xref: /openbmc/linux/drivers/ata/libata-zpodd.c (revision e15a5365)
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[ATAPI_CDB_LEN] = {  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;
56 	unsigned int ret;
57 	struct rm_feature_desc *desc;
58 	struct ata_taskfile tf;
59 	static const char cdb[ATAPI_CDB_LEN] = {  GPCMD_GET_CONFIGURATION,
60 			2,      /* only 1 feature descriptor requested */
61 			0, 3,   /* 3, removable medium feature */
62 			0, 0, 0,/* reserved */
63 			0, 16,
64 			0, 0, 0,
65 	};
66 
67 	buf = kzalloc(16, GFP_KERNEL);
68 	if (!buf)
69 		return ODD_MECH_TYPE_UNSUPPORTED;
70 	desc = (void *)(buf + 8);
71 
72 	ata_tf_init(dev, &tf);
73 	tf.flags = ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
74 	tf.command = ATA_CMD_PACKET;
75 	tf.protocol = ATAPI_PROT_PIO;
76 	tf.lbam = 16;
77 
78 	ret = ata_exec_internal(dev, &tf, cdb, DMA_FROM_DEVICE,
79 				buf, 16, 0);
80 	if (ret) {
81 		kfree(buf);
82 		return ODD_MECH_TYPE_UNSUPPORTED;
83 	}
84 
85 	if (be16_to_cpu(desc->feature_code) != 3) {
86 		kfree(buf);
87 		return ODD_MECH_TYPE_UNSUPPORTED;
88 	}
89 
90 	if (desc->mech_type == 0 && desc->load == 0 && desc->eject == 1) {
91 		kfree(buf);
92 		return ODD_MECH_TYPE_SLOT;
93 	} else if (desc->mech_type == 1 && desc->load == 0 &&
94 		   desc->eject == 1) {
95 		kfree(buf);
96 		return ODD_MECH_TYPE_DRAWER;
97 	} else {
98 		kfree(buf);
99 		return ODD_MECH_TYPE_UNSUPPORTED;
100 	}
101 }
102 
103 /* Test if ODD is zero power ready by sense code */
104 static bool zpready(struct ata_device *dev)
105 {
106 	u8 sense_key, *sense_buf;
107 	unsigned int ret, asc, ascq, add_len;
108 	struct zpodd *zpodd = dev->zpodd;
109 
110 	ret = atapi_eh_tur(dev, &sense_key);
111 
112 	if (!ret || sense_key != NOT_READY)
113 		return false;
114 
115 	sense_buf = dev->link->ap->sector_buf;
116 	ret = atapi_eh_request_sense(dev, sense_buf, sense_key);
117 	if (ret)
118 		return false;
119 
120 	/* sense valid */
121 	if ((sense_buf[0] & 0x7f) != 0x70)
122 		return false;
123 
124 	add_len = sense_buf[7];
125 	/* has asc and ascq */
126 	if (add_len < 6)
127 		return false;
128 
129 	asc = sense_buf[12];
130 	ascq = sense_buf[13];
131 
132 	if (zpodd->mech_type == ODD_MECH_TYPE_SLOT)
133 		/* no media inside */
134 		return asc == 0x3a;
135 	else
136 		/* no media inside and door closed */
137 		return asc == 0x3a && ascq == 0x01;
138 }
139 
140 /*
141  * Update the zpodd->zp_ready field. This field will only be set
142  * if the ODD has stayed in ZP ready state for zpodd_poweroff_delay
143  * time, and will be used to decide if power off is allowed. If it
144  * is set, it will be cleared during resume from powered off state.
145  */
146 void zpodd_on_suspend(struct ata_device *dev)
147 {
148 	struct zpodd *zpodd = dev->zpodd;
149 	unsigned long expires;
150 
151 	if (!zpready(dev)) {
152 		zpodd->zp_sampled = false;
153 		zpodd->zp_ready = false;
154 		return;
155 	}
156 
157 	if (!zpodd->zp_sampled) {
158 		zpodd->zp_sampled = true;
159 		zpodd->last_ready = jiffies;
160 		return;
161 	}
162 
163 	expires = zpodd->last_ready +
164 		  msecs_to_jiffies(zpodd_poweroff_delay * 1000);
165 	if (time_before(jiffies, expires))
166 		return;
167 
168 	zpodd->zp_ready = true;
169 }
170 
171 bool zpodd_zpready(struct ata_device *dev)
172 {
173 	struct zpodd *zpodd = dev->zpodd;
174 	return zpodd->zp_ready;
175 }
176 
177 /*
178  * Enable runtime wake capability through ACPI and set the powered_off flag,
179  * this flag will be used during resume to decide what operations are needed
180  * to take.
