clocksource: clps711x: Add CLPS711X clocksource driver

This adds the clocksource driver for Cirrus Logic CLPS711X series SoCs.
Designed primarily for migration CLPS711X subarch for multiplatform & DT,
for this as the "OF" and "non-OF" calls implemented.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>

diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index da1ac09dc7717283fbf193491b39f372804d224b..e40435d271d8135225761515587324041bf4ad9e 100644 (file)
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_CLKSRC_DBX500_PRCMU)     += clksrc-dbx500-prcmu.o
 obj-$(CONFIG_ARMADA_370_XP_TIMER)      += time-armada-370-xp.o
 obj-$(CONFIG_ORION_TIMER)      += time-orion.o
 obj-$(CONFIG_ARCH_BCM2835)     += bcm2835_timer.o
+obj-$(CONFIG_ARCH_CLPS711X)    += clps711x-timer.o
 obj-$(CONFIG_ARCH_MARCO)       += timer-marco.o
 obj-$(CONFIG_ARCH_MOXART)      += moxart_timer.o
 obj-$(CONFIG_ARCH_MXS)         += mxs_timer.o

diff --git a/drivers/clocksource/clps711x-timer.c b/drivers/clocksource/clps711x-timer.c
new file mode 100644 (file)
index 0000000..d83ec1f
--- /dev/null
+++ b/drivers/clocksource/clps711x-timer.c
@@ -0,0 +1,131 @@
+/*
+ *  Cirrus Logic CLPS711X clocksource driver
+ *
+ *  Copyright (C) 2014 Alexander Shiyan <shc_work@mail.ru>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/clk.h>
+#include <linux/clockchips.h>
+#include <linux/clocksource.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/sched_clock.h>
+#include <linux/slab.h>
+
+enum {
+       CLPS711X_CLKSRC_CLOCKSOURCE,
+       CLPS711X_CLKSRC_CLOCKEVENT,
+};
+
+static void __iomem *tcd;
+
+static u64 notrace clps711x_sched_clock_read(void)
+{
+       return ~readw(tcd);
+}
+
+static int __init _clps711x_clksrc_init(struct clk *clock, void __iomem *base)
+{
+       unsigned long rate;
+
+       if (!base)
+               return -ENOMEM;
+       if (IS_ERR(clock))
+               return PTR_ERR(clock);
+
+       rate = clk_get_rate(clock);
+
+       tcd = base;
+
+       clocksource_mmio_init(tcd, "clps711x-clocksource", rate, 300, 16,
+                             clocksource_mmio_readw_down);
+
+       sched_clock_register(clps711x_sched_clock_read, 16, rate);
+
+       return 0;
+}
+
+static irqreturn_t clps711x_timer_interrupt(int irq, void *dev_id)
+{
+       struct clock_event_device *evt = dev_id;
+
+       evt->event_handler(evt);
+
+       return IRQ_HANDLED;
+}
+
+static void clps711x_clockevent_set_mode(enum clock_event_mode mode,
+                                        struct clock_event_device *evt)
+{
+}
+
+static int __init _clps711x_clkevt_init(struct clk *clock, void __iomem *base,
+                                       unsigned int irq)
+{
+       struct clock_event_device *clkevt;
+       unsigned long rate;
+
+       if (!irq)
+               return -EINVAL;
+       if (!base)
+               return -ENOMEM;
+       if (IS_ERR(clock))
+               return PTR_ERR(clock);
+
+       clkevt = kzalloc(sizeof(*clkevt), GFP_KERNEL);
+       if (!clkevt)
+               return -ENOMEM;
+
+       rate = clk_get_rate(clock);
+
+       /* Set Timer prescaler */
+       writew(DIV_ROUND_CLOSEST(rate, HZ), base);
+
+       clkevt->name = "clps711x-clockevent";
+       clkevt->rating = 300;
+       clkevt->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_C3STOP;
+       clkevt->set_mode = clps711x_clockevent_set_mode;
+       clkevt->cpumask = cpumask_of(0);
+       clockevents_config_and_register(clkevt, HZ, 0, 0);
+
+       return request_irq(irq, clps711x_timer_interrupt, IRQF_TIMER,
+                          "clps711x-timer", clkevt);
+}
+
+void __init clps711x_clksrc_init(void __iomem *tc1_base, void __iomem *tc2_base,
+                                unsigned int irq)
+{
+       struct clk *tc1 = clk_get_sys("clps711x-timer.0", NULL);
+       struct clk *tc2 = clk_get_sys("clps711x-timer.1", NULL);
+
+       BUG_ON(_clps711x_clksrc_init(tc1, tc1_base));
+       BUG_ON(_clps711x_clkevt_init(tc2, tc2_base, irq));
+}
+
+#ifdef CONFIG_CLKSRC_OF
+static void __init clps711x_timer_init(struct device_node *np)
+{
+       unsigned int irq = irq_of_parse_and_map(np, 0);
+       struct clk *clock = of_clk_get(np, 0);
+       void __iomem *base = of_iomap(np, 0);
+
+       switch (of_alias_get_id(np, "timer")) {
+       case CLPS711X_CLKSRC_CLOCKSOURCE:
+               BUG_ON(_clps711x_clksrc_init(clock, base));
+               break;
+       case CLPS711X_CLKSRC_CLOCKEVENT:
+               BUG_ON(_clps711x_clkevt_init(clock, base, irq));
+               break;
+       default:
+               break;
+       }
+}
+CLOCKSOURCE_OF_DECLARE(clps711x, "cirrus,clps711x-timer", clps711x_timer_init);
+#endif