1/*-
2 * Copyright (c) 2017 Ian Lepore <ian@freebsd.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26/*
27 * Support routines usable by any SoC sdhci bridge driver that uses gpio pins
28 * for card detect and write protect, and uses FDT data to describe those pins.
29 */
30
31#include <sys/cdefs.h>
32__FBSDID("$FreeBSD$");
33
34#include <sys/param.h>
35#include <sys/bus.h>
36#include <sys/gpio.h>
37#include <sys/sysctl.h>
38#include <sys/systm.h>
39#include <sys/taskqueue.h>
40
41#include <dev/gpio/gpiobusvar.h>
42#include <dev/mmc/bridge.h>
43#include <dev/ofw/ofw_bus.h>
44#include <dev/ofw/ofw_bus_subr.h>
45#include <dev/sdhci/sdhci.h>
46#include <dev/sdhci/sdhci_fdt_gpio.h>
47
48struct sdhci_fdt_gpio {
49	device_t		dev;
50	struct sdhci_slot *	slot;
51	gpio_pin_t		wp_pin;
52	gpio_pin_t		cd_pin;
53	void *			cd_ihandler;
54	struct resource *	cd_ires;
55	int			cd_irid;
56	bool			wp_disabled;
57	bool			wp_inverted;
58	bool			cd_disabled;
59	bool			cd_inverted;
60};
61
62/*
63 * Card detect interrupt handler.
64 */
65static void
66cd_intr(void *arg)
67{
68	struct sdhci_fdt_gpio *gpio = arg;
69
70	sdhci_handle_card_present(gpio->slot, sdhci_fdt_gpio_get_present(gpio));
71}
72
73/*
74 * Card detect setup.
75 */
76static void
77cd_setup(struct sdhci_fdt_gpio *gpio, phandle_t node)
78{
79	int pincaps;
80	device_t dev;
81	const char *cd_mode_str;
82
83	dev = gpio->dev;
84
85	/*
86	 * If the device is flagged as non-removable, set that slot option, and
87	 * set a flag to make sdhci_fdt_gpio_get_present() always return true.
88	 */
89	if (OF_hasprop(node, "non-removable")) {
90		gpio->slot->opt |= SDHCI_NON_REMOVABLE;
91		gpio->cd_disabled = true;
92		if (bootverbose)
93			device_printf(dev, "Non-removable media\n");
94		return;
95	}
96
97	/*
98	 * If there is no cd-gpios property, then presumably the hardware
99	 * PRESENT_STATE register and interrupts will reflect card state
100	 * properly, and there's nothing more for us to do.  Our get_present()
101	 * will return sdhci_generic_get_card_present() because cd_pin is NULL.
102	 *
103	 * If there is a property, make sure we can read the pin.
104	 */
105	if (gpio_pin_get_by_ofw_property(dev, node, "cd-gpios", &gpio->cd_pin))
106		return;
107
108	if (gpio_pin_getcaps(gpio->cd_pin, &pincaps) != 0 ||
109	    !(pincaps & GPIO_PIN_INPUT)) {
110		device_printf(dev, "Cannot read card-detect gpio pin; "
111		    "setting card-always-present flag.\n");
112		gpio->cd_disabled = true;
113		return;
114	}
115
116	if (OF_hasprop(node, "cd-inverted"))
117		gpio->cd_inverted = true;
118
119	/*
120	 * If the pin can trigger an interrupt on both rising and falling edges,
121	 * we can use it to detect card presence changes.  If not, we'll request
122	 * card presence polling instead of using interrupts.
123	 */
124	if (!(pincaps & GPIO_INTR_EDGE_BOTH)) {
125		if (bootverbose)
126			device_printf(dev, "Cannot configure "
127			    "GPIO_INTR_EDGE_BOTH for card detect\n");
128		goto without_interrupts;
129	}
130
131	/*
132	 * Create an interrupt resource from the pin and set up the interrupt.
