Re: [PATCH net-next v3 12/12] net: dsa: microchip: ksz9477: add periodic output support
From: Vladimir Oltean <olteanv@gmail.com>
Date: 2020-11-20 23:48:34
Also in:
linux-devicetree, lkml
On Wed, Nov 18, 2020 at 09:30:13PM +0100, Christian Eggers wrote:
quoted hunk ↗ jump to hunk
The KSZ9563 has a Trigger Output Unit (TOU) which can be used to generate periodic signals. The pulse length can be altered via a device attribute. Tested on a Microchip KSZ9563 switch. Signed-off-by: Christian Eggers <ceggers@arri.de> --- drivers/net/dsa/microchip/ksz9477_ptp.c | 197 +++++++++++++++++++++++- drivers/net/dsa/microchip/ksz_common.h | 5 + 2 files changed, 201 insertions(+), 1 deletion(-)diff --git a/drivers/net/dsa/microchip/ksz9477_ptp.c b/drivers/net/dsa/microchip/ksz9477_ptp.c index ce3fdc9a1f9e..3174574d52f6 100644 --- a/drivers/net/dsa/microchip/ksz9477_ptp.c +++ b/drivers/net/dsa/microchip/ksz9477_ptp.c@@ -90,6 +90,20 @@ static int ksz9477_ptp_tou_cycle_count_set(struct ksz_device *dev, u16 count) return 0; } +static int ksz9477_ptp_tou_pulse_verify(u64 pulse_ns) +{ + u32 data; + + if (pulse_ns & 0x3) + return -EINVAL; + + data = (pulse_ns / 8); + if (data != (data & TRIG_PULSE_WIDTH_M)) + return -ERANGE; + + return 0; +} + static int ksz9477_ptp_tou_pulse_set(struct ksz_device *dev, u32 pulse_ns) { u32 data;@@ -196,6 +210,7 @@ static int ksz9477_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm) return ret; } +static int ksz9477_ptp_restart_perout(struct ksz_device *dev); static int ksz9477_ptp_enable_pps(struct ksz_device *dev, int on); static int ksz9477_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)@@ -241,6 +256,15 @@ static int ksz9477_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta) case KSZ_PTP_TOU_IDLE: break; + case KSZ_PTP_TOU_PEROUT: + dev_info(dev->dev, "Restarting periodic output signal\n");
Isn't this a bit too verbose, or is there something for the user to be concerned about?
quoted hunk ↗ jump to hunk
+ + ret = ksz9477_ptp_restart_perout(dev); + if (ret) + goto error_return; + + break; + case KSZ_PTP_TOU_PPS: dev_info(dev->dev, "Restarting PPS\n");@@ -358,6 +382,15 @@ static int ksz9477_ptp_settime(struct ptp_clock_info *ptp, case KSZ_PTP_TOU_IDLE: break; + case KSZ_PTP_TOU_PEROUT: + dev_info(dev->dev, "Restarting periodic output signal\n"); + + ret = ksz9477_ptp_restart_perout(dev); + if (ret) + goto error_return; + + break; + case KSZ_PTP_TOU_PPS: dev_info(dev->dev, "Restarting PPS\n");@@ -377,6 +410,159 @@ static int ksz9477_ptp_settime(struct ptp_clock_info *ptp, return ret; } +static int ksz9477_ptp_configure_perout(struct ksz_device *dev, u32 cycle_width_ns,
Watch out for 80 characters, please!
+ u16 cycle_count, u32 pulse_width_ns,
+ struct timespec64 const *target_time)
+{
+ int ret;
+ u32 trig_ctrl;Reverse Christmas tree.
+
+ /* Enable notify, set rising edge, set periodic pattern */
+ trig_ctrl = TRIG_NOTIFY | (TRIG_POS_PERIOD << TRIG_PATTERN_S);
+ ret = ksz_write32(dev, REG_TRIG_CTRL__4, trig_ctrl);
+ if (ret)
+ return ret;
+
+ ret = ksz9477_ptp_tou_cycle_width_set(dev, cycle_width_ns);
+ if (ret)
+ return ret;
+
+ ksz9477_ptp_tou_cycle_count_set(dev, cycle_count);
+ if (ret)
+ return ret;
+
+ ret = ksz9477_ptp_tou_pulse_set(dev, pulse_width_ns);
+ if (ret)
+ return ret;
+
+ ret = ksz9477_ptp_tou_target_time_set(dev, target_time);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static int ksz9477_ptp_enable_perout(struct ksz_device *dev,
+ struct ptp_perout_request const *perout_request, int on)
+{
+ u32 gpio_stat0;
+ u64 cycle_width_ns;
+ int ret;
+
+ if (dev->ptp_tou_mode != KSZ_PTP_TOU_PEROUT && dev->ptp_tou_mode != KSZ_PTP_TOU_IDLE)
+ return -EBUSY;
+
+ ret = ksz9477_ptp_tou_reset(dev, 0);
+ if (ret)
+ return ret;
+
+ if (!on) {
+ dev->ptp_tou_mode = KSZ_PTP_TOU_IDLE;
+ return 0; /* success */
+ }
+
+ dev->ptp_perout_target_time_first.tv_sec = perout_request->start.sec;
+ dev->ptp_perout_target_time_first.tv_nsec = perout_request->start.nsec;
+
+ dev->ptp_perout_period.tv_sec = perout_request->period.sec;
+ dev->ptp_perout_period.tv_nsec = perout_request->period.nsec;
+
+ cycle_width_ns = timespec64_to_ns(&dev->ptp_perout_period);
+ if ((cycle_width_ns & GENMASK(31, 0)) != cycle_width_ns)
+ return -EINVAL;
+
+ if (perout_request->flags & PTP_PEROUT_DUTY_CYCLE) {
+ u64 value = perout_request->on.sec * NSEC_PER_SEC +
+ perout_request->on.nsec;
+
+ ret = ksz9477_ptp_tou_pulse_verify(value);
+ if (ret)
+ return ret;
+
+ dev->ptp_perout_pulse_width_ns = value;
+ }It is not guaranteed that user space will set this flag. Shouldn't you assign a default value for the pulse width? I don't know, half the period should be a good default. Also, please reject PTP_PEROUT_ONE_SHOT and PTP_PEROUT_PHASE, since you don't do anything with them, but user space might be led into believing otherwise.
+
+ ret = ksz9477_ptp_configure_perout(dev, cycle_width_ns,
+ dev->ptp_perout_cycle_count,
+ dev->ptp_perout_pulse_width_ns,
+ &dev->ptp_perout_target_time_first);
+ if (ret)
+ return ret;
+
+ /* Activate trigger unit */
+ ret = ksz9477_ptp_tou_start(dev, NULL);
+ if (ret)
+ return ret;
+
+ /* Check error flag:
+ * - the ACTIVE flag is NOT cleared an error!
+ */
+ ret = ksz_read32(dev, REG_PTP_TRIG_STATUS__4, &gpio_stat0);
+ if (ret)
+ return ret;
+
+ if (gpio_stat0 & (1 << (0 + TRIG_ERROR_S))) {What is the role of this "0 +" term here?
+ dev_err(dev->dev, "%s: Trigger unit0 error!\n", __func__); + ret = -EIO; + /* Unit will be reset on next access */ + return ret; + } + + dev->ptp_tou_mode = KSZ_PTP_TOU_PEROUT; + return 0; +}