Mercurial > vordog

comparison vordog.c @ 7:5a281ce7453c

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Add comments
author Thinker K.F. Li <thinker@branda.to>
date Tue, 08 Jul 2008 16:06:24 +0800
parents 76ce6e6624b8
children a28764b2a28e
comparison
equal deleted inserted replaced
6:76ce6e6624b8 7:5a281ce7453c
153 .d_close = vordog_close, 153 .d_close = vordog_close,
154 .d_ioctl = vordog_ioctl, 154 .d_ioctl = vordog_ioctl,
155 .d_name = "vordog", 155 .d_name = "vordog",
156 }; 156 };
157 157
158 /* Implements watchdog(9) compatible driver. */ 158 /*
159 static int 159 * Implements watchdog(9) compatible driver.
160 vordog_wd9_init(int timeout) { 160 */
161 /*! \brief Initialize timer for an interval in specified seconds.
162 */
163 static int
164 vordog_wd9_init(u_int timeout) {
161 int val; 165 int val;
162 166
163 if(timeout < 0 || timeout > 255) 167 if(timeout < 0 || timeout > 255)
164 return EINVAL; 168 return EINVAL;
165 169
167 val = 0x80 | (VDT_1S << 4) | VD_TIMER_RST; 171 val = 0x80 | (VDT_1S << 4) | VD_TIMER_RST;
168 outb(VD_CTR, val); 172 outb(VD_CTR, val);
169 return 0; 173 return 0;
170 } 174 }
171 175
176 /*! \brief Reset timer before it is timeout.
177 *
178 * It make the timer reload it's value from initial value register.
179 */
172 static void 180 static void
173 vordog_wd9_reset(void) { 181 vordog_wd9_reset(void) {
174 outb(VD_STATUS, 0xc0); 182 outb(VD_STATUS, 0xc0);
175 } 183 }
176 184
185 /*! \brief Stop counting of watchdog timer.
186 */
177 static void 187 static void
178 vordog_wd9_disable(void) { 188 vordog_wd9_disable(void) {
179 outb(VD_CTR, 0); 189 outb(VD_CTR, 0);
180 outb(VD_STATUS, 0xc0); 190 outb(VD_STATUS, 0xc0);
181 } 191 }
182 192
183 static void 193 /*! \brief event handler for watchdog(9).
184 vordog_wd9_evh(void *private, u_int cmd, int *error) { 194 *
195 * Timeout interval of watchdog(9) is defined by power of 2 nanoseconds.
196 * Watchdog timer of Vortex86 provides only small range of intervals.
197 * We use only the timer in seconds to simplize the code. It provides
198 * interval 1~255 seconds.
199 *
200 * Since, only SFTMR1_STS is work, in my experience, and it is triggered
201 * after 4 times of initial value. So, it only (i * 4) seconds in range
202 * of 4 ~ (255 * 4), where i is one of positive integer, are supported.
203 *
204 * The supported time intervals of watchdog(9) are 2^31~2^39 nanoseconds.
205 * vordog used a (i * 4) seconds for 2^n seconds while i * 4 seconds is
206 * smallest one of intervals that bigger than 2^n seconds.
207 */
208 static void
209 vordog_wd9_evh(void *priv_data, u_int cmd, int *error) {
185 vd_softc_t sc; 210 vd_softc_t sc;
186 u_int timeout, u; 211 u_int timeout, u;
212 /* 2^31, 2^32, ..., 2^39 nanoseconds */
187 static const int timeouts[] = { 1, 2, 3, 5, 9, 18, 35, 69, 138}; 213 static const int timeouts[] = { 1, 2, 3, 5, 9, 18, 35, 69, 138};
188 214
189 sc = (vd_softc_t)private; 215 sc = (vd_softc_t)priv_data;
190 216
191 u = cmd & WD_INTERVAL; 217 u = cmd & WD_INTERVAL;
192 if(u < 31 || u > 39) { 218 if(u < 31 || u > 39) {
219 /* Out of range! Can not be configured. */
193 vordog_wd9_disable(); 220 vordog_wd9_disable();
194 sc->init_val = 0; 221 sc->init_val = 0;
195 return; 222 return;
196 } 223 }
197 224