/Makefile
 delete mode 100644 drivers/staging/media/st-cec/TODO
 delete mode 100644 drivers/staging/media/st-cec/stih-cec.c

-- 
1.9.1

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Patch

diff --git a/Documentation/devicetree/bindings/media/stih-cec.txt b/Documentation/devicetree/bindings/media/stih-cec.txt
index 71c4b2f..7d82121 100644
--- a/Documentation/devicetree/bindings/media/stih-cec.txt
+++ b/Documentation/devicetree/bindings/media/stih-cec.txt
@@ -9,6 +9,7 @@  Required properties:
  - pinctrl-names: Contains only one value - "default"
  - pinctrl-0: Specifies the pin control groups used for CEC hardware.
  - resets: Reference to a reset controller
+ - st,hdmi-handle: Phandle to the HMDI controller
 
 Example for STIH407:
 
@@ -22,4 +23,5 @@  sti-cec@094a087c {
 	pinctrl-names = "default";
 	pinctrl-0 = <&pinctrl_cec0_default>;
 	resets = <&softreset STIH407_LPM_SOFTRESET>;
+	st,hdmi-handle = <&hdmi>;
 };
diff --git a/drivers/media/platform/Kconfig b/drivers/media/platform/Kconfig
index 0d7acf1..e5f680e 100644
--- a/drivers/media/platform/Kconfig
+++ b/drivers/media/platform/Kconfig
@@ -408,6 +408,16 @@  config VIDEO_SAMSUNG_S5P_CEC
          CEC bus is present in the HDMI connector and enables communication
          between compatible devices.
 
+config VIDEO_STI_HDMI_CEC
+       tristate "STMicroelectronics STiH4xx HDMI CEC driver"
+       depends on VIDEO_DEV && MEDIA_CEC_SUPPORT && (ARCH_STI || COMPILE_TEST)
+       select HPD_NOTIFIER
+       ---help---
+         This is a driver for STIH4xx HDMI CEC interface. It uses the
+         generic CEC framework interface.
+         CEC bus is present in the HDMI connector and enables communication
+         between compatible devices.
+
 endif #V4L_CEC_DRIVERS
 
 menuconfig V4L_TEST_DRIVERS
diff --git a/drivers/media/platform/Makefile b/drivers/media/platform/Makefile
index ad3bf22..01b689c 100644
--- a/drivers/media/platform/Makefile
+++ b/drivers/media/platform/Makefile
@@ -39,6 +39,7 @@  obj-$(CONFIG_VIDEO_SAMSUNG_EXYNOS_GSC)	+= exynos-gsc/
 obj-$(CONFIG_VIDEO_STI_BDISP)		+= sti/bdisp/
 obj-$(CONFIG_VIDEO_STI_HVA)		+= sti/hva/
 obj-$(CONFIG_DVB_C8SECTPFE)		+= sti/c8sectpfe/
+obj-$(CONFIG_VIDEO_STI_HDMI_CEC) 	+= sti/cec/
 
 obj-$(CONFIG_BLACKFIN)                  += blackfin/
 
diff --git a/drivers/media/platform/sti/cec/Makefile b/drivers/media/platform/sti/cec/Makefile
new file mode 100644
index 0000000..f07905e
--- /dev/null
+++ b/drivers/media/platform/sti/cec/Makefile
@@ -0,0 +1 @@ 
+obj-$(CONFIG_VIDEO_STI_HDMI_CEC) += stih-cec.o
diff --git a/drivers/media/platform/sti/cec/stih-cec.c b/drivers/media/platform/sti/cec/stih-cec.c
new file mode 100644
index 0000000..e50e916
--- /dev/null
+++ b/drivers/media/platform/sti/cec/stih-cec.c
@@ -0,0 +1,404 @@ 
+/*
+ * STIH4xx CEC driver
+ * Copyright (C) STMicroelectronic SA 2016
+ *
+ * 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/hpd-notifier.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+
+#include <media/cec.h>
+
+#define CEC_NAME	"stih-cec"
+
+/* CEC registers  */
