xref: /freebsd/sys/dev/sdhci/sdhci_fdt_gpio.c (revision 22cf89c938886d14f5796fc49f9f020c23ea8eaf)
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 #include <sys/param.h>
33 #include <sys/bus.h>
34 #include <sys/gpio.h>
35 #include <sys/sysctl.h>
36 #include <sys/systm.h>
37 #include <sys/taskqueue.h>
38 
39 #include <dev/gpio/gpiobusvar.h>
40 #include <dev/mmc/bridge.h>
41 #include <dev/ofw/ofw_bus.h>
42 #include <dev/ofw/ofw_bus_subr.h>
43 #include <dev/sdhci/sdhci.h>
44 #include <dev/sdhci/sdhci_fdt_gpio.h>
45 
46 struct sdhci_fdt_gpio {
47 	device_t		dev;
48 	struct sdhci_slot *	slot;
49 	gpio_pin_t		wp_pin;
50 	gpio_pin_t		cd_pin;
51 	void *			cd_ihandler;
52 	struct resource *	cd_ires;
53 	int			cd_irid;
54 	bool			wp_disabled;
55 	bool			wp_inverted;
56 	bool			cd_disabled;
57 	bool			cd_inverted;
58 };
59 
60 /*
61  * Card detect interrupt handler.
62  */
63 static void
64 cd_intr(void *arg)
65 {
66 	struct sdhci_fdt_gpio *gpio = arg;
67 
68 	sdhci_handle_card_present(gpio->slot, sdhci_fdt_gpio_get_present(gpio));
69 }
70 
71 /*
72  * Card detect setup.
73  */
74 static void
75 cd_setup(struct sdhci_fdt_gpio *gpio, phandle_t node)
76 {
77 	int pincaps;
78 	device_t dev;
79 	const char *cd_mode_str;
80 
81 	dev = gpio->dev;
82 
83 	/*
84 	 * If the device is flagged as non-removable, set that slot option, and
85 	 * set a flag to make sdhci_fdt_gpio_get_present() always return true.
86 	 */
87 	if (OF_hasprop(node, "non-removable")) {
88 		gpio->slot->opt |= SDHCI_NON_REMOVABLE;
89 		gpio->cd_disabled = true;
90 		if (bootverbose)
91 			device_printf(dev, "Non-removable media\n");
92 		return;
93 	}
94 
95 	/*
96 	 * If there is no cd-gpios property, then presumably the hardware
97 	 * PRESENT_STATE register and interrupts will reflect card state
98 	 * properly, and there's nothing more for us to do.  Our get_present()
99 	 * will return sdhci_generic_get_card_present() because cd_pin is NULL.
100 	 *
101 	 * If there is a property, make sure we can read the pin.
102 	 */
103 	if (gpio_pin_get_by_ofw_property(dev, node, "cd-gpios", &gpio->cd_pin))
104 		return;
105 
106 	if (gpio_pin_getcaps(gpio->cd_pin, &pincaps) != 0 ||
107 	    !(pincaps & GPIO_PIN_INPUT)) {
108 		device_printf(dev, "Cannot read card-detect gpio pin; "
109 		    "setting card-always-present flag.\n");
110 		gpio->cd_disabled = true;
111 		return;
112 	}
113 
114 	if (OF_hasprop(node, "cd-inverted"))
115 		gpio->cd_inverted = true;
116 
117 	/*
118 	 * If the pin can trigger an interrupt on both rising and falling edges,
119 	 * we can use it to detect card presence changes.  If not, we'll request
120 	 * card presence polling instead of using interrupts.
121 	 */
122 	if (!(pincaps & GPIO_INTR_EDGE_BOTH)) {
123 		if (bootverbose)
124 			device_printf(dev, "Cannot configure "
125 			    "GPIO_INTR_EDGE_BOTH for card detect\n");
126 		goto without_interrupts;
127 	}
128 
129 	/*
130 	 * Create an interrupt resource from the pin and set up the interrupt.
131 	 */
132 	if ((gpio->cd_ires = gpio_alloc_intr_resource(dev, &gpio->cd_irid,
133 	    RF_ACTIVE, gpio->cd_pin, GPIO_INTR_EDGE_BOTH)) == NULL) {
134 		if (bootverbose)
135 			device_printf(dev, "Cannot allocate an IRQ for card "
136 			    "detect GPIO\n");
137 		goto without_interrupts;
138 	}
139 
140 	if (bus_setup_intr(dev, gpio->cd_ires, INTR_TYPE_BIO | INTR_MPSAFE,
141 	    NULL, cd_intr, gpio, &gpio->cd_ihandler) != 0) {
142 		device_printf(dev, "Unable to setup card-detect irq handler\n");
143 		gpio->cd_ihandler = NULL;
144 		goto without_interrupts;
145 	}
146 
147 without_interrupts:
148 
149 	/*
150 	 * If we have a readable gpio pin, but didn't successfully configure
151 	 * gpio interrupts, ask the sdhci driver to poll from a callout.
