Merge tag 'drivers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

Pull ARM SoC driver changes from Olof Johansson:
 "This is a rather large set of patches for device drivers that for one
  reason or another the subsystem maintainer preferred to get merged
  through the arm-soc tree.  There are both new drivers as well as
  existing drivers that are getting converted from platform-specific
  code into standalone drivers using the appropriate subsystem specific
  interfaces.

  In particular, we can now have pinctrl, clk, clksource and irqchip
  drivers in one file per driver, without the need to call into platform
  specific interface, or to get called from platform specific code, as
  long as all information about the hardware is provided through a
  device tree.

  Most of the drivers we touch this time are for clocksource.  Since now
  most of them are part of drivers/clocksource, I expect that we won't
  have to touch these again from arm-soc and can let the clocksource
  maintainers take care of these in the future.

  Another larger part of this series is specific to the exynos platform,
  which is seeing some significant effort in upstreaming and
  modernization of its device drivers this time around, which
  unfortunately is also the cause for the churn and a lot of the merge
  conflicts.

  There is one new subsystem that gets merged as part of this series:
  the reset controller interface, which is a very simple interface for
  taking devices on the SoC out of reset or back into reset.  Patches to
  use this interface on i.MX follow later in this merge window, and we
  are going to have other platforms (at least tegra and sirf) get
  converted in 3.11.  This will let us get rid of platform specific
  callbacks in a number of platform independent device drivers."

* tag 'drivers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (256 commits)
  irqchip: s3c24xx: add missing __init annotations
  ARM: dts: Disable the RTC by default on exynos5
  clk: exynos5250: Fix parent clock for sclk_mmc{0,1,2,3}
  ARM: exynos: restore mach/regs-clock.h for exynos5
  clocksource: exynos_mct: fix build error on non-DT
  pinctrl: vt8500: wmt: Fix checking return value of pinctrl_register()
  irqchip: vt8500: Convert arch-vt8500 to new irqchip infrastructure
  reset: NULL deref on allocation failure
  reset: Add reset controller API
  dt: describe base reset signal binding
  ARM: EXYNOS: Add arm-pmu DT binding for exynos421x
  ARM: EXYNOS: Add arm-pmu DT binding for exynos5250
  ARM: EXYNOS: Enable PMUs for exynos4
  irqchip: exynos-combiner: Correct combined IRQs for exynos4
  irqchip: exynos-combiner: Add set_irq_affinity function for combiner_irq
  ARM: EXYNOS: fix compilation error introduced due to common clock migration
  clk: exynos5250: Fix divider values for sclk_mmc{0,1,2,3}
  clk: exynos4: export clocks required for fimc-is
  clk: samsung: Fix compilation error
  clk: tegra: fix enum tegra114_clk to match binding
  ...

1 files changed, 436 insertions, 0 deletions

diff --git a/drivers/clocksource/cadence_ttc_timer.c b/drivers/clocksource/cadence_ttc_timer.c
new file mode 100644
index 000000000000..685bc60e210a
--- /dev/null
+++ b/drivers/clocksource/cadence_ttc_timer.c
@@ -0,0 +1,436 @@
+/*
+ * This file contains driver for the Cadence Triple Timer Counter Rev 06
+ *
+ *  Copyright (C) 2011-2013 Xilinx
+ *
+ * based on arch/mips/kernel/time.c timer driver
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/clockchips.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/slab.h>
+#include <linux/clk-provider.h>
+
+/*
+ * This driver configures the 2 16-bit count-up timers as follows:
+ *
+ * T1: Timer 1, clocksource for generic timekeeping
+ * T2: Timer 2, clockevent source for hrtimers
+ * T3: Timer 3, <unused>
+ *
+ * The input frequency to the timer module for emulation is 2.5MHz which is
+ * common to all the timer channels (T1, T2, and T3). With a pre-scaler of 32,
+ * the timers are clocked at 78.125KHz (12.8 us resolution).
+
+ * The input frequency to the timer module in silicon is configurable and
+ * obtained from device tree. The pre-scaler of 32 is used.
