xref: /freebsd/sys/dev/sdhci/sdhci_fdt_gpio.c (revision 3f0efe05432b1633991114ca4ca330102a561959)
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/param.h>
32 #include <sys/bus.h>
33 #include <sys/gpio.h>
34 #include <sys/sysctl.h>
35 #include <sys/systm.h>
36 #include <sys/taskqueue.h>
37 
38 #include <dev/gpio/gpiobusvar.h>
39 #include <dev/mmc/bridge.h>
40 #include <dev/ofw/ofw_bus.h>
41 #include <dev/ofw/ofw_bus_subr.h>
42 #include <dev/sdhci/sdhci.h>
43 #include <dev/sdhci/sdhci_fdt_gpio.h>
44 
45 struct sdhci_fdt_gpio {
46 	device_t		dev;
47 	struct sdhci_slot *	slot;
48 	gpio_pin_t		wp_pin;
49 	gpio_pin_t		cd_pin;
50 	void *			cd_ihandler;
51 	struct resource *	cd_ires;
52 	int			cd_irid;
53 	bool			wp_disabled;
54 	bool			wp_inverted;
55 	bool			cd_disabled;
56 	bool			cd_inverted;
57 };
58 
59 /*
60  * Card detect interrupt handler.
61  */
62 static void
63 cd_intr(void *arg)
64 {
65 	struct sdhci_fdt_gpio *gpio = arg;
66 
67 	sdhci_handle_card_present(gpio->slot, sdhci_fdt_gpio_get_present(gpio));
68 }
69 
70 /*
71  * Card detect setup.
72  */
73 static void
74 cd_setup(struct sdhci_fdt_gpio *gpio, phandle_t node)
75 {
76 	int pincaps;
77 	device_t dev;
78 	const char *cd_mode_str;
79 
80 	dev = gpio->dev;
81 
82 	/*
83 	 * If the device is flagged as non-removable, set that slot option, and
84 	 * set a flag to make sdhci_fdt_gpio_get_present() always return true.
85 	 */
86 	if (OF_hasprop(node, "non-removable")) {
87 		gpio->slot->opt |= SDHCI_NON_REMOVABLE;
88 		gpio->cd_disabled = true;
89 		if (bootverbose)
90 			device_printf(dev, "Non-removable media\n");
91 		return;
92 	}
93 
94 	/*
95 	 * If there is no cd-gpios property, then presumably the hardware
96 	 * PRESENT_STATE register and interrupts will reflect card state
97 	 * properly, and there's nothing more for us to do.  Our get_present()
98 	 * will return sdhci_generic_get_card_present() because cd_pin is NULL.
99 	 *
100 	 * If there is a property, make sure we can read the pin.
101 	 */
102 	if (gpio_pin_get_by_ofw_property(dev, node, "cd-gpios", &gpio->cd_pin))
103 		return;
104 
105 	if (gpio_pin_getcaps(gpio->cd_pin, &pincaps) != 0 ||
106 	    !(pincaps & GPIO_PIN_INPUT)) {
107 		device_printf(dev, "Cannot read card-detect gpio pin; "
108 		    "setting card-always-present flag.\n");
109 		gpio->cd_disabled = true;
110 		return;
111 	}
112 
113 	if (OF_hasprop(node, "cd-inverted"))
114 		gpio->cd_inverted = true;
115 
116 	/*
117 	 * If the pin can trigger an interrupt on both rising and falling edges,
118 	 * we can use it to detect card presence changes.  If not, we'll request
119 	 * card presence polling instead of using interrupts.
120 	 */
121 	if (!(pincaps & GPIO_INTR_EDGE_BOTH)) {
122 		if (bootverbose)
123 			device_printf(dev, "Cannot configure "
124 			    "GPIO_INTR_EDGE_BOTH for card detect\n");
125 		goto without_interrupts;
126 	}
127 
128 	/*
129 	 * Create an interrupt resource from the pin and set up the interrupt.
130 	 */
131 	if ((gpio->cd_ires = gpio_alloc_intr_resource(dev, &gpio->cd_irid,
132 	    RF_ACTIVE, gpio->cd_pin, GPIO_INTR_EDGE_BOTH)) == NULL) {
133 		if (bootverbose)
134 			device_printf(dev, "Cannot allocate an IRQ for card "
135 			    "detect GPIO\n");
136 		goto without_interrupts;
137 	}
138 
139 	if (bus_setup_intr(dev, gpio->cd_ires, INTR_TYPE_BIO | INTR_MPSAFE,
140 	    NULL, cd_intr, gpio, &gpio->cd_ihandler) != 0) {
141 		device_printf(dev, "Unable to setup card-detect irq handler\n");
142 		gpio->cd_ihandler = NULL;
143 		goto without_interrupts;
144 	}
145 
146 without_interrupts:
147 
148 	/*
149 	 * If we have a readable gpio pin, but didn't successfully configure
150 	 * gpio interrupts, ask the sdhci driver to poll from a callout.
