diff mbox series

[v12,4/6] counter: Add Renesas RZ/G2L MTU3a counter driver

Message ID 20230202165732.305650-5-biju.das.jz@bp.renesas.com (mailing list archive)
State Superseded
Delegated to: Geert Uytterhoeven
Headers show
Series Add RZ/G2L MTU3a Core, Counter and pwm driver | expand

Commit Message

Biju Das Feb. 2, 2023, 4:57 p.m. UTC
Add RZ/G2L MTU3a counter driver. This IP supports the following
phase counting modes on MTU1 and MTU2 channels

1) 16-bit phase counting modes on MTU1 and MTU2 channels.
2) 32-bit phase counting mode by cascading MTU1 and MTU2 channels.

This patch adds 3 counter value channels.
	count0: 16-bit phase counter value channel on MTU1
	count1: 16-bit phase counter value channel on MTU2
	count2: 32-bit phase counter value channel by cascading
                MTU1 and MTU2 channels.

The external input phase clock pin for the counter value channels
are as follows:
	count0: "MTCLKA-MTCLKB"
	count1: "MTCLKA-MTCLKB" or "MTCLKC-MTCLKD"
	count2: "MTCLKA-MTCLKB" or "MTCLKC-MTCLKD"

Use the sysfs variable "external_input_phase_clock_select" to select the
external input phase clock pin and "cascade_counts_enable" to enable/
disable cascading of channels.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: William Breathitt Gray <william.gray@linaro.org>
---
v11->v12:
 * Updated header file to <linux/mfd/rz-mtu3.h> as core driver is moved to MFD.
v10->v11:
 * Added Rb tag from William Breathitt Gray
 * Replaced count2 channel name from "combined"->"cascaded", as channels
   are cascaded
 * Simplified the locking by adding the helper functions
   rz_mtu3_lock_if_counter_is_valid, rz_mtu3_lock_if_count_is_enabled,
   and rz_mtu3_lock_if_ch0_is_enabled.
v9->v10:
 * Added helper function for rz_mtu3_count_{action,function}_read
 * Added priv->lock in rz_mtu3_count_function_read and rz_mtu3_count_
   direction_read.
 * Added ch->is_busy check for rz_mtu3_action_read()
 * Added rz_mtu3_is_ch0_enabled() for device specific sysfs variables.
 * Added ch->is_busy check for device specific sysfs variables.
v8->v9:
 * Added count_is_enabled variable to struct rz_mtu3_cnt
 * Added check for ch->is_busy and count_is_enabled before every Counter
   callback to ensure we do not try to access a busy channel used by other
   subsystem(eg: pwm).
 * Removed id parameter from rz_mtu3_32bit_cnt_setting()
 * Made definition of rz_mtu3_get_ch() in single line.
 * Replaced break->return in rz_mtu3_32bit_cnt_setting(),
   rz_mtu3_count_function_read() and rz_mtu3_initialize_counter()
   and removed redundant return 0.
 * Simplified synapse signal check for rz_mtu3_action_read().
v7->v8:
 * Simplified rz_mtu3_initialize_counter by calling rz_mtu3_request_
   channel() and release the acquired sibling channel in case of error.
 * Simplified rz_mtu3_terminate_counter by calling rz_mtu3_release_
   channel().
 * Removed unused ceiling and ch_id from rz_mtu3_count_write()
 * Replaced the error -EINVAL->-EBUSY for rz_mtu3_is_counter_invalid()
 * Avoided race between rz_mtu3_count_{read, write} with rz_mtu3_
   cascade_counts_enable_set() by adding locks and moved the lock
   before rz_mtu3_is_counter_invalid()
 * Protected the rz_mtu3_count_ceiling_read() function with a lock
   to make sure the cascade operation mode doesn't not change and
   that the priv data structure accesses don't race when they are
   changed in the ceiling_write() callback.
 * Added lock in rz_mtu3_cascade_enable_set() to make sure the other
   callbacks don't try to read the LWA state while updating LWA.
 * Added lock in rz_mtu3_ext_input_phase_clock_select_set() to ensure
   the other callbacks don't try to read the PHCKSEL state while updating
   PHCKSEL.
 * Added lock to avoid race between rz_mtu3_count_function_write() and
   rz_mtu3_action_read()
 * Updated rz_mtu3_action_read to return 0, if Synapse is in COUNTER_SYNAPSE
   _ACTION_NONE state.
 * Replaced sysfs variable cascade_enable->cascade_counts_enable
 * Renamed rz_mtu3_cascade_enable_get->rz_mtu3_cascade_counts_enable_get
 * Renamed rz_mtu3_cascade_enable_set->rz_mtu3_cascade_counts_enable_set
 * Removed redundent ceiling assignment from rz_mtu3_count_ceiling_read()
 * Removed unused ceiling and ch_id from rz_mtu3_count_write().
v6->v7:
 * Updated commit description
 * Added Register descriptions
 * Opimized size of cache variable by using union
 * Used test_bit() in rz_mtu3_is_counter_invalid()
 * Replaced val->timer_mode in rz_mtu3_count_function_{read,write}
 * Added TODO comment phase3 and phase5 modes.
 * replaced if-else with ternary expression in rz_mtu3_count_direction_read()
 * Used switch statement in rz_mtu3_count_ceiling_read to consistent with write
 * Provided default case for all switch statement.
 * Add mutex lock for avoiding races with other devices
 * Updated comments in rz_mtu3_action_read
 * Replaced COUNTER_COMP_DEVICE_BOOL->COUNTER_COMP_DEVICE_BOOL for 
   cascade_enable
 * Replaced RZ_MTU3_GET_HW_CH->rz_mtu3_get_hw_ch
 * Added rz_mtu3_get_ch() to get channels
 * used rz_mtu3_shared_reg_update_bit for cascade_enable and
   selecting phase input clock.
 * Added rz_mtu3_is_counter_invalid() check in rz_mtu3_count_ceiling_read()
v5->v6:
 * Updated KConfig and commit description
 * Sorted header
 * Fixed RZ_MTU3_GET_HW_CH Macro for argument reuse 'id' - 
   possible side-effects?
 * Replaced SET_RUNTIME_PM_OPS->DEFINE_RUNTIME_DEV_PM_OPS and removed
   __maybe_unused from suspend/resume()
v4->v5:
 * Updated the Kconfig with SoC vendor name
 * Introduced rz_mtu3_is_counter_invalid()
 * replaced pointer to an array of struct rz_mtu3_channel with
   a simple pointer to struct rz_mtu3_channel.
 * Added long_word_access_ctrl_mode sysfs entry for 16-bit and
   32-bit access
 * Added external_input_phase_clock_select sysfs entry for
   selecting input clocks.
 * used preprocessor defines represent SIGNAL_{A,B,C,D}_ID instead of
   signal ids.
v3->v4:
 * There is no resource associated with "rz-mtu3-counter" compatible
   and moved the code to mfd subsystem as it binds against "rz-mtu".
 * Removed struct platform_driver rz_mtu3_cnt_driver.
 * Updated commit description
 * Updated Kconfig description
 * Added macros RZ_MTU3_16_BIT_MTU{1,2}_CH for MTU1 and MTU2 channels
 * Added RZ_MTU3_GET_HW_CH macro for getting channel ID.
 * replaced priv->ch[id]->priv->ch[0] in rz_mtu3_count_read()
 * Cached counter max values
 * replaced cnt->tsr in rz_mtu3_count_direction_read()
 * Added comments for RZ_MTU3_TCR_CCLR_NONE
 * Replaced if with switch in rz_mtu3_initialize_counter() and
   rz_mtu3_count_ceiling_write()
 * Added locks in initialize, terminate and enable_read to prevent races.
 * Updated rz_mtu3_action_read to take care of MTU2 signals.
 * Added separate distinct array for each group of Synapse.
 * Moved pm handling to parent.

