ptp: Added a clock driver for the IXP46x.
This patch adds a driver for the hardware time stamping unit found on the
IXP465. The basic clock operations and an external trigger are implemented.
Signed-off-by: Richard Cochran <richard.cochran@omicron.at>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: John Stultz <john.stultz@linaro.org>
Acked-by: Krzysztof Halasa <khc@pm.waw.pl>
Signed-off-by: John Stultz <john.stultz@linaro.org>
diff --git a/drivers/ptp/ptp_ixp46x.c b/drivers/ptp/ptp_ixp46x.c
new file mode 100644
index 0000000..803d665
--- /dev/null
+++ b/drivers/ptp/ptp_ixp46x.c
@@ -0,0 +1,332 @@
+/*
+ * PTP 1588 clock using the IXP46X
+ *
+ * Copyright (C) 2010 OMICRON electronics GmbH
+ *
+ * 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.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/gpio.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include <linux/ptp_clock_kernel.h>
+#include <mach/ixp46x_ts.h>
+
+#define DRIVER "ptp_ixp46x"
+#define N_EXT_TS 2
+#define MASTER_GPIO 8
+#define MASTER_IRQ 25
+#define SLAVE_GPIO 7
+#define SLAVE_IRQ 24
+
+struct ixp_clock {
+ struct ixp46x_ts_regs *regs;
+ struct ptp_clock *ptp_clock;
+ struct ptp_clock_info caps;
+ int exts0_enabled;
+ int exts1_enabled;
+};
+
+DEFINE_SPINLOCK(register_lock);
+
+/*
+ * Register access functions
+ */
+
+static u64 ixp_systime_read(struct ixp46x_ts_regs *regs)
+{
+ u64 ns;
+ u32 lo, hi;
+
+ lo = __raw_readl(®s->systime_lo);
+ hi = __raw_readl(®s->systime_hi);
+
+ ns = ((u64) hi) << 32;
+ ns |= lo;
+ ns <<= TICKS_NS_SHIFT;
+
+ return ns;
+}
+
+static void ixp_systime_write(struct ixp46x_ts_regs *regs, u64 ns)
+{
+ u32 hi, lo;
+
+ ns >>= TICKS_NS_SHIFT;
+ hi = ns >> 32;
+ lo = ns & 0xffffffff;
+
+ __raw_writel(lo, ®s->systime_lo);
+ __raw_writel(hi, ®s->systime_hi);
+}
+
+/*
+ * Interrupt service routine
+ */
+
+static irqreturn_t isr(int irq, void *priv)
+{
+ struct ixp_clock *ixp_clock = priv;
+ struct ixp46x_ts_regs *regs = ixp_clock->regs;
+ struct ptp_clock_event event;
+ u32 ack = 0, lo, hi, val;
+
+ val = __raw_readl(®s->event);
+
+ if (val & TSER_SNS) {
+ ack |= TSER_SNS;
+ if (ixp_clock->exts0_enabled) {
+ hi = __raw_readl(®s->asms_hi);
+ lo = __raw_readl(®s->asms_lo);
+ event.type = PTP_CLOCK_EXTTS;
+ event.index = 0;
+ event.timestamp = ((u64) hi) << 32;
+ event.timestamp |= lo;
+ event.timestamp <<= TICKS_NS_SHIFT;
+ ptp_clock_event(ixp_clock->ptp_clock, &event);
+ }
+ }
+
+ if (val & TSER_SNM) {
+ ack |= TSER_SNM;
+ if (ixp_clock->exts1_enabled) {
+ hi = __raw_readl(®s->amms_hi);
+ lo = __raw_readl(®s->amms_lo);
+ event.type = PTP_CLOCK_EXTTS;
+ event.index = 1;
+ event.timestamp = ((u64) hi) << 32;
+ event.timestamp |= lo;
+ event.timestamp <<= TICKS_NS_SHIFT;
+ ptp_clock_event(ixp_clock->ptp_clock, &event);
+ }
+ }
+
+ if (val & TTIPEND)
+ ack |= TTIPEND; /* this bit seems to be always set */
+
+ if (ack) {
+ __raw_writel(ack, ®s->event);
+ return IRQ_HANDLED;
+ } else
+ return IRQ_NONE;
+}
+
+/*
+ * PTP clock operations
+ */
+
+static int ptp_ixp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
+{
+ u64 adj;
+ u32 diff, addend;
+ int neg_adj = 0;
+ struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
+ struct ixp46x_ts_regs *regs = ixp_clock->regs;
+
+ if (ppb < 0) {
+ neg_adj = 1;
+ ppb = -ppb;
+ }
+ addend = DEFAULT_ADDEND;
+ adj = addend;
+ adj *= ppb;
+ diff = div_u64(adj, 1000000000ULL);
+
+ addend = neg_adj ? addend - diff : addend + diff;
+
+ __raw_writel(addend, ®s->addend);
+
+ return 0;
+}
+
+static int ptp_ixp_adjtime(struct ptp_clock_info *ptp, s64 delta)
+{
+ s64 now;
+ unsigned long flags;
+ struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
+ struct ixp46x_ts_regs *regs = ixp_clock->regs;
