1/* $NetBSD: tcagpio.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: tcagpio.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#include <sys/gpio.h>
40
41#include <dev/i2c/i2cvar.h>
42
43#include <dev/fdt/fdtvar.h>
44
45#define	PORT_BANK(pin)		(pin / 8)
46#define	PORT_BIT(pin)		__BIT(pin % 8)
47
48#define	PORT_IN(pin)		(0x00 + PORT_BANK(pin))
49#define	PORT_OUT(pin)		(0x02 + PORT_BANK(pin))
50#define	PORT_POLARITY(pin)	(0x04 + PORT_BANK(pin))
51#define	PORT_CFG(pin)		(0x06 + PORT_BANK(pin))
52
53#define	TCA_PIN_COUNT		16
54
55struct tcagpio_softc {
56	device_t	sc_dev;
57	i2c_tag_t	sc_i2c;
58	i2c_addr_t	sc_addr;
59	int		sc_phandle;
60
61	int		sc_npins;
62};
63
64struct tcagpio_pin {
65	struct tcagpio_softc	*pin_sc;
66	int			pin_num;
67	int			pin_flags;
68	bool			pin_actlo;
69};
70
71static const struct device_compatible_entry compat_data[] = {
72	{ .compat = "ti,tca9539" },
73	DEVICE_COMPAT_EOL
74};
75
76static uint8_t
77tcagpio_read(struct tcagpio_softc *sc, uint8_t reg, int flags)
78{
79	uint8_t val = 0;
80	int error;
81
82	error = iic_exec(sc->sc_i2c, I2C_OP_READ_WITH_STOP, sc->sc_addr,
83	    &reg, 1, &val, 1, flags);
84	if (error != 0)
85		aprint_error_dev(sc->sc_dev, "error reading reg %#x: %d\n", reg, error);
86
87	return val;
88}
89
90static void
91tcagpio_write(struct tcagpio_softc *sc, uint8_t reg, uint8_t val, int flags)
92{
93	uint8_t buf[2];
94	int error;
95
96	buf[0] = reg;
97	buf[1] = val;
98
99	error = iic_exec(sc->sc_i2c, I2C_OP_WRITE_WITH_STOP, sc->sc_addr,
100	    NULL, 0, buf, 2, flags);
101	if (error != 0)
102		aprint_error_dev(sc->sc_dev, "error writing reg %#x: %d\n", reg, error);
103}
104
105#define	I2C_READ(sc, reg)	tcagpio_read((sc), (reg), 0)
106#define	I2C_WRITE(sc, reg, val)	tcagpio_write((sc), (reg), (val), 0)
107#define	I2C_LOCK(sc)		iic_acquire_bus((sc)->sc_i2c, 0)
108#define	I2C_UNLOCK(sc)		iic_release_bus((sc)->sc_i2c, 0)
109
110static int
111tcagpio_gpio_config(struct tcagpio_softc *sc, int pin, int flags)
112{
113	uint16_t gpio;
114
115	KASSERT(pin >= 0 && pin < sc->sc_npins);
116
117	gpio = I2C_READ(sc, PORT_CFG(pin));
118
119	switch (flags & (GPIO_PIN_INPUT|GPIO_PIN_OUTPUT)) {
120	case GPIO_PIN_INPUT:
121		gpio |= PORT_BIT(pin);
122		break;
123	case GPIO_PIN_OUTPUT:
124		gpio &= ~PORT_BIT(pin);
125		break;
126	default:
127		return EINVAL;
128	}
129
130	I2C_WRITE(sc, PORT_CFG(pin), gpio);
131
132	return 0;
133}
134
135static void *
136tcagpio_gpio_acquire(device_t dev, const void *data, size_t len, int flags)
137{
138	struct tcagpio_softc * const sc = device_private(dev);
139	struct tcagpio_pin *gpin;
140	const u_int *gpio = data;
141	int error;
142
143	if (len != 12)
144		return NULL;
145
146	const uint8_t pin = be32toh(gpio[1]) & 0xff;
147	const bool actlo = (be32toh(gpio[2]) & __BIT(0)) != 0;
148
149	if (pin >= sc->sc_npins)
150		return NULL;
151
152	I2C_LOCK(sc);
153	error = tcagpio_gpio_config(sc, pin, flags);
154	I2C_UNLOCK(sc);
155
156	if (error != 0) {
157		device_printf(dev, "bad pin %d config %#x\n", pin, flags);
