Thread (80 messages) 80 messages, 11 authors, 2018-04-03
STALE3017d
Revisions (3)
  1. v1 [diff vs current]
  2. v1 current
  3. v1 [diff vs current]

[PATCH v2 5/6] clocksource: Add a new timer-ingenic driver

From: Paul Cercueil <paul@crapouillou.net>
Date: 2018-01-01 15:21:22
Also in: linux-devicetree, lkml
Subsystem: clocksource, clockevent drivers, open firmware and flattened device tree bindings, the rest · Maintainers: Daniel Lezcano, Thomas Gleixner, Rob Herring, Krzysztof Kozlowski, Conor Dooley, Linus Torvalds

This driver will use the TCU (Timer Counter Unit) present on the Ingenic
JZ47xx SoCs to provide the kernel with a clocksource and timers.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
---
 .../devicetree/bindings/timer/ingenic,tcu.txt      |  35 +++
 drivers/clocksource/Kconfig                        |   8 +
 drivers/clocksource/Makefile                       |   1 +
 drivers/clocksource/timer-ingenic.c                | 256 +++++++++++++++++++++
 4 files changed, 300 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/timer/ingenic,tcu.txt
 create mode 100644 drivers/clocksource/timer-ingenic.c

 v2: Use SPDX identifier for the license
diff --git a/Documentation/devicetree/bindings/timer/ingenic,tcu.txt b/Documentation/devicetree/bindings/timer/ingenic,tcu.txt
new file mode 100644
index 000000000000..e4944972ea53
--- /dev/null
+++ b/Documentation/devicetree/bindings/timer/ingenic,tcu.txt
@@ -0,0 +1,35 @@
+Ingenic JZ47xx SoCs Timer/Counter Unit driver
+---------------------------------------------
+
+Required properties:
+
+- compatible : should be "ingenic,<socname>-tcu". Valid strings are:
+  * ingenic,jz4740-tcu
+  * ingenic,jz4770-tcu
+  * ingenic,jz4780-tcu
+- interrupt-parent : phandle of the TCU interrupt controller.
+- interrupts : Specifies the interrupts the controller is connected to.
+- clocks : List of phandle & clock specifiers for the TCU clocks.
+- clock-names : List of name strings for the TCU clocks.
+- ingenic,channels: a list of TCU channels to be used as timers.
+
+Example:
+
+/ {
+	regmap {
+		compatible = "simple-mfd", "syscon";
+		reg = <0x10002000 0x1000>;
+
+		tcu: timer {
+			compatible = "ingenic,jz4740-tcu";
+
+			clocks = <&tcu 0>, <&tcu 1>;
+			clock-names = "timer0", "timer1";
+
+			interrupt-parent = <&tcu>;
+			interrupts = <0>, <1>;
+
+			ingenic,channels = <0>, <1>;
+		};
+	};
+};
diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig
index c729a88007d0..7b6dedf0347d 100644
--- a/drivers/clocksource/Kconfig
+++ b/drivers/clocksource/Kconfig
@@ -583,4 +583,12 @@ config CLKSRC_ST_LPC
 	  Enable this option to use the Low Power controller timer
 	  as clocksource.
 
