diff options
Diffstat (limited to 'drivers/misc/rp1-pio.c')
| -rw-r--r-- | drivers/misc/rp1-pio.c | 1371 |
1 files changed, 1371 insertions, 0 deletions
diff --git a/drivers/misc/rp1-pio.c b/drivers/misc/rp1-pio.c new file mode 100644 index 000000000000..e1ee5016a354 --- /dev/null +++ b/drivers/misc/rp1-pio.c @@ -0,0 +1,1371 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * PIO driver for RP1 + * + * Copyright (C) 2023-2024 Raspberry Pi Ltd. + * + * Parts of this driver are based on: + * - vcio.c, by Noralf Trønnes + * Copyright (C) 2010 Broadcom + * Copyright (C) 2015 Noralf Trønnes + * Copyright (C) 2021 Raspberry Pi (Trading) Ltd. + * - bcm2835_smi.c & bcm2835_smi_dev.c by Luke Wren + * Copyright (c) 2015 Raspberry Pi (Trading) Ltd. + */ + +#include <linux/cdev.h> +#include <linux/compat.h> +#include <linux/device.h> +#include <linux/dmaengine.h> +#include <linux/dma-mapping.h> +#include <linux/fs.h> +#include <linux/init.h> +#include <linux/ioctl.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/pio_rp1.h> +#include <linux/platform_device.h> +#include <linux/rp1-firmware.h> +#include <linux/semaphore.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/uaccess.h> +#include <uapi/misc/rp1_pio_if.h> + +#include "rp1-fw-pio.h" + +#define DRIVER_NAME "rp1-pio" + +#define RP1_PIO_SMS_COUNT 4 +#define RP1_PIO_INSTR_COUNT 32 + +#define MAX_ARG_SIZE 256 + +#define RP1_PIO_FIFO_TX0 0x00 +#define RP1_PIO_FIFO_TX1 0x04 +#define RP1_PIO_FIFO_TX2 0x08 +#define RP1_PIO_FIFO_TX3 0x0c +#define RP1_PIO_FIFO_RX0 0x10 +#define RP1_PIO_FIFO_RX1 0x14 +#define RP1_PIO_FIFO_RX2 0x18 +#define RP1_PIO_FIFO_RX3 0x1c + +#define RP1_PIO_DMACTRL_DEFAULT 0x80000104 + +#define HANDLER(_n, _f) \ + [_IOC_NR(PIO_IOC_ ## _n)] = { #_n, rp1_pio_ ## _f, _IOC_SIZE(PIO_IOC_ ## _n) } + + +#define ROUND_UP(x, y) (((x) + (y) - 1) - (((x) + (y) - 1) % (y))) + +#define DMA_BOUNCE_BUFFER_SIZE 0x1000 +#define DMA_BOUNCE_BUFFER_COUNT 4 + +struct dma_xfer_state { + struct dma_info *dma; + void (*callback)(void *param); + void *callback_param; +}; + +struct dma_buf_info { + void *buf; + dma_addr_t dma_addr; + struct scatterlist sgl; +}; + +struct dma_info { + struct semaphore buf_sem; + struct dma_chan *chan; + size_t buf_size; + size_t buf_count; + unsigned int head_idx; + unsigned int tail_idx; + struct dma_buf_info bufs[DMA_BOUNCE_BUFFER_COUNT]; +}; + +struct rp1_pio_device { + struct platform_device *pdev; + struct rp1_firmware *fw; + uint16_t fw_pio_base; + uint16_t fw_pio_count; + dev_t dev_num; + struct class *dev_class; + struct cdev cdev; + phys_addr_t phys_addr; + uint32_t claimed_sms; + uint32_t claimed_dmas; + spinlock_t lock; + struct mutex instr_mutex; + struct dma_info dma_configs[RP1_PIO_SMS_COUNT][RP1_PIO_DIR_COUNT]; + uint32_t used_instrs; + uint8_t instr_refcounts[RP1_PIO_INSTR_COUNT]; + uint16_t instrs[RP1_PIO_INSTR_COUNT]; + uint client_count; +}; + +struct rp1_pio_client { + struct rp1_pio_device *pio; + uint32_t claimed_sms; + uint32_t claimed_instrs; + uint32_t claimed_dmas; + int error; +}; + +static struct rp1_pio_device *g_pio; + +static int rp1_pio_message(struct rp1_pio_device *pio, + uint16_t op, const void *data, unsigned int data_len) +{ + uint32_t rc; + int ret; + + if (op >= pio->fw_pio_count) + return -EOPNOTSUPP; + ret = rp1_firmware_message(pio->fw, pio->fw_pio_base + op, + data, data_len, + &rc, sizeof(rc)); + if (ret == 4) + ret = rc; + return ret; +} + +static int rp1_pio_message_resp(struct rp1_pio_device *pio, + uint16_t op, const void *data, unsigned int data_len, + void *resp, void __user *userbuf, unsigned int resp_len) +{ + uint32_t resp_buf[1 + 32]; + int ret; + + if (op >= pio->fw_pio_count) + return -EOPNOTSUPP; + if (resp_len + 4 >= sizeof(resp_buf)) + return -EINVAL; + if (!resp && !userbuf) + return -EINVAL; + ret = rp1_firmware_message(pio->fw, pio->fw_pio_base + op, + data, data_len, + resp_buf, resp_len + 4); + if (ret >= 4 && !resp_buf[0]) { + ret -= 4; + if (resp) + memcpy(resp, &resp_buf[1], ret); + else if (copy_to_user(userbuf, &resp_buf[1], ret)) + ret = -EFAULT; + } else if (ret >= 0) { + ret = -EIO; + } + return ret; +} + +static int rp1_pio_read_hw(struct rp1_pio_client *client, void *param) +{ + struct rp1_pio_device *pio = client->pio; + struct rp1_access_hw_args *args = param; + + return rp1_pio_message_resp(pio, READ_HW, + args, 8, NULL, args->data, args->len); +} + +static int rp1_pio_write_hw(struct rp1_pio_client *client, void *param) +{ + struct rp1_pio_device *pio = client->pio; + struct rp1_access_hw_args *args = param; + uint32_t write_buf[32 + 1]; + int len; + + len = min(args->len, sizeof(write_buf) - 4); + write_buf[0] = args->addr; + if (copy_from_user(&write_buf[1], args->data, len)) + return -EFAULT; + return rp1_firmware_message(pio->fw, pio->fw_pio_base + WRITE_HW, + write_buf, 4 + len, NULL, 0); +} + +static int rp1_pio_find_program(struct rp1_pio_device *pio, + struct rp1_pio_add_program_args *prog) +{ + uint start, end, prog_size; + uint32_t used_mask; + uint i; + + start = (prog->origin != RP1_PIO_ORIGIN_ANY) ? prog->origin : 0; + end = (prog->origin != RP1_PIO_ORIGIN_ANY) ? prog->origin : + (RP1_PIO_INSTRUCTION_COUNT - prog->num_instrs); + prog_size = sizeof(prog->instrs[0]) * prog->num_instrs; + used_mask = (uint32_t)(~0) >> (32 - prog->num_instrs); + + /* Find the best match */ + for (i = start; i <= end; i++) { + uint32_t mask = used_mask << i; + + if ((pio->used_instrs & mask) != mask) + continue; + if (!memcmp(pio->instrs + i, prog->instrs, prog_size)) + return i; + } + + return -1; +} + +int rp1_pio_can_add_program(struct rp1_pio_client *client, void *param) +{ + struct rp1_pio_add_program_args *args = param; + struct rp1_pio_device *pio = client->pio; + int offset; + + if (args->num_instrs > RP1_PIO_INSTR_COUNT || + ((args->origin != RP1_PIO_ORIGIN_ANY) && + (args->origin >= RP1_PIO_INSTR_COUNT || + ((args->origin + args->num_instrs) > RP1_PIO_INSTR_COUNT)))) + return -EINVAL; + + mutex_lock(&pio->instr_mutex); + offset = rp1_pio_find_program(pio, args); + mutex_unlock(&pio->instr_mutex); + if (offset >= 0) + return offset; + + /* Don't send the instructions, just the header */ + return rp1_pio_message(pio, PIO_CAN_ADD_PROGRAM, args, + offsetof(struct rp1_pio_add_program_args, instrs)); +} +EXPORT_SYMBOL_GPL(rp1_pio_can_add_program); + +int rp1_pio_add_program(struct rp1_pio_client *client, void *param) +{ + struct rp1_pio_add_program_args *args = param; + struct rp1_pio_device *pio = client->pio; + int offset; + uint i; + + if (args->num_instrs > RP1_PIO_INSTR_COUNT || + ((args->origin != RP1_PIO_ORIGIN_ANY) && + (args->origin >= RP1_PIO_INSTR_COUNT || + ((args->origin + args->num_instrs) > RP1_PIO_INSTR_COUNT)))) + return -EINVAL; + + mutex_lock(&pio->instr_mutex); + offset = rp1_pio_find_program(pio, args); + if (offset < 0) + offset = rp1_pio_message(client->pio, PIO_ADD_PROGRAM, args, sizeof(*args)); + + if (offset >= 0) { + uint32_t used_mask; + uint prog_size; + + used_mask = ((uint32_t)(~0) >> (-args->num_instrs & 0x1f)) << offset; + prog_size = sizeof(args->instrs[0]) * args->num_instrs; + + if ((pio->used_instrs & used_mask) != used_mask) { + pio->used_instrs |= used_mask; + memcpy(pio->instrs + offset, args->instrs, prog_size); + } + client->claimed_instrs |= used_mask; + for (i = 0; i < args->num_instrs; i++) + pio->instr_refcounts[offset + i]++; + } + mutex_unlock(&pio->instr_mutex); + return offset; +} +EXPORT_SYMBOL_GPL(rp1_pio_add_program); + +static void rp1_pio_remove_instrs(struct rp1_pio_device *pio, uint32_t mask) +{ + struct rp1_pio_remove_program_args args; + uint i; + + mutex_lock(&pio->instr_mutex); + args.num_instrs = 0; + for (i = 0; ; i++, mask >>= 1) { + if ((mask & 1) && pio->instr_refcounts[i] && !