/* $NetBSD: rpi_vcmbox.c,v 1.8 2021/03/08 13:53:08 mlelstv Exp $ */

/*-
 * Copyright (c) 2013 Jared D. McNeill <jmcneill@invisible.ca>
 * All rights reserved.
 *
 * 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.
 */

/*
 * Raspberry Pi VC Mailbox Interface
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: rpi_vcmbox.c,v 1.8 2021/03/08 13:53:08 mlelstv Exp $");

#include <sys/param.h>
#include <sys/types.h>
#include <sys/bus.h>
#include <sys/conf.h>
#include <sys/device.h>
#include <sys/endian.h>
#include <sys/kmem.h>
#include <sys/systm.h>
#include <sys/sysctl.h>

#include <dev/sysmon/sysmonvar.h>

#include <arm/broadcom/bcm2835_mbox.h>

#include <evbarm/rpi/vcio.h>
#include <evbarm/rpi/vcprop.h>

struct vcmbox_temp_request {
	struct vcprop_buffer_hdr	vb_hdr;
	struct vcprop_tag_temperature	vbt_temp;
	struct vcprop_tag end;
} __packed;

struct vcmbox_clockrate_request {
	struct vcprop_buffer_hdr	vb_hdr;
	struct vcprop_tag_clockrate	vbt_clockrate;
	struct vcprop_tag end;
} __packed;

#define RATE2MHZ(rate)	((rate) / 1000000)
#define MHZ2RATE(mhz)	((mhz) * 1000000)

#define VCMBOX_INIT_REQUEST(r)		VCPROP_INIT_REQUEST(r)
#define VCMBOX_INIT_TAG(s, t)		VCPROP_INIT_TAG(s, t)

struct vcmbox_softc {
	device_t		sc_dev;

	/* temperature sensor */
	struct sysmon_envsys	*sc_sme;
#define VCMBOX_SENSOR_TEMP	0
#define VCMBOX_NSENSORS		1
	envsys_data_t		sc_sensor[VCMBOX_NSENSORS];

	/* cpu frequency scaling */
	struct sysctllog	*sc_log;
	uint32_t		sc_cpu_minrate;
	uint32_t		sc_cpu_maxrate;
	int			sc_node_target;
	int			sc_node_current;
	int			sc_node_min;
	int			sc_node_max;
};

static const char *vcmbox_sensor_name[VCMBOX_NSENSORS] = {
	"temperature",
};

static int vcmbox_sensor_id[VCMBOX_NSENSORS] = {
	VCPROP_TEMP_SOC,
};

static int	vcmbox_match(device_t, cfdata_t, void *);
static void	vcmbox_attach(device_t, device_t, void *);

static int	vcmbox_read_temp(struct vcmbox_softc *, uint32_t, int,
				 uint32_t *);
static int	vcmbox_read_clockrate(struct vcmbox_softc *, uint32_t, int,
				 uint32_t *);
static int	vcmbox_write_clockrate(struct vcmbox_softc *, uint32_t, int,
				 uint32_t);

static int	vcmbox_cpufreq_init(struct vcmbox_softc *);
static int	vcmbox_cpufreq_sysctl_helper(SYSCTLFN_PROTO);

static void	vcmbox_create_sensors(struct vcmbox_softc *);
static void	vcmbox_sensor_get_limits(struct sysmon_envsys *,
					 envsys_data_t *,
					 sysmon_envsys_lim_t *, uint32_t *);
static void	vcmbox_sensor_refresh(struct sysmon_envsys *,
				      envsys_data_t *);

