Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/hskinnemoen/tclib into base

5 files changed, 498 insertions, 0 deletions

diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile
index a52225470225..1525882190fd 100644
--- a/drivers/clocksource/Makefile
+++ b/drivers/clocksource/Makefile
@@ -1,3 +1,4 @@
+obj-$(CONFIG_ATMEL_TCB_CLKSRC)  += tcb_clksrc.o
 obj-$(CONFIG_X86_CYCLONE_TIMER) += cyclone.o
 obj-$(CONFIG_X86_PM_TIMER)      += acpi_pm.o
 obj-$(CONFIG_SCx200HR_TIMER)    += scx200_hrt.o
diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
new file mode 100644
index 000000000000..f450588e5858
--- /dev/null
+++ b/drivers/clocksource/tcb_clksrc.c
@@ -0,0 +1,302 @@
+#include <linux/init.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/ioport.h>
+#include <linux/io.h>
+#include <linux/platform_device.h>
+#include <linux/atmel_tc.h>
+
+
+/*
+ * We're configured to use a specific TC block, one that's not hooked
+ * up to external hardware, to provide a time solution:
+ *
+ *   - Two channels combine to create a free-running 32 bit counter
+ *     with a base rate of 5+ MHz, packaged as a clocksource (with
+ *     resolution better than 200 nsec).
+ *
+ *   - The third channel may be used to provide a 16-bit clockevent
+ *     source, used in either periodic or oneshot mode.  This runs
+ *     at 32 KiHZ, and can handle delays of up to two seconds.
+ *
+ * A boot clocksource and clockevent source are also currently needed,
+ * unless the relevant platforms (ARM/AT91, AVR32/AT32) are changed so
+ * this code can be used when init_timers() is called, well before most
+ * devices are set up.  (Some low end AT91 parts, which can run uClinux,
+ * have only the timers in one TC block... they currently don't support
+ * the tclib code, because of that initialization issue.)
+ *
+ * REVISIT behavior during system suspend states... we should disable
+ * all clocks and save the power.  Easily done for clockevent devices,
+ * but clocksources won't necessarily get the needed notifications.
+ * For deeper system sleep states, this will be mandatory...
+ */
+
+static void __iomem *tcaddr;
+
+static cycle_t tc_get_cycles(void)
+{
+        unsigned long   flags;
+        u32             lower, upper;
+
+        raw_local_irq_save(flags);
+        do {
+                upper = __raw_readl(tcaddr + ATMEL_TC_REG(1, CV));
+                lower = __raw_readl(tcaddr + ATMEL_TC_REG(0, CV));
+        } while (upper != __raw_readl(tcaddr + ATMEL_TC_REG(1, CV)));
+
+        raw_local_irq_restore(flags);
+        return (upper << 16) | lower;
+}
+
+static struct clocksource clksrc = {
+        .name           = "tcb_clksrc",
+        .rating         = 200,
+        .read           = tc_get_cycles,
+        .mask           = CLOCKSOURCE_MASK(32),
+        .shift          = 18,
+        .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+#ifdef CONFIG_GENERIC_CLOCKEVENTS
+
+struct tc_clkevt_device {
+        struct clock_event_device       clkevt;
+        struct clk                      *clk;
+        void __iomem                    *regs;
+};
+
+static struct tc_clkevt_device *to_tc_clkevt(struct clock_event_device *clkevt)
+{
+        return container_of(clkevt, struct tc_clkevt_device, clkevt);
+}
+
+/* For now, we always use the 32K clock ... this optimizes for NO_HZ,
+ * because using one of the divided clocks would usually mean the
+ * tick rate can never be less than several dozen Hz (vs 0.5 Hz).
+ *
+ * A divided clock could be good for high resolution timers, since
+ * 30.5 usec resolution can seem "low".
