xref: /openbmc/linux/drivers/ata/libata-zpodd.c (revision e3b9f1e8)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/libata.h>
3 #include <linux/cdrom.h>
4 #include <linux/pm_runtime.h>
5 #include <linux/module.h>
6 #include <linux/pm_qos.h>
7 #include <scsi/scsi_device.h>
8 
9 #include "libata.h"
10 
11 static int zpodd_poweroff_delay = 30; /* 30 seconds for power off delay */
12 module_param(zpodd_poweroff_delay, int, 0644);
13 MODULE_PARM_DESC(zpodd_poweroff_delay, "Poweroff delay for ZPODD in seconds");
14 
15 enum odd_mech_type {
16 	ODD_MECH_TYPE_SLOT,
17 	ODD_MECH_TYPE_DRAWER,
18 	ODD_MECH_TYPE_UNSUPPORTED,
19 };
20 
21 struct zpodd {
22 	enum odd_mech_type	mech_type; /* init during probe, RO afterwards */
23 	struct ata_device	*dev;
24 
25 	/* The following fields are synchronized by PM core. */
26 	bool			from_notify; /* resumed as a result of
27 					      * acpi wake notification */
28 	bool			zp_ready; /* ZP ready state */
29 	unsigned long		last_ready; /* last ZP ready timestamp */
30 	bool			zp_sampled; /* ZP ready state sampled */
31 	bool			powered_off; /* ODD is powered off
32 					      *	during suspend */
33 };
34 
35 static int eject_tray(struct ata_device *dev)
36 {
37 	struct ata_taskfile tf;
38 	static const char cdb[] = {  GPCMD_START_STOP_UNIT,
39 		0, 0, 0,
40 		0x02,     /* LoEj */
41 		0, 0, 0, 0, 0, 0, 0,
42 	};
43 
44 	ata_tf_init(dev, &tf);
45 	tf.flags = ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
46 	tf.command = ATA_CMD_PACKET;
47 	tf.protocol = ATAPI_PROT_NODATA;
48 
49 	return ata_exec_internal(dev, &tf, cdb, DMA_NONE, NULL, 0, 0);
50 }
51 
52 /* Per the spec, only slot type and drawer type ODD can be supported */
53 static enum odd_mech_type zpodd_get_mech_type(struct ata_device *dev)
54 {
55 	char buf[16];
56 	unsigned int ret;
57 	struct rm_feature_desc *desc = (void *)(buf + 8);
58 	struct ata_taskfile tf;
59 	static const char cdb[] = {  GPCMD_GET_CONFIGURATION,
60 			2,      /* only 1 feature descriptor requested */
61 			0, 3,   /* 3, removable medium feature */
62 			0, 0, 0,/* reserved */
63 			0, sizeof(buf),
64 			0, 0, 0,
65 	};
66 
67 	ata_tf_init(dev, &tf);
68 	tf.flags = ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
69 	tf.command = ATA_CMD_PACKET;
70 	tf.protocol = ATAPI_PROT_PIO;
71 	tf.lbam = sizeof(buf);
72 
73 	ret = ata_exec_internal(dev, &tf, cdb, DMA_FROM_DEVICE,
74 				buf, sizeof(buf), 0);
75 	if (ret)
76 		return ODD_MECH_TYPE_UNSUPPORTED;
77 
78 	if (be16_to_cpu(desc->feature_code) != 3)
79 		return ODD_MECH_TYPE_UNSUPPORTED;
80 
81 	if (desc->mech_type == 0 && desc->load == 0 && desc->eject == 1)
82 		return ODD_MECH_TYPE_SLOT;
83 	else if (desc->mech_type == 1 && desc->load == 0 && desc->eject == 1)
84 		return ODD_MECH_TYPE_DRAWER;
85 	else
86 		return ODD_MECH_TYPE_UNSUPPORTED;
87 }
88 
89 /* Test if ODD is zero power ready by sense code */
90 static bool zpready(struct ata_device *dev)
91 {
92 	u8 sense_key, *sense_buf;
93 	unsigned int ret, asc, ascq, add_len;
94 	struct zpodd *zpodd = dev->zpodd;
95 
96 	ret = atapi_eh_tur(dev, &sense_key);
97 
98 	if (!ret || sense_key != NOT_READY)
99 		return false;
100 
101 	sense_buf = dev->link->ap->sector_buf;
102 	ret = atapi_eh_request_sense(dev, sense_buf, sense_key);
103 	if (ret)
104 		return false;
105 
106 	/* sense valid */
107 	if ((sense_buf[0] & 0x7f) != 0x70)
108 		return false;
109 
110 	add_len = sense_buf[7];
111 	/* has asc and ascq */
112 	if (add_len < 6)
113 		return false;
114 
115 	asc = sense_buf[12];
116 	ascq = sense_buf[13];
117 
118 	if (zpodd->mech_type == ODD_MECH_TYPE_SLOT)
119 		/* no media inside */
120 		return asc == 0x3a;
121 	else
122 		/* no media inside and door closed */
123 		return asc == 0x3a && ascq == 0x01;
124 }
125 
126 /*
127  * Update the zpodd->zp_ready field. This field will only be set
128  * if the ODD has stayed in ZP ready state for zpodd_poweroff_delay
129  * time, and will be used to decide if power off is allowed. If it
130  * is set, it will be cleared during resume from powered off state.