v1->v3:
 * Modelled as a counter device supporting 3 counters(2 16-bit and 
   32-bit)
 * Add kernel-doc comments to document struct rz_mtu3_cnt
 * Removed mmio variable from struct rz_mtu3_cnt
 * Removed cnt local variable from rz_mtu3_count_read()
 * Replaced -EINVAL->-ERANGE for out of range error conditions.
 * Removed explicit cast from write functions.
 * Removed local variable val from rz_mtu3_count_ceiling_read()
 * Added lock for RMW for counter/ceiling updates.
 * Added different synapses for counter0 and counter{1,2}
 * Used ARRAY for assigning num_counts.
 * Added PM runtime for managing clocks.
 * Add MODULE_IMPORT_NS(COUNTER) to import the COUNTER namespace.
---
 drivers/counter/Kconfig       |  11 +
 drivers/counter/Makefile      |   1 +
 drivers/counter/rz-mtu3-cnt.c | 902 ++++++++++++++++++++++++++++++++++
 3 files changed, 914 insertions(+)
 create mode 100644 drivers/counter/rz-mtu3-cnt.c

Comments

Lee Jones Feb. 3, 2023, 8:01 a.m. UTC | #1
On Thu, 02 Feb 2023, Biju Das wrote:

> Add RZ/G2L MTU3a counter driver. This IP supports the following
> phase counting modes on MTU1 and MTU2 channels
> 
> 1) 16-bit phase counting modes on MTU1 and MTU2 channels.
> 2) 32-bit phase counting mode by cascading MTU1 and MTU2 channels.
> 
> This patch adds 3 counter value channels.
> 	count0: 16-bit phase counter value channel on MTU1
> 	count1: 16-bit phase counter value channel on MTU2
> 	count2: 32-bit phase counter value channel by cascading
>                 MTU1 and MTU2 channels.
> 
> The external input phase clock pin for the counter value channels
> are as follows:
> 	count0: "MTCLKA-MTCLKB"
> 	count1: "MTCLKA-MTCLKB" or "MTCLKC-MTCLKD"
> 	count2: "MTCLKA-MTCLKB" or "MTCLKC-MTCLKD"
> 
> Use the sysfs variable "external_input_phase_clock_select" to select the
> external input phase clock pin and "cascade_counts_enable" to enable/
> disable cascading of channels.
> 
> Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> Reviewed-by: William Breathitt Gray <william.gray@linaro.org>

When we come to merge this, an Ack will be required.
Biju Das Feb. 3, 2023, 8:58 a.m. UTC | #2
Hi Lee Jones,

Thanks for the feedback.

> -----Original Message-----
> From: Lee Jones <lee@kernel.org>
> Sent: Friday, February 3, 2023 8:01 AM
> To: Biju Das <biju.das.jz@bp.renesas.com>
> Cc: William Breathitt Gray <william.gray@linaro.org>; linux-
> iio@vger.kernel.org; Daniel Lezcano <daniel.lezcano@linaro.org>; Thierry
> Reding <thierry.reding@gmail.com>; Uwe Kleine-König <u.kleine-
> koenig@pengutronix.de>; Geert Uytterhoeven <geert+renesas@glider.be>; Chris
> Paterson <Chris.Paterson2@renesas.com>; Prabhakar Mahadev Lad
> <prabhakar.mahadev-lad.rj@bp.renesas.com>; linux-renesas-soc@vger.kernel.org
> Subject: Re: [PATCH v12 4/6] counter: Add Renesas RZ/G2L MTU3a counter
> driver
> 
> On Thu, 02 Feb 2023, Biju Das wrote:
> 
> > Add RZ/G2L MTU3a counter driver. This IP supports the following phase
> > counting modes on MTU1 and MTU2 channels
> >
> > 1) 16-bit phase counting modes on MTU1 and MTU2 channels.
> > 2) 32-bit phase counting mode by cascading MTU1 and MTU2 channels.
> >
> > This patch adds 3 counter value channels.
> > 	count0: 16-bit phase counter value channel on MTU1
> > 	count1: 16-bit phase counter value channel on MTU2
> > 	count2: 32-bit phase counter value channel by cascading
> >                 MTU1 and MTU2 channels.
> >
> > The external input phase clock pin for the counter value channels are
> > as follows:
> > 	count0: "MTCLKA-MTCLKB"
> > 	count1: "MTCLKA-MTCLKB" or "MTCLKC-MTCLKD"
> > 	count2: "MTCLKA-MTCLKB" or "MTCLKC-MTCLKD"
> >
> > Use the sysfs variable "external_input_phase_clock_select" to select
> > the external input phase clock pin and "cascade_counts_enable" to
> > enable/ disable cascading of channels.
> >
> > Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> > Reviewed-by: William Breathitt Gray <william.gray@linaro.org>
> 
> When we come to merge this, an Ack will be required.

You mean an Ack from William Breathitt Gray and you can take it through
MFD (ie, core + counter patches together)??

or 

You will apply core driver and create an immutable branch, counter subsystem
can use that branch to avoid build issues while applying??

Please share your view on this.

Cheers,
Biju
Lee Jones Feb. 3, 2023, 10:15 a.m. UTC | #3
On Fri, 03 Feb 2023, Biju Das wrote:

