Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

3 files changed, 1523 insertions, 0 deletions

diff --git a/drivers/media/cec/platform/meson/Makefile b/drivers/media/cec/platform/meson/Makefile
new file mode 100644
index 0000000000..34fc5d444d
--- /dev/null
+++ b/drivers/media/cec/platform/meson/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0-only
+obj-$(CONFIG_CEC_MESON_AO)	+= ao-cec.o
+obj-$(CONFIG_CEC_MESON_G12A_AO)	+= ao-cec-g12a.o
diff --git a/drivers/media/cec/platform/meson/ao-cec-g12a.c b/drivers/media/cec/platform/meson/ao-cec-g12a.c
new file mode 100644
index 0000000000..51294b9b6c
--- /dev/null
+++ b/drivers/media/cec/platform/meson/ao-cec-g12a.c
@@ -0,0 +1,792 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Driver for Amlogic Meson AO CEC G12A Controller
+ *
+ * Copyright (C) 2017 Amlogic, Inc. All rights reserved
+ * Copyright (C) 2019 BayLibre, SAS
+ * Author: Neil Armstrong <narmstrong@baylibre.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+#include <linux/interrupt.h>
+#include <linux/reset.h>
+#include <linux/slab.h>
+#include <linux/regmap.h>
+#include <media/cec.h>
+#include <media/cec-notifier.h>
+#include <linux/clk-provider.h>
+
+/* CEC Registers */
+
+#define CECB_CLK_CNTL_REG0		0x00
+
+#define CECB_CLK_CNTL_N1		GENMASK(11, 0)
+#define CECB_CLK_CNTL_N2		GENMASK(23, 12)
+#define CECB_CLK_CNTL_DUAL_EN		BIT(28)
+#define CECB_CLK_CNTL_OUTPUT_EN		BIT(30)
+#define CECB_CLK_CNTL_INPUT_EN		BIT(31)
+
+#define CECB_CLK_CNTL_REG1		0x04
+
+#define CECB_CLK_CNTL_M1		GENMASK(11, 0)
+#define CECB_CLK_CNTL_M2		GENMASK(23, 12)
+#define CECB_CLK_CNTL_BYPASS_EN		BIT(24)
+
+/*
+ * [14:12] Filter_del. For glitch-filtering CEC line, ignore signal
+ *       change pulse width < filter_del * T(filter_tick) * 3.
+ * [9:8] Filter_tick_sel: Select which periodical pulse for
+ *       glitch-filtering CEC line signal.
+ *  - 0=Use T(xtal)*3 = 125ns;
+ *  - 1=Use once-per-1us pulse;
+ *  - 2=Use once-per-10us pulse;
+ *  - 3=Use once-per-100us pulse.
+ * [3]   Sysclk_en. 0=Disable system clock; 1=Enable system clock.
+ * [2:1] cntl_clk
+ *  - 0 = Disable clk (Power-off mode)
+ *  - 1 = Enable gated clock (Normal mode)
+ *  - 2 = Enable free-run clk (Debug mode)
+ * [0] SW_RESET 1=Apply reset; 0=No reset.
+ */
+#define CECB_GEN_CNTL_REG		0x08
+
+#define CECB_GEN_CNTL_RESET		BIT(0)
+#define CECB_GEN_CNTL_CLK_DISABLE	0
+#define CECB_GEN_CNTL_CLK_ENABLE	1
+#define CECB_GEN_CNTL_CLK_ENABLE_DBG	2
+#define CECB_GEN_CNTL_CLK_CTRL_MASK	GENMASK(2, 1)
+#define CECB_GEN_CNTL_SYS_CLK_EN	BIT(3)
+#define CECB_GEN_CNTL_FILTER_TICK_125NS	0
+#define CECB_GEN_CNTL_FILTER_TICK_1US	1
+#define CECB_GEN_CNTL_FILTER_TICK_10US	2
+#define CECB_GEN_CNTL_FILTER_TICK_100US	3
+#define CECB_GEN_CNTL_FILTER_TICK_SEL	GENMASK(9, 8)
+#define CECB_GEN_CNTL_FILTER_DEL	GENMASK(14, 12)
+
+/*
+ * [7:0] cec_reg_addr
+ * [15:8] cec_reg_wrdata
+ * [16] cec_reg_wr
+ *  - 0 = Read
+ *  - 1 = Write
+ * [31:24] cec_reg_rddata
+ */
+#define CECB_RW_REG			0x0c
+
+#define CECB_RW_ADDR			GENMASK(7, 0)
+#define CECB_RW_WR_DATA			GENMASK(15, 8)
+#define CECB_RW_WRITE_EN		BIT(16)
+#define CECB_RW_BUS_BUSY		BIT(23)
+#define CECB_RW_RD_DATA			GENMASK(31, 24)
+
+/*
+ * [0] DONE Interrupt
+ * [1] End Of Message Interrupt
+ * [2] Not Acknowlegde Interrupt
+ * [3] Arbitration Loss Interrupt
+ * [4] Initiator Error Interrupt
+ * [5] Follower Error Interrupt
+ * [6] Wake-Up Interrupt
+ */
+#define CECB_INTR_MASKN_REG		0x10
+#define CECB_INTR_CLR_REG		0x14
+#define CECB_INTR_STAT_REG		0x18
+
+#define CECB_INTR_DONE			BIT(0)
+#define CECB_INTR_EOM			BIT(1)
+#define CECB_INTR_NACK			BIT(2)
+#define CECB_INTR_ARB_LOSS		BIT(3)
+#define CECB_INTR_INITIATOR_ERR		BIT(4)
+#define CECB_INTR_FOLLOWER_ERR		BIT(5)
+#define CECB_INTR_WAKE_UP		BIT(6)
+
+/* CEC Commands */
+
+#define CECB_CTRL		0x00
+
+#define CECB_CTRL_SEND		BIT(0)
+#define CECB_CTRL_TYPE		GENMASK(2, 1)
+#define CECB_CTRL_TYPE_RETRY	0
+#define CECB_CTRL_TYPE_NEW	1
+#define CECB_CTRL_TYPE_NEXT	2
+
+#define CECB_CTRL2		0x01
+
+#define CECB_CTRL2_RISE_DEL_MAX	GENMASK(4, 0)
+
+#define CECB_INTR_MASK		0x02
+#define CECB_LADD_LOW		0x05
+#define CECB_LADD_HIGH		0x06
+#define CECB_TX_CNT		0x07
+#define CECB_RX_CNT		0x08
+#define CECB_STAT0		0x09
+#define CECB_TX_DATA00		0x10
+#define CECB_TX_DATA01		0x11
+#define CECB_TX_DATA02		0x12
+#define CECB_TX_DATA03		0x13
+#define CECB_TX_DATA04		0x14
+#define CECB_TX_DATA05		0x15
+#define CECB_TX_DATA06		0x16
+#define CECB_TX_DATA07		0x17
+#define CECB_TX_DATA08		0x18
+#define CECB_TX_DATA09		0x19
+#define CECB_TX_DATA10		0x1A
+#define CECB_TX_DATA11		0x1B
+#define CECB_TX_DATA12		0x1C
+#define CECB_TX_DATA13		0x1D
+#define CECB_TX_DATA14		0x1E
+#define CECB_TX_DATA15		0x1F
+#define CECB_RX_DATA00		0x20
+#define CECB_RX_DATA01		0x21
+#define CECB_RX_DATA02		0x22
+#define CECB_RX_DATA03		0x23
+#define CECB_RX_DATA04		0x24
+#define CECB_RX_DATA05		0x25
+#define CECB_RX_DATA06		0x26
+#define CECB_RX_DATA07		0x27
+#define CECB_RX_DATA08		0x28
+#define CECB_RX_DATA09		0x29
+#define CECB_RX_DATA10		0x2A
+#define CECB_RX_DATA11		0x2B
+#define CECB_RX_DATA12		0x2C
+#define CECB_RX_DATA13		0x2D
+#define CECB_RX_DATA14		0x2E
+#define CECB_RX_DATA15		0x2F
+#define CECB_LOCK_BUF		0x30
+
+#define CECB_LOCK_BUF_EN	BIT(0)
+
+#define CECB_WAKEUPCTRL		0x31
+
+struct meson_ao_cec_g12a_data {
+	/* Setup the internal CECB_CTRL2 register */
+	bool				ctrl2_setup;
+};
+
+struct meson_ao_cec_g12a_device {
+	struct platform_device		*pdev;
+	struct regmap			*regmap;
+	struct regmap			*regmap_cec;
+	spinlock_t			cec_reg_lock;
+	struct cec_notifier		*notify;
+	struct cec_adapter		*adap;
+	struct cec_msg			rx_msg;
+	struct clk			*oscin;
+	struct clk			*core;
+	const struct meson_ao_cec_g12a_data *data;
+};
+
+static const struct regmap_config meson_ao_cec_g12a_regmap_conf = {
+	.reg_bits = 8,
+	.val_bits = 32,
+	.reg_stride = 4,
+	.max_register = CECB_INTR_STAT_REG,
+};
+
+/*
+ * The AO-CECB embeds a dual/divider to generate a more precise
+ * 32,768KHz clock for CEC core clock.