+#define CEC_CLK_DIV           0x0
+#define CEC_CTRL              0x4
+#define CEC_IRQ_CTRL          0x8
+#define CEC_STATUS            0xC
+#define CEC_EXT_STATUS        0x10
+#define CEC_TX_CTRL           0x14
+#define CEC_FREE_TIME_THRESH  0x18
+#define CEC_BIT_TOUT_THRESH   0x1C
+#define CEC_BIT_PULSE_THRESH  0x20
+#define CEC_DATA              0x24
+#define CEC_TX_ARRAY_CTRL     0x28
+#define CEC_CTRL2             0x2C
+#define CEC_TX_ERROR_STS      0x30
+#define CEC_ADDR_TABLE        0x34
+#define CEC_DATA_ARRAY_CTRL   0x38
+#define CEC_DATA_ARRAY_STATUS 0x3C
+#define CEC_TX_DATA_BASE      0x40
+#define CEC_TX_DATA_TOP       0x50
+#define CEC_TX_DATA_SIZE      0x1
+#define CEC_RX_DATA_BASE      0x54
+#define CEC_RX_DATA_TOP       0x64
+#define CEC_RX_DATA_SIZE      0x1
+
+/* CEC_CTRL2 */
+#define CEC_LINE_INACTIVE_EN   BIT(0)
+#define CEC_AUTO_BUS_ERR_EN    BIT(1)
+#define CEC_STOP_ON_ARB_ERR_EN BIT(2)
+#define CEC_TX_REQ_WAIT_EN     BIT(3)
+
+/* CEC_DATA_ARRAY_CTRL */
+#define CEC_TX_ARRAY_EN          BIT(0)
+#define CEC_RX_ARRAY_EN          BIT(1)
+#define CEC_TX_ARRAY_RESET       BIT(2)
+#define CEC_RX_ARRAY_RESET       BIT(3)
+#define CEC_TX_N_OF_BYTES_IRQ_EN BIT(4)
+#define CEC_TX_STOP_ON_NACK      BIT(7)
+
+/* CEC_TX_ARRAY_CTRL */
+#define CEC_TX_N_OF_BYTES  0x1F
+#define CEC_TX_START       BIT(5)
+#define CEC_TX_AUTO_SOM_EN BIT(6)
+#define CEC_TX_AUTO_EOM_EN BIT(7)
+
+/* CEC_IRQ_CTRL */
+#define CEC_TX_DONE_IRQ_EN   BIT(0)
+#define CEC_ERROR_IRQ_EN     BIT(2)
+#define CEC_RX_DONE_IRQ_EN   BIT(3)
+#define CEC_RX_SOM_IRQ_EN    BIT(4)
+#define CEC_RX_EOM_IRQ_EN    BIT(5)
+#define CEC_FREE_TIME_IRQ_EN BIT(6)
+#define CEC_PIN_STS_IRQ_EN   BIT(7)
+
+/* CEC_CTRL */
+#define CEC_IN_FILTER_EN    BIT(0)
+#define CEC_PWR_SAVE_EN     BIT(1)
+#define CEC_EN              BIT(4)
+#define CEC_ACK_CTRL        BIT(5)
+#define CEC_RX_RESET_EN     BIT(6)
+#define CEC_IGNORE_RX_ERROR BIT(7)
+
+/* CEC_STATUS */
+#define CEC_TX_DONE_STS       BIT(0)
+#define CEC_TX_ACK_GET_STS    BIT(1)
+#define CEC_ERROR_STS         BIT(2)
+#define CEC_RX_DONE_STS       BIT(3)
+#define CEC_RX_SOM_STS        BIT(4)
+#define CEC_RX_EOM_STS        BIT(5)
+#define CEC_FREE_TIME_IRQ_STS BIT(6)
+#define CEC_PIN_STS           BIT(7)
+#define CEC_SBIT_TOUT_STS     BIT(8)
+#define CEC_DBIT_TOUT_STS     BIT(9)
+#define CEC_LPULSE_ERROR_STS  BIT(10)
+#define CEC_HPULSE_ERROR_STS  BIT(11)
+#define CEC_TX_ERROR          BIT(12)
+#define CEC_TX_ARB_ERROR      BIT(13)
+#define CEC_RX_ERROR_MIN      BIT(14)
+#define CEC_RX_ERROR_MAX      BIT(15)
+
+/* Signal free time in bit periods (2.4ms) */
+#define CEC_PRESENT_INIT_SFT 7
+#define CEC_NEW_INIT_SFT     5
+#define CEC_RETRANSMIT_SFT   3
+
+/* Constants for CEC_BIT_TOUT_THRESH register */
+#define CEC_SBIT_TOUT_47MS BIT(1)
+#define CEC_SBIT_TOUT_48MS (BIT(0) | BIT(1))
+#define CEC_SBIT_TOUT_50MS BIT(2)
+#define CEC_DBIT_TOUT_27MS BIT(0)
+#define CEC_DBIT_TOUT_28MS BIT(1)
+#define CEC_DBIT_TOUT_29MS (BIT(0) | BIT(1))
+
+/* Constants for CEC_BIT_PULSE_THRESH register */
+#define CEC_BIT_LPULSE_03MS BIT(1)
