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 }
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