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author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 15:20:36 -0700 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/macintosh/via-cuda.c | |
download | lwn-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz lwn-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.zip |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'drivers/macintosh/via-cuda.c')
-rw-r--r-- | drivers/macintosh/via-cuda.c | 628 |
1 files changed, 628 insertions, 0 deletions
diff --git a/drivers/macintosh/via-cuda.c b/drivers/macintosh/via-cuda.c new file mode 100644 index 000000000000..417deb5de108 --- /dev/null +++ b/drivers/macintosh/via-cuda.c @@ -0,0 +1,628 @@ +/* + * Device driver for the via-cuda on Apple Powermacs. + * + * The VIA (versatile interface adapter) interfaces to the CUDA, + * a 6805 microprocessor core which controls the ADB (Apple Desktop + * Bus) which connects to the keyboard and mouse. The CUDA also + * controls system power and the RTC (real time clock) chip. + * + * Copyright (C) 1996 Paul Mackerras. + */ +#include <stdarg.h> +#include <linux/config.h> +#include <linux/types.h> +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/delay.h> +#include <linux/sched.h> +#include <linux/adb.h> +#include <linux/cuda.h> +#include <linux/spinlock.h> +#include <linux/interrupt.h> +#ifdef CONFIG_PPC +#include <asm/prom.h> +#include <asm/machdep.h> +#else +#include <asm/macintosh.h> +#include <asm/macints.h> +#include <asm/machw.h> +#include <asm/mac_via.h> +#endif +#include <asm/io.h> +#include <asm/system.h> +#include <linux/init.h> + +static volatile unsigned char __iomem *via; +static DEFINE_SPINLOCK(cuda_lock); + +#ifdef CONFIG_MAC +#define CUDA_IRQ IRQ_MAC_ADB +#define __openfirmware +#define eieio() +#else +#define CUDA_IRQ vias->intrs[0].line +#endif + +/* VIA registers - spaced 0x200 bytes apart */ +#define RS 0x200 /* skip between registers */ +#define B 0 /* B-side data */ +#define A RS /* A-side data */ +#define DIRB (2*RS) /* B-side direction (1=output) */ +#define DIRA (3*RS) /* A-side direction (1=output) */ +#define T1CL (4*RS) /* Timer 1 ctr/latch (low 8 bits) */ +#define T1CH (5*RS) /* Timer 1 counter (high 8 bits) */ +#define T1LL (6*RS) /* Timer 1 latch (low 8 bits) */ +#define T1LH (7*RS) /* Timer 1 latch (high 8 bits) */ +#define T2CL (8*RS) /* Timer 2 ctr/latch (low 8 bits) */ +#define T2CH (9*RS) /* Timer 2 counter (high 8 bits) */ +#define SR (10*RS) /* Shift register */ +#define ACR (11*RS) /* Auxiliary control register */ +#define PCR (12*RS) /* Peripheral control register */ +#define IFR (13*RS) /* Interrupt flag register */ +#define IER (14*RS) /* Interrupt enable register */ +#define ANH (15*RS) /* A-side data, no handshake */ + +/* Bits in B data register: all active low */ +#define TREQ 0x08 /* Transfer request (input) */ +#define TACK 0x10 /* Transfer acknowledge (output) */ +#define TIP 0x20 /* Transfer in progress (output) */ + +/* Bits in ACR */ +#define SR_CTRL 0x1c /* Shift register control bits */ +#define SR_EXT 0x0c /* Shift on external clock */ +#define SR_OUT 0x10 /* Shift out if 1 */ + +/* Bits in IFR and IER */ +#define IER_SET 0x80 /* set bits in IER */ +#define IER_CLR 