risc-v: add a StarFive JH71[01]0 temperature sensor driver

Author: skrll

sys/arch/riscv/conf/GENERIC64

@@ -1,4 +1,4 @@
-# $NetBSD: GENERIC64,v 1.19 2025/01/01 17:53:07 skrll Exp $
+# $NetBSD: GENERIC64,v 1.20 2025/01/03 11:49:04 skrll Exp $
 #
 # GENERIC machine description file
 #
@@ -103,5 +103,8 @@ micphy* 	at mii? phy ?		# Micrel KSZ[89]xxx PHYs
 mcommphy* 	at mii? phy ?		# Motorcomm YT8511C/YT8511H PHYs
 ukphy* 		at mii? phy ?		# generic unknown PHYs
 
+# Temperature sensor
+jh71x0temp* 	at fdt?			# StarFive JH71x0 Temperature sensor
+
 # Pull in optional local configuration - always at end
 cinclude 	"arch/riscv/conf/GENERIC64.local"

sys/arch/riscv/starfive/files.starfive

@@ -1,4 +1,4 @@
-#	$NetBSD: files.starfive,v 1.9 2025/01/01 17:53:08 skrll Exp $
+#	$NetBSD: files.starfive,v 1.10 2025/01/03 11:49:04 skrll Exp $
 #
 # Configuration info for StarFive SoCs
 #
@@ -54,3 +54,8 @@ file	arch/riscv/starfive/jh7110_pcie.c		jh7110_pcie
 device	jh7110syscon
 attach	jh7110syscon at fdt with jh7110_syscon
 file	arch/riscv/starfive/jh7110_syscon.c		jh7110_syscon
+
+# JH71x0 temperature sensor
+device	jh71x0temp
+attach	jh71x0temp at fdt with jh71x0_temp
+file	arch/riscv/starfive/jh71x0_temp.c		jh71x0_temp