+ *                      ______   ______
+ *                     |      | |      |
+ *         ______      | Div1 |-| Cnt1 |       ______
+ *        |      |    /|______| |______|\     |      |
+ * Xtal-->| Gate |---|  ______   ______  X-X--| Gate |-->
+ *        |______| |  \|      | |      |/  |  |______|
+ *                 |   | Div2 |-| Cnt2 |   |
+ *                 |   |______| |______|   |
+ *                 |_______________________|
+ *
+ * The dividing can be switched to single or dual, with a counter
+ * for each divider to set when the switching is done.
+ * The entire dividing mechanism can be also bypassed.
+ */
+
+struct meson_ao_cec_g12a_dualdiv_clk {
+	struct clk_hw hw;
+	struct regmap *regmap;
+};
+
+#define hw_to_meson_ao_cec_g12a_dualdiv_clk(_hw)			\
+	container_of(_hw, struct meson_ao_cec_g12a_dualdiv_clk, hw)	\
+
+static unsigned long
+meson_ao_cec_g12a_dualdiv_clk_recalc_rate(struct clk_hw *hw,
+					  unsigned long parent_rate)
+{
+	struct meson_ao_cec_g12a_dualdiv_clk *dualdiv_clk =
+		hw_to_meson_ao_cec_g12a_dualdiv_clk(hw);
+	unsigned long n1;
+	u32 reg0, reg1;
+
+	regmap_read(dualdiv_clk->regmap, CECB_CLK_CNTL_REG0, &reg0);
+	regmap_read(dualdiv_clk->regmap, CECB_CLK_CNTL_REG0, &reg1);
+
+	if (reg1 & CECB_CLK_CNTL_BYPASS_EN)
+		return parent_rate;
+
+	if (reg0 & CECB_CLK_CNTL_DUAL_EN) {
+		unsigned long n2, m1, m2, f1, f2, p1, p2;
+
+		n1 = FIELD_GET(CECB_CLK_CNTL_N1, reg0) + 1;
+		n2 = FIELD_GET(CECB_CLK_CNTL_N2, reg0) + 1;
+
+		m1 = FIELD_GET(CECB_CLK_CNTL_M1, reg1) + 1;
+		m2 = FIELD_GET(CECB_CLK_CNTL_M1, reg1) + 1;
+
+		f1 = DIV_ROUND_CLOSEST(parent_rate, n1);
+		f2 = DIV_ROUND_CLOSEST(parent_rate, n2);
+
+		p1 = DIV_ROUND_CLOSEST(100000000 * m1, f1 * (m1 + m2));
+		p2 = DIV_ROUND_CLOSEST(100000000 * m2, f2 * (m1 + m2));
+
+		return DIV_ROUND_UP(100000000, p1 + p2);
+	}
+
+	n1 = FIELD_GET(CECB_CLK_CNTL_N1, reg0) + 1;
+
+	return DIV_ROUND_CLOSEST(parent_rate, n1);
+}
+
+static int meson_ao_cec_g12a_dualdiv_clk_enable(struct clk_hw *hw)
+{
+	struct meson_ao_cec_g12a_dualdiv_clk *dualdiv_clk =
+		hw_to_meson_ao_cec_g12a_dualdiv_clk(hw);
+
+
+	/* Disable Input & Output */
+	regmap_update_bits(dualdiv_clk->regmap, CECB_CLK_CNTL_REG0,
+			   CECB_CLK_CNTL_INPUT_EN | CECB_CLK_CNTL_OUTPUT_EN,
+			   0);
+
+	/* Set N1 & N2 */
+	regmap_update_bits(dualdiv_clk->regmap, CECB_CLK_CNTL_REG0,
+			   CECB_CLK_CNTL_N1,
+			   FIELD_PREP(CECB_CLK_CNTL_N1, 733 - 1));
+
+	regmap_update_bits(dualdiv_clk->regmap, CECB_CLK_CNTL_REG0,
+			   CECB_CLK_CNTL_N2,
+			   FIELD_PREP(CECB_CLK_CNTL_N2, 732 - 1));
+
+	/* Set M1 & M2 */
+	regmap_update_bits(dualdiv_clk->regmap, CECB_CLK_CNTL_REG1,
+			   CECB_CLK_CNTL_M1,
+			   FIELD_PREP(CECB_CLK_CNTL_M1, 8 - 1));
+
+	regmap_update_bits(dualdiv_clk->regmap, CECB_CLK_CNTL_REG1,
+			   CECB_CLK_CNTL_M2,
+			   FIELD_PREP(CECB_CLK_CNTL_M2, 11 - 1));
+
+	/* Enable Dual divisor */
+	regmap_update_bits(dualdiv_clk->regmap, CECB_CLK_CNTL_REG0,
+			   CECB_CLK_CNTL_DUAL_EN, CECB_CLK_CNTL_DUAL_EN);
+
+	/* Disable divisor bypass */
+	regmap_update_bits(dualdiv_clk->regmap, CECB_CLK_CNTL_REG1,
+			   CECB_CLK_CNTL_BYPASS_EN, 0);
+
+	/* Enable Input & Output */
+	regmap_update_bits(dualdiv_clk->regmap, CECB_CLK_CNTL_REG0,
+			   CECB_CLK_CNTL_INPUT_EN | CECB_CLK_CNTL_OUTPUT_EN,
+			   CECB_CLK_CNTL_INPUT_EN | CECB_CLK_CNTL_OUTPUT_EN);
+
+	return 0;
+}
+
+static void meson_ao_cec_g12a_dualdiv_clk_disable(struct clk_hw *hw)
+{
+	struct meson_ao_cec_g12a_dualdiv_clk *dualdiv_clk =
+		hw_to_meson_ao_cec_g12a_dualdiv_clk(hw);
+
+	regmap_update_bits(dualdiv_clk->regmap, CECB_CLK_CNTL_REG0,
+			   CECB_CLK_CNTL_INPUT_EN | CECB_CLK_CNTL_OUTPUT_EN,
+			   0);
+}
+
+static int meson_ao_cec_g12a_dualdiv_clk_is_enabled(struct clk_hw *hw)
+{
+	struct meson_ao_cec_g12a_dualdiv_clk *dualdiv_clk =
+		hw_to_meson_ao_cec_g12a_dualdiv_clk(hw);
+	int val;
+
+	regmap_read(dualdiv_clk->regmap, CECB_CLK_CNTL_REG0, &val);
+
+	return !!(val & (CECB_CLK_CNTL_INPUT_EN | CECB_CLK_CNTL_OUTPUT_EN));
+}
+
+static const struct clk_ops meson_ao_cec_g12a_dualdiv_clk_ops = {
+	.recalc_rate	= meson_ao_cec_g12a_dualdiv_clk_recalc_rate,
+	.is_enabled	= meson_ao_cec_g12a_dualdiv_clk_is_enabled,
+	.enable		= meson_ao_cec_g12a_dualdiv_clk_enable,
+	.disable	= meson_ao_cec_g12a_dualdiv_clk_disable,
+};
+
+static int meson_ao_cec_g12a_setup_clk(struct meson_ao_cec_g12a_device *ao_cec)
+{
+	struct meson_ao_cec_g12a_dualdiv_clk *dualdiv_clk;
+	struct device *dev = &ao_cec->pdev->dev;
+	struct clk_init_data init;
+	const char *parent_name;
+	struct clk *clk;
+	char *name;
+
+	dualdiv_clk = devm_kzalloc(dev, sizeof(*dualdiv_clk), GFP_KERNEL);
+	if (!dualdiv_clk)
+		return -ENOMEM;
+
+	name = kasprintf(GFP_KERNEL, "%s#dualdiv_clk", dev_name(dev));
+	if (!name)
+		return -ENOMEM;
+
+	parent_name = __clk_get_name(ao_cec->oscin);
+
+	init.name = name;
+	init.ops = &meson_ao_cec_g12a_dualdiv_clk_ops;
+	init.flags = 0;
+	init.parent_names = &parent_name;
+	init.num_parents = 1;
+	dualdiv_clk->regmap = ao_cec->regmap;
+	dualdiv_clk->hw.init = &init;
+
+	clk = devm_clk_register(dev, &dualdiv_clk->hw);
+	kfree(name);
+	if (IS_ERR(clk)) {
