| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Sven Van Asbroeck | 6486 | 99.92% | 4 | 80.00% |
| Nicholas Mc Guire | 5 | 0.08% | 1 | 20.00% |
| Total | 6491 | 5 |
// SPDX-License-Identifier: GPL-2.0 /* * HMS Anybus-S Host Driver * * Copyright (C) 2018 Arcx Inc */ /* * Architecture Overview * ===================== * This driver (running on the CPU/SoC) and the Anybus-S card communicate * by reading and writing data to/from the Anybus-S Dual-Port RAM (dpram). * This is memory connected to both the SoC and Anybus-S card, which both sides * can access freely and concurrently. * * Synchronization happens by means of two registers located in the dpram: * IND_AB: written exclusively by the Anybus card; and * IND_AP: written exclusively by this driver. * * Communication happens using one of the following mechanisms: * 1. reserve, read/write, release dpram memory areas: * using an IND_AB/IND_AP protocol, the driver is able to reserve certain * memory areas. no dpram memory can be read or written except if reserved. * (with a few limited exceptions) * 2. send and receive data structures via a shared mailbox: * using an IND_AB/IND_AP protocol, the driver and Anybus card are able to * exchange commands and responses using a shared mailbox. * 3. receive software interrupts: * using an IND_AB/IND_AP protocol, the Anybus card is able to notify the * driver of certain events such as: bus online/offline, data available. * note that software interrupt event bits are located in a memory area * which must be reserved before it can be accessed. * * The manual[1] is silent on whether these mechanisms can happen concurrently, * or how they should be synchronized. However, section 13 (Driver Example) * provides the following suggestion for developing a driver: * a) an interrupt handler which updates global variables; * b) a continuously-running task handling area requests (1 above) * c) a continuously-running task handling mailbox requests (2 above) * The example conspicuously leaves out software interrupts (3 above), which * is the thorniest issue to get right (see below). * * The naive, straightforward way to implement this would be: * - create an isr which updates shared variables; * - create a work_struct which handles software interrupts on a queue; * - create a function which does reserve/update/unlock in a loop; * - create a function which does mailbox send/receive in a loop; * - call the above functions from the driver's read/write/ioctl; * - synchronize using mutexes/spinlocks: * + only one area request at a time * + only one mailbox request at a time * + protect AB_IND, AB_IND against data hazards (e.g. read-after-write) * * Unfortunately, the presence of the software interrupt causes subtle yet * considerable synchronization issues; especially problematic is the * requirement to reserve/release the area which contains the status bits. * * The driver architecture presented here sidesteps these synchronization issues * by accessing the dpram from a single kernel thread only. User-space throws * "tasks" (i.e. 1, 2 above) into a task queue, waits for their completion, * and the kernel thread runs them to completion. * * Each task has a task_function, which is called/run by the queue thread. * That function communicates with the Anybus card, and returns either * 0 (OK), a negative error code (error), or -EINPROGRESS (waiting). * On OK or error, the queue thread completes and dequeues the task, * which also releases the user space thread which may still be waiting for it. * On -EINPROGRESS (waiting), the queue thread will leave the task on the queue, * and revisit (call again) whenever an interrupt event comes in. * * Each task has a state machine, which is run by calling its task_function. * It ensures that the task will go through its various stages over time, * returning -EINPROGRESS if it wants to wait for an event to happen. * * Note that according to the manual's driver example, the following operations * may run independent of each other: * - area reserve/read/write/release (point 1 above) * - mailbox operations (point 2 above) * - switching power on/off * * To allow them to run independently, each operation class gets its own queue. * * Userspace processes A, B, C, D post tasks to the appropriate queue, * and wait for task completion: * * process A B C D * | | | | * v v v v * |<----- ======================================== * | | | | * | v v v-------<-------+ * | +--------------------------------------+ | * | | power q | mbox q | area q | | * | |------------|------------|------------| | * | | task | task | task | | * | | task | task | task | | * | | task wait | task wait | task wait | | * | +--------------------------------------+ | * | ^ ^ ^ | * | | | | ^ * | +--------------------------------------+ | * | | queue thread | | * | |--------------------------------------| | * | | single-threaded: | | * | | loop: | | * v | for each queue: | | * | | run task state machine | | * | | if task waiting: | | * | | leave on queue | | * | | if task done: | | * | | complete task, remove from q | | * | | if software irq event bits set: | | * | | notify userspace | | * | | post clear event bits task------>|>-------+ * | | wait for IND_AB changed event OR | * | | task added event OR | * | | timeout | * | | end loop | * | +--------------------------------------+ * | + wake up + * | +--------------------------------------+ * | ^ ^ * | | | * +-------->------- | * | * +--------------------------------------+ * | interrupt service routine | * |--------------------------------------| * | wake up queue thread on IND_AB change| * +--------------------------------------+ * * Note that the Anybus interrupt is dual-purpose: * - after a reset, triggered when the card becomes ready; * - during normal operation, triggered when AB_IND changes. * This is why the interrupt service routine doesn't just wake up the * queue thread, but also completes the card_boot completion. * * [1] https://www.anybus.com/docs/librariesprovider7/default-document-library/ * manuals-design-guides/hms-hmsi-27-275.pdf */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/init.h> #include <linux/slab.h> #include <linux/interrupt.h> #include <linux/atomic.h> #include <linux/kthread.h> #include <linux/kfifo.h> #include <linux/spinlock.h> #include <linux/uaccess.h> #include <linux/regmap.h> #include <linux/of.h> #include <linux/random.h> #include <linux/kref.h> #include <linux/of_address.h> /* move to <linux/anybuss-*.h> when taking this out of staging */ #include "anybuss-client.h" #include "anybuss-controller.h" #define DPRAM_SIZE 0x800 #define MAX_MBOX_MSG_SZ 0x0FF #define TIMEOUT (HZ * 2) #define MAX_DATA_AREA_SZ 0x200 #define MAX_FBCTRL_AREA_SZ 0x1BE #define REG_BOOTLOADER_V 0x7C0 #define REG_API_V 0x7C2 #define REG_FIELDBUS_V 0x7C4 #define REG_SERIAL_NO 0x7C6 #define REG_FIELDBUS_TYPE 0x7CC #define REG_MODULE_SW_V 0x7CE #define REG_IND_AB 0x7FF #define REG_IND_AP 0x7FE #define REG_EVENT_CAUSE 0x7ED #define MBOX_IN_AREA 0x400 #define MBOX_OUT_AREA 0x520 #define DATA_IN_AREA 0x000 #define DATA_OUT_AREA 0x200 #define FBCTRL_AREA 0x640 #define EVENT_CAUSE_DC 0x01 #define EVENT_CAUSE_FBOF 0x02 #define EVENT_CAUSE_FBON 0x04 #define IND_AB_UPDATED 0x08 #define IND_AX_MIN 0x80 #define IND_AX_MOUT 0x40 #define IND_AX_IN 0x04 #define IND_AX_OUT 0x02 #define IND_AX_FBCTRL 0x01 #define IND_AP_LOCK 0x08 #define IND_AP_ACTION 0x10 #define IND_AX_EVNT 0x20 #define IND_AP_ABITS (IND_AX_IN | IND_AX_OUT | \ IND_AX_FBCTRL | \ IND_AP_ACTION | IND_AP_LOCK) #define INFO_TYPE_FB 0x0002 #define INFO_TYPE_APP 0x0001 #define INFO_COMMAND 0x4000 #define OP_MODE_FBFC 0x0002 #define OP_MODE_FBS 0x0004 #define OP_MODE_CD 0x0200 #define CMD_START_INIT 0x0001 #define CMD_ANYBUS_INIT 0x0002 #define CMD_END_INIT 0x0003 /* * --------------------------------------------------------------- * Anybus mailbox messages - definitions * --------------------------------------------------------------- * note that we're depending on the layout of these structures being * exactly as advertised. */ struct anybus_mbox_hdr { __be16 id; __be16 info; __be16 cmd_num; __be16 data_size; __be16 frame_count; __be16 frame_num; __be16 offset_high; __be16 offset_low; __be16 extended[8]; }; struct msg_anybus_init { __be16 input_io_len; __be16 input_dpram_len; __be16 input_total_len; __be16 output_io_len; __be16 output_dpram_len; __be16 output_total_len; __be16 op_mode; __be16 notif_config; __be16 wd_val; }; /* ------------- ref counted tasks ------------- */ struct ab_task; typedef int (*ab_task_fn_t)(struct anybuss_host *cd, struct ab_task *t); typedef void (*ab_done_fn_t)(struct anybuss_host *cd); struct area_priv { bool is_write; u16 flags; u16 addr; size_t count; u8 buf[MAX_DATA_AREA_SZ]; }; struct mbox_priv { struct anybus_mbox_hdr hdr; size_t msg_out_sz; size_t msg_in_sz; u8 msg[MAX_MBOX_MSG_SZ]; }; struct ab_task { struct kmem_cache *cache; struct kref refcount; ab_task_fn_t task_fn; ab_done_fn_t done_fn; int result; struct completion done; unsigned long start_jiffies; union { struct area_priv area_pd; struct mbox_priv mbox_pd; }; }; static