> 
> Hi Lee Jones,
> 
> Thanks for the feedback.
> 
> > -----Original Message-----
> > From: Lee Jones <lee@kernel.org>
> > Sent: Friday, February 3, 2023 8:01 AM
> > To: Biju Das <biju.das.jz@bp.renesas.com>
> > Cc: William Breathitt Gray <william.gray@linaro.org>; linux-
> > iio@vger.kernel.org; Daniel Lezcano <daniel.lezcano@linaro.org>; Thierry
> > Reding <thierry.reding@gmail.com>; Uwe Kleine-König <u.kleine-
> > koenig@pengutronix.de>; Geert Uytterhoeven <geert+renesas@glider.be>; Chris
> > Paterson <Chris.Paterson2@renesas.com>; Prabhakar Mahadev Lad
> > <prabhakar.mahadev-lad.rj@bp.renesas.com>; linux-renesas-soc@vger.kernel.org
> > Subject: Re: [PATCH v12 4/6] counter: Add Renesas RZ/G2L MTU3a counter
> > driver
> > 
> > On Thu, 02 Feb 2023, Biju Das wrote:
> > 
> > > Add RZ/G2L MTU3a counter driver. This IP supports the following phase
> > > counting modes on MTU1 and MTU2 channels
> > >
> > > 1) 16-bit phase counting modes on MTU1 and MTU2 channels.
> > > 2) 32-bit phase counting mode by cascading MTU1 and MTU2 channels.
> > >
> > > This patch adds 3 counter value channels.
> > > 	count0: 16-bit phase counter value channel on MTU1
> > > 	count1: 16-bit phase counter value channel on MTU2
> > > 	count2: 32-bit phase counter value channel by cascading
> > >                 MTU1 and MTU2 channels.
> > >
> > > The external input phase clock pin for the counter value channels are
> > > as follows:
> > > 	count0: "MTCLKA-MTCLKB"
> > > 	count1: "MTCLKA-MTCLKB" or "MTCLKC-MTCLKD"
> > > 	count2: "MTCLKA-MTCLKB" or "MTCLKC-MTCLKD"
> > >
> > > Use the sysfs variable "external_input_phase_clock_select" to select
> > > the external input phase clock pin and "cascade_counts_enable" to
> > > enable/ disable cascading of channels.
> > >
> > > Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
> > > Reviewed-by: William Breathitt Gray <william.gray@linaro.org>
> > 
> > When we come to merge this, an Ack will be required.
> 
> You mean an Ack from William Breathitt Gray and you can take it through
> MFD (ie, core + counter patches together)??
> 
> or 
> 
> You will apply core driver and create an immutable branch, counter subsystem
> can use that branch to avoid build issues while applying??
> 
> Please share your view on this.

My assumption is that William provided his tag with a view to not
merging this via his own repo.

However, if there aren't any *build time* dependencies between the
patches (i.e. shared header files, etc), then the preference would be
for each commit to be merged through their own associated subsystem
trees.  However if there are build time deps, then it's common for the
entire set to be merged in via the MFD tree.  In the latter case a
subsequent pull-request would then be provided for each of the other
maintainers to pull from (if they so desire / need to).
diff mbox series

Patch

diff --git a/drivers/counter/Kconfig b/drivers/counter/Kconfig
index b5ba8fb02cf7..4228be917038 100644
--- a/drivers/counter/Kconfig
+++ b/drivers/counter/Kconfig
@@ -73,6 +73,17 @@  config MICROCHIP_TCB_CAPTURE
 	  To compile this driver as a module, choose M here: the
 	  module will be called microchip-tcb-capture.
 
+config RZ_MTU3_CNT
+	tristate "Renesas RZ/G2L MTU3a counter driver"
+	depends on RZ_MTU3 || COMPILE_TEST
+	help
+	  Enable support for MTU3a counter driver found on Renesas RZ/G2L alike
+	  SoCs. This IP supports both 16-bit and 32-bit phase counting mode
+	  support.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called rz-mtu3-cnt.
+
 config STM32_LPTIMER_CNT
 	tristate "STM32 LP Timer encoder counter driver"
 	depends on MFD_STM32_LPTIMER || COMPILE_TEST
diff --git a/drivers/counter/Makefile b/drivers/counter/Makefile
index b9a369e0d4fc..933fdd50b3e4 100644
--- a/drivers/counter/Makefile
+++ b/drivers/counter/Makefile
@@ -8,6 +8,7 @@  counter-y := counter-core.o counter-sysfs.o counter-chrdev.o
 