CFATTACH_DECL_NEW(vcmbox, sizeof(struct vcmbox_softc),
    vcmbox_match, vcmbox_attach, NULL, NULL);

static int
vcmbox_match(device_t parent, cfdata_t match, void *aux)
{
	return 1;
}

static void
vcmbox_attach(device_t parent, device_t self, void *aux)
{
	struct vcmbox_softc *sc = device_private(self);

	sc->sc_dev = self;

	aprint_naive("\n");
	aprint_normal("\n");

	vcmbox_cpufreq_init(sc);

	sc->sc_sme = sysmon_envsys_create();
	sc->sc_sme->sme_cookie = sc;
	sc->sc_sme->sme_name = device_xname(sc->sc_dev);
	sc->sc_sme->sme_refresh = vcmbox_sensor_refresh;
	sc->sc_sme->sme_get_limits = vcmbox_sensor_get_limits;
	vcmbox_create_sensors(sc);
	if (sysmon_envsys_register(sc->sc_sme) == 0)
		return;

	aprint_error_dev(self, "unable to register with sysmon\n");
	sysmon_envsys_destroy(sc->sc_sme);
}

static int
vcmbox_read_temp(struct vcmbox_softc *sc, uint32_t tag, int id, uint32_t *val)
{
	struct vcmbox_temp_request vb;
	uint32_t res;
	int error;

	VCMBOX_INIT_REQUEST(vb);
	VCMBOX_INIT_TAG(vb.vbt_temp, tag);
	vb.vbt_temp.id = htole32(id);
	error = bcmmbox_request(BCMMBOX_CHANARM2VC, &vb, sizeof(vb), &res);
	if (error)
		return error;
	if (!vcprop_buffer_success_p(&vb.vb_hdr) ||
	    !vcprop_tag_success_p(&vb.vbt_temp.tag)) {
		return EIO;
	}
	*val = le32toh(vb.vbt_temp.value);

	return 0;
}

static int
vcmbox_read_clockrate(struct vcmbox_softc *sc, uint32_t tag, int id,
    uint32_t *val)
{
	struct vcmbox_clockrate_request vb;
	uint32_t res;
	int error;

	VCMBOX_INIT_REQUEST(vb);
	VCMBOX_INIT_TAG(vb.vbt_clockrate, tag);
	vb.vbt_clockrate.id = htole32(id);
	error = bcmmbox_request(BCMMBOX_CHANARM2VC, &vb, sizeof(vb), &res);
	if (error)
		return error;
	if (!vcprop_buffer_success_p(&vb.vb_hdr) ||
	    !vcprop_tag_success_p(&vb.vbt_clockrate.tag)) {
		return EIO;
	}
	*val = le32toh(vb.vbt_clockrate.rate);

	return 0;
}

static int
vcmbox_write_clockrate(struct vcmbox_softc *sc, uint32_t tag, int id,
    uint32_t val)
{
	struct vcmbox_clockrate_request vb;
	uint32_t res;
	int error;

	VCMBOX_INIT_REQUEST(vb);
	VCMBOX_INIT_TAG(vb.vbt_clockrate, tag);
	vb.vbt_clockrate.id = htole32(id);
	vb.vbt_clockrate.rate = htole32(val);
	error = bcmmbox_request(BCMMBOX_CHANARM2VC, &vb, sizeof(vb), &res);
	if (error)
		return error;
	if (!vcprop_buffer_success_p(&vb.vb_hdr) ||
	    !vcprop_tag_success_p(&vb.vbt_clockrate.tag)) {
		return EIO;
	}

	return 0;
}


static int
vcmbox_cpufreq_init(struct vcmbox_softc *sc)
{
	const struct sysctlnode *node, *cpunode, *freqnode;
	int error;
	static char available[20];

	error = vcmbox_read_clockrate(sc, VCPROPTAG_GET_MIN_CLOCKRATE,
	    VCPROP_CLK_ARM, &sc->sc_cpu_minrate);
	if (error) {
		aprint_error_dev(sc->sc_dev, "couldn't read min clkrate (%d)\n",
		    error);
		return error;
	}
	error = vcmbox_read_clockrate(sc, VCPROPTAG_GET_MAX_CLOCKRATE,
	    VCPROP_CLK_ARM, &sc->sc_cpu_maxrate);
	if (error) {
		aprint_error_dev(sc->sc_dev, "couldn't read max clkrate (%d)\n",
		    error);
		return error;
	}