+ */
+
+/*
+ * Timer Register Offset Definitions of Timer 1, Increment base address by 4
+ * and use same offsets for Timer 2
+ */
+#define TTC_CLK_CNTRL_OFFSET		0x00 /* Clock Control Reg, RW */
+#define TTC_CNT_CNTRL_OFFSET		0x0C /* Counter Control Reg, RW */
+#define TTC_COUNT_VAL_OFFSET		0x18 /* Counter Value Reg, RO */
+#define TTC_INTR_VAL_OFFSET		0x24 /* Interval Count Reg, RW */
+#define TTC_ISR_OFFSET		0x54 /* Interrupt Status Reg, RO */
+#define TTC_IER_OFFSET		0x60 /* Interrupt Enable Reg, RW */
+
+#define TTC_CNT_CNTRL_DISABLE_MASK	0x1
+
+/*
+ * Setup the timers to use pre-scaling, using a fixed value for now that will
+ * work across most input frequency, but it may need to be more dynamic
+ */
+#define PRESCALE_EXPONENT	11	/* 2 ^ PRESCALE_EXPONENT = PRESCALE */
+#define PRESCALE		2048	/* The exponent must match this */
+#define CLK_CNTRL_PRESCALE	((PRESCALE_EXPONENT - 1) << 1)
+#define CLK_CNTRL_PRESCALE_EN	1
+#define CNT_CNTRL_RESET		(1 << 4)
+
+/**
+ * struct ttc_timer - This definition defines local timer structure
+ *
+ * @base_addr:	Base address of timer
+ * @clk:	Associated clock source
+ * @clk_rate_change_nb	Notifier block for clock rate changes
+ */
+struct ttc_timer {
+	void __iomem *base_addr;
+	struct clk *clk;
+	struct notifier_block clk_rate_change_nb;
+};
+
+#define to_ttc_timer(x) \
+		container_of(x, struct ttc_timer, clk_rate_change_nb)
+
+struct ttc_timer_clocksource {
+	struct ttc_timer	ttc;
+	struct clocksource	cs;
+};
+
+#define to_ttc_timer_clksrc(x) \
+		container_of(x, struct ttc_timer_clocksource, cs)
+
+struct ttc_timer_clockevent {
+	struct ttc_timer		ttc;
+	struct clock_event_device	ce;
+};
+
+#define to_ttc_timer_clkevent(x) \
+		container_of(x, struct ttc_timer_clockevent, ce)
+
+/**
+ * ttc_set_interval - Set the timer interval value
+ *
+ * @timer:	Pointer to the timer instance
+ * @cycles:	Timer interval ticks
+ **/
+static void ttc_set_interval(struct ttc_timer *timer,
+					unsigned long cycles)
+{
+	u32 ctrl_reg;
+
+	/* Disable the counter, set the counter value  and re-enable counter */
+	ctrl_reg = __raw_readl(timer->base_addr + TTC_CNT_CNTRL_OFFSET);
+	ctrl_reg |= TTC_CNT_CNTRL_DISABLE_MASK;
+	__raw_writel(ctrl_reg, timer->base_addr + TTC_CNT_CNTRL_OFFSET);
+
+	__raw_writel(cycles, timer->base_addr + TTC_INTR_VAL_OFFSET);
+
+	/*
+	 * Reset the counter (0x10) so that it starts from 0, one-shot
+	 * mode makes this needed for timing to be right.
