Add bdpmic(4), a driver for the ROHM BD71837 and BD71847 Power

Management IC.  For now this only allows reading and changing
the BD71847's BUCK2 voltage regulator, as used on the i.MX8MM
EVK, to allow CPU frequency scaling.

ok kettenis@

3 files changed, 230 insertions, 2 deletions

diff --git a/sys/arch/arm64/conf/GENERIC b/sys/arch/arm64/conf/GENERIC
index 5e16bdc7e51..0e8f846557c 100644
--- a/sys/arch/arm64/conf/GENERIC
+++ b/sys/arch/arm64/conf/GENERIC
@@ -1,4 +1,4 @@
-# $OpenBSD: GENERIC,v 1.145 2020/03/04 22:23:03 patrick Exp $
+# $OpenBSD: GENERIC,v 1.146 2020/03/20 09:25:42 patrick Exp $
 #
 # GENERIC machine description file
 #
@@ -127,6 +127,7 @@ fec*		at fdt?
 imxuart*	at fdt?
 imxiic*		at fdt?
 iic*		at imxiic?
+bdpmic*		at iic?
 imxesdhc*	at fdt?
 sdmmc*		at imxesdhc?
 imxspi*		at fdt?
diff --git a/sys/arch/arm64/conf/RAMDISK b/sys/arch/arm64/conf/RAMDISK
index 06c12e43aee..f069c20664f 100644
--- a/sys/arch/arm64/conf/RAMDISK
+++ b/sys/arch/arm64/conf/RAMDISK
@@ -1,4 +1,4 @@
-# $OpenBSD: RAMDISK,v 1.110 2020/02/04 01:01:09 kevlo Exp $
+# $OpenBSD: RAMDISK,v 1.111 2020/03/20 09:25:42 patrick Exp $
 #
 # GENERIC machine description file
 #
@@ -120,6 +120,7 @@ fec*		at fdt?
 imxuart*	at fdt?
 imxiic*		at fdt?
 iic*		at imxiic?
+bdpmic*		at iic?
 imxesdhc*	at fdt?
 sdmmc*		at imxesdhc?
 