152 	 */
153 	if (gpio->cd_ihandler == NULL) {
154 		cd_mode_str = "polling";
155 		gpio->slot->quirks |= SDHCI_QUIRK_POLL_CARD_PRESENT;
156 	} else {
157 		cd_mode_str = "interrupts";
158 	}
159 
160 	if (bootverbose) {
161 		device_printf(dev, "Card presence detect on %s pin %u, "
162 		    "configured for %s.\n",
163 		    device_get_nameunit(gpio->cd_pin->dev), gpio->cd_pin->pin,
164 		    cd_mode_str);
165 	}
166 }
167 
168 /*
169  * Write protect setup.
170  */
171 static void
172 wp_setup(struct sdhci_fdt_gpio *gpio, phandle_t node)
173 {
174 	device_t dev;
175 
176 	dev = gpio->dev;
177 
178 	if (OF_hasprop(node, "wp-disable")) {
179 		gpio->wp_disabled = true;
180 		if (bootverbose)
181 			device_printf(dev, "Write protect disabled\n");
182 		return;
183 	}
184 
185 	if (gpio_pin_get_by_ofw_property(dev, node, "wp-gpios", &gpio->wp_pin))
186 		return;
187 
188 	if (OF_hasprop(node, "wp-inverted"))
189 		gpio->wp_inverted = true;
190 
191 	if (bootverbose)
192 		device_printf(dev, "Write protect switch on %s pin %u\n",
193 		    device_get_nameunit(gpio->wp_pin->dev), gpio->wp_pin->pin);
194 }
195 
196 struct sdhci_fdt_gpio *
197 sdhci_fdt_gpio_setup(device_t dev, struct sdhci_slot *slot)
198 {
199 	phandle_t node;
200 	struct sdhci_fdt_gpio *gpio;
201 
202 	gpio = malloc(sizeof(*gpio), M_DEVBUF, M_ZERO | M_WAITOK);
203 	gpio->dev  = dev;
204 	gpio->slot = slot;
205 
206 	node = ofw_bus_get_node(dev);
207 
208 	wp_setup(gpio, node);
209 	cd_setup(gpio, node);
210 
211 	return (gpio);
212 }
213 
214 void
215 sdhci_fdt_gpio_teardown(struct sdhci_fdt_gpio *gpio)
216 {
217 
218 	if (gpio == NULL)
219 		return;
220 
221 	if (gpio->cd_ihandler != NULL)
222 		bus_teardown_intr(gpio->dev, gpio->cd_ires, gpio->cd_ihandler);
223 	if (gpio->wp_pin != NULL)
224 		gpio_pin_release(gpio->wp_pin);
225 	if (gpio->cd_pin != NULL)
226 		gpio_pin_release(gpio->cd_pin);
227 	if (gpio->cd_ires != NULL)
228 		bus_release_resource(gpio->dev, SYS_RES_IRQ, 0, gpio->cd_ires);
229 
230 	free(gpio, M_DEVBUF);
231 }
232 
233 bool
234 sdhci_fdt_gpio_get_present(struct sdhci_fdt_gpio *gpio)
235 {
236 	bool pinstate;
237 
238 	if (gpio->cd_disabled)
239 		return (true);
240 
241 	if (gpio->cd_pin == NULL)
242 		return (sdhci_generic_get_card_present(gpio->slot->bus,
243 		    gpio->slot));
244 
245 	gpio_pin_is_active(gpio->cd_pin, &pinstate);
246 
247 	return (pinstate ^ gpio->cd_inverted);
248 }
249 
250 int
251 sdhci_fdt_gpio_get_readonly(struct sdhci_fdt_gpio *gpio)
252 {
253 	bool pinstate;
254 
255 	if (gpio->wp_disabled)
256 		return (false);
257 
258 	if (gpio->wp_pin == NULL)
259 		return (sdhci_generic_get_ro(gpio->slot->bus, gpio->slot->dev));
260 
261 	gpio_pin_is_active(gpio->wp_pin, &pinstate);
262 
263 	return (pinstate ^ gpio->wp_inverted);
264 }
265