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Diffstat (limited to '')
| -rw-r--r-- | drivers/block/xsysace.c | 1273 |
1 files changed, 1273 insertions, 0 deletions
diff --git a/drivers/block/xsysace.c b/drivers/block/xsysace.c new file mode 100644 index 000000000..eb8ef6577 --- /dev/null +++ b/drivers/block/xsysace.c @@ -0,0 +1,1273 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Xilinx SystemACE device driver + * + * Copyright 2007 Secret Lab Technologies Ltd. + */ + +/* + * The SystemACE chip is designed to configure FPGAs by loading an FPGA + * bitstream from a file on a CF card and squirting it into FPGAs connected + * to the SystemACE JTAG chain. It also has the advantage of providing an + * MPU interface which can be used to control the FPGA configuration process + * and to use the attached CF card for general purpose storage. + * + * This driver is a block device driver for the SystemACE. + * + * Initialization: + * The driver registers itself as a platform_device driver at module + * load time. The platform bus will take care of calling the + * ace_probe() method for all SystemACE instances in the system. Any + * number of SystemACE instances are supported. ace_probe() calls + * ace_setup() which initialized all data structures, reads the CF + * id structure and registers the device. + * + * Processing: + * Just about all of the heavy lifting in this driver is performed by + * a Finite State Machine (FSM). The driver needs to wait on a number + * of events; some raised by interrupts, some which need to be polled + * for. Describing all of the behaviour in a FSM seems to be the + * easiest way to keep the complexity low and make it easy to + * understand what the driver is doing. If the block ops or the + * request function need to interact with the hardware, then they + * simply need to flag the request and kick of FSM processing. + * + * The FSM itself is atomic-safe code which can be run from any + * context. The general process flow is: + * 1. obtain the ace->lock spinlock. + * 2. loop on ace_fsm_dostate() until the ace->fsm_continue flag is + * cleared. + * 3. release the lock. + * + * Individual states do not sleep in any way. If a condition needs to + * be waited for then the state much clear the fsm_continue flag and + * either schedule the FSM to be run again at a later time, or expect + * an interrupt to call the FSM when the desired condition is met. + * + * In normal operation, the FSM is processed at interrupt context + * either when the driver's tasklet is scheduled, or when an irq is + * raised by the hardware. The tasklet can be scheduled at any time. + * The request method in particular schedules the tasklet when a new + * request has been indicated by the block layer. Once started, the + * FSM proceeds as far as it can processing the request until it + * needs on a hardware event. At this point, it must yield execution. + * + * A state has two options when yielding execution: + * 1. ace_fsm_yield() + * - Call if need to poll for event. + * - clears the fsm_continue flag to exit the processing loop + * - reschedules the tasklet to run again as soon as possible + * 2. ace_fsm_yieldirq() + * - Call if an irq is expected from the HW + * - clears the fsm_continue flag to exit the processing loop + * - does not reschedule the tasklet so the FSM will not be processed + * again until an irq is received. + * After calling a yield function, the state must return control back + * to the FSM main loop. + * + * Additionally, the driver maintains a kernel timer which can process + * the FSM. If the FSM gets stalled, typically due to a missed + * interrupt, then the kernel timer will expire and the driver can + * continue where it left off. + * + * To Do: + * - Add FPGA configuration control interface. + * - Request major number from lanana + */ + +#undef DEBUG + +#include <linux/module.h> +#include <linux/ctype.