+ */
+static u32 timer_clock;
+
+static void tc_mode(enum clock_event_mode m, struct clock_event_device *d)
+{
+        struct tc_clkevt_device *tcd = to_tc_clkevt(d);
+        void __iomem            *regs = tcd->regs;
+
+        if (tcd->clkevt.mode == CLOCK_EVT_MODE_PERIODIC
+                        || tcd->clkevt.mode == CLOCK_EVT_MODE_ONESHOT) {
+                __raw_writel(0xff, regs + ATMEL_TC_REG(2, IDR));
+                __raw_writel(ATMEL_TC_CLKDIS, regs + ATMEL_TC_REG(2, CCR));
+                clk_disable(tcd->clk);
+        }
+
+        switch (m) {
+
+        /* By not making the gentime core emulate periodic mode on top
+         * of oneshot, we get lower overhead and improved accuracy.
+         */
+        case CLOCK_EVT_MODE_PERIODIC:
+                clk_enable(tcd->clk);
+
+                /* slow clock, count up to RC, then irq and restart */
+                __raw_writel(timer_clock
+                                | ATMEL_TC_WAVE | ATMEL_TC_WAVESEL_UP_AUTO,
+                                regs + ATMEL_TC_REG(2, CMR));
+                __raw_writel((32768 + HZ/2) / HZ, tcaddr + ATMEL_TC_REG(2, RC));
+
+                /* Enable clock and interrupts on RC compare */
+                __raw_writel(ATMEL_TC_CPCS, regs + ATMEL_TC_REG(2, IER));
+
+                /* go go gadget! */
+                __raw_writel(ATMEL_TC_CLKEN | ATMEL_TC_SWTRG,
+                                regs + ATMEL_TC_REG(2, CCR));
+                break;
+
+        case CLOCK_EVT_MODE_ONESHOT:
+                clk_enable(tcd->clk);
+
+                /* slow clock, count up to RC, then irq and stop */
+                __raw_writel(timer_clock | ATMEL_TC_CPCSTOP
+                                | ATMEL_TC_WAVE | ATMEL_TC_WAVESEL_UP_AUTO,
+                                regs + ATMEL_TC_REG(2, CMR));
+                __raw_writel(ATMEL_TC_CPCS, regs + ATMEL_TC_REG(2, IER));
+
+                /* set_next_event() configures and starts the timer */
+                break;
+
+        default:
+                break;
+        }
+}
+
+static int tc_next_event(unsigned long delta, struct clock_event_device *d)
+{
+        __raw_writel(delta, tcaddr + ATMEL_TC_REG(2, RC));
+
+        /* go go gadget! */
+        __raw_writel(ATMEL_TC_CLKEN | ATMEL_TC_SWTRG,
+                        tcaddr + ATMEL_TC_REG(2, CCR));
+        return 0;
+}
+
+static struct tc_clkevt_device clkevt = {
+        .clkevt = {
+                .name           = "tc_clkevt",
+                .features       = CLOCK_EVT_FEAT_PERIODIC
+                                        | CLOCK_EVT_FEAT_ONESHOT,
+                .shift          = 32,
+                /* Should be lower than at91rm9200's system timer */
+                .rating         = 125,
+                .cpumask        = CPU_MASK_CPU0,
+                .set_next_event = tc_next_event,
+                .set_mode       = tc_mode,
+        },
+};
+
+static irqreturn_t ch2_irq(int irq, void *handle)
+{
+        struct tc_clkevt_device *dev = handle;
+        unsigned int            sr;
+
+        sr = __raw_readl(dev->regs + ATMEL_TC_REG(2, SR));
+        if (sr & ATMEL_TC_CPCS) {
+                dev->clkevt.event_handler(&dev->clkevt);
+                return IRQ_HANDLED;
+        }
+
+        return IRQ_NONE;
+}
+
+static struct irqaction tc_irqaction = {
+        .name           = "tc_clkevt",
+        .flags          = IRQF_TIMER | IRQF_DISABLED,
+        .handler        = ch2_irq,
+};
+
+static void __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
+{
+        struct clk *t2_clk = tc->clk[2];
+        int irq = tc->irq[2];
+
+        clkevt.regs = tc->regs;
+        clkevt.clk = t2_clk;
+        tc_irqaction.dev_id = &clkevt;
+
+        timer_clock = clk32k_divisor_idx;
+
+        clkevt.clkevt.mult = div_sc(32768, NSEC_PER_SEC, clkevt.clkevt.shift);
+        clkevt.clkevt.max_delta_ns
+                = clockevent_delta2ns(0xffff, &clkevt.clkevt);
+        clkevt.clkevt.min_delta_ns = clockevent_delta2ns(1, &clkevt.clkevt) + 1;
+
+        setup_irq(irq, &tc_irqaction);
+