 obj-$(CONFIG_104_QUAD_8)	+= 104-quad-8.o
 obj-$(CONFIG_INTERRUPT_CNT)		+= interrupt-cnt.o
+obj-$(CONFIG_RZ_MTU3_CNT)	+= rz-mtu3-cnt.o
 obj-$(CONFIG_STM32_TIMER_CNT)	+= stm32-timer-cnt.o
 obj-$(CONFIG_STM32_LPTIMER_CNT)	+= stm32-lptimer-cnt.o
 obj-$(CONFIG_TI_EQEP)		+= ti-eqep.o
diff --git a/drivers/counter/rz-mtu3-cnt.c b/drivers/counter/rz-mtu3-cnt.c
new file mode 100644
index 000000000000..c4b5440da878
--- /dev/null
+++ b/drivers/counter/rz-mtu3-cnt.c
@@ -0,0 +1,902 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Renesas RZ/G2L MTU3a Counter driver
+ *
+ * Copyright (C) 2022 Renesas Electronics Corporation
+ */
+
+#include <linux/clk.h>
+#include <linux/counter.h>
+#include <linux/mfd/rz-mtu3.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/types.h>
+
+/*
+ * Register descriptions
+ *   TSR: Timer Status Register
+ *   TMDR1: Timer Mode Register 1
+ *   TMDR3: Timer Mode Register 3
+ *   TIOR: Timer I/O Control Register
+ *   TCR: Timer Control Register
+ *   TCNT: Timer Counter
+ *   TGRA: Timer general register A
+ *   TCNTLW: Timer Longword Counter
+ *   TGRALW: Timer longword general register A
+ */
+
+#define RZ_MTU3_TSR_TCFD	BIT(7) /* Count Direction Flag */
+
+#define RZ_MTU3_TMDR1_PH_CNT_MODE_1	(4) /* Phase counting mode 1 */
+#define RZ_MTU3_TMDR1_PH_CNT_MODE_2	(5) /* Phase counting mode 2 */
+#define RZ_MTU3_TMDR1_PH_CNT_MODE_3	(6) /* Phase counting mode 3 */
+#define RZ_MTU3_TMDR1_PH_CNT_MODE_4	(7) /* Phase counting mode 4 */
+#define RZ_MTU3_TMDR1_PH_CNT_MODE_5	(9) /* Phase counting mode 5 */
+#define RZ_MTU3_TMDR1_PH_CNT_MODE_MASK	(0xf)
+
+/*
+ * LWA: MTU1/MTU2 Combination Longword Access Control
+ * 0: 16-bit, 1: 32-bit
+ */
+#define RZ_MTU3_TMDR3_LWA	(0)
+
+/*
+ * PHCKSEL: External Input Phase Clock Select
+ * 0: MTCLKA and MTCLKB, 1: MTCLKC and MTCLKD
+ */
+#define RZ_MTU3_TMDR3_PHCKSEL	(1)
+
+#define RZ_MTU3_16_BIT_MTU1_CH	(0)
+#define RZ_MTU3_16_BIT_MTU2_CH	(1)
+#define RZ_MTU3_32_BIT_CH	(2)
+
+#define RZ_MTU3_TIOR_NO_OUTPUT	(0) /* Output prohibited */
+#define RZ_MTU3_TIOR_IC_BOTH	(10) /* Input capture at both edges */
+
+#define SIGNAL_A_ID	(0)
+#define SIGNAL_B_ID	(1)
+#define SIGNAL_C_ID	(2)
+#define SIGNAL_D_ID	(3)
+
+#define RZ_MTU3_MAX_HW_CNTR_CHANNELS	(2)
+#define RZ_MTU3_MAX_LOGICAL_CNTR_CHANNELS	(3)
+
+/**
+ * struct rz_mtu3_cnt - MTU3 counter private data
+ *
+ * @clk: MTU3 module clock
+ * @lock: Lock to prevent concurrent access for ceiling and count
+ * @ch: HW channels for the counters
+ * @count_is_enabled: Enabled state of Counter value channel
+ * @mtu_16bit_max: Cache for 16-bit counters
+ * @mtu_32bit_max: Cache for 32-bit counters
+ */
+struct rz_mtu3_cnt {
+	struct clk *clk;
+	struct mutex lock;
+	struct rz_mtu3_channel *ch;
+	bool count_is_enabled[RZ_MTU3_MAX_LOGICAL_CNTR_CHANNELS];
+	union {
+		u16 mtu_16bit_max[RZ_MTU3_MAX_HW_CNTR_CHANNELS];
+		u32 mtu_32bit_max;
+	};
+};
+
+static const enum counter_function rz_mtu3_count_functions[] = {
+	COUNTER_FUNCTION_QUADRATURE_X4,
+	COUNTER_FUNCTION_PULSE_DIRECTION,
+	COUNTER_FUNCTION_QUADRATURE_X2_B,
+};
+
+static inline size_t rz_mtu3_get_hw_ch(const size_t id)
+{
+	return (id == RZ_MTU3_32_BIT_CH) ? 0 : id;
+}
+
+static inline struct rz_mtu3_channel *rz_mtu3_get_ch(struct counter_device *counter, int id)
+{
+	struct rz_mtu3_cnt *const priv = counter_priv(counter);
+	const size_t ch_id = rz_mtu3_get_hw_ch(id);
+
+	return &priv->ch[ch_id];
+}
+
+static bool rz_mtu3_is_counter_invalid(struct counter_device *counter, int id)
+{
+	struct rz_mtu3_cnt *const priv = counter_priv(counter);
+	unsigned long tmdr;
+
+	pm_runtime_get_sync(priv->ch->dev);
+	tmdr = rz_mtu3_shared_reg_read(priv->ch, RZ_MTU3_TMDR3);
+	pm_runtime_put(priv->ch->dev);
+
+	if (id == RZ_MTU3_32_BIT_CH && test_bit(RZ_MTU3_TMDR3_LWA, &tmdr))
+		return false;
+
+	if (id != RZ_MTU3_32_BIT_CH && !test_bit(RZ_MTU3_TMDR3_LWA, &tmdr))
+		return false;
+
+	return true;
+}
+
+static int rz_mtu3_lock_if_counter_is_valid(struct counter_device *counter,
+					    struct rz_mtu3_channel *const ch,
+					    struct rz_mtu3_cnt *const priv,
+					    int id)
+{
+	mutex_lock(&priv->lock);
+
+	if (ch->is_busy && !priv->count_is_enabled[id]) {
+		mutex_unlock(&priv->lock);
+		return -EINVAL;
+	}
+
+	if (rz_mtu3_is_counter_invalid(counter, id)) {
+		mutex_unlock(&priv->lock);
+		return -EBUSY;
+	}
+
+	return 0;
+}
+
+static int rz_mtu3_lock_if_count_is_enabled(struct rz_mtu3_channel *const ch,
+					    struct rz_mtu3_cnt *const priv,
+					    int id)
+{
+	mutex_lock(&priv->lock);
+
+	if (ch->is_busy && !priv->count_is_enabled[id]) {
+		mutex_unlock(&priv->lock);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int rz_mtu3_count_read(struct counter_device *counter,
+			      struct counter_count *count, u64 *val)
+{
+	struct rz_mtu3_channel *const ch = rz_mtu3_get_ch(counter, count->id);
+	struct rz_mtu3_cnt *const priv = counter_priv(counter);
+	int ret;
+
+	ret = rz_mtu3_lock_if_counter_is_valid(counter, ch, priv, count->id);
+	if (ret)
+		return ret;
+
+	pm_runtime_get_sync(ch->dev);
+	if (count->id == RZ_MTU3_32_BIT_CH)
+		*val = rz_mtu3_32bit_ch_read(ch, RZ_MTU3_TCNTLW);
+	else
