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authorLinus Torvalds <torvalds@linux-foundation.org>2021-07-06 00:01:53 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2021-07-06 00:01:53 +0300
commita16d8644bad461bb073b92e812080ea6715ddf2b (patch)
tree2baa375527e57c0df2bf56d28e7cf36fb97a435c /drivers/iio/chemical/sps30_serial.c
parentf5c13f1fdef9fed65b95c3c5f343d22c425ac1d7 (diff)
parent77ad1f0e99bd00af024e650b862cfda3137af660 (diff)
downloadlinux-a16d8644bad461bb073b92e812080ea6715ddf2b.tar.xz
Merge tag 'staging-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging / IIO driver updates from Greg KH: "Here is the big set of IIO and staging driver patches for 5.14-rc1. Loads of IIO driver updates and additions in here, the shortlog has the full details. For the staging side, we moved a few drivers out of staging, and deleted the kpc2000 drivers as the original developer asked us to because no one was working on them anymore. Also in here are loads of coding style cleanups due to different intern projects focusing on the staging tree to try to get experience doing kernel development. All of these have been in the linux-next tree for a while with no reported problems" * tag 'staging-5.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (744 commits) staging: hi6421-spmi-pmic: cleanup some macros staging: hi6421-spmi-pmic: change identation of a table staging: hi6421-spmi-pmic: change a return code staging: hi6421-spmi-pmic: better name IRQs staging: hi6421-spmi-pmic: use devm_request_threaded_irq() staging: hisilicon,hi6421-spmi-pmic.yaml: cleanup descriptions spmi: hisi-spmi-controller: move driver from staging phy: phy-hi3670-usb3: move driver from staging into phy staging: rtl8188eu: remove include/rtw_debug.h header staging: rtl8188eu: remove GlobalDebugLevel variable staging: rtl8188eu: remove DRIVER_PREFIX preprocessor definition staging: rtl8188eu: remove RT_TRACE macro staging: rtl8188eu: remove all RT_TRACE calls from hal/rtl8188eu_recv.c staging: rtl8188eu: remove all RT_TRACE calls from hal/hal_intf.c staging: rtl8188eu: remove all RT_TRACE calls from hal/rtl8188eu_xmit.c staging: rtl8188eu: remove all RT_TRACE calls from core/rtw_xmit.c staging: rtl8188eu: remove all RT_TRACE calls from core/rtw_pwrctrl.c staging: rtl8188eu: remove all RT_TRACE calls from core/rtw_recv.c staging: rtl8188eu: remove all RT_TRACE calls from core/rtw_ioctl_set.c staging: rtl8188eu: remove all RT_TRACE calls from core/rtw_ieee80211.c ...
Diffstat (limited to 'drivers/iio/chemical/sps30_serial.c')
-rw-r--r--drivers/iio/chemical/sps30_serial.c431
1 files changed, 431 insertions, 0 deletions
diff --git a/drivers/iio/chemical/sps30_serial.c b/drivers/iio/chemical/sps30_serial.c
new file mode 100644
index 000000000000..3f311d50087c
--- /dev/null
+++ b/drivers/iio/chemical/sps30_serial.c
@@ -0,0 +1,431 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Sensirion SPS30 particulate matter sensor serial driver
+ *
+ * Copyright (c) 2021 Tomasz Duszynski <tomasz.duszynski@octakon.com>
+ */
+#include <linux/completion.h>
+#include <linux/device.h>
+#include <linux/errno.h>
+#include <linux/iio/iio.h>
+#include <linux/minmax.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/serdev.h>
+#include <linux/types.h>
+
+#include "sps30.h"
+
+#define SPS30_SERIAL_DEV_NAME "sps30"
+
+#define SPS30_SERIAL_SOF_EOF 0x7e
+#define SPS30_SERIAL_TIMEOUT msecs_to_jiffies(20)
+#define SPS30_SERIAL_MAX_BUF_SIZE 263
+#define SPS30_SERIAL_ESCAPE_CHAR 0x7d