+#define CEC_BIT_HPULSE_03MS BIT(3)
+
+/* Constants for CEC_DATA_ARRAY_STATUS register */
+#define CEC_RX_N_OF_BYTES                     0x1F
+#define CEC_TX_N_OF_BYTES_SENT                BIT(5)
+#define CEC_RX_OVERRUN                        BIT(6)
+
+struct stih_cec {
+	struct cec_adapter	*adap;
+	struct device		*dev;
+	struct clk		*clk;
+	void __iomem		*regs;
+	int			irq;
+	u32			irq_status;
+	struct hpd_notifier	*notifier;
+};
+
+static int stih_cec_adap_enable(struct cec_adapter *adap, bool enable)
+{
+	struct stih_cec *cec = adap->priv;
+
+	if (enable) {
+		/* The doc says (input TCLK_PERIOD * CEC_CLK_DIV) = 0.1ms */
+		unsigned long clk_freq = clk_get_rate(cec->clk);
+		u32 cec_clk_div = clk_freq / 10000;
+
+		writel(cec_clk_div, cec->regs + CEC_CLK_DIV);
+
+		/* Configuration of the durations activating a timeout */
+		writel(CEC_SBIT_TOUT_47MS | (CEC_DBIT_TOUT_28MS << 4),
+		       cec->regs + CEC_BIT_TOUT_THRESH);
+
+		/* Configuration of the smallest allowed duration for pulses */
+		writel(CEC_BIT_LPULSE_03MS | CEC_BIT_HPULSE_03MS,
+		       cec->regs + CEC_BIT_PULSE_THRESH);
+
+		/* Minimum received bit period threshold */
+		writel(BIT(5) | BIT(7), cec->regs + CEC_TX_CTRL);
+
+		/* Configuration of transceiver data arrays */
+		writel(CEC_TX_ARRAY_EN | CEC_RX_ARRAY_EN | CEC_TX_STOP_ON_NACK,
+		       cec->regs + CEC_DATA_ARRAY_CTRL);
+
+		/* Configuration of the control bits for CEC Transceiver */
+		writel(CEC_IN_FILTER_EN | CEC_EN | CEC_RX_RESET_EN,
+		       cec->regs + CEC_CTRL);
+
+		/* Clear logical addresses */
+		writel(0, cec->regs + CEC_ADDR_TABLE);
+
+		/* Clear the status register */
+		writel(0x0, cec->regs + CEC_STATUS);
+
+		/* Enable the interrupts */
+		writel(CEC_TX_DONE_IRQ_EN | CEC_RX_DONE_IRQ_EN |
+		       CEC_RX_SOM_IRQ_EN | CEC_RX_EOM_IRQ_EN |
+		       CEC_ERROR_IRQ_EN,
+		       cec->regs + CEC_IRQ_CTRL);
+
+	} else {
+		/* Clear logical addresses */
+		writel(0, cec->regs + CEC_ADDR_TABLE);
+
+		/* Clear the status register */
+		writel(0x0, cec->regs + CEC_STATUS);
+
+		/* Disable the interrupts */
+		writel(0, cec->regs + CEC_IRQ_CTRL);
+	}
+
+	return 0;
+}
+
+static int stih_cec_adap_log_addr(struct cec_adapter *adap, u8 logical_addr)
+{
+	struct stih_cec *cec = adap->priv;
+	u32 reg = readl(cec->regs + CEC_ADDR_TABLE);
+
+	reg |= 1 << logical_addr;
+
+	if (logical_addr == CEC_LOG_ADDR_INVALID)
+		reg = 0;
+
+	writel(reg, cec->regs + CEC_ADDR_TABLE);
+
+	return 0;
+}
+
+static int stih_cec_adap_transmit(struct cec_adapter *adap, u8 attempts,
+				  u32 signal_free_time, struct cec_msg *msg)
+{
+	struct stih_cec *cec = adap->priv;
+	int i;
+
+	/* Copy message into registers */
+	for (i = 0; i < msg->len; i++)
+		writeb(msg->msg[i], cec->regs + CEC_TX_DATA_BASE + i);
+
+	/* Start transmission, configure hardware to add start and stop bits
+	 * Signal free time is handled by the hardware
+	 */
+	writel(CEC_TX_AUTO_SOM_EN | CEC_TX_AUTO_EOM_EN | CEC_TX_START |
+	       msg->len, cec->regs + CEC_TX_ARRAY_CTRL);
+
+	return 0;
+}
+