--pio->instr_refcounts[i]) { + pio->used_instrs &= ~(1 << i); + args.num_instrs++; + } else if (args.num_instrs) { + args.origin = i - args.num_instrs; + rp1_pio_message(pio, PIO_REMOVE_PROGRAM, &args, sizeof(args)); + args.num_instrs = 0; + } + if (!mask) + break; + } + mutex_unlock(&pio->instr_mutex); +} + +int rp1_pio_remove_program(struct rp1_pio_client *client, void *param) +{ + struct rp1_pio_remove_program_args *args = param; + uint32_t used_mask; + int ret = -ENOENT; + + if (args->num_instrs > RP1_PIO_INSTR_COUNT || + args->origin >= RP1_PIO_INSTR_COUNT || + (args->origin + args->num_instrs) > RP1_PIO_INSTR_COUNT) + return -EINVAL; + + used_mask = ((uint32_t)(~0) >> (32 - args->num_instrs)) << args->origin; + if ((client->claimed_instrs & used_mask) == used_mask) { + client->claimed_instrs &= ~used_mask; + rp1_pio_remove_instrs(client->pio, used_mask); + ret = 0; + } + return ret; +} +EXPORT_SYMBOL_GPL(rp1_pio_remove_program); + +int rp1_pio_clear_instr_mem(struct rp1_pio_client *client, void *param) +{ + struct rp1_pio_device *pio = client->pio; + + mutex_lock(&pio->instr_mutex); + (void)rp1_pio_message(client->pio, PIO_CLEAR_INSTR_MEM, NULL, 0); + memset(pio->instr_refcounts, 0, sizeof(pio->instr_refcounts)); + pio->used_instrs = 0; + client->claimed_instrs = 0; + mutex_unlock(&pio->instr_mutex); + return 0; +} +EXPORT_SYMBOL_GPL(rp1_pio_clear_instr_mem); + +int rp1_pio_sm_claim(struct rp1_pio_client *client, void *param) +{ + struct rp1_pio_sm_claim_args *args = param; + struct rp1_pio_device *pio = client->pio; + int ret; + + mutex_lock(&pio->instr_mutex); + ret = rp1_pio_message(client->pio, PIO_SM_CLAIM, args, sizeof(*args)); + if (ret >= 0) { + if (args->mask) + client->claimed_sms |= args->mask; + else + client->claimed_sms |= (1 << ret); + pio->claimed_sms |= client->claimed_sms; + } + mutex_unlock(&pio->instr_mutex); + return ret; +} +EXPORT_SYMBOL_GPL(rp1_pio_sm_claim); + +int rp1_pio_sm_unclaim(struct rp1_pio_client *client, void *param) +{ + struct rp1_pio_sm_claim_args *args = param; + struct rp1_pio_device *pio = client->pio; + + mutex_lock(&pio->instr_mutex); + (void)rp1_pio_message(client->pio, PIO_SM_UNCLAIM, args, sizeof(*args)); + client->claimed_sms &= ~args->mask; + pio->claimed_sms &= ~args->mask; + mutex_unlock(&pio->instr_mutex); + return 0; +} +EXPORT_SYMBOL_GPL(rp1_pio_sm_unclaim); + +int rp1_pio_sm_is_claimed(struct rp1_pio_client *client, void *param) +{ + struct rp1_pio_sm_claim_args *args = param; + + return rp1_pio_message(client->pio, PIO_SM_IS_CLAIMED, args, sizeof(*args)); +} +EXPORT_SYMBOL_GPL(rp1_pio_sm_is_claimed); + +int rp1_pio_sm_init(struct rp1_pio_client *client, void *param) +{ + struct rp1_pio_sm_init_args *args = param; + + return rp1_pio_message(client->pio, PIO_SM_INIT, args, sizeof(*args)); +} +EXPORT_SYMBOL_GPL(rp1_pio_sm_init); + +int rp1_pio_sm_set_config(struct rp1_pio_client *client, void *param) +{ + struct rp1_pio_sm_set_config_args *args = param; + + return rp1_pio_message(client->pio, PIO_SM_SET_CONFIG, args, sizeof(*args)); +} +EXPORT_SYMBOL_GPL(rp1_pio_sm_set_config); + +int rp1_pio_sm_exec(struct rp1_pio_client *client, void *param) +{ + struct rp1_pio_sm_exec_args *args = param; + + return rp1_pio_message(client->pio, PIO_SM_EXEC, args, sizeof(*args)); +} +EXPORT_SYMBOL_GPL(rp1_pio_sm_exec); + +int rp1_pio_sm_clear_fifos(struct rp1_pio_client *client, void *param) +{ + struct rp1_pio_sm_clear_fifos_args *args = param; + + return rp1_pio_message(client->pio, PIO_SM_CLEAR_FIFOS, args, sizeof(*args)); +} +EXPORT_SYMBOL_GPL(rp1_pio_sm_clear_fifos); + +int rp1_pio_sm_set_clkdiv(struct rp1_pio_client *client, void *param) +{ + struct rp1_pio_sm_set_clkdiv_args *args = param; + + return rp1_pio_message(client->pio, PIO_SM_SET_CLKDIV, args, sizeof(*args)); +} +EXPORT_SYMBOL_GPL(rp1_pio_sm_set_clkdiv); + +int rp1_pio_sm_set_pins(struct rp1_pio_client *client, void *param) +{ + struct rp1_pio_sm_set_pins_args *args = param; + + return rp1_pio_message(client->pio, PIO_SM_SET_PINS, args, sizeof(*args)); +} +EXPORT_SYMBOL_GPL(rp1_pio_sm_set_pins); + +int rp1_pio_sm_set_pindirs(struct