+        clockevents_register_device(&clkevt.clkevt);
+}
+
+#else /* !CONFIG_GENERIC_CLOCKEVENTS */
+
+static void __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
+{
+        /* NOTHING */
+}
+
+#endif
+
+static int __init tcb_clksrc_init(void)
+{
+        static char bootinfo[] __initdata
+                = KERN_DEBUG "%s: tc%d at %d.%03d MHz\n";
+
+        struct platform_device *pdev;
+        struct atmel_tc *tc;
+        struct clk *t0_clk;
+        u32 rate, divided_rate = 0;
+        int best_divisor_idx = -1;
+        int clk32k_divisor_idx = -1;
+        int i;
+
+        tc = atmel_tc_alloc(CONFIG_ATMEL_TCB_CLKSRC_BLOCK, clksrc.name);
+        if (!tc) {
+                pr_debug("can't alloc TC for clocksource\n");
+                return -ENODEV;
+        }
+        tcaddr = tc->regs;
+        pdev = tc->pdev;
+
+        t0_clk = tc->clk[0];
+        clk_enable(t0_clk);
+
+        /* How fast will we be counting?  Pick something over 5 MHz.  */
+        rate = (u32) clk_get_rate(t0_clk);
+        for (i = 0; i < 5; i++) {
+                unsigned divisor = atmel_tc_divisors[i];
+                unsigned tmp;
+
+                /* remember 32 KiHz clock for later */
+                if (!divisor) {
+                        clk32k_divisor_idx = i;
+                        continue;
+                }
+
+                tmp = rate / divisor;
+                pr_debug("TC: %u / %-3u [%d] --> %u\n", rate, divisor, i, tmp);
+                if (best_divisor_idx > 0) {
+                        if (tmp < 5 * 1000 * 1000)
+                                continue;
+                }
+                divided_rate = tmp;
+                best_divisor_idx = i;
+        }
+
+        clksrc.mult = clocksource_hz2mult(divided_rate, clksrc.shift);
+
+        printk(bootinfo, clksrc.name, CONFIG_ATMEL_TCB_CLKSRC_BLOCK,
+                        divided_rate / 1000000,
+                        ((divided_rate + 500000) % 1000000) / 1000);
+
+        /* tclib will give us three clocks no matter what the
+         * underlying platform supports.
+         */
+        clk_enable(tc->clk[1]);
+
+        /* channel 0:  waveform mode, input mclk/8, clock TIOA0 on overflow */
+        __raw_writel(best_divisor_idx                   /* likely divide-by-8 */
+                        | ATMEL_TC_WAVE
+                        | ATMEL_TC_WAVESEL_UP           /* free-run */
+                        | ATMEL_TC_ACPA_SET             /* TIOA0 rises at 0 */
+                        | ATMEL_TC_ACPC_CLEAR,          /* (duty cycle 50%) */
+                        tcaddr + ATMEL_TC_REG(0, CMR));
+        __raw_writel(0x0000, tcaddr + ATMEL_TC_REG(0, RA));
+        __raw_writel(0x8000, tcaddr + ATMEL_TC_REG(0, RC));
+        __raw_writel(0xff, tcaddr + ATMEL_TC_REG(0, IDR));      /* no irqs */
+        __raw_writel(ATMEL_TC_CLKEN, tcaddr + ATMEL_TC_REG(0, CCR));
+
+        /* channel 1:  waveform mode, input TIOA0 */
+        __raw_writel(ATMEL_TC_XC1                       /* input: TIOA0 */
+                        | ATMEL_TC_WAVE
+                        | ATMEL_TC_WAVESEL_UP,          /* free-run */
+                        tcaddr + ATMEL_TC_REG(1, CMR));
+        __raw_writel(0xff, tcaddr + ATMEL_TC_REG(1, IDR));      /* no irqs */
+        __raw_writel(ATMEL_TC_CLKEN, tcaddr + ATMEL_TC_REG(1, CCR));
+
+        /* chain channel 0 to channel 1, then reset all the timers */
+        __raw_writel(ATMEL_TC_TC1XC1S_TIOA0, tcaddr + ATMEL_TC_BMR);
+        __raw_writel(ATMEL_TC_SYNC, tcaddr + ATMEL_TC_BCR);
+
+        /* and away we go! */
+        clocksource_register(&clksrc);
+
+        /* channel 2:  periodic and oneshot timer support */
+        setup_clkevents(tc, clk32k_divisor_idx);
+
+        return 0;
+}
+arch_initcall(tcb_clksrc_init);
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 962817e49fba..bb94ce78a6d0 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -22,6 +22,39 @@ config ATMEL_PWM
           purposes including software controlled power-efficent backlights
           on LCD displays, motor control, and waveform generation.