+	 */
+	ctrl_reg |= CNT_CNTRL_RESET;
+	ctrl_reg &= ~TTC_CNT_CNTRL_DISABLE_MASK;
+	__raw_writel(ctrl_reg, timer->base_addr + TTC_CNT_CNTRL_OFFSET);
+}
+
+/**
+ * ttc_clock_event_interrupt - Clock event timer interrupt handler
+ *
+ * @irq:	IRQ number of the Timer
+ * @dev_id:	void pointer to the ttc_timer instance
+ *
+ * returns: Always IRQ_HANDLED - success
+ **/
+static irqreturn_t ttc_clock_event_interrupt(int irq, void *dev_id)
+{
+	struct ttc_timer_clockevent *ttce = dev_id;
+	struct ttc_timer *timer = &ttce->ttc;
+
+	/* Acknowledge the interrupt and call event handler */
+	__raw_readl(timer->base_addr + TTC_ISR_OFFSET);
+
+	ttce->ce.event_handler(&ttce->ce);
+
+	return IRQ_HANDLED;
+}
+
+/**
+ * __ttc_clocksource_read - Reads the timer counter register
+ *
+ * returns: Current timer counter register value
+ **/
+static cycle_t __ttc_clocksource_read(struct clocksource *cs)
+{
+	struct ttc_timer *timer = &to_ttc_timer_clksrc(cs)->ttc;
+
+	return (cycle_t)__raw_readl(timer->base_addr +
+				TTC_COUNT_VAL_OFFSET);
+}
+
+/**
+ * ttc_set_next_event - Sets the time interval for next event
+ *
+ * @cycles:	Timer interval ticks
+ * @evt:	Address of clock event instance
+ *
+ * returns: Always 0 - success
+ **/
+static int ttc_set_next_event(unsigned long cycles,
+					struct clock_event_device *evt)
+{
+	struct ttc_timer_clockevent *ttce = to_ttc_timer_clkevent(evt);
+	struct ttc_timer *timer = &ttce->ttc;
+
+	ttc_set_interval(timer, cycles);
+	return 0;
+}
+
+/**
+ * ttc_set_mode - Sets the mode of timer
+ *
+ * @mode:	Mode to be set
+ * @evt:	Address of clock event instance
+ **/
+static void ttc_set_mode(enum clock_event_mode mode,
+					struct clock_event_device *evt)
+{
+	struct ttc_timer_clockevent *ttce = to_ttc_timer_clkevent(evt);
+	struct ttc_timer *timer = &ttce->ttc;
+	u32 ctrl_reg;
+
+	switch (mode) {
+	case CLOCK_EVT_MODE_PERIODIC:
+		ttc_set_interval(timer,
+				DIV_ROUND_CLOSEST(clk_get_rate(ttce->ttc.clk),
+					PRESCALE * HZ));
+		break;
+	case CLOCK_EVT_MODE_ONESHOT:
+	case CLOCK_EVT_MODE_UNUSED:
+	case CLOCK_EVT_MODE_SHUTDOWN:
+		ctrl_reg = __raw_readl(timer->base_addr +
+					TTC_CNT_CNTRL_OFFSET);
+		ctrl_reg |= TTC_CNT_CNTRL_DISABLE_MASK;
+		__raw_writel(ctrl_reg,
+				timer->base_addr + TTC_CNT_CNTRL_OFFSET);
+		break;
+	case CLOCK_EVT_MODE_RESUME:
+		ctrl_reg = __raw_readl(timer->base_addr +
+					TTC_CNT_CNTRL_OFFSET);
+		ctrl_reg &= ~TTC_CNT_CNTRL_DISABLE_MASK;
+		__raw_writel(ctrl_reg,
+				timer->base_addr + TTC_CNT_CNTRL_OFFSET);
+		break;
+	}
+}
+
+static int ttc_rate_change_clocksource_cb(struct notifier_block *nb,
+		unsigned long event, void *data)
+{
+	struct clk_notifier_data *ndata = data;
+	struct ttc_timer *ttc = to_ttc_timer(nb);
+	struct ttc_timer_clocksource *ttccs = container_of(ttc,
+			struct ttc_timer_clocksource, ttc);
+
+	switch (event) {
+	case POST_RATE_CHANGE:
+		/*
+		 * Do whatever is necessary to maintain a proper time base
+		 *
+		 * I cannot find a way to adjust the currently used clocksource
+		 * to the new frequency. __clocksource_updatefreq_hz() sounds
+		 * good, but does not work. Not sure what's that missing.
+		 *
+		 * This approach works, but triggers two clocksource switches.
+		 * The first after unregister to clocksource jiffies. And
+		 * another one after the register to the newly registered timer.