+config INGENIC_TIMER
+	bool "Clocksource/timer using the TCU in Ingenic JZ SoCs"
+	depends on MACH_INGENIC || COMPILE_TEST
+	select CLKSRC_OF
+	default y
+	help
+	  Support for the timer/counter unit of the Ingenic JZ SoCs.
+
 endmenu
diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index 72711f1491e3..607c7de07d02 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -73,5 +73,6 @@ obj-$(CONFIG_ASM9260_TIMER)		+= asm9260_timer.o
 obj-$(CONFIG_H8300_TMR8)		+= h8300_timer8.o
 obj-$(CONFIG_H8300_TMR16)		+= h8300_timer16.o
 obj-$(CONFIG_H8300_TPU)			+= h8300_tpu.o
+obj-$(CONFIG_INGENIC_TIMER)		+= timer-ingenic.o
 obj-$(CONFIG_CLKSRC_ST_LPC)		+= clksrc_st_lpc.o
 obj-$(CONFIG_X86_NUMACHIP)		+= numachip.o
diff --git a/drivers/clocksource/timer-ingenic.c b/drivers/clocksource/timer-ingenic.c
new file mode 100644
index 000000000000..d9e1c0b23f81
--- /dev/null
+++ b/drivers/clocksource/timer-ingenic.c
@@ -0,0 +1,256 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Ingenic JZ47xx SoC TCU clocksource driver
+ * Copyright (C) 2018 Paul Cercueil <paul@crapouillou.net>
+ */
+
+#include <linux/clk.h>
+#include <linux/clockchips.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/mfd/syscon.h>
+#include <linux/mfd/syscon/ingenic-tcu.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#define NUM_CHANNELS	8
+
+struct ingenic_tcu;
+
+struct ingenic_tcu_channel {
+	unsigned int idx;
+	struct clk *clk;
+};
+
+struct ingenic_tcu {
+	struct ingenic_tcu_channel channels[NUM_CHANNELS];
+	unsigned long requested;
+	struct regmap *map;
+};
+
+struct ingenic_clock_event_device {
+	struct clock_event_device cevt;
+	struct ingenic_tcu_channel *channel;
+	char name[32];
+};
+
+#define ingenic_cevt(_evt) \
+	container_of(_evt, struct ingenic_clock_event_device, cevt)
+
+static inline struct ingenic_tcu *to_ingenic_tcu(struct ingenic_tcu_channel *ch)
+{
+	return container_of(ch, struct ingenic_tcu, channels[ch->idx]);
+}
+
+static int ingenic_tcu_cevt_set_state_shutdown(struct clock_event_device *evt)
+{
+	struct ingenic_clock_event_device *jzcevt = ingenic_cevt(evt);
+	struct ingenic_tcu_channel *channel = jzcevt->channel;
+	struct ingenic_tcu *tcu = to_ingenic_tcu(channel);
+	unsigned int idx = channel->idx;
+
+	regmap_write(tcu->map, REG_TECR, BIT(idx));
+	return 0;
+}
+
+static int ingenic_tcu_cevt_set_next(unsigned long next,
+		struct clock_event_device *evt)
+{
+	struct ingenic_clock_event_device *jzcevt = ingenic_cevt(evt);
+	struct ingenic_tcu_channel *channel = jzcevt->channel;
+	struct ingenic_tcu *tcu = to_ingenic_tcu(channel);
+	unsigned int idx = channel->idx;
+
+	if (next > 0xffff)
+		return -EINVAL;
+
+	regmap_write(tcu->map, REG_TDFRc(idx), (unsigned int) next);
+	regmap_write(tcu->map, REG_TCNTc(idx), 0);
+	regmap_write(tcu->map, REG_TESR, BIT(idx));
+
+	return 0;
+}
+
+static irqreturn_t ingenic_tcu_cevt_cb(int irq, void *dev_id)
+{
+	struct clock_event_device *cevt = dev_id;
+	struct ingenic_clock_event_device *jzcevt = ingenic_cevt(cevt);
+	struct ingenic_tcu_channel *channel = jzcevt->channel;
+	struct ingenic_tcu *tcu = to_ingenic_tcu(channel);
+	unsigned int idx = channel->idx;
+
+	regmap_write(tcu->map, REG_TECR, BIT(idx));
+
+	if (cevt->event_handler)
+		cevt->event_handler(cevt);
+
+	return IRQ_HANDLED;
+}
+
+static int __init ingenic_tcu_req_channel(struct ingenic_tcu_channel *channel)
+{
+	struct ingenic_tcu *tcu = to_ingenic_tcu(channel);
+	char buf[16];
+	int err;
+
+	if (test_and_set_bit(channel->idx, &tcu->requested))
+		return -EBUSY;
+
+	snprintf(buf, sizeof(buf), "timer%u", channel->idx);
+	channel->clk = clk_get(NULL, buf);
+	if (IS_ERR(channel->clk)) {
+		err = PTR_ERR(channel->clk);
+		goto out_release;
+	}
+
+	err = clk_prepare_enable(channel->clk);
+	if (err)
+		goto out_clk_put;