131  */
132 void zpodd_on_suspend(struct ata_device *dev)
133 {
134 	struct zpodd *zpodd = dev->zpodd;
135 	unsigned long expires;
136 
137 	if (!zpready(dev)) {
138 		zpodd->zp_sampled = false;
139 		zpodd->zp_ready = false;
140 		return;
141 	}
142 
143 	if (!zpodd->zp_sampled) {
144 		zpodd->zp_sampled = true;
145 		zpodd->last_ready = jiffies;
146 		return;
147 	}
148 
149 	expires = zpodd->last_ready +
150 		  msecs_to_jiffies(zpodd_poweroff_delay * 1000);
151 	if (time_before(jiffies, expires))
152 		return;
153 
154 	zpodd->zp_ready = true;
155 }
156 
157 bool zpodd_zpready(struct ata_device *dev)
158 {
159 	struct zpodd *zpodd = dev->zpodd;
160 	return zpodd->zp_ready;
161 }
162 
163 /*
164  * Enable runtime wake capability through ACPI and set the powered_off flag,
165  * this flag will be used during resume to decide what operations are needed
166  * to take.
167  *
168  * Also, media poll needs to be silenced, so that it doesn't bring the ODD
169  * back to full power state every few seconds.
170  */
171 void zpodd_enable_run_wake(struct ata_device *dev)
172 {
173 	struct zpodd *zpodd = dev->zpodd;
174 
175 	sdev_disable_disk_events(dev->sdev);
176 
177 	zpodd->powered_off = true;
178 	acpi_pm_set_device_wakeup(&dev->tdev, true);
179 }
180 
181 /* Disable runtime wake capability if it is enabled */
182 void zpodd_disable_run_wake(struct ata_device *dev)
183 {
184 	struct zpodd *zpodd = dev->zpodd;
185 
186 	if (zpodd->powered_off)
187 		acpi_pm_set_device_wakeup(&dev->tdev, false);
188 }
189 
190 /*
191  * Post power on processing after the ODD has been recovered. If the
192  * ODD wasn't powered off during suspend, it doesn't do anything.
193  *
194  * For drawer type ODD, if it is powered on due to user pressed the
195  * eject button, the tray needs to be ejected. This can only be done
196  * after the ODD has been recovered, i.e. link is initialized and
197  * device is able to process NON_DATA PIO command, as eject needs to
198  * send command for the ODD to process.
199  *
200  * The from_notify flag set in wake notification handler function
201  * zpodd_wake_dev represents if power on is due to user's action.
202  *
203  * For both types of ODD, several fields need to be reset.
204  */
205 void zpodd_post_poweron(struct ata_device *dev)
206 {
207 	struct zpodd *zpodd = dev->zpodd;
208 
209 	if (!zpodd->powered_off)
210 		return;
211 
212 	zpodd->powered_off = false;
213 
214 	if (zpodd->from_notify) {
215 		zpodd->from_notify = false;
216 		if (zpodd->mech_type == ODD_MECH_TYPE_DRAWER)
217 			eject_tray(dev);
218 	}
219 
220 	zpodd->zp_sampled = false;
221 	zpodd->zp_ready = false;
222 
223 	sdev_enable_disk_events(dev->sdev);
224 }
225 
226 static void zpodd_wake_dev(acpi_handle handle, u32 event, void *context)
227 {
228 	struct ata_device *ata_dev = context;
229 	struct zpodd *zpodd = ata_dev->zpodd;
230 	struct device *dev = &ata_dev->sdev->sdev_gendev;
231 
232 	if (event == ACPI_NOTIFY_DEVICE_WAKE && pm_runtime_suspended(dev)) {
233 		zpodd->from_notify = true;
234 		pm_runtime_resume(dev);
235 	}
236 }
237 
238 static void ata_acpi_add_pm_notifier(struct ata_device *dev)
239 {
240 	acpi_handle handle = ata_dev_acpi_handle(dev);
241 	acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
242 				    zpodd_wake_dev, dev);
243 }
244 
245 static void ata_acpi_remove_pm_notifier(struct ata_device *dev)
246 {
247 	acpi_handle handle = ata_dev_acpi_handle(dev);
248 	acpi_remove_notify_handler(handle, ACPI_SYSTEM_NOTIFY, zpodd_wake_dev);
249 }
250 
251 void zpodd_init(struct ata_device *dev)
252 {
253 	struct acpi_device *adev = ACPI_COMPANION(&dev->tdev);
254 	enum odd_mech_type mech_type;
255 	struct zpodd *zpodd;
256 
257 	if (dev->zpodd || !adev || !acpi_device_can_poweroff(adev))
258 		return;
259 
260 	mech_type = zpodd_get_mech_type(dev);
261 	if (mech_type == ODD_MECH_TYPE_UNSUPPORTED)
262 		return;
263 
264 	zpodd = kzalloc(sizeof(struct zpodd), GFP_KERNEL);
265 	if (!zpodd)
266 		return;
267 
268 	zpodd->mech_type = mech_type;
269 
270 	ata_acpi_add_pm_notifier(dev);
271 	zpodd->dev = dev;
272 	dev->zpodd = zpodd;
273 	dev_pm_qos_expose_flags(&dev->tdev, 0);
274 }
275 
276 void zpodd_exit(struct ata_device *dev)
277 {
278 	ata_acpi_remove_pm_notifier(dev);
279 	kfree(dev->zpodd);
280 	dev->zpodd = NULL;
281 }
282