1 // SPDX-License-Identifier: GPL-2.0
3  * Sensirion SPS30 particulate matter sensor serial driver
51 static int sps30_serial_xfer(struct sps30_state *state, const unsigned char *buf, size_t size)  in sps30_serial_xfer()  argument
53 	struct serdev_device *serdev = to_serdev_device(state->dev);  in sps30_serial_xfer()
54 	struct sps30_serial_priv *priv = state->priv;  in sps30_serial_xfer()
57 	priv->num = 0;  in sps30_serial_xfer()
58 	priv->escaped = false;  in sps30_serial_xfer()
59 	priv->done = false;  in sps30_serial_xfer()
65 		return -EIO;  in sps30_serial_xfer()
67 	ret = wait_for_completion_interruptible_timeout(&priv->new_frame, SPS30_SERIAL_TIMEOUT);  in sps30_serial_xfer()
71 		return -ETIMEDOUT;  in sps30_serial_xfer()
149 	chksum = sps30_serial_calc_chksum(buf + 1, num - 1);  in sps30_serial_prep_frame()
156 static bool sps30_serial_frame_valid(struct sps30_state *state, const unsigned char *buf)  in sps30_serial_frame_valid()  argument
158 	struct sps30_serial_priv *priv = state->priv;  in sps30_serial_frame_valid()
161 	if ((priv->num < SPS30_SERIAL_FRAME_MIN_SIZE) ||  in sps30_serial_frame_valid()
162 	    (priv->num != SPS30_SERIAL_FRAME_MIN_SIZE +  in sps30_serial_frame_valid()
163 	     priv->buf[SPS30_SERIAL_FRAME_MISO_LEN_OFFSET])) {  in sps30_serial_frame_valid()
164 		dev_err(state->dev, "frame has invalid number of bytes\n");  in sps30_serial_frame_valid()
168 	if ((priv->buf[SPS30_SERIAL_FRAME_ADR_OFFSET] != buf[SPS30_SERIAL_FRAME_ADR_OFFSET]) ||  in sps30_serial_frame_valid()
169 	    (priv->buf[SPS30_SERIAL_FRAME_CMD_OFFSET] != buf[SPS30_SERIAL_FRAME_CMD_OFFSET])) {  in sps30_serial_frame_valid()
170 		dev_err(state->dev, "frame has wrong ADR and CMD bytes\n");  in sps30_serial_frame_valid()
174 	if (priv->buf[SPS30_SERIAL_FRAME_MISO_STATE_OFFSET]) {  in sps30_serial_frame_valid()
175 		dev_err(state->dev, "frame with non-zero state received (0x%02x)\n",  in sps30_serial_frame_valid()
176 			priv->buf[SPS30_SERIAL_FRAME_MISO_STATE_OFFSET]);  in sps30_serial_frame_valid()
181 	chksum = sps30_serial_calc_chksum(priv->buf + 1, priv->num - 3);  in sps30_serial_frame_valid()
182 	if (priv->buf[priv->num - 2] != chksum) {  in sps30_serial_frame_valid()
183 		dev_err(state->dev, "frame integrity check failed\n");  in sps30_serial_frame_valid()
190 static int sps30_serial_command(struct sps30_state *state, unsigned char cmd,  in sps30_serial_command()  argument
193 	struct sps30_serial_priv *priv = state->priv;  in sps30_serial_command()
198 	ret = sps30_serial_xfer(state, buf, size);  in sps30_serial_command()
202 	if (!sps30_serial_frame_valid(state, buf))  in sps30_serial_command()
203 		return -EIO;  in sps30_serial_command()
206 		rsp_size = min_t(size_t, priv->buf[SPS30_SERIAL_FRAME_MISO_LEN_OFFSET], rsp_size);  in sps30_serial_command()
207 		memcpy(rsp, &priv->buf[SPS30_SERIAL_FRAME_MISO_DATA_OFFSET], rsp_size);  in sps30_serial_command()
216 	struct iio_dev *indio_dev = dev_get_drvdata(&serdev->dev);  in sps30_serial_receive_buf()
218 	struct sps30_state *state;  in sps30_serial_receive_buf()  local
225 	state = iio_priv(indio_dev);  in sps30_serial_receive_buf()
226 	priv = state->priv;  in sps30_serial_receive_buf()
229 	if (priv->done)  in sps30_serial_receive_buf()
233 	if (!priv->num && size && buf[0] != SPS30_SERIAL_SOF_EOF)  in sps30_serial_receive_buf()
236 	if (priv->num + size >= ARRAY_SIZE(priv->buf))  in sps30_serial_receive_buf()
237 		size = ARRAY_SIZE(priv->buf) - priv->num;  in sps30_serial_receive_buf()
241 		/* remove stuffed bytes on-the-fly */  in sps30_serial_receive_buf()
243 			priv->escaped = true;  in sps30_serial_receive_buf()