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/errno.h> +#include <linux/kernel.h> +#include <linux/delay.h> +#include <linux/slab.h> +#include <linux/blk-mq.h> +#include <linux/mutex.h> +#include <linux/ata.h> +#include <linux/hdreg.h> +#include <linux/platform_device.h> +#if defined(CONFIG_OF) +#include <linux/of_address.h> +#include <linux/of_device.h> +#include <linux/of_platform.h> +#endif + +MODULE_AUTHOR("Grant Likely <grant.likely@secretlab.ca>"); +MODULE_DESCRIPTION("Xilinx SystemACE device driver"); +MODULE_LICENSE("GPL"); + +/* SystemACE register definitions */ +#define ACE_BUSMODE (0x00) + +#define ACE_STATUS (0x04) +#define ACE_STATUS_CFGLOCK (0x00000001) +#define ACE_STATUS_MPULOCK (0x00000002) +#define ACE_STATUS_CFGERROR (0x00000004) /* config controller error */ +#define ACE_STATUS_CFCERROR (0x00000008) /* CF controller error */ +#define ACE_STATUS_CFDETECT (0x00000010) +#define ACE_STATUS_DATABUFRDY (0x00000020) +#define ACE_STATUS_DATABUFMODE (0x00000040) +#define ACE_STATUS_CFGDONE (0x00000080) +#define ACE_STATUS_RDYFORCFCMD (0x00000100) +#define ACE_STATUS_CFGMODEPIN (0x00000200) +#define ACE_STATUS_CFGADDR_MASK (0x0000e000) +#define ACE_STATUS_CFBSY (0x00020000) +#define ACE_STATUS_CFRDY (0x00040000) +#define ACE_STATUS_CFDWF (0x00080000) +#define ACE_STATUS_CFDSC (0x00100000) +#define ACE_STATUS_CFDRQ (0x00200000) +#define ACE_STATUS_CFCORR (0x00400000) +#define ACE_STATUS_CFERR (0x00800000) + +#define ACE_ERROR (0x08) +#define ACE_CFGLBA (0x0c) +#define ACE_MPULBA (0x10) + +#define ACE_SECCNTCMD (0x14) +#define ACE_SECCNTCMD_RESET (0x0100) +#define ACE_SECCNTCMD_IDENTIFY (0x0200) +#define ACE_SECCNTCMD_READ_DATA (0x0300) +#define ACE_SECCNTCMD_WRITE_DATA (0x0400) +#define ACE_SECCNTCMD_ABORT (0x0600) + +#define ACE_VERSION (0x16) +#define ACE_VERSION_REVISION_MASK (0x00FF) +#define ACE_VERSION_MINOR_MASK (0x0F00) +#define ACE_VERSION_MAJOR_MASK (0xF000) + +#define ACE_CTRL (0x18) +#define ACE_CTRL_FORCELOCKREQ (0x0001) +#define ACE_CTRL_LOCKREQ (0x0002) +#define ACE_CTRL_FORCECFGADDR (0x0004) +#define ACE_CTRL_FORCECFGMODE (0x0008) +#define ACE_CTRL_CFGMODE (0x0010) +#define ACE_CTRL_CFGSTART (0x0020) +#define ACE_CTRL_CFGSEL (0x0040) +#define ACE_CTRL_CFGRESET (0x0080) +#define ACE_CTRL_DATABUFRDYIRQ (0x0100) +#define ACE_CTRL_ERRORIRQ (0x0200) +#define ACE_CTRL_CFGDONEIRQ (0x0400) +#define ACE_CTRL_RESETIRQ (0x0800) +#define ACE_CTRL_CFGPROG (0x1000) +#define ACE_CTRL_CFGADDR_MASK (0xe000) + +#define ACE_FATSTAT (0x1c) + +#define ACE_NUM_MINORS 16 +#define ACE_SECTOR_SIZE (512) +#define ACE_FIFO_SIZE (32) +#define ACE_BUF_PER_SECTOR (ACE_SECTOR_SIZE / ACE_FIFO_SIZE) + +#define ACE_BUS_WIDTH_8 0 +#define ACE_BUS_WIDTH_16 1 + +struct ace_reg_ops; + +struct ace_device { + /* driver state data */ + int id; + int media_change; + int users; + struct list_head list; + + /* finite state machine data */ + struct tasklet_struct fsm_tasklet; + uint fsm_task; /* Current activity (ACE_TASK_*) */ + uint fsm_state; /* Current state (ACE_FSM_STATE_*) */ + uint fsm_continue_flag; /* cleared to exit FSM mainloop */ + uint fsm_iter_num; + struct timer_list stall_timer; + + /* Transfer state/result, use for both id and block request */ + struct request *req; /* request being processed */ + void *data_ptr; /* pointer to I/O buffer */ + int data_count; /* number of buffers remaining */ + int data_result; /* Result of transfer; 0 := success */ + + int id_req_count; /* count of id requests */ + int id_result; + struct completion id_completion; /* used when id req finishes */ + int in_irq; + + /* Details of hardware device */ + resource_size_t physaddr; + void __iomem *baseaddr; + int irq; + int bus_width; /* 0 := 8 bit; 1 := 16 bit */ + struct ace_reg_ops *reg_ops; + int lock_count; + + /* Block device data structures */ + spinlock_t lock; + struct device *dev; + struct request_queue *queue; + struct gendisk *gd; + struct blk_mq_tag_set tag_set; + struct list_head rq_list; + + /* Inserted CF card parameters */ + u16 cf_id[ATA_ID_WORDS]; +}; + +static DEFINE_MUTEX(xsysace_mutex); +static int ace_major; + +/* --------------------------------------------------------------------- + * Low level register access + */ + +struct ace_reg_ops { + u16(*in) (struct ace_device * ace, int reg); + void (*out) (struct ace_device * ace, int reg, u16 val); + void (*datain) (struct ace_device * ace); + void (*dataout) (struct ace_device * ace); +}; + +/* 8 Bit bus width */ +static u16 ace_in_8(struct ace_device *ace, int reg) +{ + void __iomem *r = ace->baseaddr + reg; + return in_8(r) | (in_8(r + 1) << 8); +} + +static void ace_out_8(struct ace_device *ace, int reg, u16 val) +{ + void __iomem *r = ace->baseaddr + reg; + out_8(r, val); + out_8(r + 1, val >> 8); +} + +static void