diff options
Diffstat (limited to 'drivers/macintosh/via-cuda.c')
-rw-r--r-- | drivers/macintosh/via-cuda.c | 802 |
1 files changed, 802 insertions, 0 deletions
diff --git a/drivers/macintosh/via-cuda.c b/drivers/macintosh/via-cuda.c new file mode 100644 index 0000000000..f8dd1e8315 --- /dev/null +++ b/drivers/macintosh/via-cuda.c @@ -0,0 +1,802 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Device driver for the Cuda and Egret system controllers found on PowerMacs + * and 68k Macs. + * + * The Cuda or Egret is a 6805 microcontroller interfaced to the 6522 VIA. + * This MCU controls system power, Parameter RAM, Real Time Clock and the + * Apple Desktop Bus (ADB) that connects to the keyboard and mouse. + * + * Copyright (C) 1996 Paul Mackerras. + */ +#include <linux/stdarg.h> +#include <linux/types.h> +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/delay.h> +#include <linux/adb.h> +#include <linux/cuda.h> +#include <linux/spinlock.h> +#include <linux/interrupt.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> + +#ifdef CONFIG_PPC +#include <asm/machdep.h> +#include <asm/pmac_feature.h> +#else +#include <asm/macintosh.h> +#include <asm/macints.h> +#include <asm/mac_via.h> +#endif +#include <asm/io.h> +#include <linux/init.h> + +static volatile unsigned char __iomem *via; +static DEFINE_SPINLOCK(cuda_lock); + +/* 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 */ + +/* + * When the Cuda design replaced the Egret, some signal names and + * logic sense changed. They all serve the same purposes, however. + * + * VIA pin | Egret pin + * ----------------+------------------------------------------ + * PB3 (input) | Transceiver session (active low) + * PB4 (output) | VIA full (active high) + * PB5 (output) | System session (active high) + * + * VIA pin | Cuda pin + * ----------------+------------------------------------------ + * PB3 (input) | Transfer request (active low) + * PB4 (output) | Byte acknowledge (active low) + * PB5 (output) | Transfer in progress (active low) + */ + +/* Bits in Port B data register */ +#define TREQ 0x08 /* Transfer request */ +#define TACK 0x10 /* Transfer acknowledge */ +#define TIP 0x20 /* Transfer in progress */ + +/* 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 */ + +/* Duration of byte acknowledgement pulse (us) */ +#define EGRET_TACK_ASSERTED_DELAY 300 +#define EGRET_TACK_NEGATED_DELAY 400 + +/* Interval from interrupt to start of session (us) */ +#define EGRET_SESSION_DELAY 450 + +#ifdef CONFIG_PPC +#define mcu_is_egret false +#else +static bool mcu_is_egret; +#endif + +static inline bool TREQ_asserted(u8 portb) +{ + return !(portb & TREQ); +} + +static inline void assert_TIP(void) +{ + if (mcu_is_egret) { + udelay(EGRET_SESSION_DELAY); + out_8(&via[B], in_8(&via[B]) | TIP); + } else + out_8(&via[B], in_8(&via[B]) & ~TIP); +} + +static inline void assert_TIP_and_TACK(void) +{ + if (mcu_is_egret) { + udelay(EGRET_SESSION_DELAY); + out_8(&via[B], in_8(&via[B]) | TIP | TACK); + } else + out_8(&via[B], in_8(&via[B]) & ~(TIP | TACK)); +} + +static inline void assert_TACK(void) +{ + if (mcu_is_egret) { + udelay(EGRET_TACK_NEGATED_DELAY); + out_8(&via[B], in_8(&via[B]) | TACK); + } else + out_8(&via[B], in_8(&via[B]) & ~TACK); +} + +static inline void toggle_TACK(void) +{ + out_8(&via[B], in_8(&via[B]) ^ TACK); +} + +static