/* * PowerMac G5 SMU driver * * Copyright 2004 J. Mayer <l_indien@magic.fr> * Copyright 2005 Benjamin Herrenschmidt, IBM Corp. * * Released under the term of the GNU GPL v2. */ /* * For now, this driver includes: * - RTC get & set * - reboot & shutdown commands * all synchronous with IRQ disabled (ugh) * * TODO: * rework in a way the PMU driver works, that is asynchronous * with a queue of commands. I'll do that as soon as I have an * SMU based machine at hand. Some more cleanup is needed too, * like maybe fitting it into a platform device, etc... * Also check what's up with cache coherency, and if we really * can't do better than flushing the cache, maybe build a table * of command len/reply len like the PMU driver to only flush * what is actually necessary. * --BenH. */ #include <linux/config.h> #include <linux/types.h> #include <linux/kernel.h> #include <linux/device.h> #include <linux/dmapool.h> #include <linux/bootmem.h> #include <linux/vmalloc.h> #include <linux/highmem.h> #include <linux/jiffies.h> #include <linux/interrupt.h> #include <linux/rtc.h> #include <asm/byteorder.h> #include <asm/io.h> #include <asm/prom.h> #include <asm/machdep.h> #include <asm/pmac_feature.h> #include <asm/smu.h> #include <asm/sections.h> #include <asm/abs_addr.h> #define DEBUG_SMU 1 #ifdef DEBUG_SMU #define DPRINTK(fmt, args...) do { printk(KERN_DEBUG fmt , ##args); } while (0) #else #define DPRINTK(fmt, args...) do { } while (0) #endif /* * This is the command buffer passed to the SMU hardware */ struct smu_cmd_buf { u8 cmd; u8 length; u8 data[0x0FFE]; }; struct smu_device { spinlock_t lock; struct device_node *of_node; int db_ack; /* doorbell ack GPIO */ int db_req; /* doorbell req GPIO */ u32 __iomem *db_buf; /* doorbell buffer */ struct smu_cmd_buf *cmd_buf; /* command buffer virtual */ u32 cmd_buf_abs; /* command buffer absolute */ }; /* * I don't think there will ever be more than one SMU, so * for now, just hard code that */ static struct smu_device *smu; /* * SMU low level communication stuff */ static inline int smu_cmd_stat(struct smu_cmd_buf *cmd_buf, u8 cmd_ack) { rmb(); return cmd_buf->cmd == cmd_ack && cmd_buf->length != 0; } static inline u8 smu_save_ack_cmd(struct smu_cmd_buf *cmd_buf) { return (~cmd_buf->cmd) & 0xff; } static void smu_send_cmd(struct smu_device *dev) { /* SMU command buf is currently cacheable, we need a physical * address. This isn't exactly a DMA mapping here, I suspect * the SMU is actually communicating with us via i2c to the * northbridge or the CPU to access RAM. */ writel(dev->cmd_buf_abs, dev->db_buf); /* Ring the SMU doorbell */ pmac_do_feature_call(PMAC_FTR_WRITE_GPIO, NULL, dev->db_req, 4); pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, dev->db_req, 4); } static int smu_cmd_done(struct smu_device *dev) { unsigned long wait = 0; int gpio; /* Check the SMU doorbell */ do { gpio = pmac_do_feature_call(PMAC_FTR_READ_GPIO, NULL, dev->db_ack); if ((gpio & 7) == 7) return 0; udelay(100); } while(++wait < 10000); printk(KERN_ERR "SMU timeout !\n"); return -ENXIO; } static int smu_do_cmd(struct smu_device *dev) { int rc; u8 cmd_ack; DPRINTK("SMU do_cmd %02x len=%d %02x\n", dev->cmd_buf->cmd, dev->cmd_buf->length, dev->cmd_buf->data[0]); cmd_ack = smu_save_ack_cmd(dev->cmd_buf); /* Clear cmd_buf cache lines */ flush_inval_dcache_range((unsigned long)dev->cmd_buf, ((unsigned long)dev->cmd_buf) + sizeof(struct smu_cmd_buf)); smu_send_cmd(dev); rc = smu_cmd_done(dev); if (rc == 0) rc = smu_cmd_stat(dev->cmd_buf, cmd_ack) ? 