+		*val = rz_mtu3_16bit_ch_read(ch, RZ_MTU3_TCNT);
+	pm_runtime_put(ch->dev);
+	mutex_unlock(&priv->lock);
+
+	return 0;
+}
+
+static int rz_mtu3_count_write(struct counter_device *counter,
+			       struct counter_count *count, const u64 val)
+{
+	struct rz_mtu3_channel *const ch = rz_mtu3_get_ch(counter, count->id);
+	struct rz_mtu3_cnt *const priv = counter_priv(counter);
+	int ret;
+
+	ret = rz_mtu3_lock_if_counter_is_valid(counter, ch, priv, count->id);
+	if (ret)
+		return ret;
+
+	pm_runtime_get_sync(ch->dev);
+	if (count->id == RZ_MTU3_32_BIT_CH)
+		rz_mtu3_32bit_ch_write(ch, RZ_MTU3_TCNTLW, val);
+	else
+		rz_mtu3_16bit_ch_write(ch, RZ_MTU3_TCNT, val);
+	pm_runtime_put(ch->dev);
+	mutex_unlock(&priv->lock);
+
+	return 0;
+}
+
+static int rz_mtu3_count_function_read_helper(struct rz_mtu3_channel *const ch,
+					      struct rz_mtu3_cnt *const priv,
+					      enum counter_function *function)
+{
+	u8 timer_mode;
+
+	pm_runtime_get_sync(ch->dev);
+	timer_mode = rz_mtu3_8bit_ch_read(ch, RZ_MTU3_TMDR1);
+	pm_runtime_put(ch->dev);
+
+	switch (timer_mode & RZ_MTU3_TMDR1_PH_CNT_MODE_MASK) {
+	case RZ_MTU3_TMDR1_PH_CNT_MODE_1:
+		*function = COUNTER_FUNCTION_QUADRATURE_X4;
+		return 0;
+	case RZ_MTU3_TMDR1_PH_CNT_MODE_2:
+		*function = COUNTER_FUNCTION_PULSE_DIRECTION;
+		return 0;
+	case RZ_MTU3_TMDR1_PH_CNT_MODE_4:
+		*function = COUNTER_FUNCTION_QUADRATURE_X2_B;
+		return 0;
+	default:
+		/*
+		 * TODO:
+		 *  - need to add RZ_MTU3_TMDR1_PH_CNT_MODE_3
+		 *  - need to add RZ_MTU3_TMDR1_PH_CNT_MODE_5
+		 */
+		return -EINVAL;
+	}
+}
+
+static int rz_mtu3_count_function_read(struct counter_device *counter,
+				       struct counter_count *count,
+				       enum counter_function *function)
+{
+	struct rz_mtu3_channel *const ch = rz_mtu3_get_ch(counter, count->id);
+	struct rz_mtu3_cnt *const priv = counter_priv(counter);
+	int ret;
+
+	ret = rz_mtu3_lock_if_count_is_enabled(ch, priv, count->id);
+	if (ret)
+		return ret;
+
+	ret = rz_mtu3_count_function_read_helper(ch, priv, function);
+	mutex_unlock(&priv->lock);
+
+	return ret;
+}
+
+static int rz_mtu3_count_function_write(struct counter_device *counter,
+					struct counter_count *count,
+					enum counter_function function)
+{
+	struct rz_mtu3_channel *const ch = rz_mtu3_get_ch(counter, count->id);
+	struct rz_mtu3_cnt *const priv = counter_priv(counter);
+	u8 timer_mode;
+	int ret;
+
+	ret = rz_mtu3_lock_if_count_is_enabled(ch, priv, count->id);
+	if (ret)
+		return ret;
+
+	switch (function) {
+	case COUNTER_FUNCTION_QUADRATURE_X4:
+		timer_mode = RZ_MTU3_TMDR1_PH_CNT_MODE_1;
+		break;
+	case COUNTER_FUNCTION_PULSE_DIRECTION:
+		timer_mode = RZ_MTU3_TMDR1_PH_CNT_MODE_2;
+		break;
+	case COUNTER_FUNCTION_QUADRATURE_X2_B:
+		timer_mode = RZ_MTU3_TMDR1_PH_CNT_MODE_4;
+		break;
+	default:
+		/*
+		 * TODO:
+		 *  - need to add RZ_MTU3_TMDR1_PH_CNT_MODE_3
+		 *  - need to add RZ_MTU3_TMDR1_PH_CNT_MODE_5
+		 */
+		mutex_unlock(&priv->lock);
+		return -EINVAL;
+	}
+
+	pm_runtime_get_sync(ch->dev);
+	rz_mtu3_8bit_ch_write(ch, RZ_MTU3_TMDR1, timer_mode);
+	pm_runtime_put(ch->dev);
+	mutex_unlock(&priv->lock);
+
+	return 0;
+}
+
+static int rz_mtu3_count_direction_read(struct counter_device *counter,
+					struct counter_count *count,
+					enum counter_count_direction *direction)
+{
+	struct rz_mtu3_channel *const ch = rz_mtu3_get_ch(counter, count->id);
+	struct rz_mtu3_cnt *const priv = counter_priv(counter);
+	int ret;
+	u8 tsr;
+
+	ret = rz_mtu3_lock_if_count_is_enabled(ch, priv, count->id);
+	if (ret)
+		return ret;
+
+	pm_runtime_get_sync(ch->dev);
+	tsr = rz_mtu3_8bit_ch_read(ch, RZ_MTU3_TSR);
+	pm_runtime_put(ch->dev);
+
+	*direction = (tsr & RZ_MTU3_TSR_TCFD) ?
+		COUNTER_COUNT_DIRECTION_FORWARD : COUNTER_COUNT_DIRECTION_BACKWARD;
+	mutex_unlock(&priv->lock);
+
+	return 0;
+}
+
+static int rz_mtu3_count_ceiling_read(struct counter_device *counter,
+				      struct counter_count *count,
+				      u64 *ceiling)
+{
+	struct rz_mtu3_channel *const ch = rz_mtu3_get_ch(counter, count->id);
+	struct rz_mtu3_cnt *const priv = counter_priv(counter);
+	const size_t ch_id = rz_mtu3_get_hw_ch(count->id);
+	int ret;
+
+	ret = rz_mtu3_lock_if_counter_is_valid(counter, ch, priv, count->id);
+	if (ret)
+		return ret;
+
+	switch (count->id) {
+	case RZ_MTU3_16_BIT_MTU1_CH:
+	case RZ_MTU3_16_BIT_MTU2_CH:
+		*ceiling = priv->mtu_16bit_max[ch_id];
+		break;
+	case RZ_MTU3_32_BIT_CH:
+		*ceiling = priv->mtu_32bit_max;
+		break;
+	default:
+		/* should never reach this path */
+		mutex_unlock(&priv->lock);
+		return -EINVAL;
+	}
+
+	mutex_unlock(&priv->lock);
+	return 0;
+}
+
+static int rz_mtu3_count_ceiling_write(struct counter_device *counter,
+				       struct counter_count *count,
+				       u64 ceiling)
+{
+	struct rz_mtu3_channel *const ch = rz_mtu3_get_ch(counter, count->id);
+	struct rz_mtu3_cnt *const priv = counter_priv(counter);
+	const size_t ch_id = rz_mtu3_get_hw_ch(count->id);
+	int ret;
+
+	ret = rz_mtu3_lock_if_counter_is_valid(counter, ch, priv, count->id);
+	if (ret)
+		return ret;
+
+	switch (count->id) {
+	case RZ_MTU3_16_BIT_MTU1_CH:
+	case RZ_MTU3_16_BIT_MTU2_CH:
+		if (ceiling > U16_MAX)