ace_datain_8(struct ace_device *ace) +{ + void __iomem *r = ace->baseaddr + 0x40; + u8 *dst = ace->data_ptr; + int i = ACE_FIFO_SIZE; + while (i--) + *dst++ = in_8(r++); + ace->data_ptr = dst; +} + +static void ace_dataout_8(struct ace_device *ace) +{ + void __iomem *r = ace->baseaddr + 0x40; + u8 *src = ace->data_ptr; + int i = ACE_FIFO_SIZE; + while (i--) + out_8(r++, *src++); + ace->data_ptr = src; +} + +static struct ace_reg_ops ace_reg_8_ops = { + .in = ace_in_8, + .out = ace_out_8, + .datain = ace_datain_8, + .dataout = ace_dataout_8, +}; + +/* 16 bit big endian bus attachment */ +static u16 ace_in_be16(struct ace_device *ace, int reg) +{ + return in_be16(ace->baseaddr + reg); +} + +static void ace_out_be16(struct ace_device *ace, int reg, u16 val) +{ + out_be16(ace->baseaddr + reg, val); +} + +static void ace_datain_be16(struct ace_device *ace) +{ + int i = ACE_FIFO_SIZE / 2; + u16 *dst = ace->data_ptr; + while (i--) + *dst++ = in_le16(ace->baseaddr + 0x40); + ace->data_ptr = dst; +} + +static void ace_dataout_be16(struct ace_device *ace) +{ + int i = ACE_FIFO_SIZE / 2; + u16 *src = ace->data_ptr; + while (i--) + out_le16(ace->baseaddr + 0x40, *src++); + ace->data_ptr = src; +} + +/* 16 bit little endian bus attachment */ +static u16 ace_in_le16(struct ace_device *ace, int reg) +{ + return in_le16(ace->baseaddr + reg); +} + +static void ace_out_le16(struct ace_device *ace, int reg, u16 val) +{ + out_le16(ace->baseaddr + reg, val); +} + +static void ace_datain_le16(struct ace_device *ace) +{ + int i = ACE_FIFO_SIZE / 2; + u16 *dst = ace->data_ptr; + while (i--) + *dst++ = in_be16(ace->baseaddr + 0x40); + ace->data_ptr = dst; +} + +static void ace_dataout_le16(struct ace_device *ace) +{ + int i = ACE_FIFO_SIZE / 2; + u16 *src = ace->data_ptr; + while (i--) + out_be16(ace->baseaddr + 0x40, *src++); + ace->data_ptr = src; +} + +static struct ace_reg_ops ace_reg_be16_ops = { + .in = ace_in_be16, + .out = ace_out_be16, + .datain = ace_datain_be16, + .dataout = ace_dataout_be16, +}; + +static struct ace_reg_ops ace_reg_le16_ops = { + .in = ace_in_le16, + .out = ace_out_le16, + .datain = ace_datain_le16, + .dataout = ace_dataout_le16, +}; + +static inline u16 ace_in(struct ace_device *ace, int reg) +{ + return ace->reg_ops->in(ace, reg); +} + +static inline u32 ace_in32(struct ace_device *ace, int reg) +{ + return ace_in(ace, reg) | (ace_in(ace, reg + 2) << 16); +} + +static inline void ace_out(struct ace_device *ace, int reg, u16 val) +{ + ace->reg_ops->out(ace, reg, val); +} + +static inline void ace_out32(struct ace_device *ace, int reg, u32 val) +{ + ace_out(ace, reg, val); + ace_out(ace, reg + 2, val >> 16); +} + +/* --------------------------------------------------------------------- + * Debug support functions + */ + +#if defined(DEBUG) +static void ace_dump_mem(void *base, int len) +{ + const char *ptr = base; + int i, j; + + for (i = 0; i < len; i += 16) { + printk(KERN_INFO "%.8x:", i); + for (j = 0; j < 16; j++) { + if (!(j % 4)) + printk(" "); + printk("%.2x", ptr[i + j]); + } + printk(" "); + for (j = 0; j < 16; j++) + printk("%c", isprint(ptr[i + j]) ? ptr[i + j] : '.'); + printk("\n"); + } +} +#else +static inline void ace_dump_mem(void *base, int len) +{ +} +#endif + +static void ace_dump_regs(struct ace_device *ace) +{ + dev_info(ace->dev, + " ctrl: %.8x seccnt/cmd: %.4x ver:%.4x\n" + " status:%.8x mpu_lba:%.8x busmode:%4x\n" + " error: %.8x cfg_lba:%.8x fatstat:%.4x\n", + ace_in32(ace, ACE_CTRL), + ace_in(ace, ACE_SECCNTCMD), + ace_in(ace, ACE_VERSION), + ace_in32(ace, ACE_STATUS), + ace_in32(ace, ACE_MPULBA), + ace_in(ace, ACE_BUSMODE), + ace_in32(ace, ACE_ERROR), + ace_in32(ace, ACE_CFGLBA), ace_in(ace, ACE_FATSTAT)); +} + +static void ace_fix_driveid(u16 *id) +{ +#if defined(__BIG_ENDIAN) + int i; + + /* All half words have wrong byte order; swap the bytes */ + for (i = 0; i < ATA_ID_WORDS; i++, id++) + *id = le16_to_cpu(*id); +#endif +} + +/* --------------------------------------------------------------------- + * Finite State Machine (FSM) implementation + */ + +/* FSM tasks; used to direct state transitions */ +#define ACE_TASK_IDLE 0 +#define ACE_TASK_IDENTIFY 1 +#define ACE_TASK_READ 2 +#define ACE_TASK_WRITE 3 +#define ACE_FSM_NUM_TASKS 4 + +/* FSM state definitions */ +#define ACE_FSM_STATE_IDLE 0 +#define ACE_FSM_STATE_REQ_LOCK 