diff --git a/sys/dev/fdt/bd718x7.c b/sys/dev/fdt/bd718x7.c
new file mode 100644
index 00000000000..afe849122bd
--- /dev/null
+++ b/sys/dev/fdt/bd718x7.c
@@ -0,0 +1,226 @@
+/*	$OpenBSD: bd718x7.c,v 1.1 2020/03/20 09:25:42 patrick Exp $	*/
+/*
+ * Copyright (c) 2019 Patrick Wildt <patrick@blueri.se>
+ * Copyright (c) 2017 Mark Kettenis <kettenis@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/device.h>
+#include <sys/malloc.h>
+
+#include <dev/ofw/openfirm.h>
+#include <dev/ofw/ofw_regulator.h>
+#include <dev/ofw/fdt.h>
+
+#include <dev/i2c/i2cvar.h>
+
+#define BDPMIC_REGLOCK			0x2f
+#define  BDPMIC_REGLOCK_PWRSEQ			(1 << 0)
+#define  BDPMIC_REGLOCK_VREG			(1 << 4)
+
+struct bdpmic_regdata {
+	const char *name;
+	uint8_t reg, mask;
+	uint32_t base, delta;
+};
+
+struct bdpmic_regdata bd71837_regdata[] = {
+	{ }
+};
+
+struct bdpmic_regdata bd71847_regdata[] = {
+	{ "BUCK2", 0x10, 0x3f, 700000, 10000 },
+	{ }
+};
+
+struct bdpmic_softc {
+	struct device	sc_dev;
+	i2c_tag_t	sc_tag;
+	i2c_addr_t	sc_addr;
+
+	struct bdpmic_regdata *sc_regdata;
+};
+
+int	bdpmic_match(struct device *, void *, void *);
+void	bdpmic_attach(struct device *, struct device *, void *);
+
+void	bdpmic_attach_regulator(struct bdpmic_softc *, int);
+uint8_t	bdpmic_reg_read(struct bdpmic_softc *, int);
+void	bdpmic_reg_write(struct bdpmic_softc *, int, uint8_t);
+
+struct cfattach bdpmic_ca = {
+	sizeof(struct bdpmic_softc), bdpmic_match, bdpmic_attach
+};
+
+struct cfdriver bdpmic_cd = {
+	NULL, "bdpmic", DV_DULL
+};
+
+int
+bdpmic_match(struct device *parent, void *match, void *aux)
+{
+	struct i2c_attach_args *ia = aux;
+	int node = *(int *)ia->ia_cookie;
+
+	return (OF_is_compatible(node, "rohm,bd71837") ||
+		OF_is_compatible(node, "rohm,bd71847"));
+}
+
+void
+bdpmic_attach(struct device *parent, struct device *self, void *aux)
+{
+	struct bdpmic_softc *sc = (struct bdpmic_softc *)self;
+	struct i2c_attach_args *ia = aux;
+	int node = *(int *)ia->ia_cookie;
+	const char *chip;
+
+	sc->sc_tag = ia->ia_tag;
+	sc->sc_addr = ia->ia_addr;
+
+	if (OF_is_compatible(node, "rohm,bd71837")) {
+		chip = "BD71837";
+		sc->sc_regdata = bd71837_regdata;
+	} else {
+		chip = "BD71847";
+		sc->sc_regdata = bd71847_regdata;
+	}
+	printf(": %s\n", chip);
+
+	node = OF_getnodebyname(node, "regulators");
+	if (node == 0)
+		return;
+	for (node = OF_child(node); node; node = OF_peer(node))
+		bdpmic_attach_regulator(sc, node);
+}
+
+struct bdpmic_regulator {
+	struct bdpmic_softc *bd_sc;
+
+	uint8_t bd_reg, bd_mask;
+	uint32_t bd_base, bd_delta;
+
+	struct regulator_device bd_rd;
+};
+
+uint32_t bdpmic_get_voltage(void *);
+int	bdpmic_set_voltage(void *, uint32_t);
+
+void
+bdpmic_attach_regulator(struct bdpmic_softc *sc, int node)
+{
+	struct bdpmic_regulator *bd;
+	char name[32];
+	int i;
+
+	name[0] = 0;
+	OF_getprop(node, "name", name, sizeof(name));
+	name[sizeof(name) - 1] = 0;
+	for (i = 0; sc->sc_regdata[i].name; i++) {
+		if (strcmp(sc->sc_regdata[i].name, name) == 0)
+			break;
+	}
+	if (sc->sc_regdata[i].name == NULL)
+		return;
+
+	bd = malloc(sizeof(*bd), M_DEVBUF, M_WAITOK | M_ZERO);
+	bd->bd_sc = sc;
+
+	bd->bd_reg = sc->sc_regdata[i].reg;
+	bd->bd_mask = sc->sc_regdata[i].mask;
+	bd->bd_base = sc->sc_regdata[i].base;
+	bd->bd_delta = sc->sc_regdata[i].delta;
+
+	bd->bd_rd.rd_node = node;
+	bd->bd_rd.rd_cookie = bd;
+	bd->bd_rd.rd_get_voltage = bdpmic_get_voltage;
+	bd->bd_rd.rd_set_voltage = bdpmic_set_voltage;
+	regulator_register(&bd->bd_rd);
+}
+
+uint32_t
+bdpmic_get_voltage(void *cookie)
+{
+	struct bdpmic_regulator *bd = cookie;
+	uint8_t vsel;
+
+	vsel = bdpmic_reg_read(bd->bd_sc, bd->bd_reg);
+	return bd->bd_base + (vsel & bd->bd_mask) * bd->bd_delta;
+}
+
+int
+bdpmic_set_voltage(void *cookie, uint32_t voltage)
+{
+	struct bdpmic_regulator *bd = cookie;
+	uint32_t vmin = bd->bd_base;
+	uint32_t vmax = vmin + bd->bd_mask * bd->bd_delta;
+	uint8_t vsel;
+
+	if (voltage < vmin || voltage > vmax)
+		return EINVAL;
+
+	/* Unlock */
+	bdpmic_reg_write(bd->bd_sc, BDPMIC_REGLOCK,
+	    BDPMIC_REGLOCK_PWRSEQ);
+
+	vsel = bdpmic_reg_read(bd->bd_sc, bd->bd_reg);
+	vsel &= ~bd->bd_mask;
+	vsel |= (voltage - bd->bd_base) / bd->bd_delta;
+	bdpmic_reg_write(bd->bd_sc, bd->bd_reg, vsel);
+
+	/* Lock */
+	bdpmic_reg_write(bd->bd_sc, BDPMIC_REGLOCK,
+	    BDPMIC_REGLOCK_PWRSEQ | BDPMIC_REGLOCK_VREG);
+
+	return 0;
+}
+
+uint8_t
+bdpmic_reg_read(struct bdpmic_softc *sc, int reg)
+{
+	uint8_t cmd = reg;
+	uint8_t val;
+	int error;
+
+	iic_acquire_bus(sc->sc_tag, I2C_F_POLL);
+	error = iic_exec(sc->sc_tag, I2C_OP_READ_WITH_STOP, sc->sc_addr,
+	    &cmd, sizeof cmd, &val, sizeof val, I2C_F_POLL);
+	iic_release_bus(sc->sc_tag, I2C_F_POLL);
+
+	if (error) {
+		printf("%s: can't read register 0x%02x\n",
+		    sc->sc_dev.dv_xname, reg);
+		val = 0xff;
+	}
+
+	return val;
+}
+
+void
+bdpmic_reg_write(struct bdpmic_softc *sc, int reg, uint8_t val)
+{
+	uint8_t cmd = reg;
+	int error;
+
+	iic_acquire_bus(sc->sc_tag, I2C_F_POLL);
+	error = iic_exec(sc->sc_tag, I2C_OP_WRITE_WITH_STOP, sc->sc_addr,
+	    &cmd, sizeof cmd, &val, sizeof val, I2C_F_POLL);
+	iic_release_bus(sc->sc_tag, I2C_F_POLL);
+
+	if (error) {
+		printf("%s: can't write register 0x%02x\n",
+		    sc->sc_dev.dv_xname, reg);
+	}
+}