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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-19 10:09:22 -0700
commitf4cdf7ca9a1fdcca413157df19753f388a5a224e (patch)
tree60a31895b2446cd7fa27514e8c2843534a0de0da /drivers/clocksource/timer-ep93xx.c
downloadlinux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.tar.gz
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Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediagrafted
Pull media updates from Mauro Carvalho Chehab: - v4l2-core: added ISP statistics support and per-block validation - v4l2-core: Allow unknown HDR10 white point and luminance - New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor - New codec: Milos: VPU v2.0 codec support - isp driver: gained support for Dreamchip RPPX1 ISP framework - vsp1 driver: gained support for RZ/T2H and RZ/N2H - Novalake driver: gained CVS support for new NVL hardware - dvb-core: fix feed leak on failed DMX_ADD_PID - several driver fixes, cleanups and minor improvements * tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits) media: ipu-bridge: check all DMI entries when overriding sensor rotation media: v4l2-async: avoid deleting unlinked ASC entry on link error media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement media: intel/ipu6: fix async notifier cleanup leak on parse error media: staging/ipu7: fix async notifier UAF on probe error path media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem() media: rcar-isp: Fix VSPX reference leaks media: rcar-isp: Release ISPCORE resources media: i2c: imx415: Release runtime PM reference on VBLANK error media: i2c: imx415: Return test pattern write errors media: renesas: vsp1: Declare index variables in for loop statement media: renesas: vsp1: Make reset control optional to support platforms without a reset line media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs media: nxp: imx8-isi: Add additional 32-bit RGB format support media: nxp: imx8-isi: Add 16-bit raw Bayer format support media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks media: nxp: imx8-isi: Correct color map between V4L2 and ISI ...
Diffstat (limited to 'drivers/clocksource/timer-ep93xx.c')
-rw-r--r--drivers/clocksource/timer-ep93xx.c189
1 files changed, 189 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-ep93xx.c b/drivers/clocksource/timer-ep93xx.c
new file mode 100644
index 000000000..1b719282c
--- /dev/null
+++ b/drivers/clocksource/timer-ep93xx.c
@@ -0,0 +1,189 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Cirrus Logic EP93xx timer driver.
+ * Copyright (C) 2021 Nikita Shubin <nikita.shubin@maquefel.me>
+ *
+ * Based on a rewrite of arch/arm/mach-ep93xx/timer.c:
+ */
+
+#include <linux/clockchips.h>
+#include <linux/clocksource.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/io-64-nonatomic-lo-hi.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/sched_clock.h>
+
+#include <asm/mach/time.h>
+
+/*************************************************************************
+ * Timer handling for EP93xx
+ *************************************************************************
+ * The ep93xx has four internal timers. Timers 1, 2 (both 16 bit) and
+ * 3 (32 bit) count down at 508 kHz, are self-reloading, and can generate
+ * an interrupt on underflow. Timer 4 (40 bit) counts down at 983.04 kHz,
+ * is free-running, and can't generate interrupts.
+ *
+ * The 508 kHz timers are ideal for use for the timer interrupt, as the
+ * most common values of HZ divide 508 kHz nicely. We pick the 32 bit
+ * timer (timer 3) to get as long sleep intervals as possible when using
+ * CONFIG_NO_HZ.
+ *
+ * The higher clock rate of timer 4 makes it a better choice than the
+ * other timers for use as clock source and for sched_clock(), providing
+ * a stable 40 bit time base.
+ *************************************************************************
+ */
+
+#define EP93XX_TIMER1_LOAD 0x00
+#define EP93XX_TIMER1_VALUE 0x04
+#define EP93XX_TIMER1_CONTROL 0x08
+#define EP93XX_TIMER123_CONTROL_ENABLE BIT(7)
+#define EP93XX_TIMER123_CONTROL_MODE BIT(6)
+#define EP93XX_TIMER123_CONTROL_CLKSEL BIT(3)
+#define EP93XX_TIMER1_CLEAR 0x0c
+#define EP93XX_TIMER2_LOAD 0x20
+#define EP93XX_TIMER2_VALUE 0x24
+#define EP93XX_TIMER2_CONTROL 0x28
+#define EP93XX_TIMER2_CLEAR 0x2c
+/*
+ * This read-only register contains the low word of the time stamp debug timer
+ * ( Timer4). When this register is read, the high byte of the Timer4 counter is
+ * saved in the Timer4ValueHigh register.