+		dev_err(dev, "failed to register clock\n");
+		return PTR_ERR(clk);
+	}
+
+	ao_cec->core = clk;
+
+	return 0;
+}
+
+static int meson_ao_cec_g12a_read(void *context, unsigned int addr,
+				  unsigned int *data)
+{
+	struct meson_ao_cec_g12a_device *ao_cec = context;
+	u32 reg = FIELD_PREP(CECB_RW_ADDR, addr);
+	int ret = 0;
+
+	ret = regmap_write(ao_cec->regmap, CECB_RW_REG, reg);
+	if (ret)
+		return ret;
+
+	ret = regmap_read_poll_timeout(ao_cec->regmap, CECB_RW_REG, reg,
+				       !(reg & CECB_RW_BUS_BUSY),
+				       5, 1000);
+	if (ret)
+		return ret;
+
+	ret = regmap_read(ao_cec->regmap, CECB_RW_REG, &reg);
+
+	*data = FIELD_GET(CECB_RW_RD_DATA, reg);
+
+	return ret;
+}
+
+static int meson_ao_cec_g12a_write(void *context, unsigned int addr,
+				   unsigned int data)
+{
+	struct meson_ao_cec_g12a_device *ao_cec = context;
+	u32 reg = FIELD_PREP(CECB_RW_ADDR, addr) |
+		  FIELD_PREP(CECB_RW_WR_DATA, data) |
+		  CECB_RW_WRITE_EN;
+
+	return regmap_write(ao_cec->regmap, CECB_RW_REG, reg);
+}
+
+static const struct regmap_config meson_ao_cec_g12a_cec_regmap_conf = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.reg_read = meson_ao_cec_g12a_read,
+	.reg_write = meson_ao_cec_g12a_write,
+	.max_register = 0xffff,
+};
+
+static inline void
+meson_ao_cec_g12a_irq_setup(struct meson_ao_cec_g12a_device *ao_cec,
+			    bool enable)
+{
+	u32 cfg = CECB_INTR_DONE | CECB_INTR_EOM | CECB_INTR_NACK |
+		  CECB_INTR_ARB_LOSS | CECB_INTR_INITIATOR_ERR |
+		  CECB_INTR_FOLLOWER_ERR;
+
+	regmap_write(ao_cec->regmap, CECB_INTR_MASKN_REG,
+		     enable ? cfg : 0);
+}
+
+static void meson_ao_cec_g12a_irq_rx(struct meson_ao_cec_g12a_device *ao_cec)
+{
+	int i, ret = 0;
+	u32 val;
+
+	ret = regmap_read(ao_cec->regmap_cec, CECB_RX_CNT, &val);
+
+	ao_cec->rx_msg.len = val;
+	if (ao_cec->rx_msg.len > CEC_MAX_MSG_SIZE)
+		ao_cec->rx_msg.len = CEC_MAX_MSG_SIZE;
+
+	for (i = 0; i < ao_cec->rx_msg.len; i++) {
+		ret |= regmap_read(ao_cec->regmap_cec,
+				   CECB_RX_DATA00 + i, &val);
+
+		ao_cec->rx_msg.msg[i] = val & 0xff;
+	}
+
+	ret |= regmap_write(ao_cec->regmap_cec, CECB_LOCK_BUF, 0);
+	if (ret)
+		return;
+
+	cec_received_msg(ao_cec->adap, &ao_cec->rx_msg);
+}
+
+static irqreturn_t meson_ao_cec_g12a_irq(int irq, void *data)
+{
+	struct meson_ao_cec_g12a_device *ao_cec = data;
+	u32 stat;
+
+	regmap_read(ao_cec->regmap, CECB_INTR_STAT_REG, &stat);
+	if (stat)
+		return IRQ_WAKE_THREAD;
+
+	return IRQ_NONE;
+}
+
+static irqreturn_t meson_ao_cec_g12a_irq_thread(int irq, void *data)
+{
+	struct meson_ao_cec_g12a_device *ao_cec = data;
+	u32 stat;
+
+	regmap_read(ao_cec->regmap, CECB_INTR_STAT_REG, &stat);
+	regmap_write(ao_cec->regmap, CECB_INTR_CLR_REG, stat);
+
+	if (stat & CECB_INTR_DONE)
+		cec_transmit_attempt_done(ao_cec->adap, CEC_TX_STATUS_OK);
+
+	if (stat & CECB_INTR_EOM)
+		meson_ao_cec_g12a_irq_rx(ao_cec);
+
+	if (stat & CECB_INTR_NACK)
+		cec_transmit_attempt_done(ao_cec->adap, CEC_TX_STATUS_NACK);
+
+	if (stat & CECB_INTR_ARB_LOSS) {
+		regmap_write(ao_cec->regmap_cec, CECB_TX_CNT, 0);
+		regmap_update_bits(ao_cec->regmap_cec, CECB_CTRL,
+				   CECB_CTRL_SEND | CECB_CTRL_TYPE, 0);
+		cec_transmit_attempt_done(ao_cec->adap, CEC_TX_STATUS_ARB_LOST);
+	}
+
+	/* Initiator reports an error on the CEC bus */
+	if (stat & CECB_INTR_INITIATOR_ERR)
+		cec_transmit_attempt_done(ao_cec->adap, CEC_TX_STATUS_ERROR);
+
+	/* Follower reports a receive error, just reset RX buffer */
+	if (stat & CECB_INTR_FOLLOWER_ERR)
+		regmap_write(ao_cec->regmap_cec, CECB_LOCK_BUF, 0);
+
+	return IRQ_HANDLED;
+}
+
+static int
+meson_ao_cec_g12a_set_log_addr(struct cec_adapter *adap, u8 logical_addr)
+{
+	struct meson_ao_cec_g12a_device *ao_cec = adap->priv;
+	int ret = 0;
+
+	if (logical_addr == CEC_LOG_ADDR_INVALID) {
+		/* Assume this will allways succeed */
+		regmap_write(ao_cec->regmap_cec, CECB_LADD_LOW, 0);
+		regmap_write(ao_cec->regmap_cec, CECB_LADD_HIGH, 0);
+
+		return 0;
+	} else if (logical_addr < 8) {
+		ret = regmap_update_bits(ao_cec->regmap_cec, CECB_LADD_LOW,
+					 BIT(logical_addr),
+					 BIT(logical_addr));
+	} else {
+		ret = regmap_update_bits(ao_cec->regmap_cec, CECB_LADD_HIGH,
+					 BIT(logical_addr - 8),
+					 BIT(logical_addr - 8));
+	}
+
+	/* Always set Broadcast/Unregistered 15 address */
+	ret |= regmap_update_bits(ao_cec->regmap_cec, CECB_LADD_HIGH,
+				  BIT(CEC_LOG_ADDR_UNREGISTERED - 8),
+				  BIT(CEC_LOG_ADDR_UNREGISTERED - 8));
+
+	return ret ? -EIO : 0;
+}
+
+static int meson_ao_cec_g12a_transmit(struct cec_adapter *adap, u8 attempts,
+				 u32 signal_free_time, struct cec_msg *msg)
+{
+	struct meson_ao_cec_g12a_device *ao_cec = adap->priv;
+	unsigned int type;
+	int ret = 0;
+	u32 val;
+	int i;
+
+	/* Check if RX is in progress */
+	ret = regmap_read(ao_cec->regmap_cec, CECB_LOCK_BUF, &val);
+	if (ret)
+		return ret;
+	if (val & CECB_LOCK_BUF_EN)
+		return -EBUSY;
+
+	/* Check if TX Busy */
+	ret = regmap_read(ao_cec->regmap_cec, CECB_CTRL, &val);
+	if (ret)
+		return ret;
+	if (val & CECB_CTRL_SEND)
+		return -EBUSY;
+
+	switch (signal_free_time) {
+	case CEC_SIGNAL_FREE_TIME_RETRY:
