1 /* -----------------------------------------------------------------------------
2 * Copyright (c) 2011 Ozmo Inc
3 * Released under the GNU General Public License Version 2 (GPLv2).
5 * This file provides protocol independent part of the implementation of the USB
7 * The implementation of this service is split into two parts the first of which
8 * is protocol independent and the second contains protocol specific details.
9 * This split is to allow alternative protocols to be defined.
10 * The implementation of this service uses ozhcd.c to implement a USB HCD.
11 * -----------------------------------------------------------------------------
13 #include <linux/init.h>
14 #include <linux/module.h>
15 #include <linux/timer.h>
16 #include <linux/sched.h>
17 #include <linux/netdevice.h>
18 #include <linux/errno.h>
19 #include <linux/input.h>
20 #include <asm/unaligned.h>
22 #include "ozprotocol.h"
30 /*------------------------------------------------------------------------------
31 * This is called once when the driver is loaded to initialise the USB service.
38 /*------------------------------------------------------------------------------
39 * This is called once when the driver is unloaded to terminate the USB service.
42 void oz_usb_term(void)
46 /*------------------------------------------------------------------------------
47 * This is called when the USB service is started or resumed for a PD.
50 int oz_usb_start(struct oz_pd *pd, int resume)
53 struct oz_usb_ctx *usb_ctx;
54 struct oz_usb_ctx *old_ctx;
56 oz_trace("USB service resumed.\n");
59 oz_trace("USB service started.\n");
60 /* Create a USB context in case we need one. If we find the PD already
61 * has a USB context then we will destroy it.
63 usb_ctx = kzalloc(sizeof(struct oz_usb_ctx), GFP_ATOMIC);
66 atomic_set(&usb_ctx->ref_count, 1);
69 /* Install the USB context if the PD doesn't already have one.
70 * If it does already have one then destroy the one we have just
73 spin_lock_bh(&pd->app_lock[OZ_APPID_USB-1]);
74 old_ctx = pd->app_ctx[OZ_APPID_USB-1];
76 pd->app_ctx[OZ_APPID_USB-1] = usb_ctx;
77 oz_usb_get(pd->app_ctx[OZ_APPID_USB-1]);
78 spin_unlock_bh(&pd->app_lock[OZ_APPID_USB-1]);
80 oz_trace("Already have USB context.\n");
84 /* Take a reference to the PD. This will be released when
85 * the USB context is destroyed.
89 /* If we already had a USB context and had obtained a port from
90 * the USB HCD then just reset the port. If we didn't have a port
91 * then report the arrival to the USB HCD so we get one.
94 oz_hcd_pd_reset(usb_ctx, usb_ctx->hport);
96 usb_ctx->hport = oz_hcd_pd_arrived(usb_ctx);
97 if (usb_ctx->hport == NULL) {
98 oz_trace("USB hub returned null port.\n");
99 spin_lock_bh(&pd->app_lock[OZ_APPID_USB-1]);
100 pd->app_ctx[OZ_APPID_USB-1] = NULL;
101 spin_unlock_bh(&pd->app_lock[OZ_APPID_USB-1]);
109 /*------------------------------------------------------------------------------
110 * This is called when the USB service is stopped or paused for a PD.
111 * Context: softirq or process
113 void oz_usb_stop(struct oz_pd *pd, int pause)
115 struct oz_usb_ctx *usb_ctx;
117 oz_trace("USB service paused.\n");
120 spin_lock_bh(&pd->app_lock[OZ_APPID_USB-1]);
121 usb_ctx = (struct oz_usb_ctx *)pd->app_ctx[OZ_APPID_USB-1];
122 pd->app_ctx[OZ_APPID_USB-1] = NULL;
123 spin_unlock_bh(&pd->app_lock[OZ_APPID_USB-1]);
125 unsigned long tout = jiffies + HZ;
126 oz_trace("USB service stopping...\n");
127 usb_ctx->stopped = 1;
128 /* At this point the reference count on the usb context should
129 * be 2 - one from when we created it and one from the hcd
130 * which claims a reference. Since stopped = 1 no one else
131 * should get in but someone may already be in. So wait
132 * until they leave but timeout after 1 second.
134 while ((atomic_read(&usb_ctx->ref_count) > 2) &&
135 time_before(jiffies, tout))
137 oz_trace("USB service stopped.\n");
138 oz_hcd_pd_departed(usb_ctx->hport);
139 /* Release the reference taken in oz_usb_start.
144 /*------------------------------------------------------------------------------
145 * This increments the reference count of the context area for a specific PD.
146 * This ensures this context area does not disappear while still in use.
149 void oz_usb_get(void *hpd)
151 struct oz_usb_ctx *usb_ctx = (struct oz_usb_ctx *)hpd;
152 atomic_inc(&usb_ctx->ref_count);
154 /*------------------------------------------------------------------------------
155 * This decrements the reference count of the context area for a specific PD
156 * and destroys the context area if the reference count becomes zero.
157 * Context: softirq or process
159 void oz_usb_put(void *hpd)
161 struct oz_usb_ctx *usb_ctx = (struct oz_usb_ctx *)hpd;
162 if (atomic_dec_and_test(&usb_ctx->ref_count)) {
163 oz_trace("Dealloc USB context.\n");
164 oz_pd_put(usb_ctx->pd);
168 /*------------------------------------------------------------------------------
171 int oz_usb_heartbeat(struct oz_pd *pd)
173 struct oz_usb_ctx *usb_ctx;
175 spin_lock_bh(&pd->app_lock[OZ_APPID_USB-1]);
176 usb_ctx = (struct oz_usb_ctx *)pd->app_ctx[OZ_APPID_USB-1];
179 spin_unlock_bh(&pd->app_lock[OZ_APPID_USB-1]);
182 if (usb_ctx->stopped)
185 if (oz_hcd_heartbeat(usb_ctx->hport))
191 /*------------------------------------------------------------------------------
194 int oz_usb_stream_create(void *hpd, u8 ep_num)
196 struct oz_usb_ctx *usb_ctx = (struct oz_usb_ctx *)hpd;
197 struct oz_pd *pd = usb_ctx->pd;
198 oz_trace("oz_usb_stream_create(0x%x)\n", ep_num);
199 if (pd->mode & OZ_F_ISOC_NO_ELTS) {
200 oz_isoc_stream_create(pd, ep_num);
203 if (oz_elt_stream_create(&pd->elt_buff, ep_num,
204 4*pd->max_tx_size)) {
211 /*------------------------------------------------------------------------------
214 int oz_usb_stream_delete(void *hpd, u8 ep_num)
216 struct oz_usb_ctx *usb_ctx = (struct oz_usb_ctx *)hpd;
218 struct oz_pd *pd = usb_ctx->pd;
220 oz_trace("oz_usb_stream_delete(0x%x)\n", ep_num);
221 if (pd->mode & OZ_F_ISOC_NO_ELTS) {
222 oz_isoc_stream_delete(pd, ep_num);
224 if (oz_elt_stream_delete(&pd->elt_buff, ep_num))
232 /*------------------------------------------------------------------------------
233 * Context: softirq or process
235 void oz_usb_request_heartbeat(void *hpd)
237 struct oz_usb_ctx *usb_ctx = (struct oz_usb_ctx *)hpd;
238 if (usb_ctx && usb_ctx->pd)
239 oz_pd_request_heartbeat(usb_ctx->pd);