 
+config ATMEL_TCLIB
+        bool "Atmel AT32/AT91 Timer/Counter Library"
+        depends on (AVR32 || ARCH_AT91)
+        help
+          Select this if you want a library to allocate the Timer/Counter
+          blocks found on many Atmel processors.  This facilitates using
+          these blocks by different drivers despite processor differences.
+
+config ATMEL_TCB_CLKSRC
+        bool "TC Block Clocksource"
+        depends on ATMEL_TCLIB && GENERIC_TIME
+        default y
+        help
+          Select this to get a high precision clocksource based on a
+          TC block with a 5+ MHz base clock rate.  Two timer channels
+          are combined to make a single 32-bit timer.
+
+          When GENERIC_CLOCKEVENTS is defined, the third timer channel
+          may be used as a clock event device supporting oneshot mode
+          (delays of up to two seconds) based on the 32 KiHz clock.
+
+config ATMEL_TCB_CLKSRC_BLOCK
+        int
+        depends on ATMEL_TCB_CLKSRC
+        prompt "TC Block" if ARCH_AT91RM9200 || ARCH_AT91SAM9260 || CPU_AT32AP700X
+        default 0
+        range 0 1
+        help
+          Some chips provide more than one TC block, so you have the
+          choice of which one to use for the clock framework.  The other
+          TC can be used for other purposes, such as PWM generation and
+          interval timing.
+
 config IBM_ASM
         tristate "Device driver for IBM RSA service processor"
         depends on X86 && PCI && INPUT && EXPERIMENTAL
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index bbc69fdd1b9d..4581b2533111 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -10,6 +10,7 @@ obj-$(CONFIG_ACER_WMI)     += acer-wmi.o
 obj-$(CONFIG_ASUS_LAPTOP)     += asus-laptop.o
 obj-$(CONFIG_ATMEL_PWM)         += atmel_pwm.o
 obj-$(CONFIG_ATMEL_SSC)         += atmel-ssc.o
+obj-$(CONFIG_ATMEL_TCLIB)       += atmel_tclib.o
 obj-$(CONFIG_TC1100_WMI)        += tc1100-wmi.o
 obj-$(CONFIG_LKDTM)             += lkdtm.o
 obj-$(CONFIG_TIFM_CORE)         += tifm_core.o
diff --git a/drivers/misc/atmel_tclib.c b/drivers/misc/atmel_tclib.c
new file mode 100644
index 000000000000..05dc8a31f280
--- /dev/null
+++ b/drivers/misc/atmel_tclib.c
@@ -0,0 +1,161 @@
+#include <linux/atmel_tc.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+
+/* Number of bytes to reserve for the iomem resource */
+#define ATMEL_TC_IOMEM_SIZE     256
+
+
+/*
+ * This is a thin library to solve the problem of how to portably allocate
+ * one of the TC blocks.  For simplicity, it doesn't currently expect to
+ * share individual timers between different drivers.
+ */
+
+#if defined(CONFIG_AVR32)
+/* AVR32 has these divide PBB */
+const u8 atmel_tc_divisors[5] = { 0, 4, 8, 16, 32, };
+EXPORT_SYMBOL(atmel_tc_divisors);
+
+#elif defined(CONFIG_ARCH_AT91)
+/* AT91 has these divide MCK */
+const u8 atmel_tc_divisors[5] = { 2, 8, 32, 128, 0, };
+EXPORT_SYMBOL(atmel_tc_divisors);
+
+#endif
+
+static DEFINE_SPINLOCK(tc_list_lock);
+static LIST_HEAD(tc_list);
+
+/**
+ * atmel_tc_alloc - allocate a specified TC block
+ * @block: which block to allocate
+ * @name: name to be associated with the iomem resource
+ *
+ * Caller allocates a block.  If it is available, a pointer to a
+ * pre-initialized struct atmel_tc is returned. The caller can access
+ * the registers directly through the "regs" field.