struct ab_task *ab_task_create_get(struct kmem_cache *cache, ab_task_fn_t task_fn) { struct ab_task *t; t = kmem_cache_alloc(cache, GFP_KERNEL); if (!t) return NULL; t->cache = cache; kref_init(&t->refcount); t->task_fn = task_fn; t->done_fn = NULL; t->result = 0; init_completion(&t->done); return t; } static void __ab_task_destroy(struct kref *refcount) { struct ab_task *t = container_of(refcount, struct ab_task, refcount); struct kmem_cache *cache = t->cache; kmem_cache_free(cache, t); } static void ab_task_put(struct ab_task *t) { kref_put(&t->refcount, __ab_task_destroy); } static struct ab_task *__ab_task_get(struct ab_task *t) { kref_get(&t->refcount); return t; } static void __ab_task_finish(struct ab_task *t, struct anybuss_host *cd) { if (t->done_fn) t->done_fn(cd); complete(&t->done); } static void ab_task_dequeue_finish_put(struct kfifo *q, struct anybuss_host *cd) { int ret; struct ab_task *t; ret = kfifo_out(q, &t, sizeof(t)); WARN_ON(!ret); __ab_task_finish(t, cd); ab_task_put(t); } static int ab_task_enqueue(struct ab_task *t, struct kfifo *q, spinlock_t *slock, wait_queue_head_t *wq) { int ret; t->start_jiffies = jiffies; __ab_task_get(t); ret = kfifo_in_spinlocked(q, &t, sizeof(t), slock); if (!ret) { ab_task_put(t); return -ENOMEM; } wake_up(wq); return 0; } static int ab_task_enqueue_wait(struct ab_task *t, struct kfifo *q, spinlock_t *slock, wait_queue_head_t *wq) { int ret; ret = ab_task_enqueue(t, q, slock, wq); if (ret) return ret; ret = wait_for_completion_interruptible(&t->done); if (ret) return ret; return t->result; } /* ------------------------ anybus hardware ------------------------ */ struct anybuss_host { struct device *dev; struct anybuss_client *client; void (*reset)(struct device *dev, bool assert); struct regmap *regmap; int irq; int host_idx; struct task_struct *qthread; wait_queue_head_t wq; struct completion card_boot; atomic_t ind_ab; spinlock_t qlock; /* protects IN side of powerq, mboxq, areaq */ struct kmem_cache *qcache; struct kfifo qs[3]; struct kfifo *powerq; struct kfifo *mboxq; struct kfifo *areaq; bool power_on; bool softint_pending; }; static void reset_assert(struct anybuss_host *cd) { cd->reset(cd->dev, true); } static void reset_deassert(struct anybuss_host *cd) { cd->reset(cd->dev, false); } static int test_dpram(struct regmap *regmap) { int i; unsigned int val; for (i = 0; i < DPRAM_SIZE; i++) regmap_write(regmap, i, (u8)i); for (i = 0; i < DPRAM_SIZE; i++) { regmap_read(regmap, i, &val); if ((u8)val != (u8)i) return -EIO; } return 0; } static int read_ind_ab(struct regmap *regmap) { unsigned long timeout = jiffies + HZ / 2; unsigned int a, b, i = 0; while (time_before_eq(jiffies, timeout)) { regmap_read(regmap, REG_IND_AB, &a); regmap_read(regmap, REG_IND_AB, &b); if (likely(a == b)) return (int)a; if (i < 10) { cpu_relax(); i++; } else { usleep_range(500, 1000); } } WARN(1, "IND_AB register not stable"); return -ETIMEDOUT; } static int write_ind_ap(struct regmap *regmap, unsigned int ind_ap) { unsigned long timeout = jiffies + HZ / 2; unsigned int v, i = 0; while (time_before_eq(jiffies, timeout)) { regmap_write(regmap, REG_IND_AP, ind_ap); regmap_read(regmap, REG_IND_AP, &v); if (likely(ind_ap == v)) return 0; if (i < 10) { cpu_relax(); i++; } else { usleep_range(500, 1000); } } WARN(1, "IND_AP register not stable"); return -ETIMEDOUT; } static irqreturn_t irq_handler(int irq, void *data) { struct anybuss_host *cd = data; int ind_ab; /* * irq handler needs exclusive access to the IND_AB register, * because the act of reading the register acks the interrupt. * * store the register value in cd->ind_ab (an atomic_t), so that the * queue thread is able to read it without causing an interrupt ack * side-effect (and without spuriously acking an interrupt). */ ind_ab = read_ind_ab(cd->regmap); if (ind_ab < 0) return IRQ_NONE; atomic_set(&cd->ind_ab, ind_ab); complete(&cd->card_boot); wake_up(&cd->wq); return IRQ_HANDLED; } /* ------------------------ power on/off tasks --------------------- */ static int task_fn_power_off(struct anybuss_host *cd, struct ab_task *t) { struct anybuss_client *client = cd->client; if (!cd->power_on) return 0; disable_irq(cd->irq); reset_assert(cd); atomic_set(&cd->ind_ab, IND_AB_UPDATED); if (client->on_online_changed) client->on_online_changed(client, false); cd->power_on = false; return 0; } static int task_fn_power_on_2(struct anybuss_host *cd, struct ab_task *t) { if (completion_done(&cd->card_boot)) { cd->power_on = true; return 0; } if (time_after(jiffies, t->start_jiffies + TIMEOUT)) { disable_irq(cd->irq); reset_assert(cd); dev_err(cd->dev, "power on timed out"); return -ETIMEDOUT; } return -EINPROGRESS; } static int task_fn_power_on(struct anybuss_host *cd, struct ab_task *t) { unsigned int dummy; if (cd->power_on) return 0; /* * anybus docs: prevent false 'init done' interrupt by * doing a dummy read of IND_AB register while in reset. */ regmap_read(cd->regmap, REG_IND_AB, &dummy); reinit_completion(&cd->card_boot); enable_irq(cd->irq); reset_deassert(cd); t->task_fn = task_fn_power_on_2; return -EINPROGRESS; } int anybuss_set_power(struct anybuss_client *client, bool power_on) { struct anybuss_host *cd = client->host; struct ab_task *t; int err; t = ab_task_create_get(cd->qcache, power_on ? task_fn_power_on : task_fn_power_off); if (!t) return -ENOMEM; err = ab_task_enqueue_wait(t, cd->powerq, &cd->qlock, &cd->wq); ab_task_put(t); return err; } EXPORT_SYMBOL_GPL(anybuss_set_power); /* ---------------------------- area tasks ------------------------ */ static int task_fn_area_3(struct anybuss_host *cd, struct ab_task *t) { struct area_priv *pd = &t->area_pd; if (!cd->power_on) return -EIO; if (atomic_read(&cd->ind_ab) & pd->flags) { /* area not released yet */ if (time_after(jiffies, t->start_jiffies + TIMEOUT)) return -ETIMEDOUT; return -EINPROGRESS; } return 0; } static int task_fn_area_2(struct anybuss_host *cd, struct ab_task *t) { struct area_priv *pd = &t->area_pd; unsigned int ind_ap; int ret; if (!cd->power_on) return -EIO; regmap_read(cd->regmap, REG_IND_AP, &ind_ap); if (!(atomic_read(&cd->ind_ab) & pd->flags)) { /* we don't own the area yet */ if (time_after(jiffies, t->start_jiffies + TIMEOUT)) { dev_warn(cd->dev, "timeout waiting for area"); dump_stack(); return -ETIMEDOUT; } return -EINPROGRESS; } /* we own the area, do what we're here to do */ if (pd->is_write) regmap_bulk_write(cd->regmap, pd->addr, pd->buf, pd->count); else regmap_bulk_read(cd->regmap, pd->addr, pd->buf, pd->count); /* ask to release the area, must use unlocked release */ ind_ap &= ~IND_AP_ABITS; ind_ap |= pd->flags; ret = write_ind_ap(cd->regmap, ind_ap); if (ret) return ret; t->task_fn = task_fn_area_3; return -EINPROGRESS; } static int task_fn_area(struct anybuss_host *cd, struct ab_task *t) { struct area_priv *pd = &t->area_pd; unsigned int ind_ap; int ret; if (!cd->power_on) return -EIO; regmap_read(cd->regmap, REG_IND_AP, &ind_ap); /* ask to take the area */ ind_ap &= ~IND_AP_ABITS; ind_ap |= pd->flags | IND_AP_ACTION | IND_AP_LOCK; ret = write_ind_ap(cd->regmap, ind_ap); if (ret) return ret; t->task_fn = task_fn_area_2; return -EINPROGRESS; } static struct ab_task * create_area_reader(struct kmem_cache *qcache, u16 flags, u16 addr, size_t count) { struct ab_task *t; struct area_priv *ap; t = ab_task_create_get(qcache, task_fn_area); if (!t) return NULL; ap = &t->area_pd; ap->flags = flags; ap->addr = addr; ap->is_write = false; ap->count = count; return t; } static struct ab_task * create_area_writer(struct kmem_cache *qcache, u16 flags, u16 addr, const void *buf, size_t count) { struct ab_task *t; struct area_priv *ap; t = ab_task_create_get(qcache, task_fn_area); if (!t) return NULL; ap = &t->area_pd; ap->flags = flags; ap->addr = addr; ap->is_write = true; ap->count = count; memcpy(ap->buf, buf, count); return t; } static struct ab_task * create_area_user_writer(struct kmem_cache *qcache, u16 flags, u16 addr, const void __user *buf, size_t count) { struct ab_task *t; struct area_priv *ap; t = ab_task_create_get(qcache, task_fn_area); if (!t) return ERR_PTR(-ENOMEM); ap = &t->area_pd; ap->flags = flags; ap->addr = addr; ap->is_write = true; ap->count = count; if (copy_from_user(ap->buf, buf, count)) { ab_task_put(t); return ERR_PTR(-EFAULT); } return t; } static bool area_range_ok(u16 addr, size_t count, u16 area_start, size_t area_sz) { u16 area_end_ex = area_start + area_sz; u16 addr_end_ex; if (addr < area_start) return false; if (addr >= area_end_ex) return false; addr_end_ex = addr + count; if (addr_end_ex > area_end_ex) return false; return true; } /* -------------------------- mailbox tasks ----------------------- */ static int task_fn_mbox_2(struct anybuss_host *cd, struct ab_task *t) { struct mbox_priv *pd = &t->mbox_pd; unsigned int ind_ap; if (!cd->power_on) return -EIO; regmap_read(cd->regmap, REG_IND_AP, &ind_ap); if (((atomic_read(&cd->ind_ab) ^ ind_ap) & IND_AX_MOUT) == 0) { /* output message not here */ if (time_after(jiffies, t->start_jiffies + TIMEOUT)) return -ETIMEDOUT; return -EINPROGRESS; } /* grab the returned header and msg */ regmap_bulk_read(cd->regmap, MBOX_OUT_AREA, &pd->hdr, sizeof(pd->hdr)); regmap_bulk_read(cd->regmap, MBOX_OUT_AREA + sizeof(pd->hdr), pd->msg, pd->msg_in_sz); /* tell anybus we've consumed the message */ ind_ap ^= IND_AX_MOUT; return write_ind_ap(cd->regmap, ind_ap); } static int task_fn_mbox(struct anybuss_host *cd, struct ab_task *t) { struct mbox_priv *pd = &t->mbox_pd; unsigned int ind_ap; int ret; if (!cd->power_on) return -EIO; regmap_read(cd->regmap, REG_IND_AP, &ind_ap); if ((atomic_read(&cd->ind_ab) ^ ind_ap) & IND_AX_MIN) { /* mbox input area busy */ if (time_after(jiffies, t->start_jiffies + TIMEOUT)) return -ETIMEDOUT; return -EINPROGRESS; } /* write the header and msg to input area */ regmap_bulk_write(cd->regmap, MBOX_IN_AREA, &pd->hdr, sizeof(pd->hdr)); regmap_bulk_write(cd->regmap, MBOX_IN_AREA + sizeof(pd->hdr), pd->msg, pd->msg_out_sz); /* tell anybus we gave it a message */ ind_ap ^= IND_AX_MIN; ret = write_ind_ap(cd->regmap, ind_ap); if (ret) return ret; t->start_jiffies = jiffies; t->task_fn = task_fn_mbox_2; return -EINPROGRESS; } static void log_invalid_other(struct device *dev, struct anybus_mbox_hdr *hdr) { size_t ext_offs = ARRAY_SIZE(hdr->extended) - 1; u16 code = be16_to_cpu(hdr->extended[ext_offs]); dev_err(dev, " Invalid other: [0x%02X]", code); } static const char * const EMSGS[] = { "Invalid Message ID", "Invalid Message Type", "Invalid Command", "Invalid Data Size", "Message Header Malformed (offset 008h)", "Message Header Malformed (offset 00Ah)", "Message Header Malformed (offset 00Ch - 00Dh)", "Invalid Address", "Invalid Response", "Flash Config Error", }; static int mbox_cmd_err(struct device *dev, struct mbox_priv *mpriv) { int i; u8 ecode; struct anybus_mbox_hdr *hdr = &mpriv->hdr; u16 info = be16_to_cpu(hdr->info); u8 *phdr = (u8 *)hdr; u8 *pmsg = mpriv->msg; if (!(info & 0x8000)) return 0; ecode = (info >> 8) & 0x0F; dev_err(dev, "mailbox command failed:"); if (ecode == 0x0F) log_invalid_other(dev, hdr); else if (ecode < ARRAY_SIZE(EMSGS)) dev_err(dev, " Error code: %s (0x%02X)", EMSGS[ecode], ecode); else dev_err(dev, " Error code: 0x%02X\n", ecode); dev_err(dev, "Failed command:"); dev_err(dev, "Message Header:"); for (i = 0; i < sizeof(mpriv->hdr); i += 2) dev_err(dev, "%02X%02X", phdr[i], phdr[i + 1]); dev_err(dev, "Message Data:"); for (i = 0; i < mpriv->msg_in_sz; i += 2) dev_err(dev, "%02X%02X", pmsg[i], pmsg[i + 1]); dev_err(dev, "Stack dump:"); dump_stack(); return -EIO; } static int _anybus_mbox_cmd(struct anybuss_host *cd, u16 cmd_num, bool is_fb_cmd, const void *msg_out, size_t msg_out_sz, void *msg_in, size_t msg_in_sz, const void *ext, size_t ext_sz) { struct ab_task *t; struct mbox_priv *pd; struct anybus_mbox_hdr *h; size_t msg_sz = max(msg_in_sz, msg_out_sz); u16 info; int err; if (msg_sz > MAX_MBOX_MSG_SZ) return -EINVAL; if (ext && ext_sz > sizeof(h->extended)) return -EINVAL; t = ab_task_create_get(cd->qcache, task_fn_mbox); if (!t) return -ENOMEM; pd = &t->mbox_pd; h = &pd->hdr; info = is_fb_cmd ? INFO_TYPE_FB : INFO_TYPE_APP; /* * prevent uninitialized memory in the header from being sent * across the anybus */ memset(h, 0, sizeof(*h)); h->info = cpu_to_be16(info | INFO_COMMAND); h->cmd_num = cpu_to_be16(cmd_num); h->data_size = cpu_to_be16(msg_out_sz); h->frame_count = cpu_to_be16(1); h->frame_num = cpu_to_be16(1); h->offset_high = cpu_to_be16(0); h->offset_low = cpu_to_be16(0); if (ext) memcpy(h->extended, ext, ext_sz); memcpy(pd->msg, msg_out, msg_out_sz); pd->msg_out_sz = msg_out_sz; pd->msg_in_sz = msg_in_sz; err = ab_task_enqueue_wait(t, cd->powerq, &cd->qlock, &cd->wq); if (err) goto out; /* * mailbox mechanism worked ok, but maybe the mbox response * contains an error ? */ err = mbox_cmd_err(cd->dev, pd); if (err) goto out; memcpy(msg_in, pd->msg, msg_in_sz); out: ab_task_put(t); return err; } /* ------------------------ anybus queues ------------------------ */ static void process_q(struct anybuss_host *cd, struct kfifo *q) { struct ab_task *t; int ret; ret = kfifo_out_peek(q, &t, sizeof(t)); if (!ret) return; t->result = t->task_fn(cd, t); if (t->result != -EINPROGRESS) ab_task_dequeue_finish_put(q, cd); } static bool qs_have_work(struct kfifo *qs, size_t num) { size_t i; struct ab_task *t; int ret; for (i = 0; i < num; i++, qs++) { ret = kfifo_out_peek(qs, &t, sizeof(t)); if (ret && (t->result != -EINPROGRESS)) return true; } return false; } static void process_qs(struct anybuss_host *cd) { size_t i; struct kfifo *qs = cd->qs; size_t nqs = ARRAY_SIZE(cd->qs); for (i = 0; i < nqs; i++, qs++) process_q(cd, qs); } static void softint_ack(struct anybuss_host *cd) { unsigned int ind_ap; cd->softint_pending = false; if (!cd->power_on) return; regmap_read(cd->regmap, REG_IND_AP, &ind_ap); ind_ap &= ~IND_AX_EVNT; ind_ap |= atomic_read(&cd->ind_ab) & IND_AX_EVNT; write_ind_ap(cd->regmap, ind_ap); } static void process_softint(struct anybuss_host *cd) { struct anybuss_client *client = cd->client; static const u8 zero; int ret; unsigned int ind_ap, ev; struct ab_task *t; if (!cd->power_on) return; if (cd->softint_pending) return; regmap_read(cd->regmap, REG_IND_AP, &ind_ap); if (!