158		return NULL;
159	}
160
161	gpin = kmem_zalloc(sizeof(*gpin), KM_SLEEP);
162	gpin->pin_sc = sc;
163	gpin->pin_num = pin;
164	gpin->pin_flags = flags;
165	gpin->pin_actlo = actlo;
166
167	return gpin;
168}
169
170static void
171tcagpio_gpio_release(device_t dev, void *priv)
172{
173	struct tcagpio_softc * const sc = device_private(dev);
174	struct tcagpio_pin *gpin = priv;
175
176	I2C_LOCK(sc);
177	tcagpio_gpio_config(sc, gpin->pin_num, GPIO_PIN_INPUT);
178	I2C_UNLOCK(sc);
179
180	kmem_free(gpin, sizeof(*gpin));
181}
182
183static int
184tcagpio_gpio_read(device_t dev, void *priv, bool raw)
185{
186	struct tcagpio_softc * const sc = device_private(dev);
187	struct tcagpio_pin *gpin = priv;
188	uint8_t gpio;
189	int val;
190
191	I2C_LOCK(sc);
192	gpio = I2C_READ(sc, PORT_IN(gpin->pin_num));
193	I2C_UNLOCK(sc);
194
195	val = __SHIFTOUT(gpio, PORT_BIT(gpin->pin_num));
196	if (!raw && gpin->pin_actlo)
197		val = !val;
198
199#ifdef TCAGPIO_DEBUG
200	device_printf(sc->sc_dev, "GPIO%d rd %02x (%d %d)\n",
201	    gpin->pin_num, gpio,
202	    (int)__SHIFTOUT(gpio, PORT_BIT(gpin->pin_num)), val);
203#endif
204
205	return val;
206}
207
208static void
209tcagpio_gpio_write(device_t dev, void *priv, int val, bool raw)
210{
211	struct tcagpio_softc * const sc = device_private(dev);
212	struct tcagpio_pin *gpin = priv;
213	uint8_t gpio;
214
215	if (!raw && gpin->pin_actlo)
216		val = !val;
217
218	I2C_LOCK(sc);
219	gpio = I2C_READ(sc, PORT_OUT(gpin->pin_num));
220	gpio &= ~PORT_BIT(gpin->pin_num);
221	gpio |= __SHIFTIN(val, PORT_BIT(gpin->pin_num));
222#ifdef TCAGPIO_DEBUG
223	device_printf(sc->sc_dev, "GPIO%d wr %02x -> %02x\n",
224	    gpin->pin_num,
225	    I2C_READ(sc, PORT_OUT(gpin->pin_num)), gpio);
226#endif
227	I2C_WRITE(sc, PORT_OUT(gpin->pin_num), gpio);
228	I2C_UNLOCK(sc);
229}
230
231static struct fdtbus_gpio_controller_func tcagpio_gpio_funcs = {
232	.acquire = tcagpio_gpio_acquire,
233	.release = tcagpio_gpio_release,
234	.read = tcagpio_gpio_read,
235	.write = tcagpio_gpio_write,
236};
237
238static void
239tcagpio_gpio_attach(struct tcagpio_softc *sc)
240{
241	fdtbus_register_gpio_controller(sc->sc_dev, sc->sc_phandle,
242	    &tcagpio_gpio_funcs);
243}
244
245static int
246tcagpio_match(device_t parent, cfdata_t match, void *aux)
247{
248	struct i2c_attach_args *ia = aux;
249	int match_result;
250
251	if (iic_use_direct_match(ia, match, compat_data, &match_result))
252		return match_result;
253
254	return 0;
255}
256
257static void
258tcagpio_attach(device_t parent, device_t self, void *aux)
259{
260	struct tcagpio_softc * const sc = device_private(self);
261	struct i2c_attach_args *ia = aux;
262
263	sc->sc_dev = self;
264	sc->sc_i2c = ia->ia_tag;
265	sc->sc_addr = ia->ia_addr;
266	sc->sc_phandle = ia->ia_cookie;
267	sc->sc_npins = TCA_PIN_COUNT;
268
269	aprint_naive("\n");
270	aprint_normal(": I2C/SMBus I/O Expander\n");
271
272	tcagpio_gpio_attach(sc);
273}
274
275CFATTACH_DECL_NEW(tcagpio, sizeof(struct tcagpio_softc),
276    tcagpio_match, tcagpio_attach, NULL, NULL);
277