+			return -ERANGE;
+		priv->mtu_16bit_max[ch_id] = ceiling;
+		break;
+	case RZ_MTU3_32_BIT_CH:
+		if (ceiling > U32_MAX)
+			return -ERANGE;
+		priv->mtu_32bit_max = ceiling;
+		break;
+	default:
+		/* should never reach this path */
+		mutex_unlock(&priv->lock);
+		return -EINVAL;
+	}
+
+	pm_runtime_get_sync(ch->dev);
+	if (count->id == RZ_MTU3_32_BIT_CH)
+		rz_mtu3_32bit_ch_write(ch, RZ_MTU3_TGRALW, ceiling);
+	else
+		rz_mtu3_16bit_ch_write(ch, RZ_MTU3_TGRA, ceiling);
+
+	rz_mtu3_8bit_ch_write(ch, RZ_MTU3_TCR, RZ_MTU3_TCR_CCLR_TGRA);
+	pm_runtime_put(ch->dev);
+	mutex_unlock(&priv->lock);
+
+	return 0;
+}
+
+static void rz_mtu3_32bit_cnt_setting(struct counter_device *counter)
+{
+	struct rz_mtu3_channel *const ch1 = rz_mtu3_get_ch(counter, 0);
+	struct rz_mtu3_channel *const ch2 = rz_mtu3_get_ch(counter, 1);
+
+	/* Phase counting mode 1 is used as default in initialization. */
+	rz_mtu3_8bit_ch_write(ch1, RZ_MTU3_TMDR1, RZ_MTU3_TMDR1_PH_CNT_MODE_1);
+
+	rz_mtu3_8bit_ch_write(ch1, RZ_MTU3_TCR, RZ_MTU3_TCR_CCLR_TGRA);
+	rz_mtu3_8bit_ch_write(ch1, RZ_MTU3_TIOR, RZ_MTU3_TIOR_IC_BOTH);
+
+	rz_mtu3_enable(ch1);
+	rz_mtu3_enable(ch2);
+}
+
+static void rz_mtu3_16bit_cnt_setting(struct counter_device *counter, int id)
+{
+	struct rz_mtu3_channel *const ch = rz_mtu3_get_ch(counter, id);
+
+	/* Phase counting mode 1 is used as default in initialization. */
+	rz_mtu3_8bit_ch_write(ch, RZ_MTU3_TMDR1, RZ_MTU3_TMDR1_PH_CNT_MODE_1);
+
+	rz_mtu3_8bit_ch_write(ch, RZ_MTU3_TCR, RZ_MTU3_TCR_CCLR_TGRA);
+	rz_mtu3_8bit_ch_write(ch, RZ_MTU3_TIOR, RZ_MTU3_TIOR_NO_OUTPUT);
+	rz_mtu3_enable(ch);
+}
+
+static int rz_mtu3_initialize_counter(struct counter_device *counter, int id)
+{
+	struct rz_mtu3_channel *const ch = rz_mtu3_get_ch(counter, id);
+	struct rz_mtu3_channel *const ch1 = rz_mtu3_get_ch(counter, 0);
+	struct rz_mtu3_channel *const ch2 = rz_mtu3_get_ch(counter, 1);
+
+	switch (id) {
+	case RZ_MTU3_16_BIT_MTU1_CH:
+	case RZ_MTU3_16_BIT_MTU2_CH:
+		if (!rz_mtu3_request_channel(ch))
+			return -EBUSY;
+
+		rz_mtu3_16bit_cnt_setting(counter, id);
+		return 0;
+	case RZ_MTU3_32_BIT_CH:
+		/*
+		 * 32-bit phase counting need MTU1 and MTU2 to create 32-bit
+		 * cascade counter.
+		 */
+		if (!rz_mtu3_request_channel(ch1))
+			return -EBUSY;
+
+		if (!rz_mtu3_request_channel(ch2)) {
+			rz_mtu3_release_channel(ch1);
+			return -EBUSY;
+		}
+
+		rz_mtu3_32bit_cnt_setting(counter);
+		return 0;
+	default:
+		/* should never reach this path */
+		return -EINVAL;
+	}
+}
+
+static void rz_mtu3_terminate_counter(struct counter_device *counter, int id)
+{
+	struct rz_mtu3_channel *const ch = rz_mtu3_get_ch(counter, id);
+	struct rz_mtu3_channel *const ch1 = rz_mtu3_get_ch(counter, 0);
+	struct rz_mtu3_channel *const ch2 = rz_mtu3_get_ch(counter, 1);
+
+	if (id == RZ_MTU3_32_BIT_CH) {
+		rz_mtu3_release_channel(ch2);
+		rz_mtu3_release_channel(ch1);
+		rz_mtu3_disable(ch2);
+		rz_mtu3_disable(ch1);
+	} else {
+		rz_mtu3_release_channel(ch);
+		rz_mtu3_disable(ch);
+	}
+}
+
+static int rz_mtu3_count_enable_read(struct counter_device *counter,
+				     struct counter_count *count, u8 *enable)
+{
+	struct rz_mtu3_channel *const ch = rz_mtu3_get_ch(counter, count->id);
+	struct rz_mtu3_channel *const ch1 = rz_mtu3_get_ch(counter, 0);
+	struct rz_mtu3_channel *const ch2 = rz_mtu3_get_ch(counter, 1);
+	struct rz_mtu3_cnt *const priv = counter_priv(counter);
+	int ret;
+
+	ret = rz_mtu3_lock_if_count_is_enabled(ch, priv, count->id);
+	if (ret)
+		return ret;
+
+	if (count->id == RZ_MTU3_32_BIT_CH)
+		*enable = rz_mtu3_is_enabled(ch1) && rz_mtu3_is_enabled(ch2);
+	else
+		*enable = rz_mtu3_is_enabled(ch);
+
+	mutex_unlock(&priv->lock);
+
+	return 0;
+}
+
+static int rz_mtu3_count_enable_write(struct counter_device *counter,
+				      struct counter_count *count, u8 enable)
+{
+	struct rz_mtu3_channel *const ch = rz_mtu3_get_ch(counter, count->id);
+	struct rz_mtu3_cnt *const priv = counter_priv(counter);
+	int ret = 0;
+
+	if (enable) {
+		pm_runtime_get_sync(ch->dev);
+		mutex_lock(&priv->lock);
+		ret = rz_mtu3_initialize_counter(counter, count->id);
+		if (ret == 0)
+			priv->count_is_enabled[count->id] = true;
+		mutex_unlock(&priv->lock);
+	} else {
+		mutex_lock(&priv->lock);
+		rz_mtu3_terminate_counter(counter, count->id);
+		priv->count_is_enabled[count->id] = false;
+		mutex_unlock(&priv->lock);
+		pm_runtime_put(ch->dev);
+	}
+
+	return ret;
+}
+
+static int rz_mtu3_lock_if_ch0_is_enabled(struct rz_mtu3_cnt *const priv)
+{
+	mutex_lock(&priv->lock);
+	if (priv->ch->is_busy && !(priv->count_is_enabled[RZ_MTU3_16_BIT_MTU1_CH] ||
+				   priv->count_is_enabled[RZ_MTU3_32_BIT_CH])) {
+		mutex_unlock(&priv->lock);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int rz_mtu3_cascade_counts_enable_get(struct counter_device *counter,
+					     u8 *cascade_enable)
+{
+	struct rz_mtu3_cnt *const priv = counter_priv(counter);
+	unsigned long tmdr;
+	int ret;
+
+	ret = rz_mtu3_lock_if_ch0_is_enabled(priv);
+	if (ret)
+		return ret;
+
+	pm_runtime_get_sync(priv->ch->dev);
+	tmdr = rz_mtu3_shared_reg_read(priv->ch, RZ_MTU3_TMDR3);
+	pm_runtime_put(priv->ch->dev);
