xref: /openbmc/linux/drivers/ata/libata-zpodd.c (revision 85ab3738)
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 /* Test if ODD is zero power ready by sense code */
89 static bool zpready(struct ata_device *dev)
90 {
91 	u8 sense_key, *sense_buf;
92 	unsigned int ret, asc, ascq, add_len;
93 	struct zpodd *zpodd = dev->zpodd;
94 
95 	ret = atapi_eh_tur(dev, &sense_key);
96 
97 	if (!ret || sense_key != NOT_READY)
98 		return false;
99 
100 	sense_buf = dev->link->ap->sector_buf;
101 	ret = atapi_eh_request_sense(dev, sense_buf, sense_key);
102 	if (ret)
103 		return false;
104 
105 	/* sense valid */
106 	if ((sense_buf[0] & 0x7f) != 0x70)
107 		return false;
108 
109 	add_len = sense_buf[7];
110 	/* has asc and ascq */
111 	if (add_len < 6)
112 		return false;
113 
114 	asc = sense_buf[12];
115 	ascq = sense_buf[13];
116 
117 	if (zpodd->mech_type == ODD_MECH_TYPE_SLOT)
118 		/* no media inside */
119 		return asc == 0x3a;
120 	else
121 		/* no media inside and door closed */
122 		return asc == 0x3a && ascq == 0x01;
123 }
124 
125 /*
126  * Update the zpodd->zp_ready field. This field will only be set
127  * if the ODD has stayed in ZP ready state for zpodd_poweroff_delay
128  * time, and will be used to decide if power off is allowed. If it
129  * is set, it will be cleared during resume from powered off state.
130  */
131 void zpodd_on_suspend(struct ata_device *dev)
132 {
133 	struct zpodd *zpodd = dev->zpodd;
134 	unsigned long expires;
135 
136 	if (!zpready(dev)) {
137 		zpodd->zp_sampled = false;
138 		zpodd->zp_ready = false;
139 		return;
140 	}
141 
142 	if (!zpodd->zp_sampled) {
143 		zpodd->zp_sampled = true;
144 		zpodd->last_ready = jiffies;
145 		return;
146 	}
147 
148 	expires = zpodd->last_ready +
149 		  msecs_to_jiffies(zpodd_poweroff_delay * 1000);
150 	if (time_before(jiffies, expires))
151 		return;
152 
153 	zpodd->zp_ready = true;
154 }
155 
156 bool zpodd_zpready(struct ata_device *dev)
157 {
158 	struct zpodd *zpodd = dev->zpodd;
159 	return zpodd->zp_ready;
160 }
161 
162 /*
163  * Enable runtime wake capability through ACPI and set the powered_off flag,
164  * this flag will be used during resume to decide what operations are needed
165  * to take.
166  *
167  * Also, media poll needs to be silenced, so that it doesn't bring the ODD
168  * back to full power state every few seconds.
169  */
170 void zpodd_enable_run_wake(struct ata_device *dev)
171 {
172 	struct zpodd *zpodd = dev->zpodd;
173 
174 	sdev_disable_disk_events(dev->sdev);
175 
176 	zpodd->powered_off = true;
177 	acpi_pm_set_device_wakeup(&dev->tdev, true);
178 }
179 
180 /* Disable runtime wake capability if it is enabled */
181 void zpodd_disable_run_wake(struct ata_device *dev)
182 {
183 	struct zpodd *zpodd = dev->zpodd;
184 
185 	if (zpodd->powered_off)
186 		acpi_pm_set_device_wakeup(&dev->tdev, false);
187 }
188 
189 /*
190  * Post power on processing after the ODD has been recovered. If the
191  * ODD wasn't powered off during suspend, it doesn't do anything.
192  *
193  * For drawer type ODD, if it is powered on due to user pressed the
194  * eject button, the tray needs to be ejected. This can only be done
195  * after the ODD has been recovered, i.e. link is initialized and
196  * device is able to process NON_DATA PIO command, as eject needs to
197  * send command for the ODD to process.
198  *
199  * The from_notify flag set in wake notification handler function
200  * zpodd_wake_dev represents if power on is due to user's action.
201  *
202  * For both types of ODD, several fields need to be reset.
203  */
204 void zpodd_post_poweron(struct ata_device *dev)
205 {
206 	struct zpodd *zpodd = dev->zpodd;
207 
208 	if (!zpodd->powered_off)
209 		return;
210 
211 	zpodd->powered_off = false;
212 
213 	if (zpodd->from_notify) {
214 		zpodd->from_notify = false;
215 		if (zpodd->mech_type == ODD_MECH_TYPE_DRAWER)
216 			eject_tray(dev);
217 	}
218 
219 	zpodd->zp_sampled = false;
220 	zpodd->zp_ready = false;
221 
222 	sdev_enable_disk_events(dev->sdev);
223 }
224 
225 static void zpodd_wake_dev(acpi_handle handle, u32 event, void *context)
226 {
227 	struct ata_device *ata_dev = context;
228 	struct zpodd *zpodd = ata_dev->zpodd;
229 	struct device *dev = &ata_dev->sdev->sdev_gendev;
230 
231 	if (event == ACPI_NOTIFY_DEVICE_WAKE && pm_runtime_suspended(dev)) {
232 		zpodd->from_notify = true;
233 		pm_runtime_resume(dev);
234 	}
235 }
236 
237 static void ata_acpi_add_pm_notifier(struct ata_device *dev)
238 {
239 	acpi_handle handle = ata_dev_acpi_handle(dev);
240 	acpi_install_notify_handler(handle, ACPI_SYSTEM_NOTIFY,
241 				    zpodd_wake_dev, dev);
242 }
243 
244 static void ata_acpi_remove_pm_notifier(struct ata_device *dev)
245 {
246 	acpi_handle handle = ata_dev_acpi_handle(dev);
247 	acpi_remove_notify_handler(handle, ACPI_SYSTEM_NOTIFY, zpodd_wake_dev);
248 }
249 
250 void zpodd_init(struct ata_device *dev)
251 {
252 	struct acpi_device *adev = ACPI_COMPANION(&dev->tdev);
253 	enum odd_mech_type mech_type;
254 	struct zpodd *zpodd;
255 
256 	if (dev->zpodd || !adev || !acpi_device_can_poweroff(adev))
257 		return;
258 
259 	mech_type = zpodd_get_mech_type(dev);
260 	if (mech_type == ODD_MECH_TYPE_UNSUPPORTED)
261 		return;
262 
263 	zpodd = kzalloc(sizeof(struct zpodd), GFP_KERNEL);
264 	if (!zpodd)
265 		return;
266 
267 	zpodd->mech_type = mech_type;
268 
269 	ata_acpi_add_pm_notifier(dev);
270 	zpodd->dev = dev;
271 	dev->zpodd = zpodd;
272 	dev_pm_qos_expose_flags(&dev->tdev, 0);
273 }
274 
275 void zpodd_exit(struct ata_device *dev)
276 {
277 	ata_acpi_remove_pm_notifier(dev);
278 	kfree(dev->zpodd);
279 	dev->zpodd = NULL;
280 }
281