mfd: Add Renesas RZ/G2L MTU3a core driver

The RZ/G2L multi-function timer pulse unit 3 (MTU3a) is embedded in
the Renesas RZ/G2L family SoCs. It consists of eight 16-bit timer
channels and one 32-bit timer channel. It supports the following
functions
 - Counter
 - Timer
 - PWM

The 8/16/32 bit registers are mixed in each channel.

Add MTU3a core driver for RZ/G2L SoC. The core driver shares the
clk and channel register access for the other child devices like
Counter, PWM and Clock event.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20230330111632.169434-3-biju.das.jz@bp.renesas.com

1 files changed, 391 insertions, 0 deletions

diff --git a/drivers/mfd/rz-mtu3.c b/drivers/mfd/rz-mtu3.c
new file mode 100644
index 000000000000..04006f4aa702
--- /dev/null
+++ b/drivers/mfd/rz-mtu3.c
@@ -0,0 +1,391 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Renesas RZ/G2L Multi-Function Timer Pulse Unit 3(MTU3a) Core driver
+ *
+ * Copyright (C) 2023 Renesas Electronics Corporation
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/rz-mtu3.h>
+#include <linux/of_platform.h>
+#include <linux/reset.h>
+#include <linux/spinlock.h>
+
+#include "rz-mtu3.h"
+
+struct rz_mtu3_priv {
+	void __iomem *mmio;
+	struct reset_control *rstc;
+	raw_spinlock_t lock;
+};
+
+/******* MTU3 registers (original offset is +0x1200) *******/
+static const unsigned long rz_mtu3_8bit_ch_reg_offs[][13] = {
+	[RZ_MTU3_CHAN_0] = MTU_8BIT_CH_0(0x104, 0x090, 0x100, 0x128, 0x101, 0x102, 0x103, 0x126),
+	[RZ_MTU3_CHAN_1] = MTU_8BIT_CH_1_2(0x184, 0x091, 0x185, 0x180, 0x194, 0x181, 0x182),
+	[RZ_MTU3_CHAN_2] = MTU_8BIT_CH_1_2(0x204, 0x092, 0x205, 0x200, 0x20c, 0x201, 0x202),
+	[RZ_MTU3_CHAN_3] = MTU_8BIT_CH_3_4_6_7(0x008, 0x093, 0x02c, 0x000, 0x04c, 0x002, 0x004, 0x005, 0x038),
+	[RZ_MTU3_CHAN_4] = MTU_8BIT_CH_3_4_6_7(0x009, 0x094, 0x02d, 0x001, 0x04d, 0x003, 0x006, 0x007, 0x039),
+	[RZ_MTU3_CHAN_5] = MTU_8BIT_CH_5(0xab2, 0x1eb, 0xab4, 0xab6, 0xa84, 0xa85, 0xa86, 0xa94, 0xa95, 0xa96, 0xaa4, 0xaa5, 0xaa6),
+	[RZ_MTU3_CHAN_6] = MTU_8BIT_CH_3_4_6_7(0x808, 0x893, 0x82c, 0x800, 0x84c, 0x802, 0x804, 0x805, 0x838),
+	[RZ_MTU3_CHAN_7] = MTU_8BIT_CH_3_4_6_7(0x809, 0x894, 0x82d, 0x801, 0x84d, 0x803, 0x806, 0x807, 0x839),
+	[RZ_MTU3_CHAN_8] = MTU_8BIT_CH_8(0x404, 0x098, 0x400, 0x406, 0x401, 0x402, 0x403)
+};
+
+static const unsigned long rz_mtu3_16bit_ch_reg_offs[][12] = {
+	[RZ_MTU3_CHAN_0] = MTU_16BIT_CH_0(0x106, 0x108, 0x10a, 0x10c, 0x10e, 0x120, 0x122),
+	[RZ_MTU3_CHAN_1] = MTU_16BIT_CH_1_2(0x186, 0x188, 0x18a),
+	[RZ_MTU3_CHAN_2] = MTU_16BIT_CH_1_2(0x206, 0x208, 0x20a),
+	[RZ_MTU3_CHAN_3] = MTU_16BIT_CH_3_6(0x010, 0x018, 0x01a, 0x024, 0x026, 0x072),
+	[RZ_MTU3_CHAN_4] = MTU_16BIT_CH_4_7(0x012, 0x01c, 0x01e, 0x028, 0x2a, 0x074, 0x076, 0x040, 0x044, 0x046, 0x048, 0x04a),
+	[RZ_MTU3_CHAN_5] = MTU_16BIT_CH_5(0xa80, 0xa82, 0xa90, 0xa92, 0xaa0, 0xaa2),
+	[RZ_MTU3_CHAN_6] = MTU_16BIT_CH_3_6(0x810, 0x818, 0x81a, 0x824, 0x826, 0x872),
+	[RZ_MTU3_CHAN_7] = MTU_16BIT_CH_4_7(0x812, 0x81c, 0x81e, 0x828, 0x82a, 0x874, 0x876, 0x840, 0x844, 0x846, 0x848, 0x84a)