+	*cascade_enable = test_bit(RZ_MTU3_TMDR3_LWA, &tmdr);
+	mutex_unlock(&priv->lock);
+
+	return 0;
+}
+
+static int rz_mtu3_cascade_counts_enable_set(struct counter_device *counter,
+					     u8 cascade_enable)
+{
+	struct rz_mtu3_cnt *const priv = counter_priv(counter);
+	int ret;
+
+	ret = rz_mtu3_lock_if_ch0_is_enabled(priv);
+	if (ret)
+		return ret;
+
+	pm_runtime_get_sync(priv->ch->dev);
+	rz_mtu3_shared_reg_update_bit(priv->ch, RZ_MTU3_TMDR3,
+				      RZ_MTU3_TMDR3_LWA, cascade_enable);
+	pm_runtime_put(priv->ch->dev);
+	mutex_unlock(&priv->lock);
+
+	return 0;
+}
+
+static int rz_mtu3_ext_input_phase_clock_select_get(struct counter_device *counter,
+						    u32 *ext_input_phase_clock_select)
+{
+	struct rz_mtu3_cnt *const priv = counter_priv(counter);
+	unsigned long tmdr;
+	int ret;
+
+	ret = rz_mtu3_lock_if_ch0_is_enabled(priv);
+	if (ret)
+		return ret;
+
+	pm_runtime_get_sync(priv->ch->dev);
+	tmdr = rz_mtu3_shared_reg_read(priv->ch, RZ_MTU3_TMDR3);
+	pm_runtime_put(priv->ch->dev);
+	*ext_input_phase_clock_select = test_bit(RZ_MTU3_TMDR3_PHCKSEL, &tmdr);
+	mutex_unlock(&priv->lock);
+
+	return 0;
+}
+
+static int rz_mtu3_ext_input_phase_clock_select_set(struct counter_device *counter,
+						    u32 ext_input_phase_clock_select)
+{
+	struct rz_mtu3_cnt *const priv = counter_priv(counter);
+	int ret;
+
+	ret = rz_mtu3_lock_if_ch0_is_enabled(priv);
+	if (ret)
+		return ret;
+
+	pm_runtime_get_sync(priv->ch->dev);
+	rz_mtu3_shared_reg_update_bit(priv->ch, RZ_MTU3_TMDR3,
+				      RZ_MTU3_TMDR3_PHCKSEL,
+				      ext_input_phase_clock_select);
+	pm_runtime_put(priv->ch->dev);
+	mutex_unlock(&priv->lock);
+
+	return 0;
+}
+
+static struct counter_comp rz_mtu3_count_ext[] = {
+	COUNTER_COMP_DIRECTION(rz_mtu3_count_direction_read),
+	COUNTER_COMP_ENABLE(rz_mtu3_count_enable_read,
+			    rz_mtu3_count_enable_write),
+	COUNTER_COMP_CEILING(rz_mtu3_count_ceiling_read,
+			     rz_mtu3_count_ceiling_write),
+};
+
+static const enum counter_synapse_action rz_mtu3_synapse_actions[] = {
+	COUNTER_SYNAPSE_ACTION_BOTH_EDGES,
+	COUNTER_SYNAPSE_ACTION_RISING_EDGE,
+	COUNTER_SYNAPSE_ACTION_NONE,
+};
+
+static int rz_mtu3_action_read(struct counter_device *counter,
+			       struct counter_count *count,
+			       struct counter_synapse *synapse,
+			       enum counter_synapse_action *action)
+{
+	const bool is_signal_ab = (synapse->signal->id == SIGNAL_A_ID) ||
+				  (synapse->signal->id == SIGNAL_B_ID);
+	struct rz_mtu3_channel *const ch = rz_mtu3_get_ch(counter, count->id);
+	struct rz_mtu3_cnt *const priv = counter_priv(counter);
+	enum counter_function function;
+	bool mtclkc_mtclkd;
+	unsigned long tmdr;
+	int ret;
+
+	ret = rz_mtu3_lock_if_count_is_enabled(ch, priv, count->id);
+	if (ret)
+		return ret;
+
+	ret = rz_mtu3_count_function_read_helper(ch, priv, &function);
+	if (ret) {
+		mutex_unlock(&priv->lock);
+		return ret;
+	}
+
+	/* Default action mode */
+	*action = COUNTER_SYNAPSE_ACTION_NONE;
+
+	if (count->id != RZ_MTU3_16_BIT_MTU1_CH) {
+		tmdr = rz_mtu3_shared_reg_read(priv->ch, RZ_MTU3_TMDR3);
+		mtclkc_mtclkd = test_bit(RZ_MTU3_TMDR3_PHCKSEL, &tmdr);
+		if ((mtclkc_mtclkd && is_signal_ab) ||
+		    (!mtclkc_mtclkd && !is_signal_ab)) {
+			mutex_unlock(&priv->lock);
+			return 0;
+		}
+	}
+
+	switch (function) {
+	case COUNTER_FUNCTION_PULSE_DIRECTION:
+		/*
+		 * Rising edges on signal A (signal C) updates the respective
+		 * count. The input level of signal B (signal D) determines
+		 * direction.
+		 */
+		if (synapse->signal->id == SIGNAL_A_ID ||
+		    synapse->signal->id == SIGNAL_C_ID)
+			*action = COUNTER_SYNAPSE_ACTION_RISING_EDGE;
+		break;
+	case COUNTER_FUNCTION_QUADRATURE_X2_B:
+		/*
+		 * Any state transition on quadrature pair signal B (signal D)
+		 * updates the respective count.
+		 */
+		if (synapse->signal->id == SIGNAL_B_ID ||
+		    synapse->signal->id == SIGNAL_D_ID)
+			*action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
+		break;
+	case COUNTER_FUNCTION_QUADRATURE_X4:
+		/* counts up/down on both edges of A (C)  and B (D) signal */
+		*action = COUNTER_SYNAPSE_ACTION_BOTH_EDGES;
+		break;
+	default:
+		/* should never reach this path */
+		mutex_unlock(&priv->lock);
+		return -EINVAL;
+	}
+
+	mutex_unlock(&priv->lock);
+
+	return 0;
+}
+
+static const struct counter_ops rz_mtu3_cnt_ops = {
+	.count_read = rz_mtu3_count_read,
+	.count_write = rz_mtu3_count_write,
+	.function_read = rz_mtu3_count_function_read,
+	.function_write = rz_mtu3_count_function_write,
+	.action_read = rz_mtu3_action_read,
+};
+
+#define RZ_MTU3_PHASE_SIGNAL(_id, _name) {		\
+	.id = (_id),				\
+	.name = (_name),			\
+}
+
+static struct counter_signal rz_mtu3_signals[] = {
+	RZ_MTU3_PHASE_SIGNAL(SIGNAL_A_ID, "MTU1 MTCLKA"),
+	RZ_MTU3_PHASE_SIGNAL(SIGNAL_B_ID, "MTU1 MTCLKB"),
+	RZ_MTU3_PHASE_SIGNAL(SIGNAL_C_ID, "MTU2 MTCLKC"),
+	RZ_MTU3_PHASE_SIGNAL(SIGNAL_D_ID, "MTU2 MTCLKD"),
+};
+
+static struct counter_synapse rz_mtu3_mtu1_count_synapses[] = {
+	{
+		.actions_list = rz_mtu3_synapse_actions,
+		.num_actions = ARRAY_SIZE(rz_mtu3_synapse_actions),
+		.signal = rz_mtu3_signals,
+	},
+	{
