Re: [PATCH V12 2/4] ptp: Added a clock that uses the eTSEC found on the MPC85xx.
From: John Stultz <hidden>
Date: 2011-03-23 21:30:30
Also in:
linux-api, linux-arm-kernel, linux-devicetree, linuxppc-dev, lkml
On Mon, 2011-02-28 at 08:57 +0100, Richard Cochran wrote:
The eTSEC includes a PTP clock with quite a few features. This patch adds support for the basic clock adjustment functions, plus two external time stamps, one alarm, and the PPS callback.
Just a minor question on the locking, but otherwise looks ok.
quoted hunk ↗ jump to hunk
--- /dev/null +++ b/drivers/net/gianfar_ptp.c@@ -0,0 +1,579 @@
[snip]
quoted hunk ↗ jump to hunk
+/* + * Register access functions + */
So what are the locking rules on the functions below? I assume the etsects->lock needs to be held prior to calling, so that should be made explicit in a comment.
quoted hunk ↗ jump to hunk
+static u64 tmr_cnt_read(struct etsects *etsects) +{ + u64 ns; + u32 lo, hi; + + lo = gfar_read(&etsects->regs->tmr_cnt_l); + hi = gfar_read(&etsects->regs->tmr_cnt_h); + ns = ((u64) hi) << 32; + ns |= lo; + return ns; +} + +static void tmr_cnt_write(struct etsects *etsects, u64 ns) +{ + u32 hi = ns >> 32; + u32 lo = ns & 0xffffffff; + + gfar_write(&etsects->regs->tmr_cnt_l, lo); + gfar_write(&etsects->regs->tmr_cnt_h, hi); +} + +static void set_alarm(struct etsects *etsects) +{ + u64 ns; + u32 lo, hi; + + ns = tmr_cnt_read(etsects) + 1500000000ULL; + ns = div_u64(ns, 1000000000UL) * 1000000000ULL; + ns -= etsects->tclk_period; + hi = ns >> 32; + lo = ns & 0xffffffff; + gfar_write(&etsects->regs->tmr_alarm1_l, lo); + gfar_write(&etsects->regs->tmr_alarm1_h, hi); +} + +static void set_fipers(struct etsects *etsects) +{ + u32 tmr_ctrl = gfar_read(&etsects->regs->tmr_ctrl); + + gfar_write(&etsects->regs->tmr_ctrl, tmr_ctrl & (~TE)); + gfar_write(&etsects->regs->tmr_prsc, etsects->tmr_prsc); + gfar_write(&etsects->regs->tmr_fiper1, etsects->tmr_fiper1); + gfar_write(&etsects->regs->tmr_fiper2, etsects->tmr_fiper2); + set_alarm(etsects); + gfar_write(&etsects->regs->tmr_ctrl, tmr_ctrl|TE); +} +
[snip]
quoted hunk ↗ jump to hunk
+static int gianfar_ptp_probe(struct platform_device *dev) +{ + struct device_node *node = dev->dev.of_node; + struct etsects *etsects; + struct timespec now; + int err = -ENOMEM; + u32 tmr_ctrl; + + etsects = kzalloc(sizeof(*etsects), GFP_KERNEL); + if (!etsects) + goto no_memory; + + err = -ENODEV; + + etsects->caps = ptp_gianfar_caps; + etsects->cksel = DEFAULT_CKSEL; + + if (get_of_u32(node, "fsl,tclk-period", &etsects->tclk_period) || + get_of_u32(node, "fsl,tmr-prsc", &etsects->tmr_prsc) || + get_of_u32(node, "fsl,tmr-add", &etsects->tmr_add) || + get_of_u32(node, "fsl,tmr-fiper1", &etsects->tmr_fiper1) || + get_of_u32(node, "fsl,tmr-fiper2", &etsects->tmr_fiper2) || + get_of_u32(node, "fsl,max-adj", &etsects->caps.max_adj)) { + pr_err("device tree node missing required elements\n"); + goto no_node; + } + + etsects->irq = platform_get_irq(dev, 0); + + if (etsects->irq == NO_IRQ) { + pr_err("irq not in device tree\n"); + goto no_node; + } + if (request_irq(etsects->irq, isr, 0, DRIVER, etsects)) { + pr_err("request_irq failed\n"); + goto no_node; + } + + etsects->rsrc = platform_get_resource(dev, IORESOURCE_MEM, 0); + if (!etsects->rsrc) { + pr_err("no resource\n"); + goto no_resource; + } + if (request_resource(&ioport_resource, etsects->rsrc)) { + pr_err("resource busy\n"); + goto no_resource; + } + + spin_lock_init(&etsects->lock); + + etsects->regs = ioremap(etsects->rsrc->start, + 1 + etsects->rsrc->end - etsects->rsrc->start); + if (!etsects->regs) { + pr_err("ioremap ptp registers failed\n"); + goto no_ioremap; + } + getnstimeofday(&now); + ptp_gianfar_settime(&etsects->caps, &now); + + tmr_ctrl = + (etsects->tclk_period & TCLK_PERIOD_MASK) << TCLK_PERIOD_SHIFT | + (etsects->cksel & CKSEL_MASK) << CKSEL_SHIFT; + + gfar_write(&etsects->regs->tmr_ctrl, tmr_ctrl); + gfar_write(&etsects->regs->tmr_add, etsects->tmr_add); + gfar_write(&etsects->regs->tmr_prsc, etsects->tmr_prsc); + gfar_write(&etsects->regs->tmr_fiper1, etsects->tmr_fiper1); + gfar_write(&etsects->regs->tmr_fiper2, etsects->tmr_fiper2); + set_alarm(etsects); + gfar_write(&etsects->regs->tmr_ctrl, tmr_ctrl|FS|RTPE|TE);
Does any of the above need a lock should an irq land in the middle of the writes? thanks -john