xref: /openbmc/linux/drivers/ata/libata-zpodd.c (revision 77d84ff8)
1 #include <linux/libata.h>
2 #include <linux/cdrom.h>
3 #include <linux/pm_runtime.h>
4 #include <linux/module.h>
5 #include <linux/pm_qos.h>
6 #include <scsi/scsi_device.h>
7 
8 #include "libata.h"
9 
10 static int zpodd_poweroff_delay = 30; /* 30 seconds for power off delay */
11 module_param(zpodd_poweroff_delay, int, 0644);
12 MODULE_PARM_DESC(zpodd_poweroff_delay, "Poweroff delay for ZPODD in seconds");
13 
14 enum odd_mech_type {
15 	ODD_MECH_TYPE_SLOT,
16 	ODD_MECH_TYPE_DRAWER,
17 	ODD_MECH_TYPE_UNSUPPORTED,
18 };
19 
20 struct zpodd {
21 	enum odd_mech_type	mech_type; /* init during probe, RO afterwards */
22 	struct ata_device	*dev;
23 
24 	/* The following fields are synchronized by PM core. */
25 	bool			from_notify; /* resumed as a result of
26 					      * acpi wake notification */
27 	bool			zp_ready; /* ZP ready state */
28 	unsigned long		last_ready; /* last ZP ready timestamp */
29 	bool			zp_sampled; /* ZP ready state sampled */
30 	bool			powered_off; /* ODD is powered off
31 					      *	during suspend */
32 };
33 
34 static int eject_tray(struct ata_device *dev)
35 {
36 	struct ata_taskfile tf;
37 	const char cdb[] = {  GPCMD_START_STOP_UNIT,
38 		0, 0, 0,
39 		0x02,     /* LoEj */
40 		0, 0, 0, 0, 0, 0, 0,
41 	};
42 
43 	ata_tf_init(dev, &tf);
44 	tf.flags = ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
45 	tf.command = ATA_CMD_PACKET;
46 	tf.protocol = ATAPI_PROT_NODATA;
47 
48 	return ata_exec_internal(dev, &tf, cdb, DMA_NONE, NULL, 0, 0);
49 }
50 
51 /* Per the spec, only slot type and drawer type ODD can be supported */
52 static enum odd_mech_type zpodd_get_mech_type(struct ata_device *dev)
53 {
54 	char buf[16];
55 	unsigned int ret;
56 	struct rm_feature_desc *desc = (void *)(buf + 8);
57 	struct ata_taskfile tf;
58 	char cdb[] = {  GPCMD_GET_CONFIGURATION,
59 			2,      /* only 1 feature descriptor requested */
60 			0, 3,   /* 3, removable medium feature */
61 			0, 0, 0,/* reserved */
62 			0, sizeof(buf),
63 			0, 0, 0,
64 	};
65 
66 	ata_tf_init(dev, &tf);
67 	tf.flags = ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
68 	tf.command = ATA_CMD_PACKET;
69 	tf.protocol = ATAPI_PROT_PIO;
70 	tf.lbam = sizeof(buf);
71 
72 	ret = ata_exec_internal(dev, &tf, cdb, DMA_FROM_DEVICE,
73 				buf, sizeof(buf), 0);
74 	if (ret)
75 		return ODD_MECH_TYPE_UNSUPPORTED;
76 
77 	if (be16_to_cpu(desc->feature_code) != 3)
78 		return ODD_MECH_TYPE_UNSUPPORTED;
79 
80 	if (desc->mech_type == 0 && desc->load == 0 && desc->eject == 1)
81 		return ODD_MECH_TYPE_SLOT;
82 	else if (desc->mech_type == 1 && desc->load == 0 && desc->eject == 1)
83 		return ODD_MECH_TYPE_DRAWER;
84 	else
85 		return ODD_MECH_TYPE_UNSUPPORTED;
86 }
87 
88 static bool odd_can_poweroff(struct ata_device *ata_dev)
89 {
90 	acpi_handle handle;
91 	struct acpi_device *acpi_dev;
92 
93 	handle = ata_dev_acpi_handle(ata_dev);
94 	if (!handle)
95 		return false;
96 
97 	if (acpi_bus_get_device(handle, &acpi_dev))
98 		return false;
99 
100 	return acpi_device_can_poweroff(acpi_dev);
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 	device_set_run_wake(&dev->tdev, true);
193 	acpi_pm_device_run_wake(&dev->tdev, true);
194 }
195 
196 /* Disable runtime wake capability if it is enabled */
197 void zpodd_disable_run_wake(struct ata_device *dev)
198 {
199 	struct zpodd *zpodd = dev->zpodd;
200 
201 	if (zpodd->powered_off) {
202 		acpi_pm_device_run_wake(&dev->tdev, false);
203 		device_set_run_wake(&dev->tdev, false);
204 	}
205 }
206 
207 /*
208  * Post power on processing after the ODD has been recovered. If the
209  * ODD wasn't powered off during suspend, it doesn't do anything.