	error = sysctl_createv(&sc->sc_log, 0, NULL, &node,
	    CTLFLAG_PERMANENT, CTLTYPE_NODE, "machdep", NULL,
	    NULL, 0, NULL, 0, CTL_MACHDEP, CTL_EOL);
	if (error)
		goto sysctl_failed;
	error = sysctl_createv(&sc->sc_log, 0, &node, &cpunode,
	    0, CTLTYPE_NODE, "cpu", NULL,
	    NULL, 0, NULL, 0, CTL_CREATE, CTL_EOL);
	if (error)
		goto sysctl_failed;
	error = sysctl_createv(&sc->sc_log, 0, &cpunode, &freqnode,
	    0, CTLTYPE_NODE, "frequency", NULL,
	    NULL, 0, NULL, 0, CTL_CREATE, CTL_EOL);
	if (error)
		goto sysctl_failed;

	error = sysctl_createv(&sc->sc_log, 0, &freqnode, &node,
	    CTLFLAG_READWRITE, CTLTYPE_INT, "target", NULL,
	    vcmbox_cpufreq_sysctl_helper, 0, (void *)sc, 0,
	    CTL_CREATE, CTL_EOL);
	if (error)
		goto sysctl_failed;
	sc->sc_node_target = node->sysctl_num;

	error = sysctl_createv(&sc->sc_log, 0, &freqnode, &node,
	    0, CTLTYPE_INT, "current", NULL,
	    vcmbox_cpufreq_sysctl_helper, 0, (void *)sc, 0,
	    CTL_CREATE, CTL_EOL);
	if (error)
		goto sysctl_failed;
	sc->sc_node_current = node->sysctl_num;

	error = sysctl_createv(&sc->sc_log, 0, &freqnode, &node,
	    0, CTLTYPE_INT, "min", NULL,
	    vcmbox_cpufreq_sysctl_helper, 0, (void *)sc, 0,
	    CTL_CREATE, CTL_EOL);
	if (error)
		goto sysctl_failed;
	sc->sc_node_min = node->sysctl_num;

	error = sysctl_createv(&sc->sc_log, 0, &freqnode, &node,
	    0, CTLTYPE_INT, "max", NULL,
	    vcmbox_cpufreq_sysctl_helper, 0, (void *)sc, 0,
	    CTL_CREATE, CTL_EOL);
	if (error)
		goto sysctl_failed;
	sc->sc_node_max = node->sysctl_num;

	snprintf(available, sizeof(available), "%" PRIu32 " %" PRIu32,
	    RATE2MHZ(sc->sc_cpu_minrate), RATE2MHZ(sc->sc_cpu_maxrate));

	error = sysctl_createv(&sc->sc_log, 0, &freqnode, &node,
	    CTLFLAG_PERMANENT, CTLTYPE_STRING, "available", NULL,
	    NULL, 0, available, strlen(available),
	    CTL_CREATE, CTL_EOL);
	if (error)
		goto sysctl_failed;

	return 0;

sysctl_failed:
	aprint_error_dev(sc->sc_dev, "couldn't create sysctl nodes (%d)\n",
	    error);
	sysctl_teardown(&sc->sc_log);
	return error;
}

static int
vcmbox_cpufreq_sysctl_helper(SYSCTLFN_ARGS)
{
	struct sysctlnode node;
	struct vcmbox_softc *sc;
	int fq, oldfq = 0, error;
	uint32_t rate;

	node = *rnode;
	sc = node.sysctl_data;

	node.sysctl_data = &fq;