0 /* clear bits in IER */ +#define SR_INT 0x04 /* Shift register full/empty */ + +static enum cuda_state { + idle, + sent_first_byte, + sending, + reading, + read_done, + awaiting_reply +} cuda_state; + +static struct adb_request *current_req; +static struct adb_request *last_req; +static unsigned char cuda_rbuf[16]; +static unsigned char *reply_ptr; +static int reading_reply; +static int data_index; +#ifdef CONFIG_PPC +static struct device_node *vias; +#endif +static int cuda_fully_inited = 0; + +#ifdef CONFIG_ADB +static int cuda_probe(void); +static int cuda_init(void); +static int cuda_send_request(struct adb_request *req, int sync); +static int cuda_adb_autopoll(int devs); +static int cuda_reset_adb_bus(void); +#endif /* CONFIG_ADB */ + +static int cuda_init_via(void); +static void cuda_start(void); +static irqreturn_t cuda_interrupt(int irq, void *arg, struct pt_regs *regs); +static void cuda_input(unsigned char *buf, int nb, struct pt_regs *regs); +void cuda_poll(void); +static int cuda_write(struct adb_request *req); + +int cuda_request(struct adb_request *req, + void (*done)(struct adb_request *), int nbytes, ...); + +#ifdef CONFIG_ADB +struct adb_driver via_cuda_driver = { + "CUDA", + cuda_probe, + cuda_init, + cuda_send_request, + cuda_adb_autopoll, + cuda_poll, + cuda_reset_adb_bus +}; +#endif /* CONFIG_ADB */ + +#ifdef CONFIG_PPC +int __init +find_via_cuda(void) +{ + int err; + struct adb_request req; + + if (vias != 0) + return 1; + vias = find_devices("via-cuda"); + if (vias == 0) + return 0; + if (vias->next != 0) + printk(KERN_WARNING "Warning: only using 1st via-cuda\n"); + +#if 0 + { int i; + + printk("find_via_cuda: node = %p, addrs =", vias->node); + for (i = 0; i < vias->n_addrs; ++i) + printk(" %x(%x)", vias->addrs[i].address, vias->addrs[i].size); + printk(", intrs ="); + for (i = 0; i < vias->n_intrs; ++i) + printk(" %x", vias->intrs[i].line); + printk("\n"); } +#endif + + if (vias->n_addrs != 1 || vias->n_intrs != 1) { + printk(KERN_ERR "via-cuda: expecting 1 address (%d) and 1 interrupt (%d)\n", + vias->n_addrs, vias->n_intrs); + if (vias->n_addrs < 1 || vias->n_intrs < 1) + return 0; + } + via = ioremap(vias->addrs->address, 0x2000); + + cuda_state = idle; + sys_ctrler = SYS_CTRLER_CUDA; + + err = cuda_init_via(); + if (err) { + printk(KERN_ERR "cuda_init_via() failed\n"); + via = NULL; + return 0; + } + + /* Clear and enable interrupts, but only on PPC. On 68K it's done */ + /* for us by the main VIA driver in arch/m68k/mac/via.c */ + +#ifndef CONFIG_MAC + out_8(&via[IFR], 0x7f); /* clear interrupts by writing 1s */ + out_8(&via[IER], IER_SET|SR_INT); /* enable interrupt from SR */ +#endif + + /* enable autopoll */ + cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, 1); + while (!req.complete) + cuda_poll(); + + return 1; +} +#endif /* CONFIG_PPC */ + +static int __init via_cuda_start(void) +{ + if (via == NULL) + return -ENODEV; + +#ifdef CONFIG_PPC + request_OF_resource(vias, 0, NULL); +#endif + + if (request_irq(CUDA_IRQ, cuda_interrupt, 0, "ADB", cuda_interrupt)) { + printk(KERN_ERR "cuda_init: can't get irq %d\n", CUDA_IRQ); + return -EAGAIN; + } + + printk("Macintosh CUDA driver v0.5 for Unified ADB.