+
+#define SPS30_SERIAL_FRAME_MIN_SIZE 7
+#define SPS30_SERIAL_FRAME_ADR_OFFSET 1
+#define SPS30_SERIAL_FRAME_CMD_OFFSET 2
+#define SPS30_SERIAL_FRAME_MOSI_LEN_OFFSET 3
+#define SPS30_SERIAL_FRAME_MISO_STATE_OFFSET 3
+#define SPS30_SERIAL_FRAME_MISO_LEN_OFFSET 4
+#define SPS30_SERIAL_FRAME_MISO_DATA_OFFSET 5
+
+#define SPS30_SERIAL_START_MEAS 0x00
+#define SPS30_SERIAL_STOP_MEAS 0x01
+#define SPS30_SERIAL_READ_MEAS 0x03
+#define SPS30_SERIAL_RESET 0xd3
+#define SPS30_SERIAL_CLEAN_FAN 0x56
+#define SPS30_SERIAL_PERIOD 0x80
+#define SPS30_SERIAL_DEV_INFO 0xd0
+#define SPS30_SERIAL_READ_VERSION 0xd1
+
+struct sps30_serial_priv {
+ struct completion new_frame;
+ unsigned char buf[SPS30_SERIAL_MAX_BUF_SIZE];
+ size_t num;
+ bool escaped;
+ bool done;
+};
+
+static int sps30_serial_xfer(struct sps30_state *state, const unsigned char *buf, size_t size)
+{
+ struct serdev_device *serdev = to_serdev_device(state->dev);
+ struct sps30_serial_priv *priv = state->priv;
+ int ret;
+
+ priv->num = 0;
+ priv->escaped = false;
+ priv->done = false;
+
+ ret = serdev_device_write(serdev, buf, size, SPS30_SERIAL_TIMEOUT);
+ if (ret < 0)
+ return ret;
+ if (ret != size)
+ return -EIO;
+
+ ret = wait_for_completion_interruptible_timeout(&priv->new_frame, SPS30_SERIAL_TIMEOUT);
+ if (ret < 0)
+ return ret;
+ if (!ret)
+ return -ETIMEDOUT;
+
+ return 0;
+}
+
+static const struct {
+ unsigned char byte;
+ unsigned char byte2;
+} sps30_serial_bytes[] = {
+ { 0x11, 0x31 },
+ { 0x13, 0x33 },
+ { 0x7e, 0x5e },
+ { 0x7d, 0x5d },
+};
+
+static int sps30_serial_put_byte(unsigned char *buf, unsigned char byte)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(sps30_serial_bytes); i++) {
+ if (sps30_serial_bytes[i].byte != byte)
+ continue;
+
+ buf[0] = SPS30_SERIAL_ESCAPE_CHAR;
+ buf[1] = sps30_serial_bytes[i].byte2;
+
+ return 2;
+ }
+
+ buf[0] = byte;
+
+ return 1;
+}
+
+static char sps30_serial_get_byte(bool escaped, unsigned char byte2)
+{
+ int i;
+
+ if (!escaped)
+ return byte2;
+
+ for (i = 0; i < ARRAY_SIZE(sps30_serial_bytes); i++) {
+ if (sps30_serial_bytes[i].byte2 != byte2)
+ continue;
+
+ return sps30_serial_bytes[i].byte;
+ }
+
+ return 0;
+}
+
+static unsigned char sps30_serial_calc_chksum(const unsigned char *buf, size_t num)
+{
+ unsigned int chksum = 0;
+ size_t i;
+
+ for (i = 0; i < num; i++)
+ chksum += buf[i];
+
+ return ~chksum;
+}
+
+static int sps30_serial_prep_frame(unsigned char *buf, unsigned char cmd,
+ const unsigned char *arg, size_t arg_size)
+{
+ unsigned char chksum;
+ int num = 0;
+ size_t i;
+
+ buf[num++] = SPS30_SERIAL_SOF_EOF;
+ buf[num++] = 0;
+ num += sps30_serial_put_byte(buf + num, cmd);
+ num += sps30_serial_put_byte(buf + num, arg_size);
+
+ for (i = 0; i < arg_size; i++)
+ num += sps30_serial_put_byte(buf + num, arg[i]);
+
+ /* SOF isn't checksummed */
+ chksum = sps30_serial_calc_chksum(buf + 1, num - 1);
+ num += sps30_serial_put_byte(buf + num, chksum);
+ buf[num++] = SPS30_SERIAL_SOF_EOF;
+
+ return num;
+}
+
+static bool sps30_serial_frame_valid(struct sps30_state *state, const unsigned char *buf)
+{
+ struct sps30_serial_priv *priv = state->priv;
+ unsigned char chksum;
+
+ if ((priv->num < SPS30_SERIAL_FRAME_MIN_SIZE) ||
+ (priv->num != SPS30_SERIAL_FRAME_MIN_SIZE +
+ priv->buf[SPS30_SERIAL_FRAME_MISO_LEN_OFFSET])) {
+ dev_err(state->dev, "frame has invalid number of bytes\n");
+ return false;
+ }
+
+ if ((priv->buf[SPS30_SERIAL_FRAME_ADR_OFFSET] != buf[SPS30_SERIAL_FRAME_ADR_OFFSET]) ||