+static void stih_tx_done(struct stih_cec *cec, u32 status)
+{
+	if (status & CEC_TX_ERROR) {
+		cec_transmit_done(cec->adap, CEC_TX_STATUS_ERROR, 0, 0, 0, 1);
+		return;
+	}
+
+	if (status & CEC_TX_ARB_ERROR) {
+		cec_transmit_done(cec->adap,
+				  CEC_TX_STATUS_ARB_LOST, 1, 0, 0, 0);
+		return;
+	}
+
+	if (!(status & CEC_TX_ACK_GET_STS)) {
+		cec_transmit_done(cec->adap, CEC_TX_STATUS_NACK, 0, 1, 0, 0);
+		return;
+	}
+
+	cec_transmit_done(cec->adap, CEC_TX_STATUS_OK, 0, 0, 0, 0);
+}
+
+static void stih_rx_done(struct stih_cec *cec, u32 status)
+{
+	struct cec_msg msg = {};
+	u8 i;
+
+	if (status & CEC_RX_ERROR_MIN)
+		return;
+
+	if (status & CEC_RX_ERROR_MAX)
+		return;
+
+	msg.len = readl(cec->regs + CEC_DATA_ARRAY_STATUS) & 0x1f;
+
+	if (!msg.len)
+		return;
+
+	if (msg.len > 16)
+		msg.len = 16;
+
+	for (i = 0; i < msg.len; i++)
+		msg.msg[i] = readl(cec->regs + CEC_RX_DATA_BASE + i);
+
+	cec_received_msg(cec->adap, &msg);
+}
+
+static irqreturn_t stih_cec_irq_handler_thread(int irq, void *priv)
+{
+	struct stih_cec *cec = priv;
+
+	if (cec->irq_status & CEC_TX_DONE_STS)
+		stih_tx_done(cec, cec->irq_status);
+
+	if (cec->irq_status & CEC_RX_DONE_STS)
+		stih_rx_done(cec, cec->irq_status);
+
+	cec->irq_status = 0;
+
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t stih_cec_irq_handler(int irq, void *priv)
+{
+	struct stih_cec *cec = priv;
+
+	cec->irq_status = readl(cec->regs + CEC_STATUS);
+	writel(cec->irq_status, cec->regs + CEC_STATUS);
+
+	return IRQ_WAKE_THREAD;
+}
+
+static const struct cec_adap_ops sti_cec_adap_ops = {
+	.adap_enable = stih_cec_adap_enable,
+	.adap_log_addr = stih_cec_adap_log_addr,
+	.adap_transmit = stih_cec_adap_transmit,
+};
+
+static int stih_cec_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct resource *res;
+	struct stih_cec *cec;
+	struct device_node *np;
+	struct platform_device *hdmi_dev;
+	int ret;
+
+	cec = devm_kzalloc(dev, sizeof(*cec), GFP_KERNEL);
+	if (!cec)
+		return -ENOMEM;
+
+	np = of_parse_phandle(pdev->dev.of_node, "st,hdmi-handle", 0);
+
+	if (!np) {
+		dev_err(&pdev->dev, "Failed to find hdmi node in device tree\n");
+		return -ENODEV;
+	}
+
+	hdmi_dev = of_find_device_by_node(np);
+	if (!hdmi_dev)
+		return -EPROBE_DEFER;
+
+	cec->notifier = hpd_notifier_get(&hdmi_dev->dev);
+	if (!cec->notifier)
+		return -ENOMEM;
+
+	cec->dev = dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	cec->regs = devm_ioremap_resource(dev, res);
+	if (IS_ERR(cec->regs))
+		return PTR_ERR(cec->regs);
+
+	cec->irq = platform_get_irq(pdev, 0);
+	if (cec->irq < 0)
+		return cec->irq;
+
+	ret = devm_request_threaded_irq(dev, cec->irq, stih_cec_irq_handler,
+					stih_cec_irq_handler_thread, 0,
+					pdev->name, cec);
+	if (ret)
+		return ret;
+
+	cec->clk = devm_clk_get(dev, "cec-clk");
+	if (IS_ERR(cec->clk)) {
+		dev_err(dev, "Cannot get cec clock\n");
+		return PTR_ERR(cec->clk);
+	}
+
+	cec->adap = cec_allocate_adapter(&sti_cec_adap_ops, cec,
+			CEC_NAME,
+			CEC_CAP_LOG_ADDRS | CEC_CAP_PASSTHROUGH |
+			CEC_CAP_TRANSMIT, 1);
+	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;