133	 */
134	if ((gpio->cd_ires = gpio_alloc_intr_resource(dev, &gpio->cd_irid,
135	    RF_ACTIVE, gpio->cd_pin, GPIO_INTR_EDGE_BOTH)) == NULL) {
136		if (bootverbose)
137			device_printf(dev, "Cannot allocate an IRQ for card "
138			    "detect GPIO\n");
139		goto without_interrupts;
140	}
141
142	if (bus_setup_intr(dev, gpio->cd_ires, INTR_TYPE_BIO | INTR_MPSAFE,
143	    NULL, cd_intr, gpio, &gpio->cd_ihandler) != 0) {
144		device_printf(dev, "Unable to setup card-detect irq handler\n");
145		gpio->cd_ihandler = NULL;
146		goto without_interrupts;
147	}
148
149without_interrupts:
150
151	/*
152	 * If we have a readable gpio pin, but didn't successfully configure
153	 * gpio interrupts, ask the sdhci driver to poll from a callout.
154	 */
155	if (gpio->cd_ihandler == NULL) {
156		cd_mode_str = "polling";
157		gpio->slot->quirks |= SDHCI_QUIRK_POLL_CARD_PRESENT;
158	} else {
159		cd_mode_str = "interrupts";
160	}
161
162	if (bootverbose) {
163		device_printf(dev, "Card presence detect on %s pin %u, "
164		    "configured for %s.\n",
165		    device_get_nameunit(gpio->cd_pin->dev), gpio->cd_pin->pin,
166		    cd_mode_str);
167	}
168}
169
170/*
171 * Write protect setup.
172 */
173static void
174wp_setup(struct sdhci_fdt_gpio *gpio, phandle_t node)
175{
176	device_t dev;
177
178	dev = gpio->dev;
179
180	if (OF_hasprop(node, "wp-disable")) {
181		gpio->wp_disabled = true;
182		if (bootverbose)
183			device_printf(dev, "Write protect disabled\n");
184		return;
185	}
186
187	if (gpio_pin_get_by_ofw_property(dev, node, "wp-gpios", &gpio->wp_pin))
188		return;
189
190	if (OF_hasprop(node, "wp-inverted"))
191		gpio->wp_inverted = true;
192
193	if (bootverbose)
194		device_printf(dev, "Write protect switch on %s pin %u\n",
195		    device_get_nameunit(gpio->wp_pin->dev), gpio->wp_pin->pin);
196}
197
198struct sdhci_fdt_gpio *
199sdhci_fdt_gpio_setup(device_t dev, struct sdhci_slot *slot)
200{
201	phandle_t node;
202	struct sdhci_fdt_gpio *gpio;
203
204	gpio = malloc(sizeof(*gpio), M_DEVBUF, M_ZERO | M_WAITOK);
205	gpio->dev  = dev;
206	gpio->slot = slot;
207
208	node = ofw_bus_get_node(dev);
209
210	wp_setup(gpio, node);
211	cd_setup(gpio, node);
212
213	return (gpio);
214}
215
216void
217sdhci_fdt_gpio_teardown(struct sdhci_fdt_gpio *gpio)
218{
219
220	if (gpio == NULL)
221		return;
222
223	if (gpio->cd_ihandler != NULL)
224		bus_teardown_intr(gpio->dev, gpio->cd_ires, gpio->cd_ihandler);
225	if (gpio->wp_pin != NULL)
226		gpio_pin_release(gpio->wp_pin);
227	if (gpio->cd_pin != NULL)
228		gpio_pin_release(gpio->cd_pin);
229	if (gpio->cd_ires != NULL)
230		bus_release_resource(gpio->dev, SYS_RES_IRQ, 0, gpio->cd_ires);
231
232	free(gpio, M_DEVBUF);
233}
234
235bool
236sdhci_fdt_gpio_get_present(struct sdhci_fdt_gpio *gpio)
237{
238	bool pinstate;
239
240	if (gpio->cd_disabled)
241		return (true);
242
243	if (gpio->cd_pin == NULL)
244		return (sdhci_generic_get_card_present(gpio->slot->bus,
245		    gpio->slot));
246
247	gpio_pin_is_active(gpio->cd_pin, &pinstate);
248
249	return (pinstate ^ gpio->cd_inverted);
250}
251
252int
253sdhci_fdt_gpio_get_readonly(struct sdhci_fdt_gpio *gpio)
254{
255	bool pinstate;
256
257	if (gpio->wp_disabled)
258		return (false);
259
260	if (gpio->wp_pin == NULL)
261		return (sdhci_generic_get_ro(gpio->slot->bus, gpio->slot->dev));
262
263	gpio_pin_is_active(gpio->wp_pin, &pinstate);
264
265	return (pinstate ^ gpio->wp_inverted);
266}
267