+		type = CECB_CTRL_TYPE_RETRY;
+		break;
+	case CEC_SIGNAL_FREE_TIME_NEXT_XFER:
+		type = CECB_CTRL_TYPE_NEXT;
+		break;
+	case CEC_SIGNAL_FREE_TIME_NEW_INITIATOR:
+	default:
+		type = CECB_CTRL_TYPE_NEW;
+		break;
+	}
+
+	for (i = 0; i < msg->len; i++)
+		ret |= regmap_write(ao_cec->regmap_cec, CECB_TX_DATA00 + i,
+				    msg->msg[i]);
+
+	ret |= regmap_write(ao_cec->regmap_cec, CECB_TX_CNT, msg->len);
+	if (ret)
+		return -EIO;
+
+	ret = regmap_update_bits(ao_cec->regmap_cec, CECB_CTRL,
+				 CECB_CTRL_SEND |
+				 CECB_CTRL_TYPE,
+				 CECB_CTRL_SEND |
+				 FIELD_PREP(CECB_CTRL_TYPE, type));
+
+	return ret;
+}
+
+static int meson_ao_cec_g12a_adap_enable(struct cec_adapter *adap, bool enable)
+{
+	struct meson_ao_cec_g12a_device *ao_cec = adap->priv;
+
+	meson_ao_cec_g12a_irq_setup(ao_cec, false);
+
+	regmap_update_bits(ao_cec->regmap, CECB_GEN_CNTL_REG,
+			   CECB_GEN_CNTL_RESET, CECB_GEN_CNTL_RESET);
+
+	if (!enable)
+		return 0;
+
+	/* Setup Filter */
+	regmap_update_bits(ao_cec->regmap, CECB_GEN_CNTL_REG,
+			   CECB_GEN_CNTL_FILTER_TICK_SEL |
+			   CECB_GEN_CNTL_FILTER_DEL,
+			   FIELD_PREP(CECB_GEN_CNTL_FILTER_TICK_SEL,
+				      CECB_GEN_CNTL_FILTER_TICK_1US) |
+			   FIELD_PREP(CECB_GEN_CNTL_FILTER_DEL, 7));
+
+	/* Enable System Clock */
+	regmap_update_bits(ao_cec->regmap, CECB_GEN_CNTL_REG,
+			   CECB_GEN_CNTL_SYS_CLK_EN,
+			   CECB_GEN_CNTL_SYS_CLK_EN);
+
+	/* Enable gated clock (Normal mode). */
+	regmap_update_bits(ao_cec->regmap, CECB_GEN_CNTL_REG,
+			   CECB_GEN_CNTL_CLK_CTRL_MASK,
+			    FIELD_PREP(CECB_GEN_CNTL_CLK_CTRL_MASK,
+				       CECB_GEN_CNTL_CLK_ENABLE));
+
+	/* Release Reset */
+	regmap_update_bits(ao_cec->regmap, CECB_GEN_CNTL_REG,
+			   CECB_GEN_CNTL_RESET, 0);
+
+	if (ao_cec->data->ctrl2_setup)
+		regmap_write(ao_cec->regmap_cec, CECB_CTRL2,
+			     FIELD_PREP(CECB_CTRL2_RISE_DEL_MAX, 2));
+
+	meson_ao_cec_g12a_irq_setup(ao_cec, true);
+
+	return 0;
+}
+
+static const struct cec_adap_ops meson_ao_cec_g12a_ops = {
+	.adap_enable = meson_ao_cec_g12a_adap_enable,
+	.adap_log_addr = meson_ao_cec_g12a_set_log_addr,
+	.adap_transmit = meson_ao_cec_g12a_transmit,
+};
+
+static int meson_ao_cec_g12a_probe(struct platform_device *pdev)
+{
+	struct meson_ao_cec_g12a_device *ao_cec;
+	struct device *hdmi_dev;
+	void __iomem *base;
+	int ret, irq;
+
+	hdmi_dev = cec_notifier_parse_hdmi_phandle(&pdev->dev);
+	if (IS_ERR(hdmi_dev))
+		return PTR_ERR(hdmi_dev);
+
+	ao_cec = devm_kzalloc(&pdev->dev, sizeof(*ao_cec), GFP_KERNEL);
+	if (!ao_cec)
+		return -ENOMEM;
+
+	ao_cec->data = of_device_get_match_data(&pdev->dev);
+	if (!ao_cec->data) {
+		dev_err(&pdev->dev, "failed to get match data\n");
+		return -ENODEV;
+	}
+
+	spin_lock_init(&ao_cec->cec_reg_lock);
+	ao_cec->pdev = pdev;
+
+	ao_cec->adap = cec_allocate_adapter(&meson_ao_cec_g12a_ops, ao_cec,
+					    "meson_g12a_ao_cec",
+					    CEC_CAP_DEFAULTS |
+					    CEC_CAP_CONNECTOR_INFO,
+					    CEC_MAX_LOG_ADDRS);
+	if (IS_ERR(ao_cec->adap))
+		return PTR_ERR(ao_cec->adap);
+
+	ao_cec->adap->owner = THIS_MODULE;
+
+	base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(base)) {
+		ret = PTR_ERR(base);
+		goto out_probe_adapter;
+	}
+
+	ao_cec->regmap = devm_regmap_init_mmio(&pdev->dev, base,
+					       &meson_ao_cec_g12a_regmap_conf);
+	if (IS_ERR(ao_cec->regmap)) {
+		ret = PTR_ERR(ao_cec->regmap);
+		goto out_probe_adapter;
+	}
+
+	ao_cec->regmap_cec = devm_regmap_init(&pdev->dev, NULL, ao_cec,
+					   &meson_ao_cec_g12a_cec_regmap_conf);
+	if (IS_ERR(ao_cec->regmap_cec)) {
+		ret = PTR_ERR(ao_cec->regmap_cec);
+		goto out_probe_adapter;
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	ret = devm_request_threaded_irq(&pdev->dev, irq,
+					meson_ao_cec_g12a_irq,
+					meson_ao_cec_g12a_irq_thread,
+					0, NULL, ao_cec);
+	if (ret) {
+		dev_err(&pdev->dev, "irq request failed\n");
+		goto out_probe_adapter;
+	}
+
+	ao_cec->oscin = devm_clk_get(&pdev->dev, "oscin");
+	if (IS_ERR(ao_cec->oscin)) {
+		dev_err(&pdev->dev, "oscin clock request failed\n");
+		ret = PTR_ERR(ao_cec->oscin);
+		goto out_probe_adapter;
+	}
+
+	ret = meson_ao_cec_g12a_setup_clk(ao_cec);
+	if (ret)
+		goto out_probe_adapter;
+
+	ret = clk_prepare_enable(ao_cec->core);
+	if (ret) {
+		dev_err(&pdev->dev, "core clock enable failed\n");
+		goto out_probe_adapter;
+	}
+
+	device_reset_optional(&pdev->dev);
+
+	platform_set_drvdata(pdev, ao_cec);
+
+	ao_cec->notify = cec_notifier_cec_adap_register(hdmi_dev, NULL,
+							ao_cec->adap);
+	if (!ao_cec->notify) {
+		ret = -ENOMEM;
+		goto out_probe_core_clk;
+	}
+
+	ret = cec_register_adapter(ao_cec->adap, &pdev->dev);
+	if (ret < 0)
+		goto out_probe_notify;
+
+	/* Setup Hardware */
+	regmap_write(ao_cec->regmap, CECB_GEN_CNTL_REG, CECB_GEN_CNTL_RESET);
+
+	return 0;
+
+out_probe_notify:
+	cec_notifier_cec_adap_unregister(ao_cec->notify, ao_cec->adap);
+
+out_probe_core_clk:
+	clk_disable_unprepare(ao_cec->core);
+
+out_probe_adapter:
+	cec_delete_adapter(ao_cec->adap);
+
+	dev_err(&pdev->dev, "CEC controller registration failed\n");
+
+	return ret;
+}
+
+static void meson_ao_cec_g12a_remove(struct platform_device *pdev)