+	}
+
+	cec_register_hpd_notifier(cec->adap, cec->notifier);
+
+	platform_set_drvdata(pdev, cec);
+	return 0;
+}
+
+static int stih_cec_remove(struct platform_device *pdev)
+{
+	struct stih_cec *cec = platform_get_drvdata(pdev);
+
+	cec_unregister_adapter(cec->adap);
+	hpd_notifier_put(cec->notifier);
+
+	return 0;
+}
+
+static const struct of_device_id stih_cec_match[] = {
+	{
+		.compatible	= "st,stih-cec",
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, stih_cec_match);
+
+static struct platform_driver stih_cec_pdrv = {
+	.probe	= stih_cec_probe,
+	.remove = stih_cec_remove,
+	.driver = {
+		.name		= CEC_NAME,
+		.of_match_table	= stih_cec_match,
+	},
+};
+
+module_platform_driver(stih_cec_pdrv);
+
+MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@linaro.org>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("STIH4xx CEC driver");
diff --git a/drivers/staging/media/Kconfig b/drivers/staging/media/Kconfig
index 1b7804c..d4f50f0 100644
--- a/drivers/staging/media/Kconfig
+++ b/drivers/staging/media/Kconfig
@@ -30,6 +30,4 @@  source "drivers/staging/media/omap4iss/Kconfig"
 # Keep LIRC at the end, as it has sub-menus
 source "drivers/staging/media/lirc/Kconfig"
 
-source "drivers/staging/media/st-cec/Kconfig"
-
 endif
diff --git a/drivers/staging/media/Makefile b/drivers/staging/media/Makefile
index e11afbf..4c9bb23 100644
--- a/drivers/staging/media/Makefile
+++ b/drivers/staging/media/Makefile
@@ -3,4 +3,3 @@  obj-$(CONFIG_DVB_CXD2099)	+= cxd2099/
 obj-$(CONFIG_LIRC_STAGING)	+= lirc/
 obj-$(CONFIG_VIDEO_DM365_VPFE)	+= davinci_vpfe/
 obj-$(CONFIG_VIDEO_OMAP4)	+= omap4iss/
-obj-$(CONFIG_VIDEO_STI_HDMI_CEC) += st-cec/
diff --git a/drivers/staging/media/st-cec/Kconfig b/drivers/staging/media/st-cec/Kconfig
deleted file mode 100644
index c04283d..0000000
--- a/drivers/staging/media/st-cec/Kconfig
+++ /dev/null
@@ -1,8 +0,0 @@ 
-config VIDEO_STI_HDMI_CEC
-       tristate "STMicroelectronics STiH4xx HDMI CEC driver"
-       depends on VIDEO_DEV && MEDIA_CEC_SUPPORT && (ARCH_STI || COMPILE_TEST)
-       ---help---
-         This is a driver for STIH4xx HDMI CEC interface. It uses the
-         generic CEC framework interface.
-         CEC bus is present in the HDMI connector and enables communication
-         between compatible devices.
diff --git a/drivers/staging/media/st-cec/Makefile b/drivers/staging/media/st-cec/Makefile
deleted file mode 100644
index f07905e..0000000
--- a/drivers/staging/media/st-cec/Makefile
+++ /dev/null
@@ -1 +0,0 @@ 
-obj-$(CONFIG_VIDEO_STI_HDMI_CEC) += stih-cec.o
diff --git a/drivers/staging/media/st-cec/TODO b/drivers/staging/media/st-cec/TODO
deleted file mode 100644
index c612897..0000000
--- a/drivers/staging/media/st-cec/TODO
+++ /dev/null
@@ -1,7 +0,0 @@ 
-This driver requires that userspace sets the physical address.
-However, this should be passed on from the corresponding
-ST HDMI driver.
-
-We have to wait until the HDMI notifier framework has been merged
-in order to handle this gracefully, until that time this driver
-has to remain in staging.
