xref: /freebsd/sys/dev/sdhci/sdhci_fdt_gpio.c (revision 389e4940069316fe667ffa263fa7d6390d0a960f)
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 
48 struct 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  */
65 static void
66 cd_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  */
76 static void
77 cd_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 
149 without_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  */
173 static void
174 wp_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 
198 struct sdhci_fdt_gpio *
199 sdhci_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 
216 void
217 sdhci_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 
235 bool
236 sdhci_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 
252 int
253 sdhci_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