0 : -1; DPRINTK("SMU do_cmd %02x len=%d %02x => %d (%02x)\n", dev->cmd_buf->cmd, dev->cmd_buf->length, dev->cmd_buf->data[0], rc, cmd_ack); return rc; } /* RTC low level commands */ static inline int bcd2hex (int n) { return (((n & 0xf0) >> 4) * 10) + (n & 0xf); } static inline int hex2bcd (int n) { return ((n / 10) << 4) + (n % 10); } #if 0 static inline void smu_fill_set_pwrup_timer_cmd(struct smu_cmd_buf *cmd_buf) { cmd_buf->cmd = 0x8e; cmd_buf->length = 8; cmd_buf->data[0] = 0x00; memset(cmd_buf->data + 1, 0, 7); } static inline void smu_fill_get_pwrup_timer_cmd(struct smu_cmd_buf *cmd_buf) { cmd_buf->cmd = 0x8e; cmd_buf->length = 1; cmd_buf->data[0] = 0x01; } static inline void smu_fill_dis_pwrup_timer_cmd(struct smu_cmd_buf *cmd_buf) { cmd_buf->cmd = 0x8e; cmd_buf->length = 1; cmd_buf->data[0] = 0x02; } #endif static inline void smu_fill_set_rtc_cmd(struct smu_cmd_buf *cmd_buf, struct rtc_time *time) { cmd_buf->cmd = 0x8e; cmd_buf->length = 8; cmd_buf->data[0] = 0x80; cmd_buf->data[1] = hex2bcd(time->tm_sec); cmd_buf->data[2] = hex2bcd(time->tm_min); cmd_buf->data[3] = hex2bcd(time->tm_hour); cmd_buf->data[4] = time->tm_wday; cmd_buf->data[5] = hex2bcd(time->tm_mday); cmd_buf->data[6] = hex2bcd(time->tm_mon) + 1; cmd_buf->data[7] = hex2bcd(time->tm_year - 100); } static inline void smu_fill_get_rtc_cmd(struct smu_cmd_buf *cmd_buf) { cmd_buf->cmd = 0x8e; cmd_buf->length = 1; cmd_buf->data[0] = 0x81; } static void smu_parse_get_rtc_reply(struct smu_cmd_buf *cmd_buf, struct rtc_time *time) { time->tm_sec = bcd2hex(cmd_buf->data[0]); time->tm_min = bcd2hex(cmd_buf->data[1]); time->tm_hour = bcd2hex(cmd_buf->data[2]); time->tm_wday = bcd2hex(cmd_buf->data[3]); time->tm_mday = bcd2hex(cmd_buf->data[4]); time->tm_mon = bcd2hex(cmd_buf->data[5]) - 1; time->tm_year = bcd2hex(cmd_buf->data[6]) + 100; } int smu_get_rtc_time(struct rtc_time *time) { unsigned long flags; int rc; if (smu == NULL) return -ENODEV; memset(time, 0, sizeof(struct rtc_time)); spin_lock_irqsave(&smu->lock, flags); smu_fill_get_rtc_cmd(smu->cmd_buf); rc = smu_do_cmd(smu); if (rc == 0) smu_parse_get_rtc_reply(smu->cmd_buf, time); spin_unlock_irqrestore(&smu->lock, flags); return rc; } int smu_set_rtc_time(struct rtc_time *time) { unsigned long flags; int rc; if (smu == NULL) return -ENODEV; spin_lock_irqsave(&smu->lock, flags); smu_fill_set_rtc_cmd(smu->cmd_buf, time); rc = smu_do_cmd(smu); spin_unlock_irqrestore(&smu->lock, flags); return rc; } void smu_shutdown(void) { const unsigned char *command = "SHUTDOWN"; unsigned long flags; if (smu == NULL) return; spin_lock_irqsave(&smu->lock, flags); smu->cmd_buf->cmd = 0xaa; smu->cmd_buf->length = strlen(command); strcpy(smu->cmd_buf->data, command); smu_do_cmd(smu); for (;;) ; spin_unlock_irqrestore(&smu->lock, flags); } void smu_restart(void) { const unsigned char *command = "RESTART"; unsigned long flags; if (smu == NULL) return; spin_lock_irqsave(&smu->lock, flags); smu->cmd_buf->cmd = 0xaa; smu->cmd_buf->length = strlen(command); strcpy(smu->cmd_buf->data, command); smu_do_cmd(smu); for (;;) ; spin_unlock_irqrestore(&smu->lock, flags); } int smu_present(void) { return smu != NULL; } int smu_init (void) { struct device_node *np; u32 *data; np = of_find_node_by_type(NULL, "smu"); if (np == NULL) return -ENODEV; if (smu_cmdbuf_abs == 0) { printk(KERN_ERR "SMU: Command buffer not allocated !\n"); return -EINVAL; } smu = alloc_bootmem(sizeof(struct smu_device)); if (smu == NULL) return -ENOMEM; memset(smu, 0, sizeof(*smu)); spin_lock_init(&smu->lock); smu->of_node = np; /* smu_cmdbuf_abs is in the low 2G of RAM, can be converted to a * 32 bits value safely */ smu->cmd_buf_abs = (u32)smu_cmdbuf_abs; smu->cmd_buf = (struct smu_cmd_buf *)abs_to_virt(smu_cmdbuf_abs); np = of_find_node_by_name(NULL, "smu-doorbell"); if (np == NULL) { printk(KERN_ERR "SMU: Can't find doorbell GPIO !\n"); goto fail; } data = (u32 *)get_property(np, "reg", NULL); of_node_put(np); if (data == NULL) { printk(KERN_ERR "SMU: Can't find doorbell GPIO address !\n"); goto fail; } /* Current setup has one doorbell GPIO that does both doorbell * and ack. GPIOs are at 0x50, best would be to find that out * in the device-tree though. */ smu->db_req = 0x50 + *data; smu->db_ack = 0x50 + *data; /* Doorbell buffer is currently hard-coded, I didn't find a proper * device-tree entry giving the address. Best would probably to use * an offset for K2 base though, but let's do it that way for now. */ smu->db_buf = ioremap(0x8000860c, 0x1000); if (smu->db_buf == NULL) { printk(KERN_ERR "SMU: Can't map doorbell buffer pointer !\n"); goto fail; } sys_ctrler = SYS_CTRLER_SMU; return 0; fail: smu = NULL; return -ENXIO; }