((atomic_read(&cd->ind_ab) ^ ind_ap) & IND_AX_EVNT)) return; /* process software interrupt */ regmap_read(cd->regmap, REG_EVENT_CAUSE, &ev); if (ev & EVENT_CAUSE_FBON) { if (client->on_online_changed) client->on_online_changed(client, true); dev_dbg(cd->dev, "Fieldbus ON"); } if (ev & EVENT_CAUSE_FBOF) { if (client->on_online_changed) client->on_online_changed(client, false); dev_dbg(cd->dev, "Fieldbus OFF"); } if (ev & EVENT_CAUSE_DC) { if (client->on_area_updated) client->on_area_updated(client); dev_dbg(cd->dev, "Fieldbus data changed"); } /* * reset the event cause bits. * this must be done while owning the fbctrl area, so we'll * enqueue a task to do that. */ t = create_area_writer(cd->qcache, IND_AX_FBCTRL, REG_EVENT_CAUSE, &zero, sizeof(zero)); if (!t) { ret = -ENOMEM; goto out; } t->done_fn = softint_ack; ret = ab_task_enqueue(t, cd->powerq, &cd->qlock, &cd->wq); ab_task_put(t); cd->softint_pending = true; out: WARN_ON(ret); if (ret) softint_ack(cd); } static int qthread_fn(void *data) { struct anybuss_host *cd = data; struct kfifo *qs = cd->qs; size_t nqs = ARRAY_SIZE(cd->qs); unsigned int ind_ab; /* * this kernel thread has exclusive access to the anybus's memory. * only exception: the IND_AB register, which is accessed exclusively * by the interrupt service routine (ISR). This thread must not touch * the IND_AB register, but it does require access to its value. * * the interrupt service routine stores the register's value in * cd->ind_ab (an atomic_t), where we may safely access it, with the * understanding that it can be modified by the ISR at any time. */ while (!kthread_should_stop()) { /* * make a local copy of IND_AB, so we can go around the loop * again in case it changed while processing queues and softint. */ ind_ab = atomic_read(&cd->ind_ab); process_qs(cd); process_softint(cd); wait_event_timeout(cd->wq, (atomic_read(&cd->ind_ab) != ind_ab) || qs_have_work(qs, nqs) || kthread_should_stop(), HZ); /* * time out so even 'stuck' tasks will run eventually, * and can time out. */ } return 0; } /* ------------------------ anybus exports ------------------------ */ int anybuss_start_init(struct anybuss_client *client, const struct anybuss_memcfg *cfg) { int ret; u16 op_mode; struct anybuss_host *cd = client->host; struct msg_anybus_init msg = { .input_io_len = cpu_to_be16(cfg->input_io), .input_dpram_len = cpu_to_be16(cfg->input_dpram), .input_total_len = cpu_to_be16(cfg->input_total), .output_io_len = cpu_to_be16(cfg->output_io), .output_dpram_len = cpu_to_be16(cfg->output_dpram), .output_total_len = cpu_to_be16(cfg->output_total), .notif_config = cpu_to_be16(0x000F), .wd_val = cpu_to_be16(0), }; switch (cfg->offl_mode) { case FIELDBUS_DEV_OFFL_MODE_CLEAR: op_mode = 0; break; case FIELDBUS_DEV_OFFL_MODE_FREEZE: op_mode = OP_MODE_FBFC; break; case FIELDBUS_DEV_OFFL_MODE_SET: op_mode = OP_MODE_FBS; break; default: return -EINVAL; } msg.op_mode = cpu_to_be16(op_mode | OP_MODE_CD); ret = _anybus_mbox_cmd(cd, CMD_START_INIT, false, NULL, 0, NULL, 0, NULL, 0); if (ret) return ret; return _anybus_mbox_cmd(cd, CMD_ANYBUS_INIT, false, &msg, sizeof(msg), NULL, 0, NULL, 0); } EXPORT_SYMBOL_GPL(anybuss_start_init); int anybuss_finish_init(struct anybuss_client *client) { struct anybuss_host *cd = client->host; return _anybus_mbox_cmd(cd, CMD_END_INIT, false, NULL, 0, NULL, 0, NULL, 0); } EXPORT_SYMBOL_GPL(anybuss_finish_init); int anybuss_read_fbctrl(struct anybuss_client *client, u16 addr, void *buf, size_t count) { struct anybuss_host *cd = client->host; struct ab_task *t; int ret; if (count == 0) return 0; if (!area_range_ok(addr, count, FBCTRL_AREA, MAX_FBCTRL_AREA_SZ)) return -EFAULT; t = create_area_reader(cd->qcache, IND_AX_FBCTRL, addr, count); if (!t) return -ENOMEM; ret = ab_task_enqueue_wait(t, cd->powerq, &cd->qlock, &cd->wq); if (ret) goto out; memcpy(buf, t->area_pd.buf, count); out: ab_task_put(t); return ret; } EXPORT_SYMBOL_GPL(anybuss_read_fbctrl); int anybuss_write_input(struct