+{
+	struct meson_ao_cec_g12a_device *ao_cec = platform_get_drvdata(pdev);
+
+	clk_disable_unprepare(ao_cec->core);
+
+	cec_notifier_cec_adap_unregister(ao_cec->notify, ao_cec->adap);
+
+	cec_unregister_adapter(ao_cec->adap);
+}
+
+static const struct meson_ao_cec_g12a_data ao_cec_g12a_data = {
+	.ctrl2_setup = false,
+};
+
+static const struct meson_ao_cec_g12a_data ao_cec_sm1_data = {
+	.ctrl2_setup = true,
+};
+
+static const struct of_device_id meson_ao_cec_g12a_of_match[] = {
+	{
+		.compatible = "amlogic,meson-g12a-ao-cec",
+		.data = &ao_cec_g12a_data,
+	},
+	{
+		.compatible = "amlogic,meson-sm1-ao-cec",
+		.data = &ao_cec_sm1_data,
+	},
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, meson_ao_cec_g12a_of_match);
+
+static struct platform_driver meson_ao_cec_g12a_driver = {
+	.probe   = meson_ao_cec_g12a_probe,
+	.remove_new = meson_ao_cec_g12a_remove,
+	.driver  = {
+		.name = "meson-ao-cec-g12a",
+		.of_match_table = of_match_ptr(meson_ao_cec_g12a_of_match),
+	},
+};
+
+module_platform_driver(meson_ao_cec_g12a_driver);
+
+MODULE_DESCRIPTION("Meson AO CEC G12A Controller driver");
+MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/media/cec/platform/meson/ao-cec.c b/drivers/media/cec/platform/meson/ao-cec.c
new file mode 100644
index 0000000000..494738daf0
--- /dev/null
+++ b/drivers/media/cec/platform/meson/ao-cec.c
@@ -0,0 +1,728 @@
+/*
+ * Driver for Amlogic Meson AO CEC Controller
+ *
+ * Copyright (C) 2015 Amlogic, Inc. All rights reserved
+ * Copyright (C) 2017 BayLibre, SAS
+ * Author: Neil Armstrong <narmstrong@baylibre.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/types.h>
+#include <linux/interrupt.h>
+#include <linux/reset.h>
+#include <media/cec.h>
+#include <media/cec-notifier.h>
+
+/* CEC Registers */
+
+/*
+ * [2:1] cntl_clk
+ *  - 0 = Disable clk (Power-off mode)
+ *  - 1 = Enable gated clock (Normal mode)
+ *  - 2 = Enable free-run clk (Debug mode)
+ */
+#define CEC_GEN_CNTL_REG		0x00
+
+#define CEC_GEN_CNTL_RESET		BIT(0)
+#define CEC_GEN_CNTL_CLK_DISABLE	0
+#define CEC_GEN_CNTL_CLK_ENABLE		1
+#define CEC_GEN_CNTL_CLK_ENABLE_DBG	2
+#define CEC_GEN_CNTL_CLK_CTRL_MASK	GENMASK(2, 1)
+
+/*
+ * [7:0] cec_reg_addr
+ * [15:8] cec_reg_wrdata
+ * [16] cec_reg_wr
+ *  - 0 = Read
+ *  - 1 = Write
+ * [23] bus free
+ * [31:24] cec_reg_rddata
+ */
+#define CEC_RW_REG			0x04
+
+#define CEC_RW_ADDR			GENMASK(7, 0)
+#define CEC_RW_WR_DATA			GENMASK(15, 8)
+#define CEC_RW_WRITE_EN			BIT(16)
+#define CEC_RW_BUS_BUSY			BIT(23)
+#define CEC_RW_RD_DATA			GENMASK(31, 24)
+
+/*
+ * [1] tx intr
+ * [2] rx intr
+ */
+#define CEC_INTR_MASKN_REG		0x08
+#define CEC_INTR_CLR_REG		0x0c
+#define CEC_INTR_STAT_REG		0x10
+
+#define CEC_INTR_TX			BIT(1)
+#define CEC_INTR_RX			BIT(2)
+
+/* CEC Commands */
+
+#define CEC_TX_MSG_0_HEADER		0x00
+#define CEC_TX_MSG_1_OPCODE		0x01
+#define CEC_TX_MSG_2_OP1		0x02
+#define CEC_TX_MSG_3_OP2		0x03
+#define CEC_TX_MSG_4_OP3		0x04
+#define CEC_TX_MSG_5_OP4		0x05
+#define CEC_TX_MSG_6_OP5		0x06
+#define CEC_TX_MSG_7_OP6		0x07
+#define CEC_TX_MSG_8_OP7		0x08
+#define CEC_TX_MSG_9_OP8		0x09
+#define CEC_TX_MSG_A_OP9		0x0A
+#define CEC_TX_MSG_B_OP10		0x0B
+#define CEC_TX_MSG_C_OP11		0x0C
+#define CEC_TX_MSG_D_OP12		0x0D
+#define CEC_TX_MSG_E_OP13		0x0E
+#define CEC_TX_MSG_F_OP14		0x0F
+#define CEC_TX_MSG_LENGTH		0x10
+#define CEC_TX_MSG_CMD			0x11
+#define CEC_TX_WRITE_BUF		0x12
+#define CEC_TX_CLEAR_BUF		0x13
+#define CEC_RX_MSG_CMD			0x14
+#define CEC_RX_CLEAR_BUF		0x15
+#define CEC_LOGICAL_ADDR0		0x16
+#define CEC_LOGICAL_ADDR1		0x17
+#define CEC_LOGICAL_ADDR2		0x18
+#define CEC_LOGICAL_ADDR3		0x19
+#define CEC_LOGICAL_ADDR4		0x1A
+#define CEC_CLOCK_DIV_H			0x1B
+#define CEC_CLOCK_DIV_L			0x1C
+#define CEC_QUIESCENT_25MS_BIT7_0	0x20
+#define CEC_QUIESCENT_25MS_BIT11_8	0x21
+#define CEC_STARTBITMINL2H_3MS5_BIT7_0	0x22
+#define CEC_STARTBITMINL2H_3MS5_BIT8	0x23
+#define CEC_STARTBITMAXL2H_3MS9_BIT7_0	0x24
+#define CEC_STARTBITMAXL2H_3MS9_BIT8	0x25
+#define CEC_STARTBITMINH_0MS6_BIT7_0	0x26
+#define CEC_STARTBITMINH_0MS6_BIT8	0x27
+#define CEC_STARTBITMAXH_1MS0_BIT7_0	0x28
+#define CEC_STARTBITMAXH_1MS0_BIT8	0x29
+#define CEC_STARTBITMINTOT_4MS3_BIT7_0	0x2A
+#define CEC_STARTBITMINTOT_4MS3_BIT9_8	0x2B
+#define CEC_STARTBITMAXTOT_4MS7_BIT7_0	0x2C
+#define CEC_STARTBITMAXTOT_4MS7_BIT9_8	0x2D
+#define CEC_LOGIC1MINL2H_0MS4_BIT7_0	0x2E
+#define CEC_LOGIC1MINL2H_0MS4_BIT8	0x2F
+#define CEC_LOGIC1MAXL2H_0MS8_BIT7_0	0x30
+#define CEC_LOGIC1MAXL2H_0MS8_BIT8	0x31
+#define CEC_LOGIC0MINL2H_1MS3_BIT7_0	0x32
+#define CEC_LOGIC0MINL2H_1MS3_BIT8	0x33
+#define CEC_LOGIC0MAXL2H_1MS7_BIT7_0	0x34
+#define CEC_LOGIC0MAXL2H_1MS7_BIT8	0x35
+#define CEC_LOGICMINTOTAL_2MS05_BIT7_0	0x36
+#define CEC_LOGICMINTOTAL_2MS05_BIT9_8	0x37
+#define CEC_LOGICMAXHIGH_2MS8_BIT7_0	0x38
+#define CEC_LOGICMAXHIGH_2MS8_BIT8	0x39
+#define CEC_LOGICERRLOW_3MS4_BIT7_0	0x3A
+#define CEC_LOGICERRLOW_3MS4_BIT8	0x3B
+#define CEC_NOMSMPPOINT_1MS05		0x3C
+#define CEC_DELCNTR_LOGICERR		0x3E
+#define CEC_TXTIME_17MS_BIT7_0		0x40
+#define CEC_TXTIME_17MS_BIT10_8		0x41
+#define CEC_TXTIME_2BIT_BIT7_0		0x42