1 +#define ACE_FSM_STATE_WAIT_LOCK 2 +#define ACE_FSM_STATE_WAIT_CFREADY 3 +#define ACE_FSM_STATE_IDENTIFY_PREPARE 4 +#define ACE_FSM_STATE_IDENTIFY_TRANSFER 5 +#define ACE_FSM_STATE_IDENTIFY_COMPLETE 6 +#define ACE_FSM_STATE_REQ_PREPARE 7 +#define ACE_FSM_STATE_REQ_TRANSFER 8 +#define ACE_FSM_STATE_REQ_COMPLETE 9 +#define ACE_FSM_STATE_ERROR 10 +#define ACE_FSM_NUM_STATES 11 + +/* Set flag to exit FSM loop and reschedule tasklet */ +static inline void ace_fsm_yieldpoll(struct ace_device *ace) +{ + tasklet_schedule(&ace->fsm_tasklet); + ace->fsm_continue_flag = 0; +} + +static inline void ace_fsm_yield(struct ace_device *ace) +{ + dev_dbg(ace->dev, "%s()\n", __func__); + ace_fsm_yieldpoll(ace); +} + +/* Set flag to exit FSM loop and wait for IRQ to reschedule tasklet */ +static inline void ace_fsm_yieldirq(struct ace_device *ace) +{ + dev_dbg(ace->dev, "ace_fsm_yieldirq()\n"); + + if (ace->irq > 0) + ace->fsm_continue_flag = 0; + else + ace_fsm_yieldpoll(ace); +} + +static bool ace_has_next_request(struct request_queue *q) +{ + struct ace_device *ace = q->queuedata; + + return !list_empty(&ace->rq_list); +} + +/* Get the next read/write request; ending requests that we don't handle */ +static struct request *ace_get_next_request(struct request_queue *q) +{ + struct ace_device *ace = q->queuedata; + struct request *rq; + + rq = list_first_entry_or_null(&ace->rq_list, struct request, queuelist); + if (rq) { + list_del_init(&rq->queuelist); + blk_mq_start_request(rq); + } + + return NULL; +} + +static void ace_fsm_dostate(struct ace_device *ace) +{ + struct request *req; + u32 status; + u16 val; + int count; + +#if defined(DEBUG) + dev_dbg(ace->dev, "fsm_state=%i, id_req_count=%i\n", + ace->fsm_state, ace->id_req_count); +#endif + + /* Verify that there is actually a CF in the slot. If not, then + * bail out back to the idle state and wake up all the waiters */ + status = ace_in32(ace, ACE_STATUS); + if ((status & ACE_STATUS_CFDETECT) == 0) { + ace->fsm_state = ACE_FSM_STATE_IDLE; + ace->media_change = 1; + set_capacity(ace->gd, 0); + dev_info(ace->dev, "No CF in slot\n"); + + /* Drop all in-flight and pending requests */ + if (ace->req) { + blk_mq_end_request(ace->req, BLK_STS_IOERR); + ace->req = NULL; + } + while ((req = ace_get_next_request(ace->queue)) != NULL) + blk_mq_end_request(req, BLK_STS_IOERR); + + /* Drop back to IDLE state and notify waiters */ + ace->fsm_state = ACE_FSM_STATE_IDLE; + ace->id_result = -EIO; + while (ace->id_req_count) { + complete(&ace->id_completion); + ace->id_req_count--; + } + } + + switch (ace->fsm_state) { + case ACE_FSM_STATE_IDLE: + /* See if there is anything to do */ + if (ace->id_req_count || ace_has_next_request(ace->queue)) { + ace->fsm_iter_num++; + ace->fsm_state = ACE_FSM_STATE_REQ_LOCK; + mod_timer(&ace->stall_timer, jiffies + HZ); + if (!timer_pending(&ace->stall_timer)) + add_timer(&ace->stall_timer); + break; + } + del_timer(&ace->stall_timer); + ace->fsm_continue_flag = 0; + break; + + case ACE_FSM_STATE_REQ_LOCK: + if (ace_in(ace, ACE_STATUS) & ACE_STATUS_MPULOCK) { + /* Already have the lock, jump to next state */ + ace->fsm_state = ACE_FSM_STATE_WAIT_CFREADY; + break; + } + + /* Request the lock */ + val = ace_in(ace, ACE_CTRL); + ace_out(ace, ACE_CTRL, val | ACE_CTRL_LOCKREQ); + ace->fsm_state = ACE_FSM_STATE_WAIT_LOCK; + break; + + case ACE_FSM_STATE_WAIT_LOCK: + if (ace_in(ace, ACE_STATUS) & ACE_STATUS_MPULOCK) { + /* got the lock; move to next state */ + ace->fsm_state = ACE_FSM_STATE_WAIT_CFREADY; + break; + } + + /* wait a bit for the lock */ + ace_fsm_yield(ace); + break; + + case ACE_FSM_STATE_WAIT_CFREADY: + status = ace_in32(ace, ACE_STATUS); + if (!(status & ACE_STATUS_RDYFORCFCMD) || + (status & ACE_STATUS_CFBSY)) { + /* CF card isn't ready; it needs to be polled */ + ace_fsm_yield(ace); + break; + } + + /* Device is ready for command; determine what to do next */ + if (ace->id_req_count) + ace->fsm_state = ACE_FSM_STATE_IDENTIFY_PREPARE; + else + ace->fsm_state = ACE_FSM_STATE_REQ_PREPARE; + break; + + case ACE_FSM_STATE_IDENTIFY_PREPARE: + /* Send identify command */ + ace->fsm_task = ACE_TASK_IDENTIFY; + ace->data_ptr = ace->cf_id; + ace->data_count = ACE_BUF_PER_SECTOR; + ace_out(ace, ACE_SECCNTCMD, ACE_SECCNTCMD_IDENTIFY); + + /* As per datasheet, put config controller in reset */ + val = ace_in(ace, ACE_CTRL); + ace_out(ace, ACE_CTRL, val | ACE_CTRL_CFGRESET); + + /* irq handler takes over from this point; wait for the + * transfer to complete */ + ace->fsm_state = ACE_FSM_STATE_IDENTIFY_TRANSFER; + ace_fsm_yieldirq(ace); + break; + + case ACE_FSM_STATE_IDENTIFY_TRANSFER: + /* Check that the sysace is ready to receive data */ + status = ace_in32(ace, ACE_STATUS); + if (status & ACE_STATUS_CFBSY) { + dev_dbg(ace->dev, "CFBSY set; t=%i iter=%i dc=%i\n", + ace->fsm_task, ace->fsm_iter_num, + ace->data_count); + ace_fsm_yield(ace); + break; + } + if (!