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>
23 #include "ozprotocol.h"
31 /*------------------------------------------------------------------------------
32 * This is called once when the driver is loaded to initialise the USB service.
39 /*------------------------------------------------------------------------------
40 * This is called once when the driver is unloaded to terminate the USB service.
43 void oz_usb_term(void)
47 /*------------------------------------------------------------------------------
48 * This is called when the USB service is started or resumed for a PD.
51 int oz_usb_start(struct oz_pd *pd, int resume)
54 struct oz_usb_ctx *usb_ctx;
55 struct oz_usb_ctx *old_ctx;
57 oz_dbg(ON, "USB service resumed\n");
60 oz_dbg(ON, "USB service started\n");
61 /* Create a USB context in case we need one. If we find the PD already
62 * has a USB context then we will destroy it.
64 usb_ctx = kzalloc(sizeof(struct oz_usb_ctx), GFP_ATOMIC);
67 atomic_set(&usb_ctx->ref_count, 1);
70 /* Install the USB context if the PD doesn't already have one.
71 * If it does already have one then destroy the one we have just
74 spin_lock_bh(&pd->app_lock[OZ_APPID_USB-1]);
75 old_ctx = pd->app_ctx[OZ_APPID_USB-1];
77 pd->app_ctx[OZ_APPID_USB-1] = usb_ctx;
78 oz_usb_get(pd->app_ctx[OZ_APPID_USB-1]);
79 spin_unlock_bh(&pd->app_lock[OZ_APPID_USB-1]);
81 oz_dbg(ON, "Already have USB context\n");
85 /* Take a reference to the PD. This will be released when
86 * the USB context is destroyed.
90 /* If we already had a USB context and had obtained a port from
91 * the USB HCD then just reset the port. If we didn't have a port
92 * then report the arrival to the USB HCD so we get one.
95 oz_hcd_pd_reset(usb_ctx, usb_ctx->hport);
97 usb_ctx->hport = oz_hcd_pd_arrived(usb_ctx);
98 if (usb_ctx->hport == NULL) {
99 oz_dbg(ON, "USB hub returned null port\n");
100 spin_lock_bh(&pd->app_lock[OZ_APPID_USB-1]);
101 pd->app_ctx[OZ_APPID_USB-1] = NULL;
102 spin_unlock_bh(&pd->app_lock[OZ_APPID_USB-1]);
110 /*------------------------------------------------------------------------------
111 * This is called when the USB service is stopped or paused for a PD.
112 * Context: softirq or process
114 void oz_usb_stop(struct oz_pd *pd, int pause)
116 struct oz_usb_ctx *usb_ctx;
118 oz_dbg(ON, "USB service paused\n");
121 spin_lock_bh(&pd->app_lock[OZ_APPID_USB-1]);
122 usb_ctx = (struct oz_usb_ctx *)pd->app_ctx[OZ_APPID_USB-1];
123 pd->app_ctx[OZ_APPID_USB-1] = NULL;
124 spin_unlock_bh(&pd->app_lock[OZ_APPID_USB-1]);
126 unsigned long tout = jiffies + HZ;
127 oz_dbg(ON, "USB service stopping...\n");
128 usb_ctx->stopped = 1;
129 /* At this point the reference count on the usb context should
130 * be 2 - one from when we created it and one from the hcd
131 * which claims a reference. Since stopped = 1 no one else
132 * should get in but someone may already be in. So wait
133 * until they leave but timeout after 1 second.
135 while ((atomic_read(&usb_ctx->ref_count) > 2) &&
136 time_before(jiffies, tout))
138 oz_dbg(ON, "USB service stopped\n");
139 oz_hcd_pd_departed(usb_ctx->hport);
140 /* Release the reference taken in oz_usb_start.
145 /*------------------------------------------------------------------------------
146 * This increments the reference count of the context area for a specific PD.
147 * This ensures this context area does not disappear while still in use.
150 void oz_usb_get(void *hpd)
152 struct oz_usb_ctx *usb_ctx = (struct oz_usb_ctx *)hpd;
153 atomic_inc(&usb_ctx->ref_count);
155 /*------------------------------------------------------------------------------
156 * This decrements the reference count of the context area for a specific PD
157 * and destroys the context area if the reference count becomes zero.
158 * Context: softirq or process
160 void oz_usb_put(void *hpd)
162 struct oz_usb_ctx *usb_ctx = (struct oz_usb_ctx *)hpd;
163 if (atomic_dec_and_test(&usb_ctx->ref_count)) {
164 oz_dbg(ON, "Dealloc USB context\n");
165 oz_pd_put(usb_ctx->pd);
169 /*------------------------------------------------------------------------------
172 int oz_usb_heartbeat(struct oz_pd *pd)
174 struct oz_usb_ctx *usb_ctx;
176 spin_lock_bh(&pd->app_lock[OZ_APPID_USB-1]);
177 usb_ctx = (struct oz_usb_ctx *)pd->app_ctx[OZ_APPID_USB-1];
180 spin_unlock_bh(&pd->app_lock[OZ_APPID_USB-1]);
183 if (usb_ctx->stopped)
186 if (oz_hcd_heartbeat(usb_ctx->hport))
192 /*------------------------------------------------------------------------------
195 int oz_usb_stream_create(void *hpd, u8 ep_num)
197 struct oz_usb_ctx *usb_ctx = (struct oz_usb_ctx *)hpd;
198 struct oz_pd *pd = usb_ctx->pd;
199 oz_dbg(ON, "%s: (0x%x)\n", __func__, ep_num);
200 if (pd->mode & OZ_F_ISOC_NO_ELTS) {
201 oz_isoc_stream_create(pd, ep_num);
204 if (oz_elt_stream_create(&pd->elt_buff, ep_num,
205 4*pd->max_tx_size)) {
212 /*------------------------------------------------------------------------------
215 int oz_usb_stream_delete(void *hpd, u8 ep_num)
217 struct oz_usb_ctx *usb_ctx = (struct oz_usb_ctx *)hpd;
219 struct oz_pd *pd = usb_ctx->pd;
221 oz_dbg(ON, "%s: (0x%x)\n", __func__, ep_num);
222 if (pd->mode & OZ_F_ISOC_NO_ELTS) {
223 oz_isoc_stream_delete(pd, ep_num);
225 if (oz_elt_stream_delete(&pd->elt_buff, ep_num))
233 /*------------------------------------------------------------------------------
234 * Context: softirq or process
236 void oz_usb_request_heartbeat(void *hpd)
238 struct oz_usb_ctx *usb_ctx = (struct oz_usb_ctx *)hpd;
239 if (usb_ctx && usb_ctx->pd)
240 oz_pd_request_heartbeat(usb_ctx->pd);