Zephyr in tree driver use - Revision history

Ted at 23:28, 18 November 2022

2022-11-18T23:28:42Z

Ted: Amending in-tree driver notes with new knowledge of stmdev_ctx_t

2022-11-18T23:14:58Z

Amending in-tree driver notes with new knowledge of stmdev_ctx_t

Ted at 06:17, 14 October 2021

2021-10-14T06:17:29Z

Ted at 05:59, 14 October 2021

2021-10-14T05:59:00Z

Ted at 05:41, 14 October 2021

2021-10-14T05:41:00Z

Ted at 05:21, 14 October 2021

2021-10-14T05:21:12Z

Ted: Starting local page for instructions on how to use, leverage a Zephyr in-tree driver.

2021-10-14T04:17:29Z

Starting local page for instructions on how to use, leverage a Zephyr in-tree driver.

New page

This page holding notes on how to use Zephyr in-tree drivers.

<i>Code excerpt:</i>
<pre>
+
+2021-10-13
+
+In file ./z4-sandbox-kionix-work/modules/hal/st/sensor/stmemsc/iis2dh_STdC/driver/iis2dh_reg.c
+
+ 789 /**
+ 790 * @defgroup IIS2DH_Common
+ 791 * @brief This section group common usefull functions
+ 792 * @{
+ 793 *
+ 794 */
+ 795
+ 796 /**
+ 797 * @brief DeviceWhoamI .[get]
+ 798 *
+ 799 * @param ctx read / write interface definitions
+ 800 * @param buff buffer that stores data read
+ 801 * @retval interface status (MANDATORY: return 0 -> no Error)
+ 802 *
+ 803 */
+ 804 int32_t iis2dh_device_id_get(stmdev_ctx_t *ctx, uint8_t *buff)
+ 805 {
+ 806 int32_t ret;
+ 807 ret = iis2dh_read_reg(ctx, IIS2DH_WHO_AM_I, buff, 1);
+ 808 return ret;
+ 809 }
+ 810 /**
+ 811 * @brief Self Test.[set]
+ 812 *
+ 813 * @param ctx read / write interface definitions
+ 814 * @param val change the values of st in reg CTRL_REG4
+ 815 * @retval interface status (MANDATORY: return 0 -> no Error)
+ 816 *
+ 817 */
+
</pre>

@@ Line 2: / Line 2: @@
 This page holding notes on how to use Zephyr in-tree drivers.  This page was started in 2021, but we're adding to it 2022 November as we revisit and refactor [https://github.com/tedhavelka/zephyr-driver-work-v2 a Zephyr driver for Kionix KX132 sensor].
-<i>Code excerpt:</i>
+<i>Code excerpt:  IIS2DH driver routine to query sensor for its WHOAMI value</i>
 <pre>
++
@@ Line 42: / Line 42: @@
-(2)
+(2)  Function prototype and opening line for IIS2DH "read WHOAMI value" function:
 <pre>

@@ Line 1: / Line 1: @@
-This page holding notes on how to use Zephyr in-tree drivers.
+This page holding notes on how to use Zephyr in-tree drivers.  This page was started in 2021, but we're adding to it 2022 November as we revisit and refactor [https://github.com/tedhavelka/zephyr-driver-work-v2 a Zephyr driver for Kionix KX132 sensor].
 <i>Code excerpt:</i>
@@ Line 52: / Line 52: @@
-(3)
+(3)  Ok now a year ahead of our first posting of this code excerpt, we can understand a little better what an `stmdev_ctx_t` data structure provides.  An "STMicro device context type" provides driver code function pointers to generalized register_read and register_write functions.  The function pointers allow for a use of Zephyr device tree macros, to conditionally select between compilation of I2C interfacing register functions and SPI interfacing register functions.  This is where the driver design provides a build time flexibility, in Zephyr RTOS context, to support both I2C and SPI.  For a given sensor instance one or the other is selected.  See [https://github.com/zephyrproject-rtos/zephyr/blob/main/drivers/sensor/iis2dh/iis2dh.h] for the conditional macros which check for valid I2C and SPI bus controller instances.
 <pre>

@@ Line 78: / Line 78: @@
-(4)
+(4) Need to understand how to initialize and use the STMicro IIS2DH driver data structure named `stmdev_ctx_t`:
 <pre>
 ./drivers/sensor/iis2dh/iis2dh_i2c.c:39:stmdev_ctx_t iis2dh_i2c_ctx = {
-</pre>
+. . . The search to find this assignment is:
 <!-- comment -->

@@ Line 57: / Line 57: @@
 zephyr/../modules/hal/st/sensor/stmemsc/iis2dh_STdC/driver/iis2dh_reg.h:119:} stmdev_ctx_t;
 </pre>
 <!-- comment -->

← Older revision		Revision as of 05:21, 14 October 2021
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	</pre>		</pre>

		+
		+	(2)
		+
		+	<pre>
		+	ted@localhost:~/projects/zephyr-based/z4-sandbox-kionix-work/modules$ grep -nr iis2dh_device_id_get ./*
		+	./hal/st/sensor/stmemsc/iis2dh_STdC/driver/iis2dh_reg.h:762:int32_t iis2dh_device_id_get(stmdev_ctx_t ctx, uint8_t buff);
		+	./hal/st/sensor/stmemsc/iis2dh_STdC/driver/iis2dh_reg.c:804:int32_t iis2dh_device_id_get(stmdev_ctx_t ctx, uint8_t buff)
		+	ted@localhost:~/projects/zephyr-based/z4-sandbox-kionix-work/modules$
		+	</pre>


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← Older revision		Revision as of 05:41, 14 October 2021
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	</pre>		</pre>

		+
		+	(3)
		+
		+	<pre>
		+	zephyr/../modules/hal/st/sensor/stmemsc/iis2dh_STdC/driver/iis2dh_reg.h:119:} stmdev_ctx_t;
		+
		+
		+
		+	</pre>

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