+		 *
+		 * Alternatively we could 'waste' another HW timer to ping pong
+		 * between clock sources. That would also use one register and
+		 * one unregister call, but only trigger one clocksource switch
+		 * for the cost of another HW timer used by the OS.
+		 */
+		clocksource_unregister(&ttccs->cs);
+		clocksource_register_hz(&ttccs->cs,
+				ndata->new_rate / PRESCALE);
+		/* fall through */
+	case PRE_RATE_CHANGE:
+	case ABORT_RATE_CHANGE:
+	default:
+		return NOTIFY_DONE;
+	}
+}
+
+static void __init ttc_setup_clocksource(struct clk *clk, void __iomem *base)
+{
+	struct ttc_timer_clocksource *ttccs;
+	int err;
+
+	ttccs = kzalloc(sizeof(*ttccs), GFP_KERNEL);
+	if (WARN_ON(!ttccs))
+		return;
+
+	ttccs->ttc.clk = clk;
+
+	err = clk_prepare_enable(ttccs->ttc.clk);
+	if (WARN_ON(err)) {
+		kfree(ttccs);
+		return;
+	}
+
+	ttccs->ttc.clk_rate_change_nb.notifier_call =
+		ttc_rate_change_clocksource_cb;
+	ttccs->ttc.clk_rate_change_nb.next = NULL;
+	if (clk_notifier_register(ttccs->ttc.clk,
+				&ttccs->ttc.clk_rate_change_nb))
+		pr_warn("Unable to register clock notifier.\n");
+
+	ttccs->ttc.base_addr = base;
+	ttccs->cs.name = "ttc_clocksource";
+	ttccs->cs.rating = 200;
+	ttccs->cs.read = __ttc_clocksource_read;
+	ttccs->cs.mask = CLOCKSOURCE_MASK(16);
+	ttccs->cs.flags = CLOCK_SOURCE_IS_CONTINUOUS;
+
+	/*
+	 * Setup the clock source counter to be an incrementing counter
+	 * with no interrupt and it rolls over at 0xFFFF. Pre-scale
+	 * it by 32 also. Let it start running now.
+	 */
+	__raw_writel(0x0,  ttccs->ttc.base_addr + TTC_IER_OFFSET);
+	__raw_writel(CLK_CNTRL_PRESCALE | CLK_CNTRL_PRESCALE_EN,
+		     ttccs->ttc.base_addr + TTC_CLK_CNTRL_OFFSET);
+	__raw_writel(CNT_CNTRL_RESET,
+		     ttccs->ttc.base_addr + TTC_CNT_CNTRL_OFFSET);
+
+	err = clocksource_register_hz(&ttccs->cs,
+			clk_get_rate(ttccs->ttc.clk) / PRESCALE);
+	if (WARN_ON(err)) {
+		kfree(ttccs);
+		return;
+	}
+}
+
+static int ttc_rate_change_clockevent_cb(struct notifier_block *nb,
+		unsigned long event, void *data)
+{
+	struct clk_notifier_data *ndata = data;
+	struct ttc_timer *ttc = to_ttc_timer(nb);
+	struct ttc_timer_clockevent *ttcce = container_of(ttc,
+			struct ttc_timer_clockevent, ttc);
+
+	switch (event) {
+	case POST_RATE_CHANGE:
+	{
+		unsigned long flags;
+
+		/*
+		 * clockevents_update_freq should be called with IRQ disabled on
+		 * the CPU the timer provides events for. The timer we use is
+		 * common to both CPUs, not sure if we need to run on both
+		 * cores.