+ */
+#define EP93XX_TIMER4_VALUE_LOW 0x60
+#define EP93XX_TIMER4_VALUE_HIGH 0x64
+#define EP93XX_TIMER4_VALUE_HIGH_ENABLE BIT(8)
+#define EP93XX_TIMER3_LOAD 0x80
+#define EP93XX_TIMER3_VALUE 0x84
+#define EP93XX_TIMER3_CONTROL 0x88
+#define EP93XX_TIMER3_CLEAR 0x8c
+
+#define EP93XX_TIMER123_RATE 508469
+#define EP93XX_TIMER4_RATE 983040
+
+struct ep93xx_tcu {
+ void __iomem *base;
+};
+
+static struct ep93xx_tcu *ep93xx_tcu;
+
+static u64 ep93xx_clocksource_read(struct clocksource *c)
+{
+ struct ep93xx_tcu *tcu = ep93xx_tcu;
+
+ return lo_hi_readq(tcu->base + EP93XX_TIMER4_VALUE_LOW) & GENMASK_ULL(39, 0);
+}
+
+static u64 notrace ep93xx_read_sched_clock(void)
+{
+ return ep93xx_clocksource_read(NULL);
+}
+
+static int ep93xx_clkevt_set_next_event(unsigned long next,
+ struct clock_event_device *evt)
+{
+ struct ep93xx_tcu *tcu = ep93xx_tcu;
+ /* Default mode: periodic, off, 508 kHz */
+ u32 tmode = EP93XX_TIMER123_CONTROL_MODE |
+ EP93XX_TIMER123_CONTROL_CLKSEL;
+
+ /* Clear timer */
+ writel(tmode, tcu->base + EP93XX_TIMER3_CONTROL);
+
+ /* Set next event */
+ writel(next, tcu->base + EP93XX_TIMER3_LOAD);
+ writel(tmode | EP93XX_TIMER123_CONTROL_ENABLE,
+ tcu->base + EP93XX_TIMER3_CONTROL);
+ return 0;
+}
+
+static int ep93xx_clkevt_shutdown(struct clock_event_device *evt)
+{
+ struct ep93xx_tcu *tcu = ep93xx_tcu;
+ /* Disable timer */
+ writel(0, tcu->base + EP93XX_TIMER3_CONTROL);
+
+ return 0;
+}
+
+static struct clock_event_device ep93xx_clockevent = {
+ .name = "timer1",
+ .features = CLOCK_EVT_FEAT_ONESHOT,
+ .set_state_shutdown = ep93xx_clkevt_shutdown,
+ .set_state_oneshot = ep93xx_clkevt_shutdown,
+ .tick_resume = ep93xx_clkevt_shutdown,
+ .set_next_event = ep93xx_clkevt_set_next_event,
+ .rating = 300,
+};
+
+static irqreturn_t ep93xx_timer_interrupt(int irq, void *dev_id)
+{
+ struct ep93xx_tcu *tcu = ep93xx_tcu;
+ struct clock_event_device *evt = dev_id;
+
+ /* Writing any value clears the timer interrupt */
+ writel(1, tcu->base + EP93XX_TIMER3_CLEAR);
+
+ evt->event_handler(evt);
+
+ return IRQ_HANDLED;
+}
+
+static int __init ep93xx_timer_of_init(struct device_node *np)
+{
+ int irq;
+ unsigned long flags = IRQF_TIMER | IRQF_IRQPOLL;
+ struct ep93xx_tcu *tcu;
+ int ret;
+
+ tcu = kzalloc_obj(*tcu);
+ if (!tcu)
+ return -ENOMEM;
+
+ tcu->base = of_iomap(np, 0);
+ if (!tcu->base) {
+ pr_err("Can't remap registers\n");
+ ret = -ENXIO;
+ goto out_free;
+ }
+
+ ep93xx_tcu = tcu;
+
+ irq = irq_of_parse_and_map(np, 0);
+ if (!irq) {
+ ret = -EINVAL;
+ pr_err("EP93XX Timer Can't parse IRQ %d", irq);
+ goto out_free;
+ }
+
+ /* Enable and register clocksource and sched_clock on timer 4 */
+ writel(EP93XX_TIMER4_VALUE_HIGH_ENABLE,
+ tcu->base + EP93XX_TIMER4_VALUE_HIGH);
+ clocksource_mmio_init(NULL, "timer4",
+ EP93XX_TIMER4_RATE, 200, 40,
+ ep93xx_clocksource_read);
+ sched_clock_register(ep93xx_read_sched_clock, 40,
+ EP93XX_TIMER4_RATE);
+
+ /* Set up clockevent on timer 3 */
+ if (request_irq(irq, ep93xx_timer_interrupt, flags, "ep93xx timer",
+ &ep93xx_clockevent))
+ pr_err("Failed to request irq %d (ep93xx timer)\n", irq);
+
+ clockevents_config_and_register(&ep93xx_clockevent,
+ EP93XX_TIMER123_RATE,
+ 1,
+ UINT_MAX);
+
+ return 0;
+
+out_free:
+ kfree(tcu);
+ return ret;
+}
+TIMER_OF_DECLARE(ep93xx_timer, "cirrus,ep9301-timer", ep93xx_timer_of_init);