diff --git a/drivers/staging/media/st-cec/stih-cec.c b/drivers/staging/media/st-cec/stih-cec.c
deleted file mode 100644
index 3c25638..0000000
--- a/drivers/staging/media/st-cec/stih-cec.c
+++ /dev/null
@@ -1,379 +0,0 @@ 
-/*
- * drivers/staging/media/st-cec/stih-cec.c
- *
- * STIH4xx CEC driver
- * Copyright (C) STMicroelectronic SA 2016
- *
- * 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/mfd/syscon.h>
-#include <linux/module.h>
-#include <linux/of.h>
-#include <linux/platform_device.h>
-
-#include <media/cec.h>
-
-#define CEC_NAME	"stih-cec"
-
-/* CEC registers  */
-#define CEC_CLK_DIV           0x0
-#define CEC_CTRL              0x4
-#define CEC_IRQ_CTRL          0x8
-#define CEC_STATUS            0xC
-#define CEC_EXT_STATUS        0x10
-#define CEC_TX_CTRL           0x14
-#define CEC_FREE_TIME_THRESH  0x18
-#define CEC_BIT_TOUT_THRESH   0x1C
-#define CEC_BIT_PULSE_THRESH  0x20
-#define CEC_DATA              0x24
-#define CEC_TX_ARRAY_CTRL     0x28
-#define CEC_CTRL2             0x2C
-#define CEC_TX_ERROR_STS      0x30
-#define CEC_ADDR_TABLE        0x34
-#define CEC_DATA_ARRAY_CTRL   0x38
-#define CEC_DATA_ARRAY_STATUS 0x3C
-#define CEC_TX_DATA_BASE      0x40
-#define CEC_TX_DATA_TOP       0x50
-#define CEC_TX_DATA_SIZE      0x1
-#define CEC_RX_DATA_BASE      0x54
-#define CEC_RX_DATA_TOP       0x64
-#define CEC_RX_DATA_SIZE      0x1
-
-/* CEC_CTRL2 */
-#define CEC_LINE_INACTIVE_EN   BIT(0)
-#define CEC_AUTO_BUS_ERR_EN    BIT(1)
-#define CEC_STOP_ON_ARB_ERR_EN BIT(2)
-#define CEC_TX_REQ_WAIT_EN     BIT(3)
-
-/* CEC_DATA_ARRAY_CTRL */
-#define CEC_TX_ARRAY_EN          BIT(0)
-#define CEC_RX_ARRAY_EN          BIT(1)
-#define CEC_TX_ARRAY_RESET       BIT(2)
-#define CEC_RX_ARRAY_RESET       BIT(3)
-#define CEC_TX_N_OF_BYTES_IRQ_EN BIT(4)
-#define CEC_TX_STOP_ON_NACK      BIT(7)
-
-/* CEC_TX_ARRAY_CTRL */
-#define CEC_TX_N_OF_BYTES  0x1F
-#define CEC_TX_START       BIT(5)
-#define CEC_TX_AUTO_SOM_EN BIT(6)
-#define CEC_TX_AUTO_EOM_EN BIT(7)
-
-/* CEC_IRQ_CTRL */
-#define CEC_TX_DONE_IRQ_EN   BIT(0)
-#define CEC_ERROR_IRQ_EN     BIT(2)
-#define CEC_RX_DONE_IRQ_EN   BIT(3)
-#define CEC_RX_SOM_IRQ_EN    BIT(4)
-#define CEC_RX_EOM_IRQ_EN    BIT(5)
-#define CEC_FREE_TIME_IRQ_EN BIT(6)
-#define CEC_PIN_STS_IRQ_EN   BIT(7)
-
-/* CEC_CTRL */
-#define CEC_IN_FILTER_EN    BIT(0)
-#define CEC_PWR_SAVE_EN     BIT(1)
-#define CEC_EN              BIT(4)
-#define CEC_ACK_CTRL        BIT(5)
-#define CEC_RX_RESET_EN     BIT(6)
-#define CEC_IGNORE_RX_ERROR BIT(7)
-
-/* CEC_STATUS */
-#define CEC_TX_DONE_STS       BIT(0)
-#define CEC_TX_ACK_GET_STS    BIT(1)
-#define CEC_ERROR_STS         BIT(2)
-#define CEC_RX_DONE_STS       BIT(3)
-#define CEC_RX_SOM_STS        BIT(4)
-#define CEC_RX_EOM_STS        BIT(5)
-#define CEC_FREE_TIME_IRQ_STS BIT(6)
-#define CEC_PIN_STS           BIT(7)
-#define CEC_SBIT_TOUT_STS     BIT(8)
-#define CEC_DBIT_TOUT_STS     BIT(9)
-#define CEC_LPULSE_ERROR_STS  BIT(10)
-#define CEC_HPULSE_ERROR_STS  BIT(11)
-#define CEC_TX_ERROR          BIT(12)
-#define CEC_TX_ARB_ERROR      BIT(13)
-#define CEC_RX_ERROR_MIN      BIT(14)
-#define CEC_RX_ERROR_MAX      BIT(15)
-
-/* Signal free time in bit periods (2.4ms) */
-#define CEC_PRESENT_INIT_SFT 7
-#define CEC_NEW_INIT_SFT     5
-#define CEC_RETRANSMIT_SFT   3
-
-/* Constants for CEC_BIT_TOUT_THRESH register */