+};
+
+static const unsigned long rz_mtu3_32bit_ch_reg_offs[][5] = {
+	[RZ_MTU3_CHAN_1] = MTU_32BIT_CH_1(0x1a0, 0x1a4, 0x1a8),
+	[RZ_MTU3_CHAN_8] = MTU_32BIT_CH_8(0x408, 0x40c, 0x410, 0x414, 0x418)
+};
+
+static bool rz_mtu3_is_16bit_shared_reg(u16 offset)
+{
+	return (offset == RZ_MTU3_TDDRA || offset == RZ_MTU3_TDDRB ||
+		offset == RZ_MTU3_TCDRA || offset == RZ_MTU3_TCDRB ||
+		offset == RZ_MTU3_TCBRA || offset == RZ_MTU3_TCBRB ||
+		offset == RZ_MTU3_TCNTSA || offset == RZ_MTU3_TCNTSB);
+}
+
+u16 rz_mtu3_shared_reg_read(struct rz_mtu3_channel *ch, u16 offset)
+{
+	struct rz_mtu3 *mtu = dev_get_drvdata(ch->dev->parent);
+	struct rz_mtu3_priv *priv = mtu->priv_data;
+
+	if (rz_mtu3_is_16bit_shared_reg(offset))
+		return readw(priv->mmio + offset);
+	else
+		return readb(priv->mmio + offset);
+}
+EXPORT_SYMBOL_GPL(rz_mtu3_shared_reg_read);
+
+u8 rz_mtu3_8bit_ch_read(struct rz_mtu3_channel *ch, u16 offset)
+{
+	struct rz_mtu3 *mtu = dev_get_drvdata(ch->dev->parent);
+	struct rz_mtu3_priv *priv = mtu->priv_data;
+	u16 ch_offs;
+
+	ch_offs = rz_mtu3_8bit_ch_reg_offs[ch->channel_number][offset];
+
+	return readb(priv->mmio + ch_offs);
+}
+EXPORT_SYMBOL_GPL(rz_mtu3_8bit_ch_read);
+
+u16 rz_mtu3_16bit_ch_read(struct rz_mtu3_channel *ch, u16 offset)
+{
+	struct rz_mtu3 *mtu = dev_get_drvdata(ch->dev->parent);
+	struct rz_mtu3_priv *priv = mtu->priv_data;
+	u16 ch_offs;
+
+	/* MTU8 doesn't have 16-bit registers */
+	if (ch->channel_number == RZ_MTU3_CHAN_8)
+		return 0;
+
+	ch_offs = rz_mtu3_16bit_ch_reg_offs[ch->channel_number][offset];
+
+	return readw(priv->mmio + ch_offs);
+}
+EXPORT_SYMBOL_GPL(rz_mtu3_16bit_ch_read);
+
+u32 rz_mtu3_32bit_ch_read(struct rz_mtu3_channel *ch, u16 offset)
+{
+	struct rz_mtu3 *mtu = dev_get_drvdata(ch->dev->parent);
+	struct rz_mtu3_priv *priv = mtu->priv_data;
+	u16 ch_offs;
+
+	if (ch->channel_number != RZ_MTU3_CHAN_1 && ch->channel_number != RZ_MTU3_CHAN_8)
+		return 0;
+
+	ch_offs = rz_mtu3_32bit_ch_reg_offs[ch->channel_number][offset];
+
+	return readl(priv->mmio + ch_offs);
+}
+EXPORT_SYMBOL_GPL(rz_mtu3_32bit_ch_read);
+
+void rz_mtu3_8bit_ch_write(struct rz_mtu3_channel *ch, u16 offset, u8 val)
+{
+	struct rz_mtu3 *mtu = dev_get_drvdata(ch->dev->parent);
+	struct rz_mtu3_priv *priv = mtu->priv_data;
+	u16 ch_offs;
+
+	ch_offs = rz_mtu3_8bit_ch_reg_offs[ch->channel_number][offset];
+	writeb(val, priv->mmio + ch_offs);
+}
+EXPORT_SYMBOL_GPL(rz_mtu3_8bit_ch_write);
+
+void rz_mtu3_16bit_ch_write(struct rz_mtu3_channel *ch, u16 offset, u16 val)
+{
+	struct rz_mtu3 *mtu = dev_get_drvdata(ch->dev->parent);
+	struct rz_mtu3_priv *priv = mtu->priv_data;
+	u16 ch_offs;
+
+	/* MTU8 doesn't have 16-bit registers */
+	if (ch->channel_number == RZ_MTU3_CHAN_8)
+		return;
+
+	ch_offs = rz_mtu3_16bit_ch_reg_offs[ch->channel_number][offset];
+	writew(val, priv->mmio + ch_offs);
+}
+EXPORT_SYMBOL_GPL(rz_mtu3_16bit_ch_write);
+
+void rz_mtu3_32bit_ch_write(struct rz_mtu3_channel *ch, u16 offset, u32 val)
