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authorLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-08-23 13:28:57 -0700
commit4352b8aee98005853aa63f57d6377282de17a33f (patch)
tree27614d7a9ef05c32d089004e104364ce42324837 /drivers/clocksource/timer-pistachio.c
downloadlinux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz
linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni: "A new driver this cycle, for the AMD AXI I3C controller. There are also new features such as IBI wakeup support, SETAASA device discovery and ACPI support for the the DAA methods, meaning we can now communicate with the SPD devices on DDR5 modules. New driver: - AMD AXI I3C master controller Subsystem: - I3C Common Command Code (CCC) handling improvements, especially around GET CCCs - SETAASA device discovery support - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as well as I2C devices on I3C bus - IBI-based wakeup support Drivers: - dw: SETAASA support - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C controller support, PIO queue management support for HCI v1.2 - renesas: improve suspend to RAM support, add runtime PM support" * tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits) i3c: dw: reduce do_daa time if there's no client i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2 i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode i3c: dw: rename "pclk" to "apb" to match dt-binding i3c: dw: make struct dw_i3c_cmd smaller i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding i3c: renesas: Don't register devices when ENTDAA times out i3c: master: dw-i3c-master: fix OD timing for first broadcast i3c: mipi-i3c-hci: Advertise IBI wakeup capability i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev() i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI i3c: master: Reject IBI requests from non-IBI-capable devices i3c: master: Add helper to query bus wakeup requirements i3c: master: Report wakeup events for IBIs i3c: master: Support IBI-based wakeup capability i3c: master: Fix potential UAF in i3c_device_match() i3c: master: Fix potential UAF in i3c_device_uevent() i3c: Make dev->desc locking assumptions explicit i3c: master: Fix use-after-free of master->this ...
Diffstat (limited to 'drivers/clocksource/timer-pistachio.c')
-rw-r--r--drivers/clocksource/timer-pistachio.c216
1 files changed, 216 insertions, 0 deletions
diff --git a/drivers/clocksource/timer-pistachio.c b/drivers/clocksource/timer-pistachio.c
new file mode 100644
index 000000000..57b2197a0
--- /dev/null
+++ b/drivers/clocksource/timer-pistachio.c
@@ -0,0 +1,216 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Pistachio clocksource based on general-purpose timers
+ *
+ * Copyright (C) 2015 Imagination Technologies
+ */
+
+#define pr_fmt(fmt) "%s: " fmt, __func__
+
+#include <linux/clk.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/sched_clock.h>
+#include <linux/time.h>
+
+/* Top level reg */
+#define CR_TIMER_CTRL_CFG 0x00
+#define TIMER_ME_GLOBAL BIT(0)
+#define CR_TIMER_REV 0x10
+
+/* Timer specific registers */
+#define TIMER_CFG 0x20
+#define TIMER_ME_LOCAL BIT(0)
+#define TIMER_RELOAD_VALUE 0x24
+#define TIMER_CURRENT_VALUE 0x28
+#define TIMER_CURRENT_OVERFLOW_VALUE 0x2C
+#define TIMER_IRQ_STATUS 0x30
+#define TIMER_IRQ_CLEAR 0x34
+#define TIMER_IRQ_MASK 0x38
+
+#define PERIP_TIMER_CONTROL 0x90
+
+/* Timer specific configuration Values */
+#define RELOAD_VALUE 0xffffffff
+
+struct pistachio_clocksource {
+ void __iomem *base;
+ raw_spinlock_t lock;
+ struct clocksource cs;
+};
+
+static struct pistachio_clocksource pcs_gpt;
+
+#define to_pistachio_clocksource(cs) \
+ container_of(cs, struct pistachio_clocksource, cs)
+
+static inline u32 gpt_readl(void __iomem *base, u32 offset, u32 gpt_id)
+{
+ return readl(base + 0x20 * gpt_id + offset);
+}
+
+static inline void gpt_writel(void __iomem *base, u32 value, u32 offset,
+ u32 gpt_id)
+{
+ writel(value, base + 0x20 * gpt_id + offset);
+}
+
+static u64 notrace
+pistachio_clocksource_read_cycles(struct clocksource *cs)
+{
+ struct pistachio_clocksource *pcs = to_pistachio_clocksource(cs);
+ __maybe_unused u32 overflow;
+ u32 counter;
+ unsigned long flags;
+
+ /*
+ * The counter value is only refreshed after the overflow value is read.
+ * And they must be read in strict order, hence raw spin lock added.
