Re: [PATCH v7] ptp: ocp: add CPLD ISP support for ADVA TimeCard X1

[Vadim Fedorenko <vadim.fedorenko@linux.dev>]

On 30.07.2026 14:43, Sagi Maimon wrote:
> The ADVA TimeCard X1 (PCI device 0x0410) uses a Lattice MachXO3 CPLD
> that is programmed over I2C using in-system programming (ISP).
> 
> The CPLD is connected to a secondary I2C bus shared with the onboard
> MicroBlaze soft CPU.
> 
> Add support for CPLD access and firmware updates on the ADVA TimeCard X1
> board by arbitration of the shared I2C bus, CPLD ISP command handling,
> status polling, and firmware upload operations using the firmware-upload
> subsystem.
> 
> Add the following X1-only user-visible interfaces:
> 
>    /sys/class/timecard/ocpN/cpld_device_id
>          report the 32-bit Lattice MachXO3 CPLD device ID
> 
>    /sys/class/timecard/ocpN/cpld_status
>          report the CPLD status register, including the DONE,
>          BUSY, and FAILED indicators
> 
> Firmware updates are performed through the firmware-upload framework,
> which acquires ownership of the shared I2C bus, erases the CPLD
> configuration flash, programs the image page-by-page, and activates
> the new image using the MachXO3 REFRESH command.
> 
> All CPLD operations are serialized and coordinated with the MicroBlaze
> firmware to ensure exclusive access to the shared I2C bus. The added
> interfaces are available only on ADVA TimeCard X1 boards.
> 
> Signed-off-by: Sagi Maimon <maimon.sagi@gmail.com>

[...]

> + * Send a 4-byte command then read data back without an intermediate STOP
> + * (Lattice combined write→repeated-START→read).
> + */
> +static int adva_x1_cpld_cmd_read(struct ptp_ocp *bp,
> +				 u32 cmd_be, u8 *out, u8 out_len)
> +{
> +	u8 cmd[4] = {
> +		(cmd_be >> 24) & 0xFF,
> +		(cmd_be >> 16) & 0xFF,
> +		(cmd_be >>  8) & 0xFF,
> +		cmd_be & 0xFF,
> +	};

this is open-coded be32_to_cpu(), please, convert the code to use it.
maybe make adva_x1_i2c_xfer() buffer pointers as void* to avoid extra cast.

> +	return adva_x1_i2c_xfer(bp, ADVA_CPLD_ADDR, cmd, 4, out, out_len, true);
> +}
> +
> +static int adva_x1_cpld_read_status(struct ptp_ocp *bp, u32 *status)
> +{
> +	u8 buf[4];
> +	int ret;
> +
> +	ret = adva_x1_cpld_cmd_read(bp, CPLD_CMD_READ_STATUS, buf, 4);
> +	if (ret)
> +		return ret;
> +	*status = ((u32)buf[0] << 24) | ((u32)buf[1] << 16) |
> +		  ((u32)buf[2] <<  8) |  (u32)buf[3];

here we have cpu_to_be32() I believe - please use lib functions.

> +	return 0;
> +}
> +
> +static int adva_x1_cpld_wait_ready(struct ptp_ocp *bp, unsigned int max_ms)
> +{
> +	u32 status;
> +	unsigned int elapsed = 0;
> +
> +	while (elapsed < max_ms) {
> +		if (adva_x1_cpld_read_status(bp, &status))
> +			return -EIO;
> +		if (status & CPLD_STATUS_FAILED)
> +			return -EIO;
> +		if (!(status & CPLD_STATUS_BUSY))
> +			return 0;
> +		usleep_range(100000, 101000);
> +		elapsed += 100;
> +	}
> +	return -ETIMEDOUT;
> +}
> +
> +/*
> + * cpld_device_id - show the Lattice device ID of the TAP CPLD.
> + *
> + * Returns the 32-bit ID as a hex string, e.g. "0x612bc043\n".
> + * Lattice LCMXO3LF-210 reports 0x612BC043.
> + */
> +static ssize_t
> +cpld_device_id_show(struct device *dev, struct device_attribute *attr,
> +		    char *buf)
> +{
> +	struct ptp_ocp *bp = dev_get_drvdata(dev);
> +	u8 data[4];
> +	u32 id = 0;
> +	int ret;
> +
> +	mutex_lock(&bp->cpld_lock);
> +	ret = adva_x1_mblaze_acquire(bp);
> +	if (ret)
> +		goto out;
> +	ret = adva_x1_mux_select(bp, ADVA_MUX_CHANNEL);
> +	if (ret)
> +		goto release;
> +	ret = adva_x1_cpld_cmd_read(bp, CPLD_CMD_READ_ID, data, 4);
> +	if (!ret)
> +		id = ((u32)data[0] << 24) | ((u32)data[1] << 16) |
> +		     ((u32)data[2] <<  8) |  (u32)data[3];

ditto

> +	adva_x1_mux_select(bp, -1);
> +release:
> +	adva_x1_mblaze_release(bp);
> +out:
> +	mutex_unlock(&bp->cpld_lock);
> +	return ret ? ret : sysfs_emit(buf, "0x%08x\n", id);
> +}
> +static DEVICE_ATTR_RO(cpld_device_id);
> +