1/* $NetBSD: sy8106a.c,v 1.8 2021/01/27 02:29:48 thorpej Exp $ */
2
3/*-
4 * Copyright (c) 2017 Jared McNeill <jmcneill@invisible.ca>
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
19 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
20 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#include <sys/cdefs.h>
30__KERNEL_RCSID(0, "$NetBSD: sy8106a.c,v 1.8 2021/01/27 02:29:48 thorpej Exp $");
31
32#include <sys/param.h>
33#include <sys/systm.h>
34#include <sys/kernel.h>
35#include <sys/device.h>
36#include <sys/conf.h>
37#include <sys/bus.h>
38#include <sys/kmem.h>
39
40#include <dev/i2c/i2cvar.h>
41
42#include <dev/fdt/fdtvar.h>
43
44#define	VOUT1_SEL		0x01
45#define	 SEL_GO			__BIT(7)
46#define	 SEL_VOLTAGE		__BITS(6,0)
47#define	  SEL_VOLTAGE_BASE	680000	/* uV */
48#define	  SEL_VOLTAGE_STEP	10000	/* uV */
49#define	VOUT_COM		0x02
50#define	 COM_DISABLE		__BIT(0)
51#define	SYS_STATUS		0x06
52
53struct sy8106a_softc {
54	device_t	sc_dev;
55	i2c_tag_t	sc_i2c;
56	i2c_addr_t	sc_addr;
57	int		sc_phandle;
58
59	u_int		sc_ramp_delay;
60};
61
62static const struct device_compatible_entry compat_data[] = {
63	{ .compat = "silergy,sy8106a" },
64	DEVICE_COMPAT_EOL
65};
66
67static uint8_t
68sy8106a_read(struct sy8106a_softc *sc, uint8_t reg, int flags)
69{
70	uint8_t val = 0;
71	int error;
72
73	error = iic_exec(sc->sc_i2c, I2C_OP_READ_WITH_STOP, sc->sc_addr,
74	    &reg, 1, &val, 1, flags);
75	if (error != 0)
76		aprint_error_dev(sc->sc_dev, "error reading reg %#x: %d\n", reg, error);
77
78	return val;
79}
80
81static void
82sy8106a_write(struct sy8106a_softc *sc, uint8_t reg, uint8_t val, int flags)
83{
84	uint8_t buf[2];
85	int error;
86
87	buf[0] = reg;
88	buf[1] = val;
89
90	error = iic_exec(sc->sc_i2c, I2C_OP_WRITE_WITH_STOP, sc->sc_addr,
91	    NULL, 0, buf, 2, flags);
92	if (error != 0)
93		aprint_error_dev(sc->sc_dev, "error writing reg %#x: %d\n", reg, error);
94}
95
96#define	I2C_READ(sc, reg)	sy8106a_read((sc), (reg), 0)
97#define	I2C_WRITE(sc, reg, val)	sy8106a_write((sc), (reg), (val), 0)
98#define	I2C_LOCK(sc)		iic_acquire_bus((sc)->sc_i2c, 0)
99#define	I2C_UNLOCK(sc)		iic_release_bus((sc)->sc_i2c, 0)
100
101static int
102sy8106a_acquire(device_t dev)
103{
104	return 0;
105}
106
107static void
108sy8106a_release(device_t dev)
109{
110}
111
112static int
113sy8106a_enable(device_t dev, bool enable)
114{
115	struct sy8106a_softc * const sc = device_private(dev);
116	uint8_t val;
117
118	I2C_LOCK(sc);
119	val = I2C_READ(sc, VOUT_COM);
120	if (enable)
121		val &= ~COM_DISABLE;
122	else
123		val |= COM_DISABLE;
124	I2C_WRITE(sc, VOUT_COM, val);
125	I2C_UNLOCK(sc);
126
127	if (sc->sc_ramp_delay)
128		delay(sc->sc_ramp_delay);
129
130	return 0;
131}
132
133static int
134sy8106a_set_voltage(device_t dev, u_int min_uvol, u_int max_uvol)
135{
136	struct sy8106a_softc * const sc = device_private(dev);
137	uint8_t val, oval;
138	u_int cur_uvol;
139
140	I2C_LOCK(sc);
141
142	/* Get current voltage */
143	oval = I2C_READ(sc, VOUT1_SEL);
144	cur_uvol = __SHIFTOUT(oval, SEL_VOLTAGE) * SEL_VOLTAGE_STEP +
145	    SEL_VOLTAGE_BASE;
146
147	/* Set new voltage */
148	val = SEL_GO | ((min_uvol - SEL_VOLTAGE_BASE) / SEL_VOLTAGE_STEP);
149	I2C_WRITE(sc, VOUT1_SEL, val);
150
151	I2C_UNLOCK(sc);
152
153	/* Time to delay is based on the number of voltage steps */
154	if (sc->sc_ramp_delay)
155		delay((abs(cur_uvol - min_uvol) / SEL_VOLTAGE_STEP) * sc->sc_ramp_delay);
156
157	return 0;
158}
159
160static int
161sy8106a_get_voltage(device_t dev, u_int *puvol)
162{
163	struct sy8106a_softc * const sc = device_private(dev);
164	uint8_t val;
165
166	I2C_LOCK(sc);
167	val = I2C_READ(sc, VOUT1_SEL);
168	I2C_UNLOCK(sc);
169
170	*puvol = __SHIFTOUT(val, SEL_VOLTAGE) * SEL_VOLTAGE_STEP +
171	    SEL_VOLTAGE_BASE;
172
173	return 0;
174}
175
176static struct fdtbus_regulator_controller_func sy8106a_funcs = {
177	.acquire = sy8106a_acquire,
178	.release = sy8106a_release,
179	.enable = sy8106a_enable,
180	.set_voltage = sy8106a_set_voltage,
181	.get_voltage = sy8106a_get_voltage,
182};
183
184static int
185sy8106a_match(device_t parent, cfdata_t match, void *aux)
186{
187	struct i2c_attach_args *ia = aux;
188	int match_result;
189
190	if (iic_use_direct_match(ia, match, compat_data, &match_result))
191		return match_result;
192
193	return 0;
194}
195
196static void
197sy8106a_attach(device_t parent, device_t self, void *aux)
198{
199	struct sy8106a_softc * const sc = device_private(self);
200	struct i2c_attach_args *ia = aux;
201
202	sc->sc_dev = self;
203	sc->sc_i2c = ia->ia_tag;
204	sc->sc_addr = ia->ia_addr;
205	sc->sc_phandle = ia->ia_cookie;
206
207	aprint_naive("\n");
208	aprint_normal(": Silergy SY8106A regulator\n");
209
210	of_getprop_uint32(sc->sc_phandle, "regulator-ramp-delay",
211	    &sc->sc_ramp_delay);
212
213	fdtbus_register_regulator_controller(self, sc->sc_phandle,
214	    &sy8106a_funcs);
215}
216
217CFATTACH_DECL_NEW(sy8106a, sizeof(struct sy8106a_softc),
218    sy8106a_match, sy8106a_attach, NULL, NULL);
219