+
+ spin_lock_irqsave(®ister_lock, flags);
+
+ now = ixp_systime_read(regs);
+ now += delta;
+ ixp_systime_write(regs, now);
+
+ spin_unlock_irqrestore(®ister_lock, flags);
+
+ return 0;
+}
+
+static int ptp_ixp_gettime(struct ptp_clock_info *ptp, struct timespec *ts)
+{
+ u64 ns;
+ u32 remainder;
+ unsigned long flags;
+ struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
+ struct ixp46x_ts_regs *regs = ixp_clock->regs;
+
+ spin_lock_irqsave(®ister_lock, flags);
+
+ ns = ixp_systime_read(regs);
+
+ spin_unlock_irqrestore(®ister_lock, flags);
+
+ ts->tv_sec = div_u64_rem(ns, 1000000000, &remainder);
+ ts->tv_nsec = remainder;
+ return 0;
+}
+
+static int ptp_ixp_settime(struct ptp_clock_info *ptp,
+ const struct timespec *ts)
+{
+ u64 ns;
+ unsigned long flags;
+ struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
+ struct ixp46x_ts_regs *regs = ixp_clock->regs;
+
+ ns = ts->tv_sec * 1000000000ULL;
+ ns += ts->tv_nsec;
+
+ spin_lock_irqsave(®ister_lock, flags);
+
+ ixp_systime_write(regs, ns);
+
+ spin_unlock_irqrestore(®ister_lock, flags);
+
+ return 0;
+}
+
+static int ptp_ixp_enable(struct ptp_clock_info *ptp,
+ struct ptp_clock_request *rq, int on)
+{
+ struct ixp_clock *ixp_clock = container_of(ptp, struct ixp_clock, caps);
+
+ switch (rq->type) {
+ case PTP_CLK_REQ_EXTTS:
+ switch (rq->extts.index) {
+ case 0:
+ ixp_clock->exts0_enabled = on ? 1 : 0;
+ break;
+ case 1:
+ ixp_clock->exts1_enabled = on ? 1 : 0;
+ break;
+ default:
+ return -EINVAL;
+ }
+ return 0;
+ default:
+ break;
+ }
+
+ return -EOPNOTSUPP;
+}
+
+static struct ptp_clock_info ptp_ixp_caps = {
+ .owner = THIS_MODULE,
+ .name = "IXP46X timer",
+ .max_adj = 66666655,
+ .n_ext_ts = N_EXT_TS,
+ .pps = 0,
+ .adjfreq = ptp_ixp_adjfreq,
+ .adjtime = ptp_ixp_adjtime,
+ .gettime = ptp_ixp_gettime,
+ .settime = ptp_ixp_settime,
+ .enable = ptp_ixp_enable,
+};
+
+/* module operations */
+
+static struct ixp_clock ixp_clock;
+
+static int setup_interrupt(int gpio)
+{
+ int irq;
+
+ gpio_line_config(gpio, IXP4XX_GPIO_IN);
+
+ irq = gpio_to_irq(gpio);
+
+ if (NO_IRQ == irq)
+ return NO_IRQ;
+
+ if (irq_set_irq_type(irq, IRQF_TRIGGER_FALLING)) {
+ pr_err("cannot set trigger type for irq %d\n", irq);
+ return NO_IRQ;
+ }
+
+ if (request_irq(irq, isr, 0, DRIVER, &ixp_clock)) {
+ pr_err("request_irq failed for irq %d\n", irq);
+ return NO_IRQ;
+ }
+
+ return irq;
+}
+
+static void __exit ptp_ixp_exit(void)
+{
+ free_irq(MASTER_IRQ, &ixp_clock);
+ free_irq(SLAVE_IRQ, &ixp_clock);
+ ptp_clock_unregister(ixp_clock.ptp_clock);
+}
+
+static int __init ptp_ixp_init(void)
+{
+ if (!cpu_is_ixp46x())
+ return -ENODEV;
+
+ ixp_clock.regs =
+ (struct ixp46x_ts_regs __iomem *) IXP4XX_TIMESYNC_BASE_VIRT;
+
+ ixp_clock.caps = ptp_ixp_caps;
+
+ ixp_clock.ptp_clock = ptp_clock_register(&ixp_clock.caps);
+
+ if (IS_ERR(ixp_clock.ptp_clock))
+ return PTR_ERR(ixp_clock.ptp_clock);
+
+ __raw_writel(DEFAULT_ADDEND, &ixp_clock.regs->addend);
+ __raw_writel(1, &ixp_clock.regs->trgt_lo);
+ __raw_writel(0, &ixp_clock.regs->trgt_hi);
+ __raw_writel(TTIPEND, &ixp_clock.regs->event);
+
+ if (MASTER_IRQ != setup_interrupt(MASTER_GPIO)) {
+ pr_err("failed to setup gpio %d as irq\n", MASTER_GPIO);
+ goto no_master;
+ }
+ if (SLAVE_IRQ != setup_interrupt(SLAVE_GPIO)) {
+ pr_err("failed to setup gpio %d as irq\n", SLAVE_GPIO);
+ goto no_slave;
+ }
+
+ return 0;
+no_slave:
+ free_irq(MASTER_IRQ, &ixp_clock);
+no_master:
+ ptp_clock_unregister(ixp_clock.ptp_clock);
+ return -ENODEV;
+}
+
+module_init(ptp_ixp_init);
+module_exit(ptp_ixp_exit);
+
+MODULE_AUTHOR("Richard Cochran <richard.cochran@omicron.at>");
+MODULE_DESCRIPTION("PTP clock using the IXP46X timer");
+MODULE_LICENSE("GPL");