+{
+	struct rz_mtu3 *mtu = dev_get_drvdata(ch->dev->parent);
+	struct rz_mtu3_priv *priv = mtu->priv_data;
+	u16 ch_offs;
+
+	if (ch->channel_number != RZ_MTU3_CHAN_1 && ch->channel_number != RZ_MTU3_CHAN_8)
+		return;
+
+	ch_offs = rz_mtu3_32bit_ch_reg_offs[ch->channel_number][offset];
+	writel(val, priv->mmio + ch_offs);
+}
+EXPORT_SYMBOL_GPL(rz_mtu3_32bit_ch_write);
+
+void rz_mtu3_shared_reg_write(struct rz_mtu3_channel *ch, u16 offset, u16 value)
+{
+	struct rz_mtu3 *mtu = dev_get_drvdata(ch->dev->parent);
+	struct rz_mtu3_priv *priv = mtu->priv_data;
+
+	if (rz_mtu3_is_16bit_shared_reg(offset))
+		writew(value, priv->mmio + offset);
+	else
+		writeb((u8)value, priv->mmio + offset);
+}
+EXPORT_SYMBOL_GPL(rz_mtu3_shared_reg_write);
+
+void rz_mtu3_shared_reg_update_bit(struct rz_mtu3_channel *ch, u16 offset,
+				   u16 pos, u8 val)
+{
+	struct rz_mtu3 *mtu = dev_get_drvdata(ch->dev->parent);
+	struct rz_mtu3_priv *priv = mtu->priv_data;
+	unsigned long tmdr, flags;
+
+	raw_spin_lock_irqsave(&priv->lock, flags);
+	tmdr = rz_mtu3_shared_reg_read(ch, offset);
+	__assign_bit(pos, &tmdr, !!val);
+	rz_mtu3_shared_reg_write(ch, offset, tmdr);
+	raw_spin_unlock_irqrestore(&priv->lock, flags);
+}
+EXPORT_SYMBOL_GPL(rz_mtu3_shared_reg_update_bit);
+
+static u16 rz_mtu3_get_tstr_offset(struct rz_mtu3_channel *ch)
+{
+	u16 offset;
+
+	switch (ch->channel_number) {
+	case RZ_MTU3_CHAN_0:
+	case RZ_MTU3_CHAN_1:
+	case RZ_MTU3_CHAN_2:
+	case RZ_MTU3_CHAN_3:
+	case RZ_MTU3_CHAN_4:
+	case RZ_MTU3_CHAN_8:
+		offset = RZ_MTU3_TSTRA;
+		break;
+	case RZ_MTU3_CHAN_5:
+		offset = RZ_MTU3_TSTR;
+		break;
+	case RZ_MTU3_CHAN_6:
+	case RZ_MTU3_CHAN_7:
+		offset = RZ_MTU3_TSTRB;
+		break;
+	default:
+		offset = 0;
+		break;
+	}
+
+	return offset;
+}
+
+static u8 rz_mtu3_get_tstr_bit_pos(struct rz_mtu3_channel *ch)
+{
+	u8 bitpos;
+
+	switch (ch->channel_number) {
+	case RZ_MTU3_CHAN_0:
+	case RZ_MTU3_CHAN_1:
+	case RZ_MTU3_CHAN_2:
+	case RZ_MTU3_CHAN_6:
+	case RZ_MTU3_CHAN_7:
+		bitpos = ch->channel_number;
+		break;
+	case RZ_MTU3_CHAN_3:
+		bitpos = 6;
+		break;
+	case RZ_MTU3_CHAN_4:
+		bitpos = 7;
+		break;
+	case RZ_MTU3_CHAN_5:
+		bitpos = 2;
+		break;
+	case RZ_MTU3_CHAN_8:
+		bitpos = 3;
+		break;
+	default:
+		bitpos = 0;
+		break;
+	}
+
+	return bitpos;
+}
+
+static void rz_mtu3_start_stop_ch(struct rz_mtu3_channel *ch, bool start)
+{
+	struct rz_mtu3 *mtu = dev_get_drvdata(ch->dev->parent);
+	struct rz_mtu3_priv *priv = mtu->priv_data;
+	unsigned long flags, tstr;
+	u16 offset;
+	u8 bitpos;
+
+	/* start stop register shared by multiple timer channels */
+	raw_spin_lock_irqsave(&priv->lock, flags);
+
+	offset = rz_mtu3_get_tstr_offset(ch);
+	bitpos = rz_mtu3_get_tstr_bit_pos(ch);
+	tstr = rz_mtu3_shared_reg_read(ch, offset);
+	__assign_bit(bitpos, &tstr, start);
+	rz_mtu3_shared_reg_write(ch, offset, tstr);
+
+	raw_spin_unlock_irqrestore(&priv->lock, flags);
+}
+
+bool rz_mtu3_is_enabled(struct rz_mtu3_channel *ch)
+{
+	struct rz_mtu3 *mtu = dev_get_drvdata(ch->dev->parent);