\n"); + + cuda_fully_inited = 1; + return 0; +} + +device_initcall(via_cuda_start); + +#ifdef CONFIG_ADB +static int +cuda_probe(void) +{ +#ifdef CONFIG_PPC + if (sys_ctrler != SYS_CTRLER_CUDA) + return -ENODEV; +#else + if (macintosh_config->adb_type != MAC_ADB_CUDA) + return -ENODEV; + via = via1; +#endif + return 0; +} + +static int __init +cuda_init(void) +{ +#ifdef CONFIG_PPC + if (via == NULL) + return -ENODEV; + return 0; +#else + int err = cuda_init_via(); + if (err) { + printk(KERN_ERR "cuda_init_via() failed\n"); + return -ENODEV; + } + + return via_cuda_start(); +#endif +} +#endif /* CONFIG_ADB */ + +#define WAIT_FOR(cond, what) \ + do { \ + int x; \ + for (x = 1000; !(cond); --x) { \ + if (x == 0) { \ + printk("Timeout waiting for " what "\n"); \ + return -ENXIO; \ + } \ + udelay(100); \ + } \ + } while (0) + +static int +cuda_init_via(void) +{ + out_8(&via[DIRB], (in_8(&via[DIRB]) | TACK | TIP) & ~TREQ); /* TACK & TIP out */ + out_8(&via[B], in_8(&via[B]) | TACK | TIP); /* negate them */ + out_8(&via[ACR] ,(in_8(&via[ACR]) & ~SR_CTRL) | SR_EXT); /* SR data in */ + (void)in_8(&via[SR]); /* clear any left-over data */ +#ifndef CONFIG_MAC + out_8(&via[IER], 0x7f); /* disable interrupts from VIA */ + (void)in_8(&via[IER]); +#endif + + /* delay 4ms and then clear any pending interrupt */ + mdelay(4); + (void)in_8(&via[SR]); + out_8(&via[IFR], in_8(&via[IFR]) & 0x7f); + + /* sync with the CUDA - assert TACK without TIP */ + out_8(&via[B], in_8(&via[B]) & ~TACK); + + /* wait for the CUDA to assert TREQ in response */ + WAIT_FOR((in_8(&via[B]) & TREQ) == 0, "CUDA response to sync"); + + /* wait for the interrupt and then clear it */ + WAIT_FOR(in_8(&via[IFR]) & SR_INT, "CUDA response to sync (2)"); + (void)in_8(&via[SR]); + out_8(&via[IFR], in_8(&via[IFR]) & 0x7f); + + /* finish the sync by negating TACK */ + out_8(&via[B], in_8(&via[B]) | TACK); + + /* wait for the CUDA to negate TREQ and the corresponding interrupt */ + WAIT_FOR(in_8(&via[B]) & TREQ, "CUDA response to sync (3)"); + WAIT_FOR(in_8(&via[IFR]) & SR_INT, "CUDA response to sync (4)"); + (void)in_8(&via[SR]); + out_8(&via[IFR], in_8(&via[IFR]) & 0x7f); + out_8(&via[B], in_8(&via[B]) | TIP); /* should be unnecessary */ + + return 0; +} + +#ifdef CONFIG_ADB +/* Send an ADB command */ +static int +cuda_send_request(struct adb_request *req, int sync) +{ + int i; + + if ((via == NULL) || !cuda_fully_inited) { + req->complete = 1; + return -ENXIO; + } + + req->reply_expected = 1; + + i = cuda_write(req); + if (i) + return i; + + if (sync) { + while (!req->complete) + cuda_poll(); + } + return 0; +} + + +/* Enable/disable autopolling */ +static int +cuda_adb_autopoll(int devs) +{ + struct adb_request req; + + if ((via == NULL) || !cuda_fully_inited) + return -ENXIO; + + cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, (devs? 1: 0)); + while (!req.complete) + cuda_poll(); + return 0; +} + +/* Reset adb bus - how do we do this?? */ +static int +cuda_reset_adb_bus(void) +{ + struct adb_request req; + + if ((via == NULL) || !cuda_fully_inited) + return -ENXIO; + + cuda_request(&req, NULL, 2, ADB_PACKET, 0); /* maybe? */ + while (!req.complete) + cuda_poll(); + return 0; +} +#endif /* CONFIG_ADB */ +/* Construct and send a cuda request */ +int +cuda_request(struct adb_request *req, void (*done)(struct adb_request *), + int nbytes, ...) +{ + va_list list; + int i; + + if (via == NULL) { + req->complete = 1; + return -ENXIO; + } + + req->nbytes = nbytes; + req->done = done; + va_start(list, nbytes); + for (i = 0; i < nbytes; ++i) + req->data[i] = va_arg(list, int); + va_end(list); + req->reply_expected = 1; + return cuda_write(req); +} + +static int +cuda_write(struct adb_request *req) +{ + unsigned long flags; + + if (req->nbytes < 2 || req->data[0] > CUDA_PACKET) { + req->complete = 1; + return -EINVAL; + } + req->next = NULL; + req->sent = 0; + req->complete = 0; + req->reply_len = 0; + + spin_lock_irqsave(&cuda_lock, flags); + if (current_req != 0) { + last_req->next = req; + last_req = req; + } else { + current_req = req; + last_req = req; + if (cuda_state == idle) + cuda_start(); + } + spin_unlock_irqrestore(&cuda_lock, flags); + + return 0; +} + +static void +cuda_start(void) +{ + struct adb_request *req; + + /* assert cuda_state == idle */ + /* get the packet to send */ + req = current_req; + if (req == 0) + return; + if ((in_8(&via[B]) & TREQ) == 0) + return; /* a byte is coming in from the CUDA */ + + /* set the shift register to shift out and send a byte */ + out_8(&via[ACR], in_8(&via[ACR]) | SR_OUT); + out_8(&via[SR], req->data[0]); + out_8(&via[B], in_8(&via[B]) & ~TIP); + cuda_state = sent_first_byte; +} + +void +cuda_poll(void) +{ + unsigned long flags; + + /* cuda_interrupt only takes a normal lock, we disable + * interrupts here to avoid re-entering and thus deadlocking. + * An option would be to disable only the IRQ source with + * disable_irq(), would that work on m68k ? --BenH + */ + local_irq_save(flags); + cuda_interrupt(0, NULL, NULL); + local_irq_restore(flags); +} + +static irqreturn_t +cuda_interrupt(int irq, void *arg, struct pt_regs *regs) +{ + int status; + struct adb_request *req = NULL; + unsigned char ibuf[16]; + int ibuf_len = 0; + int complete = 0; + unsigned char virq; + + spin_lock(&cuda_lock); + + virq = in_8(&via[IFR]) & 0x7f; + out_8(&via[IFR], virq); + if ((virq & SR_INT) == 0) { + spin_unlock(&cuda_lock); + return IRQ_NONE; + } + + status = (~in_8(&via[B]) & (TIP|TREQ)) | (in_8(&via[ACR]) & SR_OUT); + /* printk("cuda_interrupt: state=%d status=%x\n", cuda_state, status); */ + switch (cuda_state) { + case idle: + /* CUDA has sent us the first byte of data - unsolicited */ + if (status != TREQ) + printk("cuda: state=idle, status=%x\n", status); + (void)in_8(&via[SR]); + out_8(&via[B], in_8(&via[B]) & ~TIP); + cuda_state = reading; + reply_ptr = cuda_rbuf; + reading_reply = 0; + break; + + case awaiting_reply: + /* CUDA has sent us the first byte of data of a reply */ + if (status != TREQ) + printk("cuda: state=awaiting_reply, status=%x\n", status); + (void)in_8(&via[SR]); + out_8(&via[B], in_8(&via[B]) & ~TIP); + cuda_state = reading; + reply_ptr = current_req->reply; + reading_reply = 1; + break; + + case sent_first_byte: + if (status == TREQ + TIP + SR_OUT) { + /* collision */ + out_8(&via[ACR], in_8(&via[ACR]) & ~SR_OUT); + (void)in_8(&via[SR]); + out_8(&via[B], in_8(&via[B]) | TIP | TACK); + cuda_state = idle; + } else { + /* assert status == TIP + SR_OUT */ + if (status != TIP + SR_OUT) + printk("cuda: state=sent_first_byte status=%x\n", status); + out_8(&via[SR], current_req->data[1]); + out_8(&via[B], in_8(&via[B]) ^ TACK); + data_index = 2; + cuda_state = sending; + } + break; + + case sending: + req = current_req; + if (data_index >= req->nbytes) { + out_8(&via[ACR], in_8(&via[ACR]) & ~SR_OUT); + (void)in_8(&via[SR]); + out_8(&via[B], in_8(&via[B]) | TACK | TIP); + req->sent = 1; + if (req->reply_expected) { + cuda_state = awaiting_reply; + } else { + current_req = req->next; + complete = 1; + /* not sure about this */ + cuda_state = idle; + cuda_start(); + } + } else { + out_8(&via[SR], req->data[data_index++]); + out_8(&via[B], in_8(&via[B]) ^ TACK); + } + break; + + case reading: + *reply_ptr++ = in_8(&via[SR]); + if (status == TIP) { + /* that's all folks */ + out_8(&via[B], in_8(&via[B]) | TACK | TIP); + cuda_state = read_done; + } else { + /* assert status == TIP | TREQ */ + if (status != TIP + TREQ) + printk("cuda: state=reading status=%x\n", status); + out_8(&via[B], in_8(&via[B]) ^ TACK); + } + break; + + case read_done: + (void)in_8(&via[SR]); + if (reading_reply) { + req = current_req; + req->reply_len = reply_ptr - req->reply; + if (req->data[0] == ADB_PACKET) { + /* Have to adjust the reply from ADB commands */ + if (req->reply_len <= 2 || (req->reply[1] & 2) != 0) { + /* the 0x2 bit indicates no response */ + req->reply_len = 0; + } else { + /* leave just the command and result bytes in the reply */ + req->reply_len -= 2; + memmove(req->reply, req->reply + 2, req->reply_len); + } + } + current_req = req->next; + complete = 1; + } else { + /* This is tricky. We must break the spinlock to call + * cuda_input. However, doing so means we might get + * re-entered from another CPU getting an interrupt + * or calling cuda_poll(). I ended up using the stack + * (it's only for 16 bytes) and moving the actual + * call to cuda_input to outside of the lock. + */ + ibuf_len = reply_ptr - cuda_rbuf; + memcpy(ibuf, cuda_rbuf, ibuf_len); + } + if (status == TREQ) { + out_8(&via[B], in_8(&via[B]) & ~TIP); + cuda_state = reading; + reply_ptr = cuda_rbuf; + reading_reply = 0; + } else { + cuda_state = idle; + cuda_start(); + } + break; + + default: + printk("cuda_interrupt: unknown cuda_state %d?\n", cuda_state); + } + spin_unlock(&cuda_lock); + if (complete && req) { + void (*done)(struct adb_request *) = req->done; + mb(); + req->complete = 1; + /* Here, we assume that if the request has a done member, the + * struct request will survive to setting req->complete to 1 + */ + if (done) + (*done)(req); + } + if (ibuf_len) + cuda_input(ibuf, ibuf_len, regs); + return IRQ_HANDLED; +} + +static void +cuda_input(unsigned char *buf, int nb, struct pt_regs *regs) +{ + int i; + + switch (buf[0]) { + case ADB_PACKET: +#ifdef CONFIG_XMON + if (nb == 5 && buf[2] == 0x2c) { + extern int xmon_wants_key, xmon_adb_keycode; + if (xmon_wants_key) { + xmon_adb_keycode = buf[3]; + return; + } + } +#endif /* CONFIG_XMON */ +#ifdef CONFIG_ADB + adb_input(buf+2, nb-2, regs, buf[1] & 0x40); +#endif /* CONFIG_ADB */ + break; + + default: + printk("data from cuda (%d bytes):", nb); + for (i = 0; i < nb; ++i) + printk(" %.2x", buf[i]); + printk("\n"); + } +} |