+ */
+struct atmel_tc *atmel_tc_alloc(unsigned block, const char *name)
+{
+        struct atmel_tc         *tc;
+        struct platform_device  *pdev = NULL;
+        struct resource         *r;
+
+        spin_lock(&tc_list_lock);
+        list_for_each_entry(tc, &tc_list, node) {
+                if (tc->pdev->id == block) {
+                        pdev = tc->pdev;
+                        break;
+                }
+        }
+
+        if (!pdev || tc->iomem)
+                goto fail;
+
+        r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        r = request_mem_region(r->start, ATMEL_TC_IOMEM_SIZE, name);
+        if (!r)
+                goto fail;
+
+        tc->regs = ioremap(r->start, ATMEL_TC_IOMEM_SIZE);
+        if (!tc->regs)
+                goto fail_ioremap;
+
+        tc->iomem = r;
+
+out:
+        spin_unlock(&tc_list_lock);
+        return tc;
+
+fail_ioremap:
+        release_resource(r);
+fail:
+        tc = NULL;
+        goto out;
+}
+EXPORT_SYMBOL_GPL(atmel_tc_alloc);
+
+/**
+ * atmel_tc_free - release a specified TC block
+ * @tc: Timer/counter block that was returned by atmel_tc_alloc()
+ *
+ * This reverses the effect of atmel_tc_alloc(), unmapping the I/O
+ * registers, invalidating the resource returned by that routine and
+ * making the TC available to other drivers.
+ */
+void atmel_tc_free(struct atmel_tc *tc)
+{
+        spin_lock(&tc_list_lock);
+        if (tc->regs) {
+                iounmap(tc->regs);
+                release_resource(tc->iomem);
+                tc->regs = NULL;
+                tc->iomem = NULL;
+        }
+        spin_unlock(&tc_list_lock);
+}
+EXPORT_SYMBOL_GPL(atmel_tc_free);
+
+static int __init tc_probe(struct platform_device *pdev)
+{
+        struct atmel_tc *tc;
+        struct clk      *clk;
+        int             irq;
+
+        if (!platform_get_resource(pdev, IORESOURCE_MEM, 0))
+                return -EINVAL;
+
+        irq = platform_get_irq(pdev, 0);
+        if (irq < 0)
+                return -EINVAL;
+
+        tc = kzalloc(sizeof(struct atmel_tc), GFP_KERNEL);
+        if (!tc)
+                return -ENOMEM;
+
+        tc->pdev = pdev;
+
+        clk = clk_get(&pdev->dev, "t0_clk");
+        if (IS_ERR(clk)) {
+                kfree(tc);
+                return -EINVAL;
+        }
+
+        tc->clk[0] = clk;
+        tc->clk[1] = clk_get(&pdev->dev, "t1_clk");
+        if (IS_ERR(tc->clk[1]))
+                tc->clk[1] = clk;
+        tc->clk[2] = clk_get(&pdev->dev, "t2_clk");
+        if (IS_ERR(tc->clk[2]))
+                tc->clk[2] = clk;
+
+        tc->irq[0] = irq;
+        tc->irq[1] = platform_get_irq(pdev, 1);
+        if (tc->irq[1] < 0)
+                tc->irq[1] = irq;
+        tc->irq[2] = platform_get_irq(pdev, 2);
+        if (tc->irq[2] < 0)
+                tc->irq[2] = irq;
+
+        spin_lock(&tc_list_lock);
+        list_add_tail(&tc->node, &tc_list);
+        spin_unlock(&tc_list_lock);
+
+        return 0;
+}
+
+static struct platform_driver tc_driver = {
+        .driver.name    = "atmel_tcb",
+};
+
+static int __init tc_init(void)
+{
+        return platform_driver_probe(&tc_driver, tc_probe);
+}
+arch_initcall(tc_init);