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authorBirger Koblitz <git@birger-koblitz.de>2021-01-21 21:38:27 +0100
committerPetr Štetiar <ynezz@true.cz>2021-01-26 15:06:50 +0100
commit8faffa00cb6b7121fbdac3d5cff8bab9a253ae93 (patch)
treecd6346cf84692d523aaf082af5b427c74abd79fe /target/linux/realtek/files-5.4/drivers
parent03c79ca269e612faa55e3decd034c44f9b77c05c (diff)
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realtek: add support for the RTL9300 timer
this adds support for the SoC timer of the RTL9300 chips, it provides 6 independent timer/counters, of which the first one is used as a clocksource and the second one as event timer. Signed-off-by: Birger Koblitz <git@birger-koblitz.de>
Diffstat (limited to 'target/linux/realtek/files-5.4/drivers')
-rw-r--r--target/linux/realtek/files-5.4/drivers/clocksource/timer-rtl9300.c196
1 files changed, 196 insertions, 0 deletions
diff --git a/target/linux/realtek/files-5.4/drivers/clocksource/timer-rtl9300.c b/target/linux/realtek/files-5.4/drivers/clocksource/timer-rtl9300.c
new file mode 100644
index 0000000000..9ab1733fe3
--- /dev/null
+++ b/target/linux/realtek/files-5.4/drivers/clocksource/timer-rtl9300.c
@@ -0,0 +1,196 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/clockchips.h>
+#include <linux/init.h>
+#include <asm/time.h>
+#include <linux/interrupt.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/sched_clock.h>
+#include "timer-of.h"
+
+#include <mach-rtl83xx.h>
+
+/*
+ * Timer registers
+ * the RTL9300/9310 SoCs have 6 timers, each register block 0x10 apart
+ */
+#define RTL9300_TC_DATA 0x0
+#define RTL9300_TC_CNT 0x4
+#define RTL9300_TC_CTRL 0x8
+#define RTL9300_TC_CTRL_MODE BIT(24)
+#define RTL9300_TC_CTRL_EN BIT(28)
+#define RTL9300_TC_INT 0xc
+#define RTL9300_TC_INT_IP BIT(16)
+#define RTL9300_TC_INT_IE BIT(20)
+
+// Clocksource is using timer 0, clock event uses timer 1
+#define TIMER_CLK_SRC 0
+#define TIMER_CLK_EVT 1
+#define TIMER_BLK_EVT (TIMER_CLK_EVT << 4)
+
+// Timer modes
+#define TIMER_MODE_REPEAT 1
+#define TIMER_MODE_ONCE 0
+
+// Minimum divider is 2
+#define DIVISOR_RTL9300 2
+
+#define N_BITS 28
+
+static void __iomem *rtl9300_sched_reg __read_mostly;
+
+static u64 notrace rtl9300_sched_clock_read(void)
+{
+/* pr_info("In %s: %x\n", __func__, readl_relaxed(rtl9300_sched_reg));
+ dump_stack();*/
+ return readl_relaxed(rtl9300_sched_reg);
+}
+
+static irqreturn_t rtl9300_timer_interrupt(int irq, void *dev_id)
+{
+ struct clock_event_device *clk = dev_id;
+ struct timer_of *to = to_timer_of(clk);
+ u32 v = readl(timer_of_base(to) + TIMER_BLK_EVT + RTL9300_TC_INT);
+
+ // Acknowledge the IRQ
+ v |= RTL9300_TC_INT_IP;
+ writel(v, timer_of_base(to) + TIMER_BLK_EVT + RTL9300_TC_INT);
+
+ clk->event_handler(clk);
+ return IRQ_HANDLED;
+}
+
+static void rtl9300_timer_stop(struct timer_of *to)
+{
+ u32 v;
+
+ writel(0, timer_of_base(to) + TIMER_BLK_EVT + RTL9300_TC_CTRL);
+
+ // Acknowledge possibly pending IRQ
+ v = readl(timer_of_base(to) + TIMER_BLK_EVT + RTL9300_TC_INT);
+ if (v & RTL9300_TC_INT_IP)
+ writel(v, timer_of_base(to) + TIMER_BLK_EVT + RTL9300_TC_INT);
+}
+
+static void rtl9300_timer_start(struct timer_of *to, int timer, bool periodic)
+{
+ u32 v = (periodic ? RTL9300_TC_CTRL_MODE : 0) | RTL9300_TC_CTRL_EN | DIVISOR_RTL9300;
+ writel(v, timer_of_base(to) + timer * 0x10 + RTL9300_TC_CTRL);
+}
+