+
+	return 0;
+
+out_clk_put:
+	clk_put(channel->clk);
+out_release:
+	clear_bit(channel->idx, &tcu->requested);
+	return err;
+}
+
+static int __init ingenic_tcu_reset_channel(struct device_node *np,
+		struct ingenic_tcu_channel *channel)
+{
+	struct ingenic_tcu *tcu = to_ingenic_tcu(channel);
+
+	return regmap_update_bits(tcu->map, REG_TCSRc(channel->idx),
+				0xffff & ~TCSR_RESERVED_BITS, 0);
+}
+
+static void __init ingenic_tcu_free_channel(struct ingenic_tcu_channel *channel)
+{
+	struct ingenic_tcu *tcu = to_ingenic_tcu(channel);
+
+	clk_disable_unprepare(channel->clk);
+	clk_put(channel->clk);
+	clear_bit(channel->idx, &tcu->requested);
+}
+
+static const char * const ingenic_tcu_timer_names[] = {
+	"TCU0", "TCU1", "TCU2", "TCU3", "TCU4", "TCU5", "TCU6", "TCU7",
+};
+
+static int __init ingenic_tcu_setup_cevt(struct device_node *np,
+		struct ingenic_tcu *tcu, unsigned int idx)
+{
+	struct ingenic_tcu_channel *channel = &tcu->channels[idx];
+	struct ingenic_clock_event_device *jzcevt;
+	unsigned long rate;
+	int err, virq;
+
+	err = ingenic_tcu_req_channel(channel);
+	if (err)
+		return err;
+
+	err = ingenic_tcu_reset_channel(np, channel);
+	if (err)
+		goto err_out_free_channel;
+
+	rate = clk_get_rate(channel->clk);
+	if (!rate) {
+		err = -EINVAL;
+		goto err_out_free_channel;
+	}
+
+	jzcevt = kzalloc(sizeof(*jzcevt), GFP_KERNEL);
+	if (!jzcevt) {
+		err = -ENOMEM;
+		goto err_out_free_channel;
+	}
+
+	virq = irq_of_parse_and_map(np, idx);
+	if (!virq) {
+		err = -EINVAL;
+		goto err_out_kfree_jzcevt;
+	}
+
+	err = request_irq(virq, ingenic_tcu_cevt_cb, IRQF_TIMER,
+			ingenic_tcu_timer_names[idx], &jzcevt->cevt);
+	if (err)
+		goto err_out_irq_dispose_mapping;
+
+	jzcevt->channel = channel;
+	snprintf(jzcevt->name, sizeof(jzcevt->name), "ingenic-tcu-chan%u",
+		 channel->idx);
+
+	jzcevt->cevt.cpumask = cpumask_of(smp_processor_id());
+	jzcevt->cevt.features = CLOCK_EVT_FEAT_ONESHOT;
+	jzcevt->cevt.name = jzcevt->name;
+	jzcevt->cevt.rating = 200;
+	jzcevt->cevt.set_state_shutdown = ingenic_tcu_cevt_set_state_shutdown;
+	jzcevt->cevt.set_next_event = ingenic_tcu_cevt_set_next;
+
+	clockevents_config_and_register(&jzcevt->cevt, rate, 10, (1 << 16) - 1);
+
+	return 0;
+
+err_out_irq_dispose_mapping:
+	irq_dispose_mapping(virq);
+err_out_kfree_jzcevt:
+	kfree(jzcevt);
+err_out_free_channel:
+	ingenic_tcu_free_channel(channel);
+	return err;
+}
+
+static int __init ingenic_tcu_init(struct device_node *np)
+{
+	struct ingenic_tcu *tcu;
+	unsigned int i;
+	int err, num_timers;
+
+	num_timers = of_property_count_elems_of_size(np, "ingenic,channels", 4);
+	if (num_timers < 0) {
+		pr_err("timer-ingenic: Unable to read DTS node");
+		return num_timers;
+	}
+
+	tcu = kzalloc(sizeof(*tcu), GFP_KERNEL);
+	if (!tcu)
+		return -ENOMEM;
+
+	tcu->map = syscon_node_to_regmap(np->parent);
+	if (IS_ERR(tcu->map)) {
+		err = PTR_ERR(tcu->map);
+		kfree(tcu);
+		return err;
+	}
+
+	for (i = 0; i < NUM_CHANNELS; i++)
+		tcu->channels[i].idx = i;
+
+	for (i = 0; i < (unsigned int) num_timers; i++) {
+		u32 channel;
+
+		of_property_read_u32_index(np, "ingenic,channels", i, &channel);
+
+		if (channel > NUM_CHANNELS) {
+			pr_warn("timer-ingenic: requested TCU channel %u does not exist\n",
+					channel);
+			continue;
+		}
+
+		err = ingenic_tcu_setup_cevt(np, tcu, channel);
+		if (err) {
+			pr_warn("timer-ingenic: Unable to init TCU channel %u: %i",
+					channel, err);
+			continue;
+		}
+	}
+
+	return 0;
+}
+
+CLOCKSOURCE_OF_DECLARE(jz4740_tcu, "ingenic,jz4740-tcu", ingenic_tcu_init);
+CLOCKSOURCE_OF_DECLARE(jz4770_tcu, "ingenic,jz4770-tcu", ingenic_tcu_init);
+CLOCKSOURCE_OF_DECLARE(jz4780_tcu, "ingenic,jz4780-tcu", ingenic_tcu_init);
-- 
2.11.0
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