151 	 */
152 	if (gpio->cd_ihandler == NULL) {
153 		cd_mode_str = "polling";
154 		gpio->slot->quirks |= SDHCI_QUIRK_POLL_CARD_PRESENT;
155 	} else {
156 		cd_mode_str = "interrupts";
157 	}
158 
159 	if (bootverbose) {
160 		device_printf(dev, "Card presence detect on %s pin %u, "
161 		    "configured for %s.\n",
162 		    device_get_nameunit(gpio->cd_pin->dev), gpio->cd_pin->pin,
163 		    cd_mode_str);
164 	}
165 }
166 
167 /*
168  * Write protect setup.
169  */
170 static void
171 wp_setup(struct sdhci_fdt_gpio *gpio, phandle_t node)
172 {
173 	device_t dev;
174 
175 	dev = gpio->dev;
176 
177 	if (OF_hasprop(node, "wp-disable")) {
178 		gpio->wp_disabled = true;
179 		if (bootverbose)
180 			device_printf(dev, "Write protect disabled\n");
181 		return;
182 	}
183 
184 	if (gpio_pin_get_by_ofw_property(dev, node, "wp-gpios", &gpio->wp_pin))
185 		return;
186 
187 	if (OF_hasprop(node, "wp-inverted"))
188 		gpio->wp_inverted = true;
189 
190 	if (bootverbose)
191 		device_printf(dev, "Write protect switch on %s pin %u\n",
192 		    device_get_nameunit(gpio->wp_pin->dev), gpio->wp_pin->pin);
193 }
194 
195 struct sdhci_fdt_gpio *
196 sdhci_fdt_gpio_setup(device_t dev, struct sdhci_slot *slot)
197 {
198 	phandle_t node;
199 	struct sdhci_fdt_gpio *gpio;
200 
201 	gpio = malloc(sizeof(*gpio), M_DEVBUF, M_ZERO | M_WAITOK);
202 	gpio->dev  = dev;
203 	gpio->slot = slot;
204 
205 	node = ofw_bus_get_node(dev);
206 
207 	wp_setup(gpio, node);
208 	cd_setup(gpio, node);
209 
210 	return (gpio);
211 }
212 
213 void
214 sdhci_fdt_gpio_teardown(struct sdhci_fdt_gpio *gpio)
215 {
216 
217 	if (gpio == NULL)
218 		return;
219 
220 	if (gpio->cd_ihandler != NULL)
221 		bus_teardown_intr(gpio->dev, gpio->cd_ires, gpio->cd_ihandler);
222 	if (gpio->wp_pin != NULL)
223 		gpio_pin_release(gpio->wp_pin);
224 	if (gpio->cd_pin != NULL)
225 		gpio_pin_release(gpio->cd_pin);
226 	if (gpio->cd_ires != NULL)
227 		bus_release_resource(gpio->dev, SYS_RES_IRQ, 0, gpio->cd_ires);
228 
229 	free(gpio, M_DEVBUF);
230 }
231 
232 bool
233 sdhci_fdt_gpio_get_present(struct sdhci_fdt_gpio *gpio)
234 {
235 	bool pinstate;
236 
237 	if (gpio->cd_disabled)
238 		return (true);
239 
240 	if (gpio->cd_pin == NULL)
241 		return (sdhci_generic_get_card_present(gpio->slot->bus,
242 		    gpio->slot));
243 
244 	gpio_pin_is_active(gpio->cd_pin, &pinstate);
245 
246 	return (pinstate ^ gpio->cd_inverted);
247 }
248 
249 int
250 sdhci_fdt_gpio_get_readonly(struct sdhci_fdt_gpio *gpio)
251 {
252 	bool pinstate;
253 
254 	if (gpio->wp_disabled)
255 		return (false);
256 
257 	if (gpio->wp_pin == NULL)
258 		return (sdhci_generic_get_ro(gpio->slot->bus, gpio->slot->dev));
259 
260 	gpio_pin_is_active(gpio->wp_pin, &pinstate);
261 
262 	return (pinstate ^ gpio->wp_inverted);
263 }
264