+	struct rz_mtu3_priv *priv = mtu->priv_data;
+	unsigned long flags, tstr;
+	bool ret = false;
+	u16 offset;
+	u8 bitpos;
+
+	/* start stop register shared by multiple timer channels */
+	raw_spin_lock_irqsave(&priv->lock, flags);
+
+	offset = rz_mtu3_get_tstr_offset(ch);
+	bitpos = rz_mtu3_get_tstr_bit_pos(ch);
+	tstr = rz_mtu3_shared_reg_read(ch, offset);
+	ret = tstr & BIT(bitpos);
+
+	raw_spin_unlock_irqrestore(&priv->lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(rz_mtu3_is_enabled);
+
+int rz_mtu3_enable(struct rz_mtu3_channel *ch)
+{
+	/* enable channel */
+	rz_mtu3_start_stop_ch(ch, true);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(rz_mtu3_enable);
+
+void rz_mtu3_disable(struct rz_mtu3_channel *ch)
+{
+	/* disable channel */
+	rz_mtu3_start_stop_ch(ch, false);
+}
+EXPORT_SYMBOL_GPL(rz_mtu3_disable);
+
+static void rz_mtu3_reset_assert(void *data)
+{
+	struct rz_mtu3 *mtu = dev_get_drvdata(data);
+	struct rz_mtu3_priv *priv = mtu->priv_data;
+
+	mfd_remove_devices(data);
+	reset_control_assert(priv->rstc);
+}
+
+static const struct mfd_cell rz_mtu3_devs[] = {
+	{
+		.name = "rz-mtu3-counter",
+	},
+	{
+		.name = "pwm-rz-mtu3",
+	},
+};
+
+static int rz_mtu3_probe(struct platform_device *pdev)
+{
+	struct rz_mtu3_priv *priv;
+	struct rz_mtu3 *ddata;
+	unsigned int i;
+	int ret;
+
+	ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL);
+	if (!ddata)
+		return -ENOMEM;
+
+	ddata->priv_data = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!ddata->priv_data)
+		return -ENOMEM;
+
+	priv = ddata->priv_data;
+
+	priv->mmio = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->mmio))
+		return PTR_ERR(priv->mmio);
+
+	priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
+	if (IS_ERR(priv->rstc))
+		return PTR_ERR(priv->rstc);
+
+	ddata->clk = devm_clk_get(&pdev->dev, NULL);
+	if (IS_ERR(ddata->clk))
+		return PTR_ERR(ddata->clk);
+
+	reset_control_deassert(priv->rstc);
+	raw_spin_lock_init(&priv->lock);
+	platform_set_drvdata(pdev, ddata);
+
+	for (i = 0; i < RZ_MTU_NUM_CHANNELS; i++) {
+		ddata->channels[i].channel_number = i;
+		ddata->channels[i].is_busy = false;
+		mutex_init(&ddata->channels[i].lock);
+	}
+
+	ret = mfd_add_devices(&pdev->dev, 0, rz_mtu3_devs,
+			      ARRAY_SIZE(rz_mtu3_devs), NULL, 0, NULL);
+	if (ret < 0)
+		goto err_assert;
+
+	return devm_add_action_or_reset(&pdev->dev, rz_mtu3_reset_assert,
+					&pdev->dev);
+
+err_assert:
+	reset_control_assert(priv->rstc);
+	return ret;
+}
+
+static const struct of_device_id rz_mtu3_of_match[] = {
+	{ .compatible = "renesas,rz-mtu3", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, rz_mtu3_of_match);
+
+static struct platform_driver rz_mtu3_driver = {
+	.probe = rz_mtu3_probe,
+	.driver	= {
+		.name = "rz-mtu3",
+		.of_match_table = rz_mtu3_of_match,
+	},
+};
+module_platform_driver(rz_mtu3_driver);
+
+MODULE_AUTHOR("Biju Das <biju.das.jz@bp.renesas.com>");
+MODULE_DESCRIPTION("Renesas RZ/G2L MTU3a Core Driver");
+MODULE_LICENSE("GPL");