rp1_pio_client *client, void *param) +{ + struct rp1_pio_sm_set_pindirs_args *args = param; + + return rp1_pio_message(client->pio, PIO_SM_SET_PINDIRS, args, sizeof(*args)); +} +EXPORT_SYMBOL_GPL(rp1_pio_sm_set_pindirs); + +int rp1_pio_sm_set_enabled(struct rp1_pio_client *client, void *param) +{ + struct rp1_pio_sm_set_enabled_args *args = param; + + return rp1_pio_message(client->pio, PIO_SM_SET_ENABLED, args, sizeof(*args)); +} +EXPORT_SYMBOL_GPL(rp1_pio_sm_set_enabled); + +int rp1_pio_sm_restart(struct rp1_pio_client *client, void *param) +{ + struct rp1_pio_sm_restart_args *args = param; + + return rp1_pio_message(client->pio, PIO_SM_RESTART, args, sizeof(*args)); +} +EXPORT_SYMBOL_GPL(rp1_pio_sm_restart); + +int rp1_pio_sm_clkdiv_restart(struct rp1_pio_client *client, void *param) +{ + struct rp1_pio_sm_restart_args *args = param; + + return rp1_pio_message(client->pio, PIO_SM_CLKDIV_RESTART, args, sizeof(*args)); +} +EXPORT_SYMBOL_GPL(rp1_pio_sm_clkdiv_restart); + +int rp1_pio_sm_enable_sync(struct rp1_pio_client *client, void *param) +{ + struct rp1_pio_sm_enable_sync_args *args = param; + + return rp1_pio_message(client->pio, PIO_SM_ENABLE_SYNC, args, sizeof(*args)); +} +EXPORT_SYMBOL_GPL(rp1_pio_sm_enable_sync); + +int rp1_pio_sm_put(struct rp1_pio_client *client, void *param) +{ + struct rp1_pio_sm_put_args *args = param; + + return rp1_pio_message(client->pio, PIO_SM_PUT, args, sizeof(*args)); +} +EXPORT_SYMBOL_GPL(rp1_pio_sm_put); + +int rp1_pio_sm_get(struct rp1_pio_client *client, void *param) +{ + struct rp1_pio_sm_get_args *args = param; + int ret; + + ret = rp1_pio_message_resp(client->pio, PIO_SM_GET, args, sizeof(*args), + &args->data, NULL, sizeof(args->data)); + if (ret >= 0) + return offsetof(struct rp1_pio_sm_get_args, data) + ret; + return ret; +} +EXPORT_SYMBOL_GPL(rp1_pio_sm_get); + +int rp1_pio_sm_set_dmactrl(struct rp1_pio_client *client, void *param) +{ + struct rp1_pio_sm_set_dmactrl_args *args = param; + + return rp1_pio_message(client->pio, PIO_SM_SET_DMACTRL, args, sizeof(*args)); +} +EXPORT_SYMBOL_GPL(rp1_pio_sm_set_dmactrl); + +int rp1_pio_sm_fifo_state(struct rp1_pio_client *client, void *param) +{ + struct rp1_pio_sm_fifo_state_args *args = param; + const int level_offset = offsetof(struct rp1_pio_sm_fifo_state_args, level); + int ret; + + ret = rp1_pio_message_resp(client->pio, PIO_SM_FIFO_STATE, args, sizeof(*args), + &args->level, NULL, sizeof(*args) - level_offset); + if (ret >= 0) + return level_offset + ret; + return ret; +} +EXPORT_SYMBOL_GPL(rp1_pio_sm_fifo_state); + +int rp1_pio_sm_drain_tx(struct rp1_pio_client *client, void *param) +{ + struct rp1_pio_sm_clear_fifos_args *args = param; + + return rp1_pio_message(client->pio, PIO_SM_DRAIN_TX, args, sizeof(*args)); +} +EXPORT_SYMBOL_GPL(rp1_pio_sm_drain_tx); + +int rp1_pio_gpio_init(struct rp1_pio_client *client, void *param) +{ + struct rp1_gpio_init_args *args = param; + + return rp1_pio_message(client->pio, GPIO_INIT, args, sizeof(*args)); +} +EXPORT_SYMBOL_GPL(rp1_pio_gpio_init); + +int rp1_pio_gpio_set_function(struct rp1_pio_client *client, void *param) +{ + struct rp1_gpio_set_function_args *args = param; + + return rp1_pio_message(client->pio, GPIO_SET_FUNCTION, args, sizeof(*args)); +} +EXPORT_SYMBOL_GPL(rp1_pio_gpio_set_function); + +int rp1_pio_gpio_set_pulls(struct rp1_pio_client *client, void *param) +{ + struct rp1_gpio_set_pulls_args *args = param; + + return rp1_pio_message(client->pio, GPIO_SET_PULLS, args, sizeof(*args)); +} +EXPORT_SYMBOL_GPL(rp1_pio_gpio_set_pulls); + +int rp1_pio_gpio_set_outover(struct rp1_pio_client *client, void *param) +{ + struct rp1_gpio_set_args *args = param; + + return rp1_pio_message(client->pio, GPIO_SET_OUTOVER, args, sizeof(*args)); +} +EXPORT_SYMBOL_GPL(rp1_pio_gpio_set_outover); + +int rp1_pio_gpio_set_inover(struct rp1_pio_client *client, void *param) +{ + struct rp1_gpio_set_args *args = param; + + return