+ (priv->buf[SPS30_SERIAL_FRAME_CMD_OFFSET] != buf[SPS30_SERIAL_FRAME_CMD_OFFSET])) {
+ dev_err(state->dev, "frame has wrong ADR and CMD bytes\n");
+ return false;
+ }
+
+ if (priv->buf[SPS30_SERIAL_FRAME_MISO_STATE_OFFSET]) {
+ dev_err(state->dev, "frame with non-zero state received (0x%02x)\n",
+ priv->buf[SPS30_SERIAL_FRAME_MISO_STATE_OFFSET]);
+ return false;
+ }
+
+ /* SOF, checksum and EOF are not checksummed */
+ chksum = sps30_serial_calc_chksum(priv->buf + 1, priv->num - 3);
+ if (priv->buf[priv->num - 2] != chksum) {
+ dev_err(state->dev, "frame integrity check failed\n");
+ return false;
+ }
+
+ return true;
+}
+
+static int sps30_serial_command(struct sps30_state *state, unsigned char cmd,
+ const void *arg, size_t arg_size, void *rsp, size_t rsp_size)
+{
+ struct sps30_serial_priv *priv = state->priv;
+ unsigned char buf[SPS30_SERIAL_MAX_BUF_SIZE];
+ int ret, size;
+
+ size = sps30_serial_prep_frame(buf, cmd, arg, arg_size);
+ ret = sps30_serial_xfer(state, buf, size);
+ if (ret)
+ return ret;
+
+ if (!sps30_serial_frame_valid(state, buf))
+ return -EIO;
+
+ if (rsp) {
+ rsp_size = min_t(size_t, priv->buf[SPS30_SERIAL_FRAME_MISO_LEN_OFFSET], rsp_size);
+ memcpy(rsp, &priv->buf[SPS30_SERIAL_FRAME_MISO_DATA_OFFSET], rsp_size);
+ }
+
+ return rsp_size;
+}
+
+static int sps30_serial_receive_buf(struct serdev_device *serdev,
+ const unsigned char *buf, size_t size)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(&serdev->dev);
+ struct sps30_serial_priv *priv;
+ struct sps30_state *state;
+ unsigned char byte;
+ size_t i;
+
+ if (!indio_dev)
+ return 0;
+
+ state = iio_priv(indio_dev);
+ priv = state->priv;
+
+ /* just in case device put some unexpected data on the bus */
+ if (priv->done)
+ return size;
+
+ /* wait for the start of frame */
+ if (!priv->num && size && buf[0] != SPS30_SERIAL_SOF_EOF)
+ return 1;
+
+ if (priv->num + size >= ARRAY_SIZE(priv->buf))
+ size = ARRAY_SIZE(priv->buf) - priv->num;
+
+ for (i = 0; i < size; i++) {
+ byte = buf[i];
+ /* remove stuffed bytes on-the-fly */
+ if (byte == SPS30_SERIAL_ESCAPE_CHAR) {
+ priv->escaped = true;
+ continue;
+ }
+
+ byte = sps30_serial_get_byte(priv->escaped, byte);
+ if (priv->escaped && !byte)
+ dev_warn(state->dev, "unrecognized escaped char (0x%02x)\n", byte);
+
+ priv->buf[priv->num++] = byte;
+
+ /* EOF received */
+ if (!priv->escaped && byte == SPS30_SERIAL_SOF_EOF) {
+ if (priv->num < SPS30_SERIAL_FRAME_MIN_SIZE)
+ continue;
+
+ priv->done = true;
+ complete(&priv->new_frame);
+ i++;
+ break;
+ }
+
+ priv->escaped = false;
+ }
+
+ return i;
+}
+
+static const struct serdev_device_ops sps30_serial_device_ops = {
+ .receive_buf = sps30_serial_receive_buf,
+ .write_wakeup = serdev_device_write_wakeup,
+};
+
+static int sps30_serial_start_meas(struct sps30_state *state)
+{
+ /* request BE IEEE754 formatted data */
+ unsigned char buf[] = { 0x01, 0x03 };
+
+ return sps30_serial_command(state, SPS30_SERIAL_START_MEAS, buf, sizeof(buf), NULL, 0);
+}
+
+static int sps30_serial_stop_meas(struct sps30_state *state)
+{
+ return sps30_serial_command(state, SPS30_SERIAL_STOP_MEAS, NULL, 0, NULL, 0);
+}
+
+static int sps30_serial_reset(struct sps30_state *state)
+{
+ int ret;
+
+ ret = sps30_serial_command(state, SPS30_SERIAL_RESET, NULL, 0, NULL, 0);
+ msleep(500);
+
+ return ret;
+}
+
+static int sps30_serial_read_meas(struct sps30_state *state, __be32 *meas, size_t num)
+{
+ int ret;
+
+ /* measurements are ready within a second */