+ */
+
+ raw_spin_lock_irqsave(&pcs->lock, flags);
+ overflow = gpt_readl(pcs->base, TIMER_CURRENT_OVERFLOW_VALUE, 0);
+ counter = gpt_readl(pcs->base, TIMER_CURRENT_VALUE, 0);
+ raw_spin_unlock_irqrestore(&pcs->lock, flags);
+
+ return (u64)~counter;
+}
+
+static u64 notrace pistachio_read_sched_clock(void)
+{
+ return pistachio_clocksource_read_cycles(&pcs_gpt.cs);
+}
+
+static void pistachio_clksrc_set_mode(struct clocksource *cs, int timeridx,
+ int enable)
+{
+ struct pistachio_clocksource *pcs = to_pistachio_clocksource(cs);
+ u32 val;
+
+ val = gpt_readl(pcs->base, TIMER_CFG, timeridx);
+ if (enable)
+ val |= TIMER_ME_LOCAL;
+ else
+ val &= ~TIMER_ME_LOCAL;
+
+ gpt_writel(pcs->base, val, TIMER_CFG, timeridx);
+}
+
+static void pistachio_clksrc_enable(struct clocksource *cs, int timeridx)
+{
+ struct pistachio_clocksource *pcs = to_pistachio_clocksource(cs);
+
+ /* Disable GPT local before loading reload value */
+ pistachio_clksrc_set_mode(cs, timeridx, false);
+ gpt_writel(pcs->base, RELOAD_VALUE, TIMER_RELOAD_VALUE, timeridx);
+ pistachio_clksrc_set_mode(cs, timeridx, true);
+}
+
+static void pistachio_clksrc_disable(struct clocksource *cs, int timeridx)
+{
+ /* Disable GPT local */
+ pistachio_clksrc_set_mode(cs, timeridx, false);
+}
+
+static int pistachio_clocksource_enable(struct clocksource *cs)
+{
+ pistachio_clksrc_enable(cs, 0);
+ return 0;
+}
+
+static void pistachio_clocksource_disable(struct clocksource *cs)
+{
+ pistachio_clksrc_disable(cs, 0);
+}
+
+/* Desirable clock source for pistachio platform */
+static struct pistachio_clocksource pcs_gpt = {
+ .cs = {
+ .name = "gptimer",
+ .rating = 300,
+ .enable = pistachio_clocksource_enable,
+ .disable = pistachio_clocksource_disable,
+ .read = pistachio_clocksource_read_cycles,
+ .mask = CLOCKSOURCE_MASK(32),
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS |
+ CLOCK_SOURCE_SUSPEND_NONSTOP,
+ },
+};
+
+static int __init pistachio_clksrc_of_init(struct device_node *node)
+{
+ struct clk *sys_clk, *fast_clk;
+ struct regmap *periph_regs;
+ unsigned long rate;
+ int ret;
+
+ pcs_gpt.base = of_iomap(node, 0);
+ if (!pcs_gpt.base) {
+ pr_err("cannot iomap\n");
+ return -ENXIO;
+ }
+
+ periph_regs = syscon_regmap_lookup_by_phandle(node, "img,cr-periph");
+ if (IS_ERR(periph_regs)) {
+ pr_err("cannot get peripheral regmap (%ld)\n",
+ PTR_ERR(periph_regs));
+ return PTR_ERR(periph_regs);
+ }
+
+ /* Switch to using the fast counter clock */
+ ret = regmap_update_bits(periph_regs, PERIP_TIMER_CONTROL,
+ 0xf, 0x0);
+ if (ret)
+ return ret;
+
+ sys_clk = of_clk_get_by_name(node, "sys");
+ if (IS_ERR(sys_clk)) {
+ pr_err("clock get failed (%ld)\n", PTR_ERR(sys_clk));
+ return PTR_ERR(sys_clk);
+ }
+
+ fast_clk = of_clk_get_by_name(node, "fast");
+ if (IS_ERR(fast_clk)) {
+ pr_err("clock get failed (%lu)\n", PTR_ERR(fast_clk));
+ return PTR_ERR(fast_clk);
+ }
+
+ ret = clk_prepare_enable(sys_clk);
+ if (ret < 0) {
+ pr_err("failed to enable clock (%d)\n", ret);
+ return ret;
+ }
+
+ ret = clk_prepare_enable(fast_clk);
+ if (ret < 0) {
+ pr_err("failed to enable clock (%d)\n", ret);
+ clk_disable_unprepare(sys_clk);
+ return ret;
+ }
+
+ rate = clk_get_rate(fast_clk);
+
+ /* Disable irq's for clocksource usage */
+ gpt_writel(pcs_gpt.base, 0, TIMER_IRQ_MASK, 0);
+ gpt_writel(pcs_gpt.base, 0, TIMER_IRQ_MASK, 1);
+ gpt_writel(pcs_gpt.base, 0, TIMER_IRQ_MASK, 2);
+ gpt_writel(pcs_gpt.base, 0, TIMER_IRQ_MASK, 3);
+
+ /* Enable timer block */
+ writel(TIMER_ME_GLOBAL, pcs_gpt.base);
+
+ raw_spin_lock_init(&pcs_gpt.lock);
+ sched_clock_register(pistachio_read_sched_clock, 32, rate);
+ return clocksource_register_hz(&pcs_gpt.cs, rate);
+}
+TIMER_OF_DECLARE(pistachio_gptimer, "img,pistachio-gptimer",
+ pistachio_clksrc_of_init);