+#define CEC_TXTIME_2BIT_BIT10_8		0x43
+#define CEC_TXTIME_4BIT_BIT7_0		0x44
+#define CEC_TXTIME_4BIT_BIT10_8		0x45
+#define CEC_STARTBITNOML2H_3MS7_BIT7_0	0x46
+#define CEC_STARTBITNOML2H_3MS7_BIT8	0x47
+#define CEC_STARTBITNOMH_0MS8_BIT7_0	0x48
+#define CEC_STARTBITNOMH_0MS8_BIT8	0x49
+#define CEC_LOGIC1NOML2H_0MS6_BIT7_0	0x4A
+#define CEC_LOGIC1NOML2H_0MS6_BIT8	0x4B
+#define CEC_LOGIC0NOML2H_1MS5_BIT7_0	0x4C
+#define CEC_LOGIC0NOML2H_1MS5_BIT8	0x4D
+#define CEC_LOGIC1NOMH_1MS8_BIT7_0	0x4E
+#define CEC_LOGIC1NOMH_1MS8_BIT8	0x4F
+#define CEC_LOGIC0NOMH_0MS9_BIT7_0	0x50
+#define CEC_LOGIC0NOMH_0MS9_BIT8	0x51
+#define CEC_LOGICERRLOW_3MS6_BIT7_0	0x52
+#define CEC_LOGICERRLOW_3MS6_BIT8	0x53
+#define CEC_CHKCONTENTION_0MS1		0x54
+#define CEC_PREPARENXTBIT_0MS05_BIT7_0	0x56
+#define CEC_PREPARENXTBIT_0MS05_BIT8	0x57
+#define CEC_NOMSMPACKPOINT_0MS45	0x58
+#define CEC_ACK0NOML2H_1MS5_BIT7_0	0x5A
+#define CEC_ACK0NOML2H_1MS5_BIT8	0x5B
+#define CEC_BUGFIX_DISABLE_0		0x60
+#define CEC_BUGFIX_DISABLE_1		0x61
+#define CEC_RX_MSG_0_HEADER		0x80
+#define CEC_RX_MSG_1_OPCODE		0x81
+#define CEC_RX_MSG_2_OP1		0x82
+#define CEC_RX_MSG_3_OP2		0x83
+#define CEC_RX_MSG_4_OP3		0x84
+#define CEC_RX_MSG_5_OP4		0x85
+#define CEC_RX_MSG_6_OP5		0x86
+#define CEC_RX_MSG_7_OP6		0x87
+#define CEC_RX_MSG_8_OP7		0x88
+#define CEC_RX_MSG_9_OP8		0x89
+#define CEC_RX_MSG_A_OP9		0x8A
+#define CEC_RX_MSG_B_OP10		0x8B
+#define CEC_RX_MSG_C_OP11		0x8C
+#define CEC_RX_MSG_D_OP12		0x8D
+#define CEC_RX_MSG_E_OP13		0x8E
+#define CEC_RX_MSG_F_OP14		0x8F
+#define CEC_RX_MSG_LENGTH		0x90
+#define CEC_RX_MSG_STATUS		0x91
+#define CEC_RX_NUM_MSG			0x92
+#define CEC_TX_MSG_STATUS		0x93
+#define CEC_TX_NUM_MSG			0x94
+
+
+/* CEC_TX_MSG_CMD definition */
+#define TX_NO_OP	0  /* No transaction */
+#define TX_REQ_CURRENT	1  /* Transmit earliest message in buffer */
+#define TX_ABORT	2  /* Abort transmitting earliest message */
+#define TX_REQ_NEXT	3  /* Overwrite earliest msg, transmit next */
+
+/* tx_msg_status definition */
+#define TX_IDLE		0  /* No transaction */
+#define TX_BUSY		1  /* Transmitter is busy */
+#define TX_DONE		2  /* Message successfully transmitted */
+#define TX_ERROR	3  /* Message transmitted with error */
+
+/* rx_msg_cmd */
+#define RX_NO_OP	0  /* No transaction */
+#define RX_ACK_CURRENT	1  /* Read earliest message in buffer */
+#define RX_DISABLE	2  /* Disable receiving latest message */
+#define RX_ACK_NEXT	3  /* Clear earliest msg, read next */
+
+/* rx_msg_status */
+#define RX_IDLE		0  /* No transaction */
+#define RX_BUSY		1  /* Receiver is busy */
+#define RX_DONE		2  /* Message has been received successfully */
+#define RX_ERROR	3  /* Message has been received with error */
+
+/* RX_CLEAR_BUF options */
+#define CLEAR_START	1
+#define CLEAR_STOP	0
+
+/* CEC_LOGICAL_ADDRx options */
+#define LOGICAL_ADDR_MASK	0xf
+#define LOGICAL_ADDR_VALID	BIT(4)
+#define LOGICAL_ADDR_DISABLE	0
+
+#define CEC_CLK_RATE		32768
+
+struct meson_ao_cec_device {
+	struct platform_device		*pdev;
+	void __iomem			*base;
+	struct clk			*core;
+	spinlock_t			cec_reg_lock;
+	struct cec_notifier		*notify;
+	struct cec_adapter		*adap;
+	struct cec_msg			rx_msg;
+};
+
+#define writel_bits_relaxed(mask, val, addr) \
+	writel_relaxed((readl_relaxed(addr) & ~(mask)) | (val), addr)
+
+static inline int meson_ao_cec_wait_busy(struct meson_ao_cec_device *ao_cec)
+{
+	ktime_t timeout = ktime_add_us(ktime_get(), 5000);
+
+	while (readl_relaxed(ao_cec->base + CEC_RW_REG) & CEC_RW_BUS_BUSY) {
+		if (ktime_compare(ktime_get(), timeout) > 0)
+			return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+static void meson_ao_cec_read(struct meson_ao_cec_device *ao_cec,
+			     unsigned long address, u8 *data,
+			     int *res)
+{
+	unsigned long flags;
+	u32 reg = FIELD_PREP(CEC_RW_ADDR, address);
+	int ret = 0;
+
+	if (res && *res)
+		return;
+
+	spin_lock_irqsave(&ao_cec->cec_reg_lock, flags);
+
+	ret = meson_ao_cec_wait_busy(ao_cec);
+	if (ret)
+		goto read_out;
+
+	writel_relaxed(reg, ao_cec->base + CEC_RW_REG);
+
+	ret = meson_ao_cec_wait_busy(ao_cec);
+	if (ret)
+		goto read_out;
+
+	*data = FIELD_GET(CEC_RW_RD_DATA,
+			  readl_relaxed(ao_cec->base + CEC_RW_REG));
+
+read_out:
+	spin_unlock_irqrestore(&ao_cec->cec_reg_lock, flags);
+
+	if (res)
+		*res = ret;
+}
+
+static void meson_ao_cec_write(struct meson_ao_cec_device *ao_cec,
+			       unsigned long address, u8 data,
+			       int *res)
+{
+	unsigned long flags;
+	u32 reg = FIELD_PREP(CEC_RW_ADDR, address) |
+		  FIELD_PREP(CEC_RW_WR_DATA, data) |
+		  CEC_RW_WRITE_EN;
+	int ret = 0;
+
+	if (res && *res)
+		return;
+
+	spin_lock_irqsave(&ao_cec->cec_reg_lock, flags);
+
+	ret = meson_ao_cec_wait_busy(ao_cec);
+	if (ret)
+		goto write_out;
+
+	writel_relaxed(reg, ao_cec->base + CEC_RW_REG);
+
+write_out:
+	spin_unlock_irqrestore(&ao_cec->cec_reg_lock, flags);
+
+	if (res)
+		*res = ret;
+}
+
+static inline void meson_ao_cec_irq_setup(struct meson_ao_cec_device *ao_cec,
+				      bool enable)
+{
+	u32 cfg = CEC_INTR_TX | CEC_INTR_RX;
+
+	writel_bits_relaxed(cfg, enable ? cfg : 0,
+			    ao_cec->base + CEC_INTR_MASKN_REG);
+}
