xref: /openbmc/linux/drivers/ata/libata-zpodd.c (revision 089a49b6)
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 	acpi_status status;
92 	struct acpi_device *acpi_dev;
93 
94 	handle = ata_dev_acpi_handle(ata_dev);
95 	if (!handle)
96 		return false;
97 
98 	status = acpi_bus_get_device(handle, &acpi_dev);
99 	if (ACPI_FAILURE(status))
100 		return false;
101 
102 	return acpi_device_can_poweroff(acpi_dev);
103 }
104 
105 /* Test if ODD is zero power ready by sense code */
106 static bool zpready(struct ata_device *dev)
107 {
108 	u8 sense_key, *sense_buf;
109 	unsigned int ret, asc, ascq, add_len;
110 	struct zpodd *zpodd = dev->zpodd;
111 
112 	ret = atapi_eh_tur(dev, &sense_key);
113 
114 	if (!ret || sense_key != NOT_READY)
115 		return false;
116 
117 	sense_buf = dev->link->ap->sector_buf;
118 	ret = atapi_eh_request_sense(dev, sense_buf, sense_key);
119 	if (ret)
120 		return false;
121 
122 	/* sense valid */
123 	if ((sense_buf[0] & 0x7f) != 0x70)
124 		return false;
125 
126 	add_len = sense_buf[7];
127 	/* has asc and ascq */
128 	if (add_len < 6)
129 		return false;
130 
131 	asc = sense_buf[12];
132 	ascq = sense_buf[13];
133 
134 	if (zpodd->mech_type == ODD_MECH_TYPE_SLOT)
135 		/* no media inside */
136 		return asc == 0x3a;
137 	else
138 		/* no media inside and door closed */
139 		return asc == 0x3a && ascq == 0x01;
140 }
141 
142 /*
143  * Update the zpodd->zp_ready field. This field will only be set
144  * if the ODD has stayed in ZP ready state for zpodd_poweroff_delay
145  * time, and will be used to decide if power off is allowed. If it
146  * is set, it will be cleared during resume from powered off state.
147  */
148 void zpodd_on_suspend(struct ata_device *dev)
149 {
150 	struct zpodd *zpodd = dev->zpodd;
151 	unsigned long expires;
152 
153 	if (!zpready(dev)) {
154 		zpodd->zp_sampled = false;
155 		zpodd->zp_ready = false;
156 		return;
157 	}
158 
159 	if (!zpodd->zp_sampled) {
160 		zpodd->zp_sampled = true;
161 		zpodd->last_ready = jiffies;
162 		return;
163 	}
164 
165 	expires = zpodd->last_ready +
166 		  msecs_to_jiffies(zpodd_poweroff_delay * 1000);
167 	if (time_before(jiffies, expires))
168 		return;
169 
170 	zpodd->zp_ready = true;
171 }
172 
173 bool zpodd_zpready(struct ata_device *dev)
174 {
175 	struct zpodd *zpodd = dev->zpodd;
176 	return zpodd->zp_ready;
177 }
178 
179 /*
180  * Enable runtime wake capability through ACPI and set the powered_off flag,
181  * this flag will be used during resume to decide what operations are needed
182  * to take.
183  *
184  * Also, media poll needs to be silenced, so that it doesn't bring the ODD
185  * back to full power state every few seconds.
186  */
187 void zpodd_enable_run_wake(struct ata_device *dev)
188 {
189 	struct zpodd *zpodd = dev->zpodd;
190 
191 	sdev_disable_disk_events(dev->sdev);
192 
193 	zpodd->powered_off = true;
194 	device_set_run_wake(&dev->tdev, true);
195 	acpi_pm_device_run_wake(&dev->tdev, true);
196 }
197 
198 /* Disable runtime wake capability if it is enabled */
199 void zpodd_disable_run_wake(struct ata_device *dev)
200 {
201 	struct zpodd *zpodd = dev->zpodd;
202 
203 	if (zpodd->powered_off) {
204 		acpi_pm_device_run_wake(&dev->tdev, false);
205 		device_set_run_wake(&dev->tdev, false);
206 	}
207 }
208 
209 /*
210  * Post power on processing after the ODD has been recovered. If the
211  * ODD wasn't powered off during suspend, it doesn't do anything.
212  *
213  * For drawer type ODD, if it is powered on due to user pressed the
214  * eject button, the tray needs to be ejected. This can only be done
215  * after the ODD has been recovered, i.e. link is initialized and
216  * device is able to process NON_DATA PIO command, as eject needs to
217  * send command for the ODD to process.
218  *
219  * The from_notify flag set in wake notification handler function
220  * zpodd_wake_dev represents if power on is due to user's action.
221  *
222  * For both types of ODD, several fields need to be reset.
223  */
224 void zpodd_post_poweron(struct ata_device *dev)
225 {
226 	struct zpodd *zpodd = dev->zpodd;
227 
228 	if (!zpodd->powered_off)
229 		return;
230 
231 	zpodd->powered_off = false;
232 
233 	if (zpodd->from_notify) {
234 		zpodd->from_notify = false;
235 		if (zpodd->mech_type == ODD_MECH_TYPE_DRAWER)
236 			eject_tray(dev);
237 	}
238 
239 	zpodd->zp_sampled = false;
240 	zpodd->zp_ready = false;
241 
242 	sdev_enable_disk_events(dev->sdev);
243 }
244 
245 static void zpodd_wake_dev(acpi_handle handle, u32 event, void *context)
246 {
247 	struct ata_device *ata_dev = context;
248 	struct zpodd *zpodd = ata_dev->zpodd;
249 	struct device *dev = &ata_dev->sdev->sdev_gendev;
250 
251 	if (event == ACPI_NOTIFY_DEVICE_WAKE && pm_runtime_suspended(dev)) {
252 		zpodd->from_notify = true;
253 		pm_runtime_resume(dev);
254 	}
255 }
256 
257 static void ata_acpi_add_pm_notifier(struct ata_device *dev)
258 {
259 	acpi_handle handle = ata_dev_acpi_handle(dev);
260 	acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
261 				    zpodd_wake_dev, dev);
262 }
263 
264 static void ata_acpi_remove_pm_notifier(struct ata_device *dev)
265 {
266 	acpi_handle handle = ata_dev_acpi_handle(dev);
267 	acpi_remove_notify_handler(handle, ACPI_SYSTEM_NOTIFY, zpodd_wake_dev);
268 }
269 
270 void zpodd_init(struct ata_device *dev)
271 {
272 	enum odd_mech_type mech_type;
273 	struct zpodd *zpodd;
274 
275 	if (dev->zpodd)
276 		return;
277 
278 	if (!odd_can_poweroff(dev))
279 		return;
280 
281 	mech_type = zpodd_get_mech_type(dev);
282 	if (mech_type == ODD_MECH_TYPE_UNSUPPORTED)
283 		return;
284 
285 	zpodd = kzalloc(sizeof(struct zpodd), GFP_KERNEL);
286 	if (!zpodd)
287 		return;
288 
289 	zpodd->mech_type = mech_type;
290 
291 	ata_acpi_add_pm_notifier(dev);
292 	zpodd->dev = dev;
293 	dev->zpodd = zpodd;
294 	dev_pm_qos_expose_flags(&dev->tdev, 0);
295 }
296 
297 void zpodd_exit(struct ata_device *dev)
298 {
299 	ata_acpi_remove_pm_notifier(dev);
300 	kfree(dev->zpodd);
301 	dev->zpodd = NULL;
302 }
303