(status & ACE_STATUS_DATABUFRDY)) { + ace_fsm_yield(ace); + break; + } + + /* Transfer the next buffer */ + ace->reg_ops->datain(ace); + ace->data_count--; + + /* If there are still buffers to be transfers; jump out here */ + if (ace->data_count != 0) { + ace_fsm_yieldirq(ace); + break; + } + + /* transfer finished; kick state machine */ + dev_dbg(ace->dev, "identify finished\n"); + ace->fsm_state = ACE_FSM_STATE_IDENTIFY_COMPLETE; + break; + + case ACE_FSM_STATE_IDENTIFY_COMPLETE: + ace_fix_driveid(ace->cf_id); + ace_dump_mem(ace->cf_id, 512); /* Debug: Dump out disk ID */ + + if (ace->data_result) { + /* Error occurred, disable the disk */ + ace->media_change = 1; + set_capacity(ace->gd, 0); + dev_err(ace->dev, "error fetching CF id (%i)\n", + ace->data_result); + } else { + ace->media_change = 0; + + /* Record disk parameters */ + set_capacity(ace->gd, + ata_id_u32(ace->cf_id, ATA_ID_LBA_CAPACITY)); + dev_info(ace->dev, "capacity: %i sectors\n", + ata_id_u32(ace->cf_id, ATA_ID_LBA_CAPACITY)); + } + + /* We're done, drop to IDLE state and notify waiters */ + ace->fsm_state = ACE_FSM_STATE_IDLE; + ace->id_result = ace->data_result; + while (ace->id_req_count) { + complete(&ace->id_completion); + ace->id_req_count--; + } + break; + + case ACE_FSM_STATE_REQ_PREPARE: + req = ace_get_next_request(ace->queue); + if (!req) { + ace->fsm_state = ACE_FSM_STATE_IDLE; + break; + } + + /* Okay, it's a data request, set it up for transfer */ + dev_dbg(ace->dev, + "request: sec=%llx hcnt=%x, ccnt=%x, dir=%i\n", + (unsigned long long)blk_rq_pos(req), + blk_rq_sectors(req), blk_rq_cur_sectors(req), + rq_data_dir(req)); + + ace->req = req; + ace->data_ptr = bio_data(req->bio); + ace->data_count = blk_rq_cur_sectors(req) * ACE_BUF_PER_SECTOR; + ace_out32(ace, ACE_MPULBA, blk_rq_pos(req) & 0x0FFFFFFF); + + count = blk_rq_sectors(req); + if (rq_data_dir(req)) { + /* Kick off write request */ + dev_dbg(ace->dev, "write data\n"); + ace->fsm_task = ACE_TASK_WRITE; + ace_out(ace, ACE_SECCNTCMD, + count | ACE_SECCNTCMD_WRITE_DATA); + } else { + /* Kick off read request */ + dev_dbg(ace->dev, "read data\n"); + ace->fsm_task = ACE_TASK_READ; + ace_out(ace, ACE_SECCNTCMD, + count | ACE_SECCNTCMD_READ_DATA); + } + + /* As per datasheet, put config controller in reset */ + val = ace_in(ace, ACE_CTRL); + ace_out(ace, ACE_CTRL, val | ACE_CTRL_CFGRESET); + + /* Move to the transfer state. The systemace will raise + * an interrupt once there is something to do + */ + ace->fsm_state = ACE_FSM_STATE_REQ_TRANSFER; + if (ace->fsm_task == ACE_TASK_READ) + ace_fsm_yieldirq(ace); /* wait for data ready */ + break; + + case ACE_FSM_STATE_REQ_TRANSFER: + /* Check that the sysace is ready to receive data */ + status = ace_in32(ace, ACE_STATUS); + if (status & ACE_STATUS_CFBSY) { + dev_dbg(ace->dev, + "CFBSY set; t=%i iter=%i c=%i dc=%i irq=%i\n", + ace->fsm_task, ace->fsm_iter_num, + blk_rq_cur_sectors(ace->req) * 16, + ace->data_count, ace->in_irq); + ace_fsm_yield(ace); /* need to poll CFBSY bit */ + break; + } + if (!(status & ACE_STATUS_DATABUFRDY)) { + dev_dbg(ace->dev, + "DATABUF not set; t=%i iter=%i c=%i dc=%i irq=%i\n", + ace->fsm_task, ace->fsm_iter_num, + blk_rq_cur_sectors(ace->req) * 16, + ace->data_count, ace->in_irq); + ace_fsm_yieldirq(ace); + break; + } + + /* Transfer the next buffer */ + if (ace->fsm_task == ACE_TASK_WRITE) + ace->reg_ops->dataout(ace); + else + ace->reg_ops->datain(ace); + ace->data_count--; + + /* If there are still buffers to be transfers; jump out here */ + if (ace->data_count != 0) { + ace_fsm_yieldirq(ace); + break; + } + + /* bio finished; is there another one? */ + if (blk_update_request(ace->req, BLK_STS_OK, + blk_rq_cur_bytes(ace->req))) { + /* dev_dbg(ace->dev, "next block; h=%u