+		 */
+		local_irq_save(flags);
+		clockevents_update_freq(&ttcce->ce,
+				ndata->new_rate / PRESCALE);
+		local_irq_restore(flags);
+
+		/* fall through */
+	}
+	case PRE_RATE_CHANGE:
+	case ABORT_RATE_CHANGE:
+	default:
+		return NOTIFY_DONE;
+	}
+}
+
+static void __init ttc_setup_clockevent(struct clk *clk,
+						void __iomem *base, u32 irq)
+{
+	struct ttc_timer_clockevent *ttcce;
+	int err;
+
+	ttcce = kzalloc(sizeof(*ttcce), GFP_KERNEL);
+	if (WARN_ON(!ttcce))
+		return;
+
+	ttcce->ttc.clk = clk;
+
+	err = clk_prepare_enable(ttcce->ttc.clk);
+	if (WARN_ON(err)) {
+		kfree(ttcce);
+		return;
+	}
+
+	ttcce->ttc.clk_rate_change_nb.notifier_call =
+		ttc_rate_change_clockevent_cb;
+	ttcce->ttc.clk_rate_change_nb.next = NULL;
+	if (clk_notifier_register(ttcce->ttc.clk,
+				&ttcce->ttc.clk_rate_change_nb))
+		pr_warn("Unable to register clock notifier.\n");
+
+	ttcce->ttc.base_addr = base;
+	ttcce->ce.name = "ttc_clockevent";
+	ttcce->ce.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
+	ttcce->ce.set_next_event = ttc_set_next_event;
+	ttcce->ce.set_mode = ttc_set_mode;
+	ttcce->ce.rating = 200;
+	ttcce->ce.irq = irq;
+	ttcce->ce.cpumask = cpu_possible_mask;
+
+	/*
+	 * Setup the clock event timer to be an interval timer which
+	 * is prescaled by 32 using the interval interrupt. Leave it
+	 * disabled for now.
+	 */
+	__raw_writel(0x23, ttcce->ttc.base_addr + TTC_CNT_CNTRL_OFFSET);
+	__raw_writel(CLK_CNTRL_PRESCALE | CLK_CNTRL_PRESCALE_EN,
+		     ttcce->ttc.base_addr + TTC_CLK_CNTRL_OFFSET);
+	__raw_writel(0x1,  ttcce->ttc.base_addr + TTC_IER_OFFSET);
+
+	err = request_irq(irq, ttc_clock_event_interrupt,
+			  IRQF_DISABLED | IRQF_TIMER,
+			  ttcce->ce.name, ttcce);
+	if (WARN_ON(err)) {
+		kfree(ttcce);
+		return;
+	}
+
+	clockevents_config_and_register(&ttcce->ce,
+			clk_get_rate(ttcce->ttc.clk) / PRESCALE, 1, 0xfffe);
+}
+
+/**
+ * ttc_timer_init - Initialize the timer
+ *
+ * Initializes the timer hardware and register the clock source and clock event
+ * timers with Linux kernal timer framework
+ */
+static void __init ttc_timer_init(struct device_node *timer)
+{
+	unsigned int irq;
+	void __iomem *timer_baseaddr;
+	struct clk *clk;
+	static int initialized;
+
+	if (initialized)
+		return;
+
+	initialized = 1;
+
+	/*
+	 * Get the 1st Triple Timer Counter (TTC) block from the device tree
+	 * and use it. Note that the event timer uses the interrupt and it's the
+	 * 2nd TTC hence the irq_of_parse_and_map(,1)
+	 */
+	timer_baseaddr = of_iomap(timer, 0);
+	if (!timer_baseaddr) {
+		pr_err("ERROR: invalid timer base address\n");
+		BUG();
+	}
+
+	irq = irq_of_parse_and_map(timer, 1);
+	if (irq <= 0) {
+		pr_err("ERROR: invalid interrupt number\n");
+		BUG();
+	}
+
+	clk = of_clk_get_by_name(timer, "cpu_1x");
+	if (IS_ERR(clk)) {
+		pr_err("ERROR: timer input clock not found\n");
+		BUG();
+	}
+
+	ttc_setup_clocksource(clk, timer_baseaddr);
+	ttc_setup_clockevent(clk, timer_baseaddr + 4, irq);
+
+	pr_info("%s #0 at %p, irq=%d\n", timer->name, timer_baseaddr, irq);
+}
+
+CLOCKSOURCE_OF_DECLARE(ttc, "cdns,ttc", ttc_timer_init);