-#define CEC_SBIT_TOUT_47MS BIT(1)
-#define CEC_SBIT_TOUT_48MS (BIT(0) | BIT(1))
-#define CEC_SBIT_TOUT_50MS BIT(2)
-#define CEC_DBIT_TOUT_27MS BIT(0)
-#define CEC_DBIT_TOUT_28MS BIT(1)
-#define CEC_DBIT_TOUT_29MS (BIT(0) | BIT(1))
-
-/* Constants for CEC_BIT_PULSE_THRESH register */
-#define CEC_BIT_LPULSE_03MS BIT(1)
-#define CEC_BIT_HPULSE_03MS BIT(3)
-
-/* Constants for CEC_DATA_ARRAY_STATUS register */
-#define CEC_RX_N_OF_BYTES                     0x1F
-#define CEC_TX_N_OF_BYTES_SENT                BIT(5)
-#define CEC_RX_OVERRUN                        BIT(6)
-
-struct stih_cec {
-	struct cec_adapter	*adap;
-	struct device		*dev;
-	struct clk		*clk;
-	void __iomem		*regs;
-	int			irq;
-	u32			irq_status;
-};
-
-static int stih_cec_adap_enable(struct cec_adapter *adap, bool enable)
-{
-	struct stih_cec *cec = adap->priv;
-
-	if (enable) {
-		/* The doc says (input TCLK_PERIOD * CEC_CLK_DIV) = 0.1ms */
-		unsigned long clk_freq = clk_get_rate(cec->clk);
-		u32 cec_clk_div = clk_freq / 10000;
-
-		writel(cec_clk_div, cec->regs + CEC_CLK_DIV);
-
-		/* Configuration of the durations activating a timeout */
-		writel(CEC_SBIT_TOUT_47MS | (CEC_DBIT_TOUT_28MS << 4),
-		       cec->regs + CEC_BIT_TOUT_THRESH);
-
-		/* Configuration of the smallest allowed duration for pulses */
-		writel(CEC_BIT_LPULSE_03MS | CEC_BIT_HPULSE_03MS,
-		       cec->regs + CEC_BIT_PULSE_THRESH);
-
-		/* Minimum received bit period threshold */
-		writel(BIT(5) | BIT(7), cec->regs + CEC_TX_CTRL);
-
-		/* Configuration of transceiver data arrays */
-		writel(CEC_TX_ARRAY_EN | CEC_RX_ARRAY_EN | CEC_TX_STOP_ON_NACK,
-		       cec->regs + CEC_DATA_ARRAY_CTRL);
-
-		/* Configuration of the control bits for CEC Transceiver */
-		writel(CEC_IN_FILTER_EN | CEC_EN | CEC_RX_RESET_EN,
-		       cec->regs + CEC_CTRL);
-
-		/* Clear logical addresses */
-		writel(0, cec->regs + CEC_ADDR_TABLE);
-
-		/* Clear the status register */
-		writel(0x0, cec->regs + CEC_STATUS);
-
-		/* Enable the interrupts */
-		writel(CEC_TX_DONE_IRQ_EN | CEC_RX_DONE_IRQ_EN |
-		       CEC_RX_SOM_IRQ_EN | CEC_RX_EOM_IRQ_EN |
-		       CEC_ERROR_IRQ_EN,
-		       cec->regs + CEC_IRQ_CTRL);
-
-	} else {
-		/* Clear logical addresses */
-		writel(0, cec->regs + CEC_ADDR_TABLE);
-
-		/* Clear the status register */
-		writel(0x0, cec->regs + CEC_STATUS);
-
-		/* Disable the interrupts */
-		writel(0, cec->regs + CEC_IRQ_CTRL);
-	}
-
-	return 0;
-}
-
-static int stih_cec_adap_log_addr(struct cec_adapter *adap, u8 logical_addr)
-{
-	struct stih_cec *cec = adap->priv;
-	u32 reg = readl(cec->regs + CEC_ADDR_TABLE);
-
-	reg |= 1 << logical_addr;
-
-	if (logical_addr == CEC_LOG_ADDR_INVALID)
-		reg = 0;
-
-	writel(reg, cec->regs + CEC_ADDR_TABLE);
-
-	return 0;
-}
-
-static int stih_cec_adap_transmit(struct cec_adapter *adap, u8 attempts,
-				  u32 signal_free_time, struct cec_msg *msg)
-{
-	struct stih_cec *cec = adap->priv;
-	int i;
-
-	/* Copy message into registers */
-	for (i = 0; i < msg->len; i++)
-		writeb(msg->msg[i], cec->regs + CEC_TX_DATA_BASE + i);
-
-	/* Start transmission, configure hardware to add start and stop bits
-	 * Signal free time is handled by the hardware
-	 */
-	writel(CEC_TX_AUTO_SOM_EN | CEC_TX_AUTO_EOM_EN | CEC_TX_START |
-	       msg->len, cec->regs + CEC_TX_ARRAY_CTRL);
-
-	return 0;
-}
-
-static void stih_tx_done(struct stih_cec *cec, u32 status)