c=%u\n", + * blk_rq_sectors(ace->req), + * blk_rq_cur_sectors(ace->req)); + */ + ace->data_ptr = bio_data(ace->req->bio); + ace->data_count = blk_rq_cur_sectors(ace->req) * 16; + ace_fsm_yieldirq(ace); + break; + } + + ace->fsm_state = ACE_FSM_STATE_REQ_COMPLETE; + break; + + case ACE_FSM_STATE_REQ_COMPLETE: + ace->req = NULL; + + /* Finished request; go to idle state */ + ace->fsm_state = ACE_FSM_STATE_IDLE; + break; + + default: + ace->fsm_state = ACE_FSM_STATE_IDLE; + break; + } +} + +static void ace_fsm_tasklet(unsigned long data) +{ + struct ace_device *ace = (void *)data; + unsigned long flags; + + spin_lock_irqsave(&ace->lock, flags); + + /* Loop over state machine until told to stop */ + ace->fsm_continue_flag = 1; + while (ace->fsm_continue_flag) + ace_fsm_dostate(ace); + + spin_unlock_irqrestore(&ace->lock, flags); +} + +static void ace_stall_timer(struct timer_list *t) +{ + struct ace_device *ace = from_timer(ace, t, stall_timer); + unsigned long flags; + + dev_warn(ace->dev, + "kicking stalled fsm; state=%i task=%i iter=%i dc=%i\n", + ace->fsm_state, ace->fsm_task, ace->fsm_iter_num, + ace->data_count); + spin_lock_irqsave(&ace->lock, flags); + + /* Rearm the stall timer *before* entering FSM (which may then + * delete the timer) */ + mod_timer(&ace->stall_timer, jiffies + HZ); + + /* Loop over state machine until told to stop */ + ace->fsm_continue_flag = 1; + while (ace->fsm_continue_flag) + ace_fsm_dostate(ace); + + spin_unlock_irqrestore(&ace->lock, flags); +} + +/* --------------------------------------------------------------------- + * Interrupt handling routines + */ +static int ace_interrupt_checkstate(struct ace_device *ace) +{ + u32 sreg = ace_in32(ace, ACE_STATUS); + u16 creg = ace_in(ace, ACE_CTRL); + + /* Check for error occurrence */ + if ((sreg & (ACE_STATUS_CFGERROR | ACE_STATUS_CFCERROR)) && + (creg & ACE_CTRL_ERRORIRQ)) { + dev_err(ace->dev, "transfer failure\n"); + ace_dump_regs(ace); + return -EIO; + } + + return 0; +} + +static irqreturn_t ace_interrupt(int irq, void *dev_id) +{ + u16 creg; + struct ace_device *ace = dev_id; + + /* be safe and get the lock */ + spin_lock(&ace->lock); + ace->in_irq = 1; + + /* clear the interrupt */ + creg = ace_in(ace, ACE_CTRL); + ace_out(ace, ACE_CTRL, creg | ACE_CTRL_RESETIRQ); + ace_out(ace, ACE_CTRL, creg); + + /* check for IO failures */ + if (ace_interrupt_checkstate(ace)) + ace->data_result = -EIO; + + if (ace->fsm_task == 0) { + dev_err(ace->dev, + "spurious irq; stat=%.8x ctrl=%.8x cmd=%.4x\n", + ace_in32(ace, ACE_STATUS), ace_in32(ace, ACE_CTRL), + ace_in(ace, ACE_SECCNTCMD)); + dev_err(ace->dev, "fsm_task=%i fsm_state=%i data_count=%i\n", + ace->fsm_task, ace->fsm_state, ace->data_count); + } + + /* Loop over state machine until told to stop */ + ace->fsm_continue_flag = 1; + while (ace->fsm_continue_flag) + ace_fsm_dostate(ace); + + /* done with interrupt; drop the lock */ + ace->in_irq = 0; + spin_unlock(&ace->lock); + + return IRQ_HANDLED; +} + +/* --------------------------------------------------------------------- + * Block ops + */ +static blk_status_t ace_queue_rq(struct blk_mq_hw_ctx *hctx, + const struct blk_mq_queue_data *bd) +{ + struct ace_device *ace = hctx->queue->queuedata; + struct request *req = bd->rq; + + if (blk_rq_is_passthrough(req)) { + blk_mq_start_request(req); + return BLK_STS_IOERR; + } + + spin_lock_irq(&ace->lock); + list_add_tail(&req->queuelist, &ace->rq_list); + spin_unlock_irq(&ace->lock); + + tasklet_schedule(&ace->fsm_tasklet); + return BLK_STS_OK; +} + +static unsigned int ace_check_events(struct gendisk *gd, unsigned int clearing) +{ + struct ace_device *ace = gd->private_data; + dev_dbg(ace->dev, "ace_check_events(): %i\n", ace->media_change); + + return ace->media_change ? DISK_EVENT_MEDIA_CHANGE : 0; +} + +static void ace_media_changed(struct ace_device *ace) +{ + unsigned long flags; + + dev_dbg(ace->dev, "requesting cf id and scheduling tasklet\n"); + + spin_lock_irqsave(&ace->lock, flags); + ace->id_req_count++; + spin_unlock_irqrestore(&ace->lock, flags); + + tasklet_schedule(&ace->fsm_tasklet); + wait_for_completion(&ace->id_completion); + + dev_dbg(ace->dev, "revalidate complete\n"); +} + +static int ace_open(struct block_device *bdev, fmode_t mode) +{ + struct ace_device *ace = bdev->bd_disk->private_data; + unsigned long