anybuss_client *client, const char __user *buf, size_t size, loff_t *offset) { ssize_t len = min_t(loff_t, MAX_DATA_AREA_SZ - *offset, size); struct anybuss_host *cd = client->host; struct ab_task *t; int ret; if (len <= 0) return 0; t = create_area_user_writer(cd->qcache, IND_AX_IN, DATA_IN_AREA + *offset, buf, len); if (IS_ERR(t)) return PTR_ERR(t); ret = ab_task_enqueue_wait(t, cd->powerq, &cd->qlock, &cd->wq); ab_task_put(t); if (ret) return ret; /* success */ *offset += len; return len; } EXPORT_SYMBOL_GPL(anybuss_write_input); int anybuss_read_output(struct anybuss_client *client, char __user *buf, size_t size, loff_t *offset) { ssize_t len = min_t(loff_t, MAX_DATA_AREA_SZ - *offset, size); struct anybuss_host *cd = client->host; struct ab_task *t; int ret; if (len <= 0) return 0; t = create_area_reader(cd->qcache, IND_AX_OUT, DATA_OUT_AREA + *offset, len); if (!t) return -ENOMEM; ret = ab_task_enqueue_wait(t, cd->powerq, &cd->qlock, &cd->wq); if (ret) goto out; if (copy_to_user(buf, t->area_pd.buf, len)) ret = -EFAULT; out: ab_task_put(t); if (ret) return ret; /* success */ *offset += len; return len; } EXPORT_SYMBOL_GPL(anybuss_read_output); int anybuss_send_msg(struct anybuss_client *client, u16 cmd_num, const void *buf, size_t count) { struct anybuss_host *cd = client->host; return _anybus_mbox_cmd(cd, cmd_num, true, buf, count, NULL, 0, NULL, 0); } EXPORT_SYMBOL_GPL(anybuss_send_msg); int anybuss_send_ext(struct anybuss_client *client, u16 cmd_num, const void *buf, size_t count) { struct anybuss_host *cd = client->host; return _anybus_mbox_cmd(cd, cmd_num, true, NULL, 0, NULL, 0, buf, count); } EXPORT_SYMBOL_GPL(anybuss_send_ext); int anybuss_recv_msg(struct anybuss_client *client, u16 cmd_num, void *buf, size_t count) { struct anybuss_host *cd = client->host; return _anybus_mbox_cmd(cd, cmd_num, true, NULL, 0, buf, count, NULL, 0); } EXPORT_SYMBOL_GPL(anybuss_recv_msg); /* ------------------------ bus functions ------------------------ */ static int anybus_bus_match(struct device *dev, struct device_driver *drv) { struct anybuss_client_driver *adrv = to_anybuss_client_driver(drv); struct anybuss_client *adev = to_anybuss_client(dev); return adrv->anybus_id == be16_to_cpu(adev->anybus_id); } static int anybus_bus_probe(struct device *dev) { struct anybuss_client_driver *adrv = to_anybuss_client_driver(dev->driver); struct anybuss_client *adev = to_anybuss_client(dev); if (!adrv->probe) return -ENODEV; return adrv->probe(adev); } static int anybus_bus_remove(struct device *dev) { struct anybuss_client_driver *adrv = to_anybuss_client_driver(dev->driver); if (adrv->remove) return adrv->remove(to_anybuss_client(dev)); return 0; } static struct bus_type anybus_bus = { .name = "anybuss", .match = anybus_bus_match, .probe = anybus_bus_probe, .remove = anybus_bus_remove, }; int anybuss_client_driver_register(struct anybuss_client_driver *drv) { drv->driver.bus = &anybus_bus; return driver_register(&drv->driver); } EXPORT_SYMBOL_GPL(anybuss_client_driver_register); void anybuss_client_driver_unregister(struct anybuss_client_driver *drv) { return driver_unregister(&drv->driver); } EXPORT_SYMBOL_GPL(anybuss_client_driver_unregister); static void client_device_release(struct device *dev) { kfree(to_anybuss_client(dev)); } static int taskq_alloc(struct device *dev, struct kfifo *q) { void *buf; size_t size = 64 * sizeof(struct ab_task *); buf = devm_kzalloc(dev, size, GFP_KERNEL); if (!buf) return -EIO; return kfifo_init(q, buf, size); } static int anybus_of_get_host_idx(struct device_node *np) { const __be32 *host_idx; host_idx = of_get_address(np, 0, NULL, NULL); if (!host_idx) return -ENOENT; return __be32_to_cpu(*host_idx); } static struct device_node * anybus_of_find_child_device(struct device *dev, int host_idx) { struct device_node *node; if (!dev || !dev->of_node) return NULL; for_each_child_of_node(dev->of_node, node) { if (anybus_of_get_host_idx(node) == host_idx) return node; } return NULL; } struct anybuss_host * __must_check anybuss_host_common_probe(struct device *dev, const struct anybuss_ops *ops) { int ret, i; u8 val[4]; __be16 fieldbus_type; struct anybuss_host *cd; cd = devm_kzalloc(dev, sizeof(*cd), GFP_KERNEL); if (!cd) return ERR_PTR(-ENOMEM); cd->dev = dev; cd->host_idx = ops->host_idx; init_completion(&cd->card_boot); init_waitqueue_head(&cd->wq); for (i = 0; i < ARRAY_SIZE(cd->qs); i++) { ret = taskq_alloc(dev, &cd->qs[i]); if (ret) return ERR_PTR(ret); } if (WARN_ON(ARRAY_SIZE(cd->qs) < 3)) return ERR_PTR(-EINVAL); cd->powerq = &cd->qs[0]; cd->mboxq = &cd->qs[1]; cd->areaq = &cd->qs[2]; cd->reset = ops->reset; if (!cd->reset) return ERR_PTR(-EINVAL); cd->regmap = ops->regmap; if (!cd->regmap) return ERR_PTR(-EINVAL); spin_lock_init(&cd->qlock); cd->qcache = kmem_cache_create(dev_name(dev), sizeof(struct ab_task), 0, 0, NULL); if (!cd->qcache) return ERR_PTR(-ENOMEM); cd->irq = ops->irq; if (cd->irq <= 0) { ret = -EINVAL; goto err_qcache; } /* * use a dpram test to check if a card is present, this is only * possible while in reset. */ reset_assert(cd); if (test_dpram(cd->regmap)) { dev_err(dev, "no Anybus-S card in slot"); ret = -ENODEV; goto err_qcache; } ret = devm_request_threaded_irq(dev, cd->irq, NULL, irq_handler, IRQF_ONESHOT, dev_name(dev), cd); if (ret) { dev_err(dev, "could not request irq"); goto err_qcache; } /* * startup sequence: * perform dummy IND_AB read to prevent false 'init done' irq * (already done by test_dpram() above) * release reset * wait for first interrupt * interrupt came in: ready to go ! */ reset_deassert(cd); if (!wait_for_completion_timeout(&cd->card_boot, TIMEOUT)) { ret = -ETIMEDOUT; goto err_reset; } /* * according to the anybus docs, we're allowed to read these * without handshaking / reserving the area */ dev_info(dev, "Anybus-S card detected"); regmap_bulk_read(cd->regmap, REG_BOOTLOADER_V, val, 2); dev_info(dev, "Bootloader version: %02X%02X", val[0], val[1]); regmap_bulk_read(cd->regmap, REG_API_V, val, 2); dev_info(dev, "API version: %02X%02X", val[0], val[1]); regmap_bulk_read(cd->regmap, REG_FIELDBUS_V, val, 2); dev_info(dev, "Fieldbus version: %02X%02X", val[0], val[1]); regmap_bulk_read(cd->regmap, REG_SERIAL_NO, val, 4); dev_info(dev, "Serial number: %02X%02X%02X%02X", val[0], val[1], val[2], val[3]); add_device_randomness(&val, 4); regmap_bulk_read(cd->regmap, REG_FIELDBUS_TYPE, &fieldbus_type, sizeof(fieldbus_type)); dev_info(dev, "Fieldbus type: %04X", be16_to_cpu(fieldbus_type)); regmap_bulk_read(cd->regmap, REG_MODULE_SW_V, val, 2); dev_info(dev, "Module SW version: %02X%02X", val[0], val[1]); /* put card back reset until a client driver releases it */ disable_irq(cd->irq); reset_assert(cd); atomic_set(&cd->ind_ab, IND_AB_UPDATED); /* fire up the queue thread */ cd->qthread = kthread_run(qthread_fn, cd, dev_name(dev)); if (IS_ERR(cd->qthread)) { dev_err(dev, "could not create kthread"); ret = PTR_ERR(cd->qthread); goto err_reset; } /* * now advertise that we've detected a client device (card). * the bus infrastructure will match it to a client driver. */ cd->client = kzalloc(sizeof(*cd->client), GFP_KERNEL); if (!cd->client) { ret = -ENOMEM; goto err_kthread; } cd->client->anybus_id = fieldbus_type; cd->client->host = cd; cd->client->dev.bus = &anybus_bus; cd->client->dev.parent = dev; cd->client->dev.release = client_device_release; cd->client->dev.of_node = anybus_of_find_child_device(dev, cd->host_idx); dev_set_name(&cd->client->dev, "anybuss.card%d", cd->host_idx); ret = device_register(&cd->client->dev); if (ret) goto err_device; return cd; err_device: device_unregister(&cd->client->dev); err_kthread: kthread_stop(cd->qthread); err_reset: reset_assert(cd); err_qcache: kmem_cache_destroy(cd->qcache); return ERR_PTR(ret); } EXPORT_SYMBOL_GPL(anybuss_host_common_probe); void anybuss_host_common_remove(struct anybuss_host *host) { struct anybuss_host *cd = host; device_unregister(&cd->client->dev); kthread_stop(cd->qthread); reset_assert(cd); kmem_cache_destroy(cd->qcache); } EXPORT_SYMBOL_GPL(anybuss_host_common_remove); static void host_release(struct device *dev, void *res) { struct anybuss_host **dr = res; anybuss_host_common_remove(*dr); } struct anybuss_host * __must_check devm_anybuss_host_common_probe(struct device *dev, const struct anybuss_ops *ops) { struct anybuss_host **dr; struct anybuss_host *host; dr = devres_alloc(host_release, sizeof(struct anybuss_host *), GFP_KERNEL); if (!dr) return ERR_PTR(-ENOMEM); host = anybuss_host_common_probe(dev, ops); if (IS_ERR(host)) { devres_free(dr); return host; } *dr = host; devres_add(dev, dr); return host; } EXPORT_SYMBOL_GPL(devm_anybuss_host_common_probe); static int __init anybus_init(void) { int ret; ret = bus_register(&anybus_bus); if (ret) pr_err("could not register Anybus-S bus: %d\n", ret); return ret; } module_init(anybus_init); static void __exit anybus_exit(void) { bus_unregister(&anybus_bus); } module_exit(anybus_exit); MODULE_DESCRIPTION("HMS Anybus-S Host Driver"); MODULE_AUTHOR("Sven Van Asbroeck <TheSven73@gmail.com>"); MODULE_LICENSE("GPL v2");
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