inline void negate_TACK(void) +{ + if (mcu_is_egret) { + udelay(EGRET_TACK_ASSERTED_DELAY); + out_8(&via[B], in_8(&via[B]) & ~TACK); + } else + out_8(&via[B], in_8(&via[B]) | TACK); +} + +static inline void negate_TIP_and_TACK(void) +{ + if (mcu_is_egret) { + udelay(EGRET_TACK_ASSERTED_DELAY); + out_8(&via[B], in_8(&via[B]) & ~(TIP | TACK)); + } else + out_8(&via[B], in_8(&via[B]) | TIP | TACK); +} + +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; +static int cuda_irq; +#ifdef CONFIG_PPC +static struct device_node *vias; +#endif +static int cuda_fully_inited; + +#ifdef CONFIG_ADB +static int cuda_probe(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); +static void cuda_input(unsigned char *buf, int nb); +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 = { + .name = "CUDA", + .probe = cuda_probe, + .send_request = cuda_send_request, + .autopoll = cuda_adb_autopoll, + .poll = cuda_poll, + .reset_bus = cuda_reset_adb_bus, +}; +#endif /* CONFIG_ADB */ + +#ifdef CONFIG_MAC +int __init find_via_cuda(void) +{ + struct adb_request req; + int err; + + if (macintosh_config->adb_type != MAC_ADB_CUDA && + macintosh_config->adb_type != MAC_ADB_EGRET) + return 0; + + via = via1; + cuda_state = idle; + mcu_is_egret = macintosh_config->adb_type == MAC_ADB_EGRET; + + err = cuda_init_via(); + if (err) { + printk(KERN_ERR "cuda_init_via() failed\n"); + via = NULL; + return 0; + } + + /* enable autopoll */ + cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, 1); + while (!req.complete) + cuda_poll(); + + return 1; +} +#else +int __init find_via_cuda(void) +{ + struct adb_request req; + struct resource res; + int err; + + if (vias) + return 1; + vias = of_find_node_by_name(NULL, "via-cuda"); + if (!vias) + return 0; + + err = of_address_to_resource(vias, 0, &res); + if (err) { + printk(KERN_ERR "via-cuda: Error getting \"reg\" property !\n"); + goto fail; + } + via = ioremap(res.start, 0x2000); + if (via == NULL) { + printk(KERN_ERR "via-cuda: Can't map address !\n"); + goto fail; + } + + 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 */ + + out_8(&via[IFR], 0x7f); /* clear interrupts by writing 1s */ + out_8(&via[IER], IER_SET|SR_INT); /* enable interrupt from SR */ + + /* enable autopoll */ + cuda_request(&req, NULL, 3, CUDA_PACKET, CUDA_AUTOPOLL, 1); + while (!req.complete) + cuda_poll(); + + return 1; + + fail: + of_node_put(vias); + vias = NULL; + return 0; +} +#endif /* !defined CONFIG_MAC */ + +static int __init via_cuda_start(void) +{ + if (via == NULL) + return -ENODEV; + +#ifdef CONFIG_MAC + cuda_irq = IRQ_MAC_ADB; +#else + cuda_irq = irq_of_parse_and_map(vias, 0); + if (!cuda_irq) { + printk(KERN_ERR "via-cuda: can't map interrupts for %pOF\n", + vias); + return -ENODEV; + } +#endif + + if (request_irq(cuda_irq, cuda_interrupt, 0, "ADB", cuda_interrupt)) { + printk(KERN_ERR "via-cuda: can't request irq %d\n", cuda_irq); + return -EAGAIN; + } + + pr_info("Macintosh Cuda and Egret driver.