From 32d7b75bb7589d762387416bb8702d089a1b262d Mon Sep 17 00:00:00 2001
From: Jerzy Kasenberg <jerzy.kasenberg@codecoup.pl>
Date: Mon, 9 Sep 2024 12:46:30 +0200
Subject: [PATCH] hw/drivers/bme280: Fix writes to I2C

I2C writes when driver was enabled clear MSB of register
address.

This prevented any write to control registers.

Now registers MSB is cleared on write only for SPI.

Writing registers also requires single start condition.
Code was doing write with restart condtion that does not
seem to work correctly

Signed-off-by: Jerzy Kasenberg <jerzy.kasenberg@codecoup.pl>
---
 .../sensors/bme280/include/bme280/bme280.h    |  1 +
 hw/drivers/sensors/bme280/src/bme280.c        | 27 ++++++++++++++-----
 2 files changed, 21 insertions(+), 7 deletions(-)

diff --git a/hw/drivers/sensors/bme280/include/bme280/bme280.h b/hw/drivers/sensors/bme280/include/bme280/bme280.h
index 42b877fcfb..276f1a961b 100644
--- a/hw/drivers/sensors/bme280/include/bme280/bme280.h
+++ b/hw/drivers/sensors/bme280/include/bme280/bme280.h
@@ -111,6 +111,7 @@ struct bme280 {
         struct bus_i2c_node i2c_node;
         struct bus_spi_node spi_node;
     };
+    bool node_is_spi;
 #else
     struct os_dev dev;
 #endif
diff --git a/hw/drivers/sensors/bme280/src/bme280.c b/hw/drivers/sensors/bme280/src/bme280.c
index 384803005d..93fadb6d7f 100644
--- a/hw/drivers/sensors/bme280/src/bme280.c
+++ b/hw/drivers/sensors/bme280/src/bme280.c
@@ -75,6 +75,14 @@ static const struct sensor_driver g_bme280_sensor_driver = {
     bme280_sensor_get_config
 };
 
+#if MYNEWT_VAL(BUS_DRIVER_PRESENT)
+static bool
+bme280_uses_spi(struct sensor_itf *itf)
+{
+    return ((struct bme280 *)(itf->si_dev))->node_is_spi;
+}
+#endif
+
 static int
 bme280_default_cfg(struct bme280_cfg *cfg)
 {
@@ -894,6 +902,12 @@ bme280_writelen(struct sensor_itf *itf, uint8_t addr, uint8_t *payload,
     int rc;
 
 #if MYNEWT_VAL(BUS_DRIVER_PRESENT)
+    uint8_t buf[4];
+
+    if (len > 3) {
+        return SYS_EINVAL;
+    }
+
     struct os_dev *dev = itf->si_dev;
 
     rc = bus_node_lock(dev, OS_TIMEOUT_NEVER);
@@ -901,16 +915,15 @@ bme280_writelen(struct sensor_itf *itf, uint8_t addr, uint8_t *payload,
         return SYS_EINVAL;
     }
 
-    addr &= ~BME280_SPI_READ_CMD_BIT;
-
-    rc = bus_node_write(dev, &addr, 1, OS_TIMEOUT_NEVER, BUS_F_NOSTOP);
-    if (rc) {
-        goto done;
+    if (bme280_uses_spi(itf)) {
+        addr &= ~BME280_SPI_READ_CMD_BIT;
     }
 
-    rc = bus_node_simple_write(dev, payload, len);
+    buf[0] = addr;
+    memcpy(buf + 1, payload, len);
+
+    rc = bus_node_simple_write(dev, buf, len + 1);
 
-done:
     (void)bus_node_unlock(dev);
 #else
     int i;