-{
-	if (status & CEC_TX_ERROR) {
-		cec_transmit_done(cec->adap, CEC_TX_STATUS_ERROR, 0, 0, 0, 1);
-		return;
-	}
-
-	if (status & CEC_TX_ARB_ERROR) {
-		cec_transmit_done(cec->adap,
-				  CEC_TX_STATUS_ARB_LOST, 1, 0, 0, 0);
-		return;
-	}
-
-	if (!(status & CEC_TX_ACK_GET_STS)) {
-		cec_transmit_done(cec->adap, CEC_TX_STATUS_NACK, 0, 1, 0, 0);
-		return;
-	}
-
-	cec_transmit_done(cec->adap, CEC_TX_STATUS_OK, 0, 0, 0, 0);
-}
-
-static void stih_rx_done(struct stih_cec *cec, u32 status)
-{
-	struct cec_msg msg = {};
-	u8 i;
-
-	if (status & CEC_RX_ERROR_MIN)
-		return;
-
-	if (status & CEC_RX_ERROR_MAX)
-		return;
-
-	msg.len = readl(cec->regs + CEC_DATA_ARRAY_STATUS) & 0x1f;
-
-	if (!msg.len)
-		return;
-
-	if (msg.len > 16)
-		msg.len = 16;
-
-	for (i = 0; i < msg.len; i++)
-		msg.msg[i] = readl(cec->regs + CEC_RX_DATA_BASE + i);
-
-	cec_received_msg(cec->adap, &msg);
-}
-
-static irqreturn_t stih_cec_irq_handler_thread(int irq, void *priv)
-{
-	struct stih_cec *cec = priv;
-
-	if (cec->irq_status & CEC_TX_DONE_STS)
-		stih_tx_done(cec, cec->irq_status);
-
-	if (cec->irq_status & CEC_RX_DONE_STS)
-		stih_rx_done(cec, cec->irq_status);
-
-	cec->irq_status = 0;
-
-	return IRQ_HANDLED;
-}
-
-static irqreturn_t stih_cec_irq_handler(int irq, void *priv)
-{
-	struct stih_cec *cec = priv;
-
-	cec->irq_status = readl(cec->regs + CEC_STATUS);
-	writel(cec->irq_status, cec->regs + CEC_STATUS);
-
-	return IRQ_WAKE_THREAD;
-}
-
-static const struct cec_adap_ops sti_cec_adap_ops = {
-	.adap_enable = stih_cec_adap_enable,
-	.adap_log_addr = stih_cec_adap_log_addr,
-	.adap_transmit = stih_cec_adap_transmit,
-};
-
-static int stih_cec_probe(struct platform_device *pdev)
-{
-	struct device *dev = &pdev->dev;
-	struct resource *res;
-	struct stih_cec *cec;
-	int ret;
-
-	cec = devm_kzalloc(dev, sizeof(*cec), GFP_KERNEL);
-	if (!cec)
-		return -ENOMEM;
-
-	cec->dev = dev;
-
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	cec->regs = devm_ioremap_resource(dev, res);
-	if (IS_ERR(cec->regs))
-		return PTR_ERR(cec->regs);
-
-	cec->irq = platform_get_irq(pdev, 0);
-	if (cec->irq < 0)
-		return cec->irq;
-
-	ret = devm_request_threaded_irq(dev, cec->irq, stih_cec_irq_handler,
-					stih_cec_irq_handler_thread, 0,
-					pdev->name, cec);
-	if (ret)
-		return ret;
-
-	cec->clk = devm_clk_get(dev, "cec-clk");
-	if (IS_ERR(cec->clk)) {
-		dev_err(dev, "Cannot get cec clock\n");
-		return PTR_ERR(cec->clk);
-	}
-
-	cec->adap = cec_allocate_adapter(&sti_cec_adap_ops, cec,
-			CEC_NAME,
-			CEC_CAP_LOG_ADDRS | CEC_CAP_PASSTHROUGH |
-			CEC_CAP_PHYS_ADDR | CEC_CAP_TRANSMIT, 1);
-	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;
-	}
-
-	platform_set_drvdata(pdev, cec);
-	return 0;
-}
-
-static int stih_cec_remove(struct platform_device *pdev)
-{
-	return 0;
-}
-
-static const struct of_device_id stih_cec_match[] = {
-	{
-		.compatible	= "st,stih-cec",
-	},
-	{},
-};
-MODULE_DEVICE_TABLE(of, stih_cec_match);
-
-static struct platform_driver stih_cec_pdrv = {
-	.probe	= stih_cec_probe,
-	.remove = stih_cec_remove,
-	.driver = {
-		.name		= CEC_NAME,
-		.of_match_table	= stih_cec_match,
-	},
-};
-
-module_platform_driver(stih_cec_pdrv);
-
-MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@linaro.org>");
-MODULE_LICENSE("GPL");
-MODULE_DESCRIPTION("STIH4xx CEC driver");