\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 && + macintosh_config->adb_type != MAC_ADB_EGRET) + return -ENODEV; +#endif + if (via == NULL) + return -ENODEV; + return 0; +} +#endif /* CONFIG_ADB */ + +static int __init sync_egret(void) +{ + if (TREQ_asserted(in_8(&via[B]))) { + /* Complete the inbound transfer */ + assert_TIP_and_TACK(); + while (1) { + negate_TACK(); + mdelay(1); + (void)in_8(&via[SR]); + assert_TACK(); + if (!TREQ_asserted(in_8(&via[B]))) + break; + } + negate_TIP_and_TACK(); + } else if (in_8(&via[B]) & TIP) { + /* Terminate the outbound transfer */ + negate_TACK(); + assert_TACK(); + mdelay(1); + negate_TIP_and_TACK(); + } + /* Clear shift register interrupt */ + if (in_8(&via[IFR]) & SR_INT) + (void)in_8(&via[SR]); + return 0; +} + +#define WAIT_FOR(cond, what) \ + do { \ + int x; \ + for (x = 1000; !(cond); --x) { \ + if (x == 0) { \ + pr_err("Timeout waiting for " what "\n"); \ + return -ENXIO; \ + } \ + udelay(100); \ + } \ + } while (0) + +static int +__init cuda_init_via(void) +{ +#ifdef CONFIG_PPC + out_8(&via[IER], 0x7f); /* disable interrupts from VIA */ + (void)in_8(&via[IER]); +#else + out_8(&via[IER], SR_INT); /* disable SR interrupt from VIA */ +#endif + + out_8(&via[DIRB], (in_8(&via[DIRB]) | TACK | TIP) & ~TREQ); /* TACK & TIP out */ + 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 */ + + if (mcu_is_egret) + return sync_egret(); + + negate_TIP_and_TACK(); + + /* delay 4ms and then clear any pending interrupt */ + mdelay(4); + (void)in_8(&via[SR]); + out_8(&via[IFR], SR_INT); + + /* sync with the CUDA - assert TACK without TIP */ + assert_TACK(); + + /* wait for the CUDA to assert TREQ in response */ + WAIT_FOR(TREQ_asserted(in_8(&via[B])), "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], SR_INT); + + /* finish the sync by negating TACK */ + negate_TACK(); + + /* wait for the CUDA to negate TREQ and the corresponding interrupt */ + WAIT_FOR(!TREQ_asserted(in_8(&via[B])), "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], SR_INT); + + 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); +} +EXPORT_SYMBOL(cuda_request); + +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) { + 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) +{ + /* assert cuda_state == idle */ + if (current_req == NULL) + return; + data_index = 0; + if (TREQ_asserted(in_8(&via[B]))) + 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], current_req->data[data_index++]); + if (mcu_is_egret) + assert_TIP_and_TACK(); + else + assert_TIP(); + cuda_state = sent_first_byte; +} + +void +cuda_poll(void) +{ + cuda_interrupt(0, NULL); +} +EXPORT_SYMBOL(cuda_poll); + +#define ARRAY_FULL(a, p) ((p) - (a) == ARRAY_SIZE(a)) + +static irqreturn_t +cuda_interrupt(int irq, void *arg) +{ + unsigned long flags; + u8 status; + struct adb_request *req = NULL; + unsigned char ibuf[16]; + int ibuf_len = 0; + int complete = 0; + bool full; + + spin_lock_irqsave(&cuda_lock, flags); + + /* On powermacs, this handler is registered for the VIA IRQ. But they use + * just the shift register IRQ -- other VIA interrupt sources are disabled. + * On m68k macs, the VIA IRQ sources are dispatched individually. Unless + * we are polling, the shift register IRQ flag has already been cleared. + */ + +#ifdef CONFIG_MAC + if (!arg) +#endif + { + if ((in_8(&via[IFR]) & SR_INT) == 0) { + spin_unlock_irqrestore(&cuda_lock, flags); + return IRQ_NONE; + } else { + out_8(&via[IFR], SR_INT); + } + } + + status = in_8(&via[B]) & (TIP | TACK | TREQ); + + switch (cuda_state) { + case idle: + /* System controller has unsolicited data for us */ + (void)in_8(&via[SR]); +idle_state: + assert_TIP(); + cuda_state = reading; + reply_ptr = cuda_rbuf; + reading_reply = 0; + break; + + case awaiting_reply: + /* System controller has reply data for us */ + (void)in_8(&via[SR]); + assert_TIP(); + cuda_state = reading; + reply_ptr = current_req->reply; + reading_reply = 1; + break; + + case sent_first_byte: + if (TREQ_asserted(status)) { + /* collision */ + out_8(&via[ACR], in_8(&via[ACR]) & ~SR_OUT); + (void)in_8(&via[SR]); + negate_TIP_and_TACK(); + cuda_state = idle; + /* Egret does not raise an "aborted" interrupt */ + if (mcu_is_egret) + goto idle_state; + } else { + out_8(&via[SR], current_req->data[data_index++]); + toggle_TACK(); + if (mcu_is_egret) + assert_TACK(); + 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]); + negate_TIP_and_TACK(); + 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++]); + toggle_TACK(); + if (mcu_is_egret) + assert_TACK(); + } + break; + + case reading: + full = reading_reply ? ARRAY_FULL(current_req->reply, reply_ptr) + : ARRAY_FULL(cuda_rbuf, reply_ptr); + if (full) + (void)in_8(&via[SR]); + else + *reply_ptr++ = in_8(&via[SR]); + if (!TREQ_asserted(status) || full) { + if (mcu_is_egret) + assert_TACK(); + /* that's all folks */ + negate_TIP_and_TACK(); + cuda_state = read_done; + /* Egret does not raise a "read done" interrupt */ + if (mcu_is_egret) + goto read_done_state; + } else { + toggle_TACK(); + if (mcu_is_egret) + negate_TACK(); + } + break; + + case read_done: + (void)in_8(&via[SR]); +read_done_state: + 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; + reading_reply = 0; + } 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); + } + reply_ptr = cuda_rbuf; + cuda_state = idle; + cuda_start(); + if (cuda_state == idle && TREQ_asserted(in_8(&via[B]))) { + assert_TIP(); + cuda_state = reading; + } + break; + + default: + pr_err("cuda_interrupt: unknown cuda_state %d?\n", cuda_state); + } + spin_unlock_irqrestore(&cuda_lock, flags); + 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); + return IRQ_HANDLED; +} + +static void +cuda_input(unsigned char *buf, int nb) +{ + 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, buf[1] & 0x40); +#endif /* CONFIG_ADB */ + break; + + case TIMER_PACKET: + /* Egret sends these periodically. Might be useful as a 'heartbeat' + * to trigger a recovery for the VIA shift register errata. + */ + break; + + default: + print_hex_dump(KERN_INFO, "cuda_input: ", DUMP_PREFIX_NONE, 32, 1, + buf, nb, false); + } +} + +/* Offset between Unix time (1970-based) and Mac time (1904-based) */ +#define RTC_OFFSET 2082844800 + +time64_t cuda_get_time(void) +{ + struct adb_request req; + u32 now; + + if (cuda_request(&req, NULL, 2, CUDA_PACKET, CUDA_GET_TIME) < 0) + return 0; + while (!req.complete) + cuda_poll(); + if (req.reply_len != 7) + pr_err("%s: got %d byte reply\n", __func__, req.reply_len); + now = (req.reply[3] << 24) + (req.reply[4] << 16) + + (req.reply[5] << 8) + req.reply[6]; + return (time64_t)now - RTC_OFFSET; +} + +int cuda_set_rtc_time(struct rtc_time *tm) +{ + u32 now; + struct adb_request req; + + now = lower_32_bits(rtc_tm_to_time64(tm) + RTC_OFFSET); + if (cuda_request(&req, NULL, 6, CUDA_PACKET, CUDA_SET_TIME, + now >> 24, now >> 16, now >> 8, now) < 0) + return -ENXIO; + while (!req.complete) + cuda_poll(); + if ((req.reply_len != 3) && (req.reply_len != 7)) + pr_err("%s: got %d byte reply\n", __func__, req.reply_len); + return 0; +} |