+		.actions_list = rz_mtu3_synapse_actions,
+		.num_actions = ARRAY_SIZE(rz_mtu3_synapse_actions),
+		.signal = rz_mtu3_signals + 1,
+	}
+};
+
+static struct counter_synapse rz_mtu3_mtu2_count_synapses[] = {
+	{
+		.actions_list = rz_mtu3_synapse_actions,
+		.num_actions = ARRAY_SIZE(rz_mtu3_synapse_actions),
+		.signal = rz_mtu3_signals,
+	},
+	{
+		.actions_list = rz_mtu3_synapse_actions,
+		.num_actions = ARRAY_SIZE(rz_mtu3_synapse_actions),
+		.signal = rz_mtu3_signals + 1,
+	},
+	{
+		.actions_list = rz_mtu3_synapse_actions,
+		.num_actions = ARRAY_SIZE(rz_mtu3_synapse_actions),
+		.signal = rz_mtu3_signals + 2,
+	},
+	{
+		.actions_list = rz_mtu3_synapse_actions,
+		.num_actions = ARRAY_SIZE(rz_mtu3_synapse_actions),
+		.signal = rz_mtu3_signals + 3,
+	}
+};
+
+static struct counter_count rz_mtu3_counts[] = {
+	{
+		.id = RZ_MTU3_16_BIT_MTU1_CH,
+		.name = "Channel 1 Count",
+		.functions_list = rz_mtu3_count_functions,
+		.num_functions = ARRAY_SIZE(rz_mtu3_count_functions),
+		.synapses = rz_mtu3_mtu1_count_synapses,
+		.num_synapses = ARRAY_SIZE(rz_mtu3_mtu1_count_synapses),
+		.ext = rz_mtu3_count_ext,
+		.num_ext = ARRAY_SIZE(rz_mtu3_count_ext),
+	},
+	{
+		.id = RZ_MTU3_16_BIT_MTU2_CH,
+		.name = "Channel 2 Count",
+		.functions_list = rz_mtu3_count_functions,
+		.num_functions = ARRAY_SIZE(rz_mtu3_count_functions),
+		.synapses = rz_mtu3_mtu2_count_synapses,
+		.num_synapses = ARRAY_SIZE(rz_mtu3_mtu2_count_synapses),
+		.ext = rz_mtu3_count_ext,
+		.num_ext = ARRAY_SIZE(rz_mtu3_count_ext),
+	},
+	{
+		.id = RZ_MTU3_32_BIT_CH,
+		.name = "Channel 1 and 2 (cascaded) Count",
+		.functions_list = rz_mtu3_count_functions,
+		.num_functions = ARRAY_SIZE(rz_mtu3_count_functions),
+		.synapses = rz_mtu3_mtu2_count_synapses,
+		.num_synapses = ARRAY_SIZE(rz_mtu3_mtu2_count_synapses),
+		.ext = rz_mtu3_count_ext,
+		.num_ext = ARRAY_SIZE(rz_mtu3_count_ext),
+	}
+};
+
+static const char *const rz_mtu3_ext_input_phase_clock_select[] = {
+	"MTCLKA-MTCLKB",
+	"MTCLKC-MTCLKD",
+};
+
+static DEFINE_COUNTER_ENUM(rz_mtu3_ext_input_phase_clock_select_enum,
+			   rz_mtu3_ext_input_phase_clock_select);
+
+static struct counter_comp rz_mtu3_device_ext[] = {
+	COUNTER_COMP_DEVICE_BOOL("cascade_counts_enable",
+				 rz_mtu3_cascade_counts_enable_get,
+				 rz_mtu3_cascade_counts_enable_set),
+	COUNTER_COMP_DEVICE_ENUM("external_input_phase_clock_select",
+				 rz_mtu3_ext_input_phase_clock_select_get,
+				 rz_mtu3_ext_input_phase_clock_select_set,
+				 rz_mtu3_ext_input_phase_clock_select_enum),
+};
+
+static int rz_mtu3_cnt_pm_runtime_suspend(struct device *dev)
+{
+	struct clk *const clk = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(clk);
+
+	return 0;
+}
+
+static int rz_mtu3_cnt_pm_runtime_resume(struct device *dev)
+{
+	struct clk *const clk = dev_get_drvdata(dev);
+
+	clk_prepare_enable(clk);
+
+	return 0;
+}
+
+static DEFINE_RUNTIME_DEV_PM_OPS(rz_mtu3_cnt_pm_ops,
+				 rz_mtu3_cnt_pm_runtime_suspend,
+				 rz_mtu3_cnt_pm_runtime_resume, NULL);
+
+static void rz_mtu3_cnt_pm_disable(void *data)
+{
+	struct device *dev = data;
+
+	pm_runtime_disable(dev);
+	pm_runtime_set_suspended(dev);
+}
+
+static int rz_mtu3_cnt_probe(struct platform_device *pdev)
+{
+	struct rz_mtu3 *ddata = dev_get_drvdata(pdev->dev.parent);
+	struct device *dev = &pdev->dev;
+	struct counter_device *counter;
+	struct rz_mtu3_channel *ch;
+	struct rz_mtu3_cnt *priv;
+	unsigned int i;
+	int ret;
+
+	counter = devm_counter_alloc(dev, sizeof(*priv));
+	if (!counter)
+		return -ENOMEM;
+
+	priv = counter_priv(counter);
+	priv->clk = ddata->clk;
+	priv->mtu_32bit_max = U32_MAX;
+	priv->ch = &ddata->channels[RZ_MTU1];
+	ch = &priv->ch[0];
+	for (i = 0; i < RZ_MTU3_MAX_HW_CNTR_CHANNELS; i++) {
+		ch->dev = dev;
+		priv->mtu_16bit_max[i] = U16_MAX;
+		ch++;
+	}
+
+	mutex_init(&priv->lock);
+	platform_set_drvdata(pdev, priv->clk);
+	clk_prepare_enable(priv->clk);
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+	ret = devm_add_action_or_reset(&pdev->dev, rz_mtu3_cnt_pm_disable, dev);
+	if (ret < 0)
+		goto disable_clock;
+
+	counter->name = dev_name(dev);
+	counter->parent = dev;
+	counter->ops = &rz_mtu3_cnt_ops;
+	counter->counts = rz_mtu3_counts;
+	counter->num_counts = ARRAY_SIZE(rz_mtu3_counts);
+	counter->signals = rz_mtu3_signals;
+	counter->num_signals = ARRAY_SIZE(rz_mtu3_signals);
+	counter->ext = rz_mtu3_device_ext;
+	counter->num_ext = ARRAY_SIZE(rz_mtu3_device_ext);
+
+	/* Register Counter device */
+	ret = devm_counter_add(dev, counter);
+	if (ret < 0) {
+		dev_err_probe(dev, ret, "Failed to add counter\n");
+		goto disable_clock;
+	}
+
+	return 0;
+
+disable_clock:
+	clk_disable_unprepare(priv->clk);
+
+	return ret;
+}
+
+static struct platform_driver rz_mtu3_cnt_driver = {
+	.probe = rz_mtu3_cnt_probe,
+	.driver = {
+		.name = "rz-mtu3-counter",
+		.pm = pm_ptr(&rz_mtu3_cnt_pm_ops),
+	},
+};
+module_platform_driver(rz_mtu3_cnt_driver);
+
+MODULE_AUTHOR("Biju Das <biju.das.jz@bp.renesas.com>");
+MODULE_ALIAS("platform:rz-mtu3-counter");
+MODULE_DESCRIPTION("Renesas RZ/G2L MTU3a counter driver");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(COUNTER);