181  *
182  * Also, media poll needs to be silenced, so that it doesn't bring the ODD
183  * back to full power state every few seconds.
184  */
185 void zpodd_enable_run_wake(struct ata_device *dev)
186 {
187 	struct zpodd *zpodd = dev->zpodd;
188 
189 	sdev_disable_disk_events(dev->sdev);
190 
191 	zpodd->powered_off = true;
192 	acpi_pm_set_device_wakeup(&dev->tdev, true);
193 }
194 
195 /* Disable runtime wake capability if it is enabled */
196 void zpodd_disable_run_wake(struct ata_device *dev)
197 {
198 	struct zpodd *zpodd = dev->zpodd;
199 
200 	if (zpodd->powered_off)
201 		acpi_pm_set_device_wakeup(&dev->tdev, false);
202 }
203 
204 /*
205  * Post power on processing after the ODD has been recovered. If the
206  * ODD wasn't powered off during suspend, it doesn't do anything.
207  *
208  * For drawer type ODD, if it is powered on due to user pressed the
209  * eject button, the tray needs to be ejected. This can only be done
210  * after the ODD has been recovered, i.e. link is initialized and
211  * device is able to process NON_DATA PIO command, as eject needs to
212  * send command for the ODD to process.
213  *
214  * The from_notify flag set in wake notification handler function
215  * zpodd_wake_dev represents if power on is due to user's action.
216  *
217  * For both types of ODD, several fields need to be reset.
218  */
219 void zpodd_post_poweron(struct ata_device *dev)
220 {
221 	struct zpodd *zpodd = dev->zpodd;
222 
223 	if (!zpodd->powered_off)
224 		return;
225 
226 	zpodd->powered_off = false;
227 
228 	if (zpodd->from_notify) {
229 		zpodd->from_notify = false;
230 		if (zpodd->mech_type == ODD_MECH_TYPE_DRAWER)
231 			eject_tray(dev);
232 	}
233 
234 	zpodd->zp_sampled = false;
235 	zpodd->zp_ready = false;
236 
237 	sdev_enable_disk_events(dev->sdev);
238 }
239 
240 static void zpodd_wake_dev(acpi_handle handle, u32 event, void *context)
241 {
242 	struct ata_device *ata_dev = context;
243 	struct zpodd *zpodd = ata_dev->zpodd;
244 	struct device *dev = &ata_dev->sdev->sdev_gendev;
245 
246 	if (event == ACPI_NOTIFY_DEVICE_WAKE && pm_runtime_suspended(dev)) {
247 		zpodd->from_notify = true;
248 		pm_runtime_resume(dev);
249 	}
250 }
251 
252 static void ata_acpi_add_pm_notifier(struct ata_device *dev)
253 {
254 	acpi_handle handle = ata_dev_acpi_handle(dev);
255 	acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
256 				    zpodd_wake_dev, dev);
257 }
258 
259 static void ata_acpi_remove_pm_notifier(struct ata_device *dev)
260 {
261 	acpi_handle handle = ata_dev_acpi_handle(dev);
262 	acpi_remove_notify_handler(handle, ACPI_SYSTEM_NOTIFY, zpodd_wake_dev);
263 }
264 
265 void zpodd_init(struct ata_device *dev)
266 {
267 	struct acpi_device *adev = ACPI_COMPANION(&dev->tdev);
268 	enum odd_mech_type mech_type;
269 	struct zpodd *zpodd;
270 
271 	if (dev->zpodd || !adev || !acpi_device_can_poweroff(adev))
272 		return;
273 
274 	mech_type = zpodd_get_mech_type(dev);
275 	if (mech_type == ODD_MECH_TYPE_UNSUPPORTED)
276 		return;
277 
278 	zpodd = kzalloc(sizeof(struct zpodd), GFP_KERNEL);
279 	if (!zpodd)
280 		return;
281 
282 	zpodd->mech_type = mech_type;
283 
284 	ata_acpi_add_pm_notifier(dev);
285 	zpodd->dev = dev;
286 	dev->zpodd = zpodd;
287 	dev_pm_qos_expose_flags(&dev->tdev, 0);
288 }
289 
290 void zpodd_exit(struct ata_device *dev)
291 {
292 	ata_acpi_remove_pm_notifier(dev);
293 	kfree(dev->zpodd);
294 	dev->zpodd = NULL;
295 }
296