210  *
211  * For drawer type ODD, if it is powered on due to user pressed the
212  * eject button, the tray needs to be ejected. This can only be done
213  * after the ODD has been recovered, i.e. link is initialized and
214  * device is able to process NON_DATA PIO command, as eject needs to
215  * send command for the ODD to process.
216  *
217  * The from_notify flag set in wake notification handler function
218  * zpodd_wake_dev represents if power on is due to user's action.
219  *
220  * For both types of ODD, several fields need to be reset.
221  */
222 void zpodd_post_poweron(struct ata_device *dev)
223 {
224 	struct zpodd *zpodd = dev->zpodd;
225 
226 	if (!zpodd->powered_off)
227 		return;
228 
229 	zpodd->powered_off = false;
230 
231 	if (zpodd->from_notify) {
232 		zpodd->from_notify = false;
233 		if (zpodd->mech_type == ODD_MECH_TYPE_DRAWER)
234 			eject_tray(dev);
235 	}
236 
237 	zpodd->zp_sampled = false;
238 	zpodd->zp_ready = false;
239 
240 	sdev_enable_disk_events(dev->sdev);
241 }
242 
243 static void zpodd_wake_dev(acpi_handle handle, u32 event, void *context)
244 {
245 	struct ata_device *ata_dev = context;
246 	struct zpodd *zpodd = ata_dev->zpodd;
247 	struct device *dev = &ata_dev->sdev->sdev_gendev;
248 
249 	if (event == ACPI_NOTIFY_DEVICE_WAKE && pm_runtime_suspended(dev)) {
250 		zpodd->from_notify = true;
251 		pm_runtime_resume(dev);
252 	}
253 }
254 
255 static void ata_acpi_add_pm_notifier(struct ata_device *dev)
256 {
257 	acpi_handle handle = ata_dev_acpi_handle(dev);
258 	acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
259 				    zpodd_wake_dev, dev);
260 }
261 
262 static void ata_acpi_remove_pm_notifier(struct ata_device *dev)
263 {
264 	acpi_handle handle = ata_dev_acpi_handle(dev);
265 	acpi_remove_notify_handler(handle, ACPI_SYSTEM_NOTIFY, zpodd_wake_dev);
266 }
267 
268 void zpodd_init(struct ata_device *dev)
269 {
270 	enum odd_mech_type mech_type;
271 	struct zpodd *zpodd;
272 
273 	if (dev->zpodd)
274 		return;
275 
276 	if (!odd_can_poweroff(dev))
277 		return;
278 
279 	mech_type = zpodd_get_mech_type(dev);
280 	if (mech_type == ODD_MECH_TYPE_UNSUPPORTED)
281 		return;
282 
283 	zpodd = kzalloc(sizeof(struct zpodd), GFP_KERNEL);
284 	if (!zpodd)
285 		return;
286 
287 	zpodd->mech_type = mech_type;
288 
289 	ata_acpi_add_pm_notifier(dev);
290 	zpodd->dev = dev;
291 	dev->zpodd = zpodd;
292 	dev_pm_qos_expose_flags(&dev->tdev, 0);
293 }
294 
295 void zpodd_exit(struct ata_device *dev)
296 {
297 	ata_acpi_remove_pm_notifier(dev);
298 	kfree(dev->zpodd);
299 	dev->zpodd = NULL;
300 }
301