rp1_pio_message(client->pio, GPIO_SET_INOVER, args, sizeof(*args)); +} +EXPORT_SYMBOL_GPL(rp1_pio_gpio_set_inover); + +int rp1_pio_gpio_set_oeover(struct rp1_pio_client *client, void *param) +{ + struct rp1_gpio_set_args *args = param; + + return rp1_pio_message(client->pio, GPIO_SET_OEOVER, args, sizeof(*args)); +} +EXPORT_SYMBOL_GPL(rp1_pio_gpio_set_oeover); + +int rp1_pio_gpio_set_input_enabled(struct rp1_pio_client *client, void *param) +{ + struct rp1_gpio_set_args *args = param; + + return rp1_pio_message(client->pio, GPIO_SET_INPUT_ENABLED, args, sizeof(*args)); +} +EXPORT_SYMBOL_GPL(rp1_pio_gpio_set_input_enabled); + +int rp1_pio_gpio_set_drive_strength(struct rp1_pio_client *client, void *param) +{ + struct rp1_gpio_set_args *args = param; + + return rp1_pio_message(client->pio, GPIO_SET_DRIVE_STRENGTH, args, sizeof(*args)); +} +EXPORT_SYMBOL_GPL(rp1_pio_gpio_set_drive_strength); + +static void rp1_pio_sm_dma_callback(void *param) +{ + struct dma_info *dma = param; + + up(&dma->buf_sem); +} + +static void rp1_pio_sm_kernel_dma_callback(void *param) +{ + struct dma_xfer_state *dxs = param; + + dxs->dma->tail_idx++; + up(&dxs->dma->buf_sem); + + dxs->callback(dxs->callback_param); + + kfree(dxs); +} + +static void rp1_pio_sm_dma_free(struct device *dev, struct dma_info *dma) +{ + dmaengine_terminate_all(dma->chan); + while (dma->buf_count > 0) { + dma->buf_count--; + dma_free_coherent(dev, ROUND_UP(dma->buf_size, PAGE_SIZE), + dma->bufs[dma->buf_count].buf, + dma->bufs[dma->buf_count].dma_addr); + } + + dma_release_channel(dma->chan); +} + +static int rp1_pio_sm_config_xfer_internal(struct rp1_pio_client *client, uint sm, uint dir, + uint buf_size, uint buf_count) +{ + struct rp1_pio_sm_set_dmactrl_args set_dmactrl_args; + struct rp1_pio_device *pio = client->pio; + struct platform_device *pdev = pio->pdev; + struct device *dev = &pdev->dev; + struct dma_slave_config config = {}; + phys_addr_t fifo_addr; + struct dma_info *dma; + uint32_t dma_mask; + char chan_name[4]; + int ret = 0; + + if (sm >= RP1_PIO_SMS_COUNT || dir >= RP1_PIO_DIR_COUNT) + return -EINVAL; + if ((buf_count || buf_size) && + (!buf_size || (buf_size & 3) || + !buf_count || buf_count > DMA_BOUNCE_BUFFER_COUNT)) + return -EINVAL; + + dma_mask = 1 << (sm * 2 + dir); + + dma = &pio->dma_configs[sm][dir]; + + spin_lock(&pio->lock); + if (pio->claimed_dmas & dma_mask) + rp1_pio_sm_dma_free(dev, dma); + pio->claimed_dmas |= dma_mask; + client->claimed_dmas |= dma_mask; + spin_unlock(&pio->lock); + + dma->buf_size = buf_size; + /* Round up the allocations */ + buf_size = ROUND_UP(buf_size, PAGE_SIZE); + sema_init(&dma->buf_sem, 0); + + /* Allocate and configure a DMA channel */ + /* Careful - each SM FIFO has its own DREQ value */ + chan_name[0] = (dir == RP1_PIO_DIR_TO_SM) ? 't' : 'r'; + chan_name[1] = 'x'; + chan_name[2] = '0' + sm; + chan_name[3] = '\0'; + + dma->chan = dma_request_chan(dev, chan_name); + if (IS_ERR(dma->chan)) + return PTR_ERR(dma->chan); + + /* Alloc and map bounce buffers */ + for (dma->buf_count = 0; dma->buf_count < buf_count; dma->buf_count++) { + struct dma_buf_info *dbi = &dma->bufs[dma->buf_count]; + + dbi->buf = dma_alloc_coherent(dma->chan->device->dev, buf_size, + &dbi->dma_addr, GFP_KERNEL); + if (!dbi->buf) { + ret = -ENOMEM; + goto err_dma_free; + } + sg_init_table(&dbi->sgl, 1); + sg_dma_address(&dbi->sgl) = dbi->dma_addr; + } + + fifo_addr = pio->phys_addr; + fifo_addr += sm * (RP1_PIO_FIFO_TX1 - RP1_PIO_FIFO_TX0); + fifo_addr += (dir == RP1_PIO_DIR_TO_SM) ? RP1_PIO_FIFO_TX0 : RP1_PIO_FIFO_RX0; + + config.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; + config.