247 		byte = sps30_serial_get_byte(priv->escaped, byte);  in sps30_serial_receive_buf()
248 		if (priv->escaped && !byte)  in sps30_serial_receive_buf()
249 			dev_warn(state->dev, "unrecognized escaped char (0x%02x)\n", byte);  in sps30_serial_receive_buf()
251 		priv->buf[priv->num++] = byte;  in sps30_serial_receive_buf()
254 		if (!priv->escaped && byte == SPS30_SERIAL_SOF_EOF) {  in sps30_serial_receive_buf()
255 			if (priv->num < SPS30_SERIAL_FRAME_MIN_SIZE)  in sps30_serial_receive_buf()
258 			priv->done = true;  in sps30_serial_receive_buf()
259 			complete(&priv->new_frame);  in sps30_serial_receive_buf()
264 		priv->escaped = false;  in sps30_serial_receive_buf()
275 static int sps30_serial_start_meas(struct sps30_state *state)  in sps30_serial_start_meas()  argument
280 	return sps30_serial_command(state, SPS30_SERIAL_START_MEAS, buf, sizeof(buf), NULL, 0);  in sps30_serial_start_meas()
283 static int sps30_serial_stop_meas(struct sps30_state *state)  in sps30_serial_stop_meas()  argument
285 	return sps30_serial_command(state, SPS30_SERIAL_STOP_MEAS, NULL, 0, NULL, 0);  in sps30_serial_stop_meas()
288 static int sps30_serial_reset(struct sps30_state *state)  in sps30_serial_reset()  argument
292 	ret = sps30_serial_command(state, SPS30_SERIAL_RESET, NULL, 0, NULL, 0);  in sps30_serial_reset()
298 static int sps30_serial_read_meas(struct sps30_state *state, __be32 *meas, size_t num)  in sps30_serial_read_meas()  argument
304 		return -EINTR;  in sps30_serial_read_meas()
306 	ret = sps30_serial_command(state, SPS30_SERIAL_READ_MEAS, NULL, 0, meas, num * sizeof(num));  in sps30_serial_read_meas()
311 		return -ETIMEDOUT;  in sps30_serial_read_meas()
313 		return -EIO;  in sps30_serial_read_meas()
318 static int sps30_serial_clean_fan(struct sps30_state *state)  in sps30_serial_clean_fan()  argument
320 	return sps30_serial_command(state, SPS30_SERIAL_CLEAN_FAN, NULL, 0, NULL, 0);  in sps30_serial_clean_fan()
323 static int sps30_serial_read_cleaning_period(struct sps30_state *state, __be32 *period)  in sps30_serial_read_cleaning_period()  argument
328 	ret = sps30_serial_command(state, SPS30_SERIAL_PERIOD, buf, sizeof(buf),  in sps30_serial_read_cleaning_period()
333 		return -EIO;  in sps30_serial_read_cleaning_period()
338 static int sps30_serial_write_cleaning_period(struct sps30_state *state, __be32 period)  in sps30_serial_write_cleaning_period()  argument
344 	return sps30_serial_command(state, SPS30_SERIAL_PERIOD, buf, sizeof(buf), NULL, 0);  in sps30_serial_write_cleaning_period()
347 static int sps30_serial_show_info(struct sps30_state *state)  in sps30_serial_show_info()  argument
350 	 * tell device do return serial number and add extra nul byte just in case  in sps30_serial_show_info()
351 	 * serial number isn't a valid string  in sps30_serial_show_info()
354 	struct device *dev = state->dev;  in sps30_serial_show_info()
357 	ret = sps30_serial_command(state, SPS30_SERIAL_DEV_INFO, buf, 1, buf, sizeof(buf) - 1);  in sps30_serial_show_info()
360 	if (ret != sizeof(buf) - 1)  in sps30_serial_show_info()
361 		return -EIO;  in sps30_serial_show_info()
363 	dev_info(dev, "serial number: %s\n", buf);  in sps30_serial_show_info()
365 	ret = sps30_serial_command(state, SPS30_SERIAL_READ_VERSION, NULL, 0, buf, sizeof(buf) - 1);  in sps30_serial_show_info()
369 		return -EIO;  in sps30_serial_show_info()
389 	struct device *dev = &serdev->dev;  in sps30_serial_probe()
395 		return -ENOMEM;  in sps30_serial_probe()
397 	init_completion(&priv->new_frame);  in sps30_serial_probe()
430 MODULE_DESCRIPTION("Sensirion SPS30 particulate matter sensor serial driver");