+static int rtl9300_set_next_event(unsigned long delta, struct clock_event_device *clk)
+{
+ struct timer_of *to = to_timer_of(clk);
+
+ rtl9300_timer_stop(to);
+ writel(delta, timer_of_base(to) + TIMER_BLK_EVT + RTL9300_TC_DATA);
+ rtl9300_timer_start(to, TIMER_CLK_EVT, TIMER_MODE_ONCE);
+ return 0;
+}
+
+static int rtl9300_set_state_periodic(struct clock_event_device *clk)
+{
+ struct timer_of *to = to_timer_of(clk);
+
+ rtl9300_timer_stop(to);
+ writel(to->of_clk.period, timer_of_base(to) + TIMER_BLK_EVT + RTL9300_TC_DATA);
+ rtl9300_timer_start(to, TIMER_CLK_EVT, TIMER_MODE_REPEAT);
+ return 0;
+}
+
+static int rtl9300_set_state_oneshot(struct clock_event_device *clk)
+{
+ struct timer_of *to = to_timer_of(clk);
+
+ rtl9300_timer_stop(to);
+ writel(to->of_clk.period, timer_of_base(to) + TIMER_BLK_EVT + RTL9300_TC_DATA);
+ rtl9300_timer_start(to, TIMER_CLK_EVT, TIMER_MODE_ONCE);
+ return 0;
+}
+
+static int rtl9300_set_state_shutdown(struct clock_event_device *clk)
+{
+ struct timer_of *to = to_timer_of(clk);
+
+ rtl9300_timer_stop(to);
+ return 0;
+}
+
+static struct timer_of t_of = {
+ .flags = TIMER_OF_BASE | TIMER_OF_IRQ | TIMER_OF_CLOCK,
+
+ .clkevt = {
+ .name = "rtl9300_timer",
+ .rating = 350,
+ .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+ .set_next_event = rtl9300_set_next_event,
+ .set_state_oneshot = rtl9300_set_state_oneshot,
+ .set_state_periodic = rtl9300_set_state_periodic,
+ .set_state_shutdown = rtl9300_set_state_shutdown,
+ },
+
+ .of_irq = {
+ .name = "ostimer",
+ .handler = rtl9300_timer_interrupt,
+ .flags = IRQF_TIMER,
+ },
+};
+
+static void __init rtl9300_timer_setup(u8 timer)
+{
+ u32 v;
+
+ // Disable timer
+ writel(0, timer_of_base(&t_of) + 0x10 * timer + RTL9300_TC_CTRL);
+
+ // Acknowledge possibly pending IRQ
+ v = readl(timer_of_base(&t_of) + 0x10 * timer + RTL9300_TC_INT);
+ if (v & RTL9300_TC_INT_IP)
+ writel(v, timer_of_base(&t_of) + 0x10 * timer + RTL9300_TC_INT);
+
+ // Setup maximum period (for use as clock-source)
+ writel(0x0fffffff, timer_of_base(&t_of) + 0x10 * timer + RTL9300_TC_DATA);
+}
+
+
+static int __init rtl9300_timer_init(struct device_node *node)
+{
+ int err = 0;
+ unsigned long rate;
+
+ pr_info("%s: setting up timer\n", __func__);
+
+ err = timer_of_init(node, &t_of);
+ if (err)
+ return err;
+
+ rate = timer_of_rate(&t_of) / DIVISOR_RTL9300;
+ pr_info("Frequency in dts: %ld, my rate is %ld, period %ld\n",
+ timer_of_rate(&t_of), rate, timer_of_period(&t_of));
+ pr_info("With base %08x IRQ: %d\n", (u32)timer_of_base(&t_of), timer_of_irq(&t_of));
+
+ // Configure clock source and register it for scheduling
+ rtl9300_timer_setup(TIMER_CLK_SRC);
+ rtl9300_timer_start(&t_of, TIMER_CLK_SRC, TIMER_MODE_REPEAT);
+
+ rtl9300_sched_reg = timer_of_base(&t_of) + TIMER_CLK_SRC * 0x10 + RTL9300_TC_CNT;
+
+ err = clocksource_mmio_init(rtl9300_sched_reg, node->name, rate , 100, N_BITS,
+ clocksource_mmio_readl_up);
+ if (err)
+ return err;
+
+ sched_clock_register(rtl9300_sched_clock_read, N_BITS, rate);
+
+ // Configure clock event source
+ rtl9300_timer_setup(TIMER_CLK_EVT);
+ clockevents_config_and_register(&t_of.clkevt, rate, 100, 0x0fffffff);
+
+ // Enable interrupt
+ writel(RTL9300_TC_INT_IE, timer_of_base(&t_of) + TIMER_BLK_EVT + RTL9300_TC_INT);
+
+ return err;
+}
+
+TIMER_OF_DECLARE(rtl9300_timer, "realtek,rtl9300-timer", rtl9300_timer_init);