+
+static inline int meson_ao_cec_clear(struct meson_ao_cec_device *ao_cec)
+{
+	int ret = 0;
+
+	meson_ao_cec_write(ao_cec, CEC_RX_MSG_CMD, RX_DISABLE, &ret);
+	meson_ao_cec_write(ao_cec, CEC_TX_MSG_CMD, TX_ABORT, &ret);
+	meson_ao_cec_write(ao_cec, CEC_RX_CLEAR_BUF, 1, &ret);
+	meson_ao_cec_write(ao_cec, CEC_TX_CLEAR_BUF, 1, &ret);
+	if (ret)
+		return ret;
+
+	udelay(100);
+
+	meson_ao_cec_write(ao_cec, CEC_RX_CLEAR_BUF, 0, &ret);
+	meson_ao_cec_write(ao_cec, CEC_TX_CLEAR_BUF, 0, &ret);
+	if (ret)
+		return ret;
+
+	udelay(100);
+
+	meson_ao_cec_write(ao_cec, CEC_RX_MSG_CMD, RX_NO_OP, &ret);
+	meson_ao_cec_write(ao_cec, CEC_TX_MSG_CMD, TX_NO_OP, &ret);
+
+	return ret;
+}
+
+static int meson_ao_cec_arbit_bit_time_set(struct meson_ao_cec_device *ao_cec,
+					   unsigned int bit_set,
+					   unsigned int time_set)
+{
+	int ret = 0;
+
+	switch (bit_set) {
+	case CEC_SIGNAL_FREE_TIME_RETRY:
+		meson_ao_cec_write(ao_cec, CEC_TXTIME_4BIT_BIT7_0,
+				   time_set & 0xff, &ret);
+		meson_ao_cec_write(ao_cec, CEC_TXTIME_4BIT_BIT10_8,
+				   (time_set >> 8) & 0x7, &ret);
+		break;
+
+	case CEC_SIGNAL_FREE_TIME_NEW_INITIATOR:
+		meson_ao_cec_write(ao_cec, CEC_TXTIME_2BIT_BIT7_0,
+				   time_set & 0xff, &ret);
+		meson_ao_cec_write(ao_cec, CEC_TXTIME_2BIT_BIT10_8,
+				   (time_set >> 8) & 0x7, &ret);
+		break;
+
+	case CEC_SIGNAL_FREE_TIME_NEXT_XFER:
+		meson_ao_cec_write(ao_cec, CEC_TXTIME_17MS_BIT7_0,
+				   time_set & 0xff, &ret);
+		meson_ao_cec_write(ao_cec, CEC_TXTIME_17MS_BIT10_8,
+				   (time_set >> 8) & 0x7, &ret);
+		break;
+	}
+
+	return ret;
+}
+
+static irqreturn_t meson_ao_cec_irq(int irq, void *data)
+{
+	struct meson_ao_cec_device *ao_cec = data;
+	u32 stat = readl_relaxed(ao_cec->base + CEC_INTR_STAT_REG);
+
+	if (stat)
+		return IRQ_WAKE_THREAD;
+
+	return IRQ_NONE;
+}
+
+static void meson_ao_cec_irq_tx(struct meson_ao_cec_device *ao_cec)
+{
+	unsigned long tx_status = 0;
+	u8 stat;
+	int ret = 0;
+
+	meson_ao_cec_read(ao_cec, CEC_TX_MSG_STATUS, &stat, &ret);
+	if (ret)
+		goto tx_reg_err;
+
+	switch (stat) {
+	case TX_DONE:
+		tx_status = CEC_TX_STATUS_OK;
+		break;
+
+	case TX_BUSY:
+		tx_status = CEC_TX_STATUS_ARB_LOST;
+		break;
+
+	case TX_IDLE:
+		tx_status = CEC_TX_STATUS_LOW_DRIVE;
+		break;
+
+	case TX_ERROR:
+	default:
+		tx_status = CEC_TX_STATUS_NACK;
+		break;
+	}
+
+	/* Clear Interruption */
+	writel_relaxed(CEC_INTR_TX, ao_cec->base + CEC_INTR_CLR_REG);
+
+	/* Stop TX */
+	meson_ao_cec_write(ao_cec, CEC_TX_MSG_CMD, TX_NO_OP, &ret);
+	if (ret)
+		goto tx_reg_err;
+
+	cec_transmit_attempt_done(ao_cec->adap, tx_status);
+	return;
+
+tx_reg_err:
+	cec_transmit_attempt_done(ao_cec->adap, CEC_TX_STATUS_ERROR);
+}
+
+static void meson_ao_cec_irq_rx(struct meson_ao_cec_device *ao_cec)
+{
+	int i, ret = 0;
+	u8 reg;
+
+	meson_ao_cec_read(ao_cec, CEC_RX_MSG_STATUS, &reg, &ret);
+	if (reg != RX_DONE)
+		goto rx_out;
+
+	meson_ao_cec_read(ao_cec, CEC_RX_NUM_MSG, &reg, &ret);
+	if (reg != 1)
+		goto rx_out;
+
+	meson_ao_cec_read(ao_cec, CEC_RX_MSG_LENGTH, &reg, &ret);
+
+	ao_cec->rx_msg.len = reg + 1;
+	if (ao_cec->rx_msg.len > CEC_MAX_MSG_SIZE)
+		ao_cec->rx_msg.len = CEC_MAX_MSG_SIZE;
+
+	for (i = 0; i < ao_cec->rx_msg.len; i++) {
+		u8 byte;
+
+		meson_ao_cec_read(ao_cec, CEC_RX_MSG_0_HEADER + i, &byte, &ret);
+
+		ao_cec->rx_msg.msg[i] = byte;
+	}
+
+	if (ret)
+		goto rx_out;
+
+	cec_received_msg(ao_cec->adap, &ao_cec->rx_msg);
+
+rx_out:
+	/* Clear Interruption */
+	writel_relaxed(CEC_INTR_RX, ao_cec->base + CEC_INTR_CLR_REG);
+
+	/* Ack RX message */
+	meson_ao_cec_write(ao_cec, CEC_RX_MSG_CMD, RX_ACK_CURRENT, &ret);
+	meson_ao_cec_write(ao_cec, CEC_RX_MSG_CMD, RX_NO_OP, &ret);
+
+	/* Clear RX buffer */
+	meson_ao_cec_write(ao_cec, CEC_RX_CLEAR_BUF, CLEAR_START, &ret);
+	meson_ao_cec_write(ao_cec, CEC_RX_CLEAR_BUF, CLEAR_STOP, &ret);
+}
+
+static irqreturn_t meson_ao_cec_irq_thread(int irq, void *data)
+{
+	struct meson_ao_cec_device *ao_cec = data;
+	u32 stat = readl_relaxed(ao_cec->base + CEC_INTR_STAT_REG);
+
+	if (stat & CEC_INTR_TX)
+		meson_ao_cec_irq_tx(ao_cec);
+
+	meson_ao_cec_irq_rx(ao_cec);
+
+	return IRQ_HANDLED;
+}
+
+static int meson_ao_cec_set_log_addr(struct cec_adapter *adap, u8 logical_addr)
+{
+	struct meson_ao_cec_device *ao_cec = adap->priv;
+	int ret = 0;
+
+	meson_ao_cec_write(ao_cec, CEC_LOGICAL_ADDR0,
+			   LOGICAL_ADDR_DISABLE, &ret);
+	if (ret)
+		return ret;
+
+	ret = meson_ao_cec_clear(ao_cec);
+	if (ret)
+		return ret;
+
+	if (logical_addr == CEC_LOG_ADDR_INVALID)
+		return 0;
+
+	meson_ao_cec_write(ao_cec, CEC_LOGICAL_ADDR0,
+			   logical_addr & LOGICAL_ADDR_MASK, &ret);
+	if (ret)
+		return ret;
+
+	udelay(100);
+
+	meson_ao_cec_write(ao_cec, CEC_LOGICAL_ADDR0,
+			   (logical_addr & LOGICAL_ADDR_MASK) |
+			   LOGICAL_ADDR_VALID, &ret);
+
+	return ret;
+}
+
+static int meson_ao_cec_transmit(struct cec_adapter *adap, u8 attempts,
+				 u32 signal_free_time, struct cec_msg *msg)
+{
+	struct meson_ao_cec_device *ao_cec = adap->priv;
+	int i, ret = 0;
+	u8 reg;
+
+	meson_ao_cec_read(ao_cec, CEC_TX_MSG_STATUS, &reg, &ret);
+	if (ret)
+		return ret;
+
+	if (reg == TX_BUSY) {