sys/arch/riscv/starfive/jh71x0_temp.c

@@ -0,0 +1,197 @@
+/* $NetBSD: jh71x0_temp.c,v 1.1 2025/01/03 11:49:04 skrll Exp $ */
+
+/*-
+ * Copyright (c) 2025 The NetBSD Foundation, Inc.
+ * All rights reserved.
+ *
+ * This code is derived from software contributed to The NetBSD Foundation
+ * by Nick Hudson
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+ * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
+ * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__KERNEL_RCSID(0, "$NetBSD: jh71x0_temp.c,v 1.1 2025/01/03 11:49:04 skrll Exp $");
+
+#include <sys/param.h>
+
+#include <dev/fdt/fdtvar.h>
+
+#include <dev/sysmon/sysmonvar.h>
+
+struct jh71x0_temp_softc {
+	device_t		sc_dev;
+	bus_space_tag_t		sc_bst;
+	bus_space_handle_t	sc_bsh;
+	int			sc_phandle;
+
+	struct sysmon_envsys *	sc_sme;
+	envsys_data_t		sc_sensor;
+};
+
+#define RD4(sc, reg)							       \
+    bus_space_read_4((sc)->sc_bst, (sc)->sc_bsh, (reg))
+#define WR4(sc, reg, val)						       \
+    bus_space_write_4((sc)->sc_bst, (sc)->sc_bsh, (reg), (val))
+
+/* Register definitions */
+#define JH71X0_TEMP		0x0000
+#define JH71X0_TEMP_RSTN	__BIT(0)
+#define JH71X0_TEMP_PD		__BIT(1)
+#define JH71X0_TEMP_RUN		__BIT(2)
+#define JH71X0_TEMP_DOUT_MASK	__BITS(27, 16)
+
+/* DOUT to Celcius conversion constants */
+#define JH71X0TEMP_Y1000	237500L
+#define JH71X0TEMP_Z		4094L
+#define JH71X0TEMP_K1000	81100L
+
+/* Calculate the temperature in milli Celcius */
+static int32_t
+jh71x0_temp_get(struct jh71x0_temp_softc *sc)
+{
+	uint32_t temp = RD4(sc, JH71X0_TEMP);
+	uint32_t dout = __SHIFTOUT(temp, JH71X0_TEMP_DOUT_MASK);
+
+	return (dout * JH71X0TEMP_Y1000) / JH71X0TEMP_Z - JH71X0TEMP_K1000;
+}
+
+static void
+jh71x0_temp_refresh(struct sysmon_envsys *sme, envsys_data_t *edata)
+{
+	struct jh71x0_temp_softc * const sc = sme->sme_cookie;
+
+	// Convert milli Celcius to micro Kelvin
+	sc->sc_sensor.value_cur = 273150000 + 1000 * jh71x0_temp_get(sc);
+	sc->sc_sensor.state = ENVSYS_SVALID;
+}
+
+static void
+jh71x0_temp_init(struct jh71x0_temp_softc *sc)
+{
+	/* Power down */
+	WR4(sc, JH71X0_TEMP, JH71X0_TEMP_PD);
+	delay(1);
+
+	/* Power up with reset asserted */
+	WR4(sc, JH71X0_TEMP, 0);
+	delay(60);
+
+	/* Deassert reset */
+	WR4(sc, JH71X0_TEMP, JH71X0_TEMP_RSTN);
+	delay(1);
+
+	/* Start measuring */
+	WR4(sc, JH71X0_TEMP, JH71X0_TEMP_RSTN | JH71X0_TEMP_RUN);
+}
+
+/* Compat string(s) */
+static const struct device_compatible_entry compat_data[] = {
+	{ .compat = "starfive,jh7100-temp" },
+	{ .compat = "starfive,jh7110-temp" },
+	DEVICE_COMPAT_EOL
+};
+
+static int
+jh71x0_temp_match(device_t parent, cfdata_t cf, void *aux)
+{
+	struct fdt_attach_args * const faa = aux;
+
+	return of_compatible_match(faa->faa_phandle, compat_data);
+}
+
+static void
+jh71x0_temp_attach(device_t parent, device_t self, void *aux)
+{
+	struct jh71x0_temp_softc * const sc = device_private(self);
+	struct fdt_attach_args * const faa = aux;
+	const int phandle = faa->faa_phandle;
+	bus_addr_t addr;
+	bus_size_t size;
+	int error;
+
+	if (fdtbus_get_reg(phandle, 0, &addr, &size) != 0) {
+		aprint_error(": couldn't get registers\n");
+		return;
+	}
+
+	sc->sc_dev = self;
+	sc->sc_phandle = phandle;
+	sc->sc_bst = faa->faa_bst;
+
+	error = bus_space_map(sc->sc_bst, addr, size, 0, &sc->sc_bsh);
+	if (error) {
+		aprint_error(": couldn't map %#" PRIxBUSADDR ": %d", addr,
+		    error);
+		return;
+	}
+
+	const char *crs[] = { "bus", "sense" };
+	for (size_t i = 0; i < __arraycount(crs); i++) {
+		const char *cr = crs[i];
+
+		error = fdtbus_clock_enable(phandle, cr, true);
+		if (error) {
+			aprint_error(": couldn't enable clock '%s'\n", cr);
+			return;
+		}
+		struct fdtbus_reset * rst = fdtbus_reset_get(phandle, cr);
+		if (rst == NULL) {
+			aprint_error(": couldn't get reset '%s'\n", cr);
+			return;
+		}
+		error = fdtbus_reset_deassert(rst);
+		if (error) {
+			aprint_error(": couldn't de-assert reset '%s'\n", cr);
+			return;
+		}
+	}
+
+	aprint_naive("\n");
+	aprint_normal(": JH71x0 temperature sensor\n");
+
+	jh71x0_temp_init(sc);
+
+	sc->sc_sme = sysmon_envsys_create();
+	/* Initialize sensor data. */
+	sc->sc_sensor.units = ENVSYS_STEMP;
+	sc->sc_sensor.state = ENVSYS_SINVALID;
+	(void)strlcpy(sc->sc_sensor.desc, device_xname(self),
+	    sizeof(sc->sc_sensor.desc));
+	if (sysmon_envsys_sensor_attach(sc->sc_sme, &sc->sc_sensor)) {
+		sysmon_envsys_destroy(sc->sc_sme);
+		return;
+	}
+
+	/* Hook into system monitor. */
+	sc->sc_sme->sme_name = device_xname(self);
+	sc->sc_sme->sme_cookie = sc;
+	sc->sc_sme->sme_refresh = jh71x0_temp_refresh;
+
+	if (sysmon_envsys_register(sc->sc_sme)) {
+		aprint_error_dev(self, "unable to register with sysmon\n");
+		sysmon_envsys_destroy(sc->sc_sme);
+	}
+}
+
+CFATTACH_DECL_NEW(jh71x0_temp, sizeof(struct jh71x0_temp_softc),
+	jh71x0_temp_match, jh71x0_temp_attach, NULL, NULL);