+ if (msleep_interruptible(1000))
+ return -EINTR;
+
+ ret = sps30_serial_command(state, SPS30_SERIAL_READ_MEAS, NULL, 0, meas, num * sizeof(num));
+ if (ret < 0)
+ return ret;
+ /* if measurements aren't ready sensor returns empty frame */
+ if (ret == SPS30_SERIAL_FRAME_MIN_SIZE)
+ return -ETIMEDOUT;
+ if (ret != num * sizeof(*meas))
+ return -EIO;
+
+ return 0;
+}
+
+static int sps30_serial_clean_fan(struct sps30_state *state)
+{
+ return sps30_serial_command(state, SPS30_SERIAL_CLEAN_FAN, NULL, 0, NULL, 0);
+}
+
+static int sps30_serial_read_cleaning_period(struct sps30_state *state, __be32 *period)
+{
+ unsigned char buf[] = { 0x00 };
+ int ret;
+
+ ret = sps30_serial_command(state, SPS30_SERIAL_PERIOD, buf, sizeof(buf),
+ period, sizeof(*period));
+ if (ret < 0)
+ return ret;
+ if (ret != sizeof(*period))
+ return -EIO;
+
+ return 0;
+}
+
+static int sps30_serial_write_cleaning_period(struct sps30_state *state, __be32 period)
+{
+ unsigned char buf[5] = { 0x00 };
+
+ memcpy(buf + 1, &period, sizeof(period));
+
+ return sps30_serial_command(state, SPS30_SERIAL_PERIOD, buf, sizeof(buf), NULL, 0);
+}
+
+static int sps30_serial_show_info(struct sps30_state *state)
+{
+ /*
+ * tell device do return serial number and add extra nul byte just in case
+ * serial number isn't a valid string
+ */
+ unsigned char buf[32 + 1] = { 0x03 };
+ struct device *dev = state->dev;
+ int ret;
+
+ ret = sps30_serial_command(state, SPS30_SERIAL_DEV_INFO, buf, 1, buf, sizeof(buf) - 1);
+ if (ret < 0)
+ return ret;
+ if (ret != sizeof(buf) - 1)
+ return -EIO;
+
+ dev_info(dev, "serial number: %s\n", buf);
+
+ ret = sps30_serial_command(state, SPS30_SERIAL_READ_VERSION, NULL, 0, buf, sizeof(buf) - 1);
+ if (ret < 0)
+ return ret;
+ if (ret < 2)
+ return -EIO;
+
+ dev_info(dev, "fw version: %u.%u\n", buf[0], buf[1]);
+
+ return 0;
+}
+
+static const struct sps30_ops sps30_serial_ops = {
+ .start_meas = sps30_serial_start_meas,
+ .stop_meas = sps30_serial_stop_meas,
+ .read_meas = sps30_serial_read_meas,
+ .reset = sps30_serial_reset,
+ .clean_fan = sps30_serial_clean_fan,
+ .read_cleaning_period = sps30_serial_read_cleaning_period,
+ .write_cleaning_period = sps30_serial_write_cleaning_period,
+ .show_info = sps30_serial_show_info,
+};
+
+static int sps30_serial_probe(struct serdev_device *serdev)
+{
+ struct device *dev = &serdev->dev;
+ struct sps30_serial_priv *priv;
+ int ret;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ init_completion(&priv->new_frame);
+ serdev_device_set_client_ops(serdev, &sps30_serial_device_ops);
+
+ ret = devm_serdev_device_open(dev, serdev);
+ if (ret)
+ return ret;
+
+ serdev_device_set_baudrate(serdev, 115200);
+ serdev_device_set_flow_control(serdev, false);
+
+ ret = serdev_device_set_parity(serdev, SERDEV_PARITY_NONE);
+ if (ret)
+ return ret;
+
+ return sps30_probe(dev, SPS30_SERIAL_DEV_NAME, priv, &sps30_serial_ops);
+}
+
+static const struct of_device_id sps30_serial_of_match[] = {
+ { .compatible = "sensirion,sps30" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, sps30_serial_of_match);
+
+static struct serdev_device_driver sps30_serial_driver = {
+ .driver = {
+ .name = KBUILD_MODNAME,
+ .of_match_table = sps30_serial_of_match,
+ },
+ .probe = sps30_serial_probe,
+};
+module_serdev_device_driver(sps30_serial_driver);
+
+MODULE_AUTHOR("Tomasz Duszynski <tomasz.duszynski@octakon.com>");
+MODULE_DESCRIPTION("Sensirion SPS30 particulate matter sensor serial driver");
+MODULE_LICENSE("GPL v2");