	if (rnode->sysctl_num == sc->sc_node_target ||
	    rnode->sysctl_num == sc->sc_node_current) {
		error = vcmbox_read_clockrate(sc, VCPROPTAG_GET_CLOCKRATE,
		    VCPROP_CLK_ARM, &rate);
		if (error)
			return error;
		fq = RATE2MHZ(rate);
		if (rnode->sysctl_num == sc->sc_node_target)
			oldfq = fq;
	} else if (rnode->sysctl_num == sc->sc_node_min) {
		fq = RATE2MHZ(sc->sc_cpu_minrate);
	} else if (rnode->sysctl_num == sc->sc_node_max) {
		fq = RATE2MHZ(sc->sc_cpu_maxrate);
	} else
		return EOPNOTSUPP;

	error = sysctl_lookup(SYSCTLFN_CALL(&node));
	if (error || newp == NULL)
		return error;

	if (fq == oldfq || rnode->sysctl_num != sc->sc_node_target)
		return 0;

	if (fq < RATE2MHZ(sc->sc_cpu_minrate))
		fq = RATE2MHZ(sc->sc_cpu_minrate);
	if (fq > RATE2MHZ(sc->sc_cpu_maxrate))
		fq = RATE2MHZ(sc->sc_cpu_maxrate);

	return vcmbox_write_clockrate(sc, VCPROPTAG_SET_CLOCKRATE,
	    VCPROP_CLK_ARM, MHZ2RATE(fq));
}

static void
vcmbox_create_sensors(struct vcmbox_softc *sc)
{
	uint32_t val;

	sc->sc_sensor[VCMBOX_SENSOR_TEMP].sensor = VCMBOX_SENSOR_TEMP;
	sc->sc_sensor[VCMBOX_SENSOR_TEMP].units = ENVSYS_STEMP;
	sc->sc_sensor[VCMBOX_SENSOR_TEMP].state = ENVSYS_SINVALID;
	sc->sc_sensor[VCMBOX_SENSOR_TEMP].flags = ENVSYS_FMONLIMITS |
						  ENVSYS_FHAS_ENTROPY;
	strlcpy(sc->sc_sensor[VCMBOX_SENSOR_TEMP].desc,
	    vcmbox_sensor_name[VCMBOX_SENSOR_TEMP],
	    sizeof(sc->sc_sensor[VCMBOX_SENSOR_TEMP].desc));
	if (vcmbox_read_temp(sc, VCPROPTAG_GET_MAX_TEMPERATURE,
			     vcmbox_sensor_id[VCMBOX_SENSOR_TEMP], &val) == 0) {
		sc->sc_sensor[VCMBOX_SENSOR_TEMP].value_max =
		    val * 1000 + 273150000;
		sc->sc_sensor[VCMBOX_SENSOR_TEMP].flags |= ENVSYS_FVALID_MAX;
	}
	sysmon_envsys_sensor_attach(sc->sc_sme,
	    &sc->sc_sensor[VCMBOX_SENSOR_TEMP]);
}

static void
vcmbox_sensor_get_limits(struct sysmon_envsys *sme, envsys_data_t *edata,
    sysmon_envsys_lim_t *limits, uint32_t *props)
{
	struct vcmbox_softc *sc = sme->sme_cookie;
	uint32_t val;

	*props = 0;

	if (edata->units == ENVSYS_STEMP) {
		if (vcmbox_read_temp(sc, VCPROPTAG_GET_MAX_TEMPERATURE,
				     vcmbox_sensor_id[edata->sensor], &val))
			return;
		*props = PROP_CRITMAX;
		limits->sel_critmax = val * 1000 + 273150000;
	}
}

static void
vcmbox_sensor_refresh(struct sysmon_envsys *sme, envsys_data_t *edata)
{
	struct vcmbox_softc *sc = sme->sme_cookie;
	uint32_t val;

	edata->state = ENVSYS_SINVALID;

	if (edata->units == ENVSYS_STEMP) {
		if (vcmbox_read_temp(sc, VCPROPTAG_GET_TEMPERATURE,
				     vcmbox_sensor_id[edata->sensor], &val))
			return;

		edata->value_cur = val * 1000 + 273150000;
		edata->state = ENVSYS_SVALID;
	}
}