+		dev_dbg(&ao_cec->pdev->dev, "%s: busy TX: aborting\n",
+			__func__);
+		meson_ao_cec_write(ao_cec, CEC_TX_MSG_CMD, TX_ABORT, &ret);
+	}
+
+	for (i = 0; i < msg->len; i++) {
+		meson_ao_cec_write(ao_cec, CEC_TX_MSG_0_HEADER + i,
+				   msg->msg[i], &ret);
+	}
+
+	meson_ao_cec_write(ao_cec, CEC_TX_MSG_LENGTH, msg->len - 1, &ret);
+	meson_ao_cec_write(ao_cec, CEC_TX_MSG_CMD, TX_REQ_CURRENT, &ret);
+
+	return ret;
+}
+
+static int meson_ao_cec_adap_enable(struct cec_adapter *adap, bool enable)
+{
+	struct meson_ao_cec_device *ao_cec = adap->priv;
+	int ret;
+
+	meson_ao_cec_irq_setup(ao_cec, false);
+
+	writel_bits_relaxed(CEC_GEN_CNTL_RESET, CEC_GEN_CNTL_RESET,
+			    ao_cec->base + CEC_GEN_CNTL_REG);
+
+	if (!enable)
+		return 0;
+
+	/* Enable gated clock (Normal mode). */
+	writel_bits_relaxed(CEC_GEN_CNTL_CLK_CTRL_MASK,
+			    FIELD_PREP(CEC_GEN_CNTL_CLK_CTRL_MASK,
+				       CEC_GEN_CNTL_CLK_ENABLE),
+			    ao_cec->base + CEC_GEN_CNTL_REG);
+
+	udelay(100);
+
+	/* Release Reset */
+	writel_bits_relaxed(CEC_GEN_CNTL_RESET, 0,
+			    ao_cec->base + CEC_GEN_CNTL_REG);
+
+	/* Clear buffers */
+	ret = meson_ao_cec_clear(ao_cec);
+	if (ret)
+		return ret;
+
+	/* CEC arbitration 3/5/7 bit time set. */
+	ret = meson_ao_cec_arbit_bit_time_set(ao_cec,
+					CEC_SIGNAL_FREE_TIME_RETRY,
+					0x118);
+	if (ret)
+		return ret;
+	ret = meson_ao_cec_arbit_bit_time_set(ao_cec,
+					CEC_SIGNAL_FREE_TIME_NEW_INITIATOR,
+					0x000);
+	if (ret)
+		return ret;
+	ret = meson_ao_cec_arbit_bit_time_set(ao_cec,
+					CEC_SIGNAL_FREE_TIME_NEXT_XFER,
+					0x2aa);
+	if (ret)
+		return ret;
+
+	meson_ao_cec_irq_setup(ao_cec, true);
+
+	return 0;
+}
+
+static const struct cec_adap_ops meson_ao_cec_ops = {
+	.adap_enable = meson_ao_cec_adap_enable,
+	.adap_log_addr = meson_ao_cec_set_log_addr,
+	.adap_transmit = meson_ao_cec_transmit,
+};
+
+static int meson_ao_cec_probe(struct platform_device *pdev)
+{
+	struct meson_ao_cec_device *ao_cec;
+	struct device *hdmi_dev;
+	int ret, irq;
+
+	hdmi_dev = cec_notifier_parse_hdmi_phandle(&pdev->dev);
+
+	if (IS_ERR(hdmi_dev))
+		return PTR_ERR(hdmi_dev);
+
+	ao_cec = devm_kzalloc(&pdev->dev, sizeof(*ao_cec), GFP_KERNEL);
+	if (!ao_cec)
+		return -ENOMEM;
+
+	spin_lock_init(&ao_cec->cec_reg_lock);
+
+	ao_cec->adap = cec_allocate_adapter(&meson_ao_cec_ops, ao_cec,
+					    "meson_ao_cec",
+					    CEC_CAP_DEFAULTS |
+					    CEC_CAP_CONNECTOR_INFO,
+					    1); /* Use 1 for now */
+	if (IS_ERR(ao_cec->adap))
+		return PTR_ERR(ao_cec->adap);
+
+	ao_cec->adap->owner = THIS_MODULE;
+
+	ao_cec->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(ao_cec->base)) {
+		ret = PTR_ERR(ao_cec->base);
+		goto out_probe_adapter;
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	ret = devm_request_threaded_irq(&pdev->dev, irq,
+					meson_ao_cec_irq,
+					meson_ao_cec_irq_thread,
+					0, NULL, ao_cec);
+	if (ret) {
+		dev_err(&pdev->dev, "irq request failed\n");
+		goto out_probe_adapter;
+	}
+
+	ao_cec->core = devm_clk_get(&pdev->dev, "core");
+	if (IS_ERR(ao_cec->core)) {
+		dev_err(&pdev->dev, "core clock request failed\n");
+		ret = PTR_ERR(ao_cec->core);
+		goto out_probe_adapter;
+	}
+
+	ret = clk_prepare_enable(ao_cec->core);
+	if (ret) {
+		dev_err(&pdev->dev, "core clock enable failed\n");
+		goto out_probe_adapter;
+	}
+
+	ret = clk_set_rate(ao_cec->core, CEC_CLK_RATE);
+	if (ret) {
+		dev_err(&pdev->dev, "core clock set rate failed\n");
+		goto out_probe_clk;
+	}
+
+	device_reset_optional(&pdev->dev);
+
+	ao_cec->pdev = pdev;
+	platform_set_drvdata(pdev, ao_cec);
+
+	ao_cec->notify = cec_notifier_cec_adap_register(hdmi_dev, NULL,
+							ao_cec->adap);
+	if (!ao_cec->notify) {
+		ret = -ENOMEM;
+		goto out_probe_clk;
+	}
+
+	ret = cec_register_adapter(ao_cec->adap, &pdev->dev);
+	if (ret < 0)
+		goto out_probe_notify;
+
+	/* Setup Hardware */
+	writel_relaxed(CEC_GEN_CNTL_RESET,
+		       ao_cec->base + CEC_GEN_CNTL_REG);
+
+	return 0;
+
+out_probe_notify:
+	cec_notifier_cec_adap_unregister(ao_cec->notify, ao_cec->adap);
+
+out_probe_clk:
+	clk_disable_unprepare(ao_cec->core);
+
+out_probe_adapter:
+	cec_delete_adapter(ao_cec->adap);
+
+	dev_err(&pdev->dev, "CEC controller registration failed\n");
+
+	return ret;
+}
+
+static void meson_ao_cec_remove(struct platform_device *pdev)
+{
+	struct meson_ao_cec_device *ao_cec = platform_get_drvdata(pdev);
+
+	clk_disable_unprepare(ao_cec->core);
+
+	cec_notifier_cec_adap_unregister(ao_cec->notify, ao_cec->adap);
+	cec_unregister_adapter(ao_cec->adap);
+}
+
+static const struct of_device_id meson_ao_cec_of_match[] = {
+	{ .compatible = "amlogic,meson-gx-ao-cec", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, meson_ao_cec_of_match);
+
+static struct platform_driver meson_ao_cec_driver = {
+	.probe   = meson_ao_cec_probe,
+	.remove_new = meson_ao_cec_remove,
+	.driver  = {
+		.name = "meson-ao-cec",
+		.of_match_table = meson_ao_cec_of_match,
+	},
+};
+
+module_platform_driver(meson_ao_cec_driver);
+
+MODULE_DESCRIPTION("Meson AO CEC Controller driver");
+MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
+MODULE_LICENSE("GPL");