Module Name: src
Committed By: thorpej
Date: Wed May 19 13:40:57 UTC 2021
Modified Files:
src/sys/dev/spi [thorpej-i2c-spi-conf]: mcp3k.c
Log Message:
If we were directly configured using the platform device tree, consult
the device tree for our reference voltage and make the vref sysctl read-only
in that case. Implement this for the Device Tree bindings for this device
(the "vref-supply" property points to the regulator providing the reference
voltage).
To generate a diff of this commit:
cvs rdiff -u -r1.2.36.2 -r1.2.36.3 src/sys/dev/spi/mcp3k.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/dev/spi/mcp3k.c
diff -u src/sys/dev/spi/mcp3k.c:1.2.36.2 src/sys/dev/spi/mcp3k.c:1.2.36.3
--- src/sys/dev/spi/mcp3k.c:1.2.36.2 Wed May 19 03:46:26 2021
+++ src/sys/dev/spi/mcp3k.c Wed May 19 13:40:56 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: mcp3k.c,v 1.2.36.2 2021/05/19 03:46:26 thorpej Exp $ */
+/* $NetBSD: mcp3k.c,v 1.2.36.3 2021/05/19 13:40:56 thorpej Exp $ */
/*-
* Copyright (c) 2015 The NetBSD Foundation, Inc.
@@ -45,6 +45,8 @@
* MPC3302/3304: http://ww1.microchip.com/downloads/en/DeviceDoc/21697F.pdf
*/
+#include "opt_fdt.h"
+
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/device.h>
@@ -55,6 +57,10 @@
#include <dev/sysmon/sysmonvar.h>
#include <dev/spi/spivar.h>
+#ifdef FDT
+#include <dev/fdt/fdtvar.h>
+#endif /* FDT */
+
#define M3K_MAX_SENSORS 16 /* 8 single-ended & 8 diff. */
/* mcp3x0x model description */
@@ -77,6 +83,9 @@ struct mcp3kadc_softc {
const struct mcp3kadc_model *sc_model;
uint32_t sc_adc_max;
int32_t sc_vref_mv;
+#ifdef FDT
+ struct fdtbus_regulator *sc_vref_supply;
+#endif
struct sysmon_envsys *sc_sme;
envsys_data_t sc_sensors[M3K_MAX_SENSORS];
@@ -247,14 +256,58 @@ mcp3kadc_match(device_t parent, cfdata_t
return rv;
}
+#ifdef FDT
+static bool
+mcp3kadc_vref_fdt(struct mcp3kadc_softc *sc)
+{
+ devhandle_t devhandle = device_handle(sc->sc_dev);
+ int phandle = devhandle_to_of(devhandle);
+ int error;
+ u_int uvolts;
+
+ sc->sc_vref_supply = fdtbus_regulator_acquire(phandle, "vref-supply");
+ if (sc->sc_vref_supply == NULL) {
+ aprint_error_dev(sc->sc_dev,
+ "unable to acquire \"vref-supply\"\n");
+ return false;
+ }
+
+ error = fdtbus_regulator_enable(sc->sc_vref_supply);
+ if (error) {
+ aprint_error_dev(sc->sc_dev,
+ "failed to enable \"vref-supply\" (error = %d)\n",
+ error);
+ return false;
+ }
+
+ error = fdtbus_regulator_get_voltage(sc->sc_vref_supply, &uvolts);
+ if (error) {
+ aprint_error_dev(sc->sc_dev,
+ "unable to get \"vref-supply\" voltage (error = %d)\n",
+ error);
+ (void) fdtbus_regulator_disable(sc->sc_vref_supply);
+ return false;
+ }
+
+ /*
+ * Device tree property is uV, convert to mV that we use
+ * internally.
+ */
+ sc->sc_vref_mv = uvolts / 1000;
+ return true;
+}
+#endif /* FDT */
+
static void
mcp3kadc_attach(device_t parent, device_t self, void *aux)
{
const struct sysctlnode *rnode, *node;
struct spi_attach_args *sa = aux;
struct mcp3kadc_softc *sc = device_private(self);
+ devhandle_t devhandle = device_handle(self);
const struct mcp3kadc_model *model;
int ch, i, error;
+ bool vref_read_only;
sc->sc_dev = self;
sc->sc_sh = sa->sa_handle;
@@ -277,13 +330,27 @@ mcp3kadc_attach(device_t parent, device_
return;
}
- /*
- * XXX Get vref-supply from device tree and make the sysctl
- * XXX read-only in that case.
- */
- /* set a default Vref in mV according to the chip's ADC resolution */
- sc->sc_vref_mv = 1 << ((model->flags & M3K_SIGNED) ?
- model->bits - 1 : model->bits);
+ vref_read_only = false;
+ switch (devhandle_type(devhandle)) {
+#ifdef FDT
+ case DEVHANDLE_TYPE_OF:
+ vref_read_only = mcp3kadc_vref_fdt(sc);
+ if (! vref_read_only) {
+ /* Error already displayed. */
+ return;
+ }
+ break;
+#endif /* FDT */
+ default:
+ /*
+ * set a default Vref in mV according to the chip's ADC
+ * resolution
+ */
+ sc->sc_vref_mv = 1 << ((model->flags & M3K_SIGNED) ?
+ model->bits - 1 : model->bits);
+ break;
+ }
+
/* remember maximum value for this ADC - also used for masking */
sc->sc_adc_max = (1 << model->bits) - 1;
@@ -338,9 +405,11 @@ mcp3kadc_attach(device_t parent, device_
NULL, 0, NULL, 0,
CTL_HW, CTL_CREATE, CTL_EOL);
+ const int ctlflag = vref_read_only ? CTLFLAG_READONLY
+ : CTLFLAG_READWRITE;
if (rnode != NULL)
sysctl_createv(NULL, 0, NULL, &node,
- CTLFLAG_READWRITE | CTLFLAG_OWNDESC,
+ ctlflag | CTLFLAG_OWNDESC,
CTLTYPE_INT, "vref",
SYSCTL_DESCR("ADC reference voltage"),
sysctl_mcp3kadc_vref, 0, (void *)sc, 0,