flags; + + dev_dbg(ace->dev, "ace_open() users=%i\n", ace->users + 1); + + mutex_lock(&xsysace_mutex); + spin_lock_irqsave(&ace->lock, flags); + ace->users++; + spin_unlock_irqrestore(&ace->lock, flags); + + if (bdev_check_media_change(bdev) && ace->media_change) + ace_media_changed(ace); + mutex_unlock(&xsysace_mutex); + + return 0; +} + +static void ace_release(struct gendisk *disk, fmode_t mode) +{ + struct ace_device *ace = disk->private_data; + unsigned long flags; + u16 val; + + dev_dbg(ace->dev, "ace_release() users=%i\n", ace->users - 1); + + mutex_lock(&xsysace_mutex); + spin_lock_irqsave(&ace->lock, flags); + ace->users--; + if (ace->users == 0) { + val = ace_in(ace, ACE_CTRL); + ace_out(ace, ACE_CTRL, val & ~ACE_CTRL_LOCKREQ); + } + spin_unlock_irqrestore(&ace->lock, flags); + mutex_unlock(&xsysace_mutex); +} + +static int ace_getgeo(struct block_device *bdev, struct hd_geometry *geo) +{ + struct ace_device *ace = bdev->bd_disk->private_data; + u16 *cf_id = ace->cf_id; + + dev_dbg(ace->dev, "ace_getgeo()\n"); + + geo->heads = cf_id[ATA_ID_HEADS]; + geo->sectors = cf_id[ATA_ID_SECTORS]; + geo->cylinders = cf_id[ATA_ID_CYLS]; + + return 0; +} + +static const struct block_device_operations ace_fops = { + .owner = THIS_MODULE, + .open = ace_open, + .release = ace_release, + .check_events = ace_check_events, + .getgeo = ace_getgeo, +}; + +static const struct blk_mq_ops ace_mq_ops = { + .queue_rq = ace_queue_rq, +}; + +/* -------------------------------------------------------------------- + * SystemACE device setup/teardown code + */ +static int ace_setup(struct ace_device *ace) +{ + u16 version; + u16 val; + int rc; + + dev_dbg(ace->dev, "ace_setup(ace=0x%p)\n", ace); + dev_dbg(ace->dev, "physaddr=0x%llx irq=%i\n", + (unsigned long long)ace->physaddr, ace->irq); + + spin_lock_init(&ace->lock); + init_completion(&ace->id_completion); + INIT_LIST_HEAD(&ace->rq_list); + + /* + * Map the device + */ + ace->baseaddr = ioremap(ace->physaddr, 0x80); + if (!ace->baseaddr) + goto err_ioremap; + + /* + * Initialize the state machine tasklet and stall timer + */ + tasklet_init(&ace->fsm_tasklet, ace_fsm_tasklet, (unsigned long)ace); + timer_setup(&ace->stall_timer, ace_stall_timer, 0); + + /* + * Initialize the request queue + */ + ace->queue = blk_mq_init_sq_queue(&ace->tag_set, &ace_mq_ops, 2, + BLK_MQ_F_SHOULD_MERGE); + if (IS_ERR(ace->queue)) { + rc = PTR_ERR(ace->queue); + ace->queue = NULL; + goto err_blk_initq; + } + ace->queue->queuedata = ace; + + blk_queue_logical_block_size(ace->queue, 512); + blk_queue_bounce_limit(ace->queue, BLK_BOUNCE_HIGH); + + /* + * Allocate and initialize GD structure + */ + ace->gd = alloc_disk(ACE_NUM_MINORS); + if (!ace->gd) + goto err_alloc_disk; + + ace->gd->major = ace_major; + ace->gd->first_minor = ace->id * ACE_NUM_MINORS; + ace->gd->fops = &ace_fops; + ace->gd->events = DISK_EVENT_MEDIA_CHANGE; + ace->gd->queue = ace->queue; + ace->gd->private_data = ace; + snprintf(ace->gd->disk_name, 32, "xs%c", ace->id + 'a'); + + /* set bus width */ + if (ace->bus_width == ACE_BUS_WIDTH_16) { + /* 0x0101 should work regardless of endianess */ + ace_out_le16(ace, ACE_BUSMODE, 0x0101); + + /* read it back to determine endianess */ + if (ace_in_le16(ace, ACE_BUSMODE) == 0x0001) + ace->reg_ops = &ace_reg_le16_ops; + else + ace->reg_ops = &ace_reg_be16_ops; + } else { + ace_out_8(ace, ACE_BUSMODE, 0x00); + ace->reg_ops = &ace_reg_8_ops; + } + + /* Make sure version register is sane */ + version = ace_in(ace, ACE_VERSION); + if ((version == 0) || (version == 0xFFFF)) + goto err_read; + + /* Put sysace in a sane state by clearing most control reg bits */ + ace_out(ace, ACE_CTRL, ACE_CTRL_FORCECFGMODE | + ACE_CTRL_DATABUFRDYIRQ | ACE_CTRL_ERRORIRQ); + + /* Now we can hook up the irq handler */ + if (ace->irq > 0) { + rc = request_irq(ace->irq, ace_interrupt, 0, "systemace", ace); + if (rc) { + /* Failure - fall back to polled mode */ + dev_err(ace->dev, "request_irq failed\n"); + ace->irq = rc; + } + } + + /* Enable interrupts */ + val = ace_in(ace, ACE_CTRL); + val |= ACE_CTRL_DATABUFRDYIRQ | ACE_CTRL_ERRORIRQ; + ace_out(ace, ACE_CTRL, val); + + /* Print the identification */ + dev_info(ace->dev, "Xilinx SystemACE revision %i.%i.%i\n", + (version >> 12) & 0xf, (version >> 8) & 0x0f, version & 0xff); + dev_dbg(ace->dev, "physaddr 0x%llx, mapped to 0x%p, irq=%i\n", + (unsigned long long) ace->physaddr, ace->baseaddr, ace->irq); + + ace->media_change = 1; + ace_media_changed(ace); + + /* Make the sysace device 'live' */ + add_disk(ace->gd); + + return 0; + +err_read: + /* prevent double queue cleanup */ + ace->gd->queue = NULL; + put_disk(ace->gd); +err_alloc_disk: + blk_cleanup_queue(ace->queue); + blk_mq_free_tag_set(&ace->tag_set); +err_blk_initq: + iounmap(ace->baseaddr); +err_ioremap: + dev_info(ace->dev, "xsysace: error initializing device at 0x%llx\n", + (unsigned long long) ace->physaddr); + return -ENOMEM; +} + +static void ace_teardown(struct ace_device *ace) +{ + if (ace->gd) { + del_gendisk(ace->gd); + put_disk(ace->gd); + } + + if (ace->queue) { + blk_cleanup_queue(ace->queue); + blk_mq_free_tag_set(&ace->tag_set); + } + + tasklet_kill(&ace->fsm_tasklet); + + if (ace->irq > 0) + free_irq(ace->irq, ace); + + iounmap(ace->baseaddr); +} + +static int ace_alloc(struct device *dev, int id, resource_size_t physaddr, + int irq, int bus_width) +{ + struct ace_device *ace; + int rc; + dev_dbg(dev, "ace_alloc(%p)\n", dev); + + /* Allocate and initialize the ace device structure */ + ace = kzalloc(sizeof(struct ace_device), GFP_KERNEL); + if (!ace) { + rc = -ENOMEM; + goto err_alloc; + } + + ace->dev = dev; + ace->id = id; + ace->physaddr = physaddr; + ace->irq = irq; + ace->bus_width = bus_width; + + /* Call the setup code */ + rc = ace_setup(ace); + if (rc) + goto err_setup; + + dev_set_drvdata(dev, ace); + return 0; + +err_setup: + dev_set_drvdata(dev, NULL); + kfree(ace); +err_alloc: + dev_err(dev, "could not initialize device, err=%i\n", rc); + return rc; +} + +static void ace_free(struct device *dev) +{ + struct ace_device *ace = dev_get_drvdata(dev); + dev_dbg(dev, "ace_free(%p)\n", dev); + + if (ace) { + ace_teardown(ace); + dev_set_drvdata(dev, NULL); + kfree(ace); + } +} + +/* --------------------------------------------------------------------- + * Platform Bus Support + */ + +static int ace_probe(struct platform_device *dev) +{ + int bus_width = ACE_BUS_WIDTH_16; /* FIXME: should not be hard coded */ + resource_size_t physaddr; + struct resource *res; + u32 id = dev->id; + int irq; + int i; + + dev_dbg(&dev->dev, "ace_probe(%p)\n", dev); + + /* device id and bus width */ + if (of_property_read_u32(dev->dev.of_node, "port-number", &id)) + id = 0; + if (of_find_property(dev->dev.of_node, "8-bit", NULL)) + bus_width = ACE_BUS_WIDTH_8; + + res = platform_get_resource(dev, IORESOURCE_MEM, 0); + if (!res) + return -EINVAL; + + physaddr = res->start; + if (!physaddr) + return -ENODEV; + + irq = platform_get_irq_optional(dev, 0); + + /* Call the bus-independent setup code */ + return ace_alloc(&dev->dev, id, physaddr, irq, bus_width); +} + +/* + * Platform bus remove() method + */ +static int ace_remove(struct platform_device *dev) +{ + ace_free(&dev->dev); + return 0; +} + +#if defined(CONFIG_OF) +/* Match table for of_platform binding */ +static const struct of_device_id ace_of_match[] = { + { .compatible = "xlnx,opb-sysace-1.00.b", }, + { .compatible = "xlnx,opb-sysace-1.00.c", }, + { .compatible = "xlnx,xps-sysace-1.00.a", }, + { .compatible = "xlnx,sysace", }, + {}, +}; +MODULE_DEVICE_TABLE(of, ace_of_match); +#else /* CONFIG_OF */ +#define ace_of_match NULL +#endif /* CONFIG_OF */ + +static struct platform_driver ace_platform_driver = { + .probe = ace_probe, + .remove = ace_remove, + .driver = { + .name = "xsysace", + .of_match_table = ace_of_match, + }, +}; + +/* --------------------------------------------------------------------- + * Module init/exit routines + */ +static int __init ace_init(void) +{ + int rc; + + ace_major = register_blkdev(ace_major, "xsysace"); + if (ace_major <= 0) { + rc = -ENOMEM; + goto err_blk; + } + + rc = platform_driver_register(&ace_platform_driver); + if (rc) + goto err_plat; + + pr_info("Xilinx SystemACE device driver, major=%i\n", ace_major); + return 0; + +err_plat: + unregister_blkdev(ace_major, "xsysace"); +err_blk: + printk(KERN_ERR "xsysace: registration failed; err=%i\n", rc); + return rc; +} +module_init(ace_init); + +static void __exit ace_exit(void) +{ + pr_debug("Unregistering Xilinx SystemACE driver\n"); + platform_driver_unregister(&ace_platform_driver); + unregister_blkdev(ace_major, "xsysace"); +} +module_exit(ace_exit); |