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; + config.src_addr = fifo_addr; + config.dst_addr = fifo_addr; + config.direction = (dir == RP1_PIO_DIR_TO_SM) ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM; + + ret = dmaengine_slave_config(dma->chan, &config); + if (ret) + goto err_dma_free; + + set_dmactrl_args.sm = sm; + set_dmactrl_args.is_tx = (dir == RP1_PIO_DIR_TO_SM); + set_dmactrl_args.ctrl = RP1_PIO_DMACTRL_DEFAULT; + if (dir == RP1_PIO_DIR_FROM_SM) + set_dmactrl_args.ctrl = (RP1_PIO_DMACTRL_DEFAULT & ~0x1f) | 1; + + ret = rp1_pio_sm_set_dmactrl(client, &set_dmactrl_args); + if (ret) + goto err_dma_free; + + return 0; + +err_dma_free: + rp1_pio_sm_dma_free(dev, dma); + + spin_lock(&pio->lock); + client->claimed_dmas &= ~dma_mask; + pio->claimed_dmas &= ~dma_mask; + spin_unlock(&pio->lock); + + return ret; +} + +static int rp1_pio_sm_config_xfer_user(struct rp1_pio_client *client, void *param) +{ + struct rp1_pio_sm_config_xfer_args *args = param; + + return rp1_pio_sm_config_xfer_internal(client, args->sm, args->dir, + args->buf_size, args->buf_count); +} + +static int rp1_pio_sm_tx_user(struct rp1_pio_device *pio, struct dma_info *dma, + const void __user *userbuf, size_t bytes) +{ + struct platform_device *pdev = pio->pdev; + struct dma_async_tx_descriptor *desc; + struct device *dev = &pdev->dev; + int ret = 0; + + /* Clean the slate - we're running synchronously */ + dma->head_idx = 0; + dma->tail_idx = 0; + + while (bytes > 0) { + size_t copy_bytes = min(bytes, dma->buf_size); + struct dma_buf_info *dbi; + + /* grab the next free buffer, waiting if they're all full */ + if (dma->head_idx - dma->tail_idx == dma->buf_count) { + if (down_timeout(&dma->buf_sem, + msecs_to_jiffies(1000))) { + dev_err(dev, "DMA bounce timed out\n"); + break; + } + dma->tail_idx++; + } + + dbi = &dma->bufs[dma->head_idx % dma->buf_count]; + + sg_dma_len(&dbi->sgl) = copy_bytes; + + ret = copy_from_user(dbi->buf, userbuf, copy_bytes); + if (ret < 0) + break; + + userbuf += copy_bytes; + + desc = dmaengine_prep_slave_sg(dma->chan, &dbi->sgl, 1, + DMA_MEM_TO_DEV, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK | + DMA_PREP_FENCE); + if (!desc) { + dev_err(dev, "DMA preparation failed\n"); + ret = -EIO; + break; + } + + desc->callback = rp1_pio_sm_dma_callback; + desc->callback_param = dma; + + /* Submit the buffer - the callback will kick the semaphore */ + ret = dmaengine_submit(desc); + if (ret < 0) + break; + ret = 0; + + dma_async_issue_pending(dma->chan); + + dma->head_idx++; + bytes -= copy_bytes; + } + + /* Block for completion */ + while (dma->tail_idx != dma->head_idx) { + if (down_timeout(&dma->buf_sem, msecs_to_jiffies(1000))) { + dev_err(dev, "DMA wait timed out\n"); + ret = -ETIMEDOUT; + break; + } + dma->tail_idx++; + } + + return ret; +} + +static int rp1_pio_sm_rx_user(struct rp1_pio_device *pio, struct dma_info *dma, + void __user *userbuf, size_t bytes) +{ + struct platform_device *pdev = pio->pdev; + struct dma_async_tx_descriptor *desc; + struct device *dev = &pdev->dev; + int ret = 0; + + /* Clean the slate - we're running synchronously */ + dma->head_idx = 0; + dma->tail_idx = 0; + + while (bytes || dma->tail_idx != dma->head_idx) { + size_t copy_bytes = min(bytes, dma->buf_size); + struct dma_buf_info *dbi; + + /* + * wait for the next RX to complete if all the buffers are + * outstanding or we're finishing up. + */ + if (!bytes || dma->head_idx - dma->tail_idx == dma->buf_count) { + if (down_timeout(&dma->buf_sem, + msecs_to_jiffies(1000))) { + dev_err(dev, "DMA wait timed out\n"); + ret = -ETIMEDOUT; + break; + } + + dbi = &dma->bufs[dma->tail_idx++ % dma->buf_count]; + ret = copy_to_user(userbuf, dbi->buf, sg_dma_len(&dbi->sgl)); + if (ret < 0) + break; + userbuf += sg_dma_len(&dbi->sgl); + + if (!bytes) + continue; + } + + dbi = &dma->bufs[dma->head_idx % dma->buf_count]; + sg_dma_len(&dbi->sgl) = copy_bytes; + desc = dmaengine_prep_slave_sg(dma->chan, &dbi->sgl, 1, + DMA_DEV_TO_MEM, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK | + DMA_PREP_FENCE); + if (!desc) { + dev_err(dev, "DMA preparation failed\n"); + ret = -EIO; + break; + } + + desc->callback = rp1_pio_sm_dma_callback; + desc->callback_param = dma; + + /* Submit the buffer - the callback will kick the semaphore */ + ret = dmaengine_submit(desc); + if (ret < 0) + break; + + dma_async_issue_pending(dma->chan); + + dma->head_idx++; + bytes -= copy_bytes; + } + + return ret; +} + +static int rp1_pio_sm_xfer_data32_user(struct rp1_pio_client *client, void *param) +{ + struct rp1_pio_sm_xfer_data32_args *args = param; + struct rp1_pio_device *pio = client->pio; + struct dma_info *dma; + + if (args->sm >= RP1_PIO_SMS_COUNT || args->dir >= RP1_PIO_DIR_COUNT || + !args->data_bytes || !args->data) + return -EINVAL; + + dma = &pio->dma_configs[args->sm][args->dir]; + + if (args->dir == RP1_PIO_DIR_TO_SM) + return rp1_pio_sm_tx_user(pio, dma, args->data, args->data_bytes); + else + return rp1_pio_sm_rx_user(pio, dma, args->data, args->data_bytes); +} + +static int rp1_pio_sm_xfer_data_user(struct rp1_pio_client *client, void *param) +{ + struct rp1_pio_sm_xfer_data_args *args = param; + struct rp1_pio_sm_xfer_data32_args args32; + + args32.sm = args->sm; + args32.dir = args->dir; + args32.data_bytes = args->data_bytes; + args32.data = args->data; + + return rp1_pio_sm_xfer_data32_user(client, &args32); +} + +int rp1_pio_sm_config_xfer(struct rp1_pio_client *client, uint sm, uint dir, + uint buf_size, uint buf_count) +{ + return rp1_pio_sm_config_xfer_internal(client, sm, dir, buf_size, buf_count); +} +EXPORT_SYMBOL_GPL(rp1_pio_sm_config_xfer); + +int rp1_pio_sm_xfer_data(struct rp1_pio_client *client, uint sm, uint dir, + uint data_bytes, void *data, dma_addr_t dma_addr, + void (*callback)(void *param), void *param) +{ + struct rp1_pio_device *pio = client->pio; + struct platform_device *pdev = pio->pdev; + struct dma_async_tx_descriptor *desc; + struct dma_xfer_state *dxs = NULL; + struct device *dev = &pdev->dev; + struct dma_buf_info *dbi = NULL; + struct scatterlist sg; + struct dma_info *dma; + int ret = 0; + + if (sm >= RP1_PIO_SMS_COUNT || dir >= RP1_PIO_DIR_COUNT) + return -EINVAL; + + dma = &pio->dma_configs[sm][dir]; + + if (!dma_addr) { + dxs = kmalloc(sizeof(*dxs), GFP_KERNEL); + dxs->dma = dma; + dxs->callback = callback; + dxs->callback_param = param; + callback = rp1_pio_sm_kernel_dma_callback; + param = dxs; + + if (!dma->buf_count || data_bytes > dma->buf_size) + return -EINVAL; + + /* Grab a dma buffer */ + if (dma->head_idx - dma->tail_idx == dma->buf_count) { + if (down_timeout(&dma->buf_sem, msecs_to_jiffies(1000))) { + dev_err(dev, "DMA wait timed out\n"); + return -ETIMEDOUT; + } + } + + dbi = &dma->bufs[dma->head_idx % dma->buf_count]; + dma_addr = dbi->dma_addr; + + if (dir == PIO_DIR_TO_SM) + memcpy(dbi->buf, data, data_bytes); + } + + sg_init_table(&sg, 1); + sg_dma_address(&sg) = dma_addr; + sg_dma_len(&sg) = data_bytes; + + desc = dmaengine_prep_slave_sg(dma->chan, &sg, 1, + (dir == PIO_DIR_TO_SM) ? DMA_MEM_TO_DEV : DMA_DEV_TO_MEM, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK | + DMA_PREP_FENCE); + if (!desc) { + dev_err(dev, "DMA preparation failed\n"); + return -EIO; + } + + desc->callback = callback; + desc->callback_param = param; + + ret = dmaengine_submit(desc); + if (ret < 0) { + dev_err(dev, "dmaengine_submit failed (%d)\n", ret); + return ret; + } + + dma_async_issue_pending(dma->chan); + + return 0; +} +EXPORT_SYMBOL_GPL(rp1_pio_sm_xfer_data); + +struct handler_info { + const char *name; + int (*func)(struct rp1_pio_client *client, void *param); + int argsize; +} ioctl_handlers[] = { + HANDLER(SM_CONFIG_XFER, sm_config_xfer_user), + HANDLER(SM_XFER_DATA, sm_xfer_data_user), + HANDLER(SM_XFER_DATA32, sm_xfer_data32_user), + + HANDLER(CAN_ADD_PROGRAM, can_add_program), + HANDLER(ADD_PROGRAM, add_program), + HANDLER(REMOVE_PROGRAM, remove_program), + HANDLER(CLEAR_INSTR_MEM, clear_instr_mem), + + HANDLER(SM_CLAIM, sm_claim), + HANDLER(SM_UNCLAIM, sm_unclaim), + HANDLER(SM_IS_CLAIMED, sm_is_claimed), + + HANDLER(SM_INIT, sm_init), + HANDLER(SM_SET_CONFIG, sm_set_config), + HANDLER(SM_EXEC, sm_exec), + HANDLER(SM_CLEAR_FIFOS, sm_clear_fifos), + HANDLER(SM_SET_CLKDIV, sm_set_clkdiv), + HANDLER(SM_SET_PINS, sm_set_pins), + HANDLER(SM_SET_PINDIRS, sm_set_pindirs), + HANDLER(SM_SET_ENABLED, sm_set_enabled), + HANDLER(SM_RESTART, sm_restart), + HANDLER(SM_CLKDIV_RESTART, sm_clkdiv_restart), + HANDLER(SM_ENABLE_SYNC, sm_enable_sync), + HANDLER(SM_PUT, sm_put), + HANDLER(SM_GET, sm_get), + HANDLER(SM_SET_DMACTRL, sm_set_dmactrl), + HANDLER(SM_FIFO_STATE, sm_fifo_state), + HANDLER(SM_DRAIN_TX, sm_drain_tx), + + HANDLER(GPIO_INIT, gpio_init), + HANDLER(GPIO_SET_FUNCTION, gpio_set_function), + HANDLER(GPIO_SET_PULLS, gpio_set_pulls), + HANDLER(GPIO_SET_OUTOVER, gpio_set_outover), + HANDLER(GPIO_SET_INOVER, gpio_set_inover), + HANDLER(GPIO_SET_OEOVER, gpio_set_oeover), + HANDLER(GPIO_SET_INPUT_ENABLED, gpio_set_input_enabled), + HANDLER(GPIO_SET_DRIVE_STRENGTH, gpio_set_drive_strength), + + HANDLER(READ_HW, read_hw), + HANDLER(WRITE_HW, write_hw), +}; + +struct rp1_pio_client *rp1_pio_open(void) +{ + struct rp1_pio_client *client; + + if (!g_pio) + return ERR_PTR(-ENOENT); + + client = kzalloc(sizeof(*client), GFP_KERNEL); + if (!client) + return ERR_PTR(-ENOMEM); + + client->pio = g_pio; + + return client; +} +EXPORT_SYMBOL_GPL(rp1_pio_open); + +void rp1_pio_close(struct rp1_pio_client *client) +{ + struct rp1_pio_device *pio = client->pio; + uint claimed_dmas = client->claimed_dmas; + int i; + + /* Free any allocated resources */ + + for (i = 0; claimed_dmas; i++) { + uint mask = (1 << i); + + if (claimed_dmas & mask) { + struct dma_info *dma = &pio->dma_configs[i >> 1][i & 1]; + + claimed_dmas &= ~mask; + rp1_pio_sm_dma_free(&pio->pdev->dev, dma); + } + } + + spin_lock(&pio->lock); + pio->claimed_dmas &= ~client->claimed_dmas; + spin_unlock(&pio->lock); + + if (client->claimed_sms) { + struct rp1_pio_sm_set_enabled_args se_args = { + .mask = client->claimed_sms, .enable = 0 + }; + struct rp1_pio_sm_claim_args uc_args = { + .mask = client->claimed_sms + }; + + rp1_pio_sm_set_enabled(client, &se_args); + rp1_pio_sm_unclaim(client, &uc_args); + } + + if (client->claimed_instrs) + rp1_pio_remove_instrs(pio, client->claimed_instrs); + + /* Reinitialise the SM? */ + + kfree(client); +} +EXPORT_SYMBOL_GPL(rp1_pio_close); + +void rp1_pio_set_error(struct rp1_pio_client *client, int err) +{ + client->error = err; +} +EXPORT_SYMBOL_GPL(rp1_pio_set_error); + +int rp1_pio_get_error(const struct rp1_pio_client *client) +{ + return client->error; +} +EXPORT_SYMBOL_GPL(rp1_pio_get_error); + +void rp1_pio_clear_error(struct rp1_pio_client *client) +{ + client->error = 0; +} +EXPORT_SYMBOL_GPL(rp1_pio_clear_error); + +static int rp1_pio_file_open(struct inode *inode, struct file *filp) +{ + struct rp1_pio_client *client; + + client = rp1_pio_open(); + if (IS_ERR(client)) + return PTR_ERR(client); + + filp->private_data = client; + + return 0; +} + +static int rp1_pio_file_release(struct inode *inode, struct file *filp) +{ + struct rp1_pio_client *client = filp->private_data; + + rp1_pio_close(client); + + return 0; +} + +static long rp1_pio_ioctl(struct file *filp, unsigned int ioctl_num, + unsigned long ioctl_param) +{ + struct rp1_pio_client *client = filp->private_data; + struct device *dev = &client->pio->pdev->dev; + void __user *argp = (void __user *)ioctl_param; + int nr = _IOC_NR(ioctl_num); + int sz = _IOC_SIZE(ioctl_num); + struct handler_info *hdlr = &ioctl_handlers[nr]; + uint32_t argbuf[MAX_ARG_SIZE/sizeof(uint32_t)]; + int ret; + + if (nr >= ARRAY_SIZE(ioctl_handlers) || !hdlr->func) { + dev_err(dev, "unknown ioctl: %x\n", ioctl_num); + return -EOPNOTSUPP; + } + + if (sz != hdlr->argsize) { + dev_err(dev, "wrong %s argsize (expected %d, got %d)\n", + hdlr->name, hdlr->argsize, sz); + return -EINVAL; + } + + if (copy_from_user(argbuf, argp, sz)) + return -EFAULT; + + ret = (hdlr->func)(client, argbuf); + dev_dbg(dev, "%s: %s -> %d\n", __func__, hdlr->name, ret); + if (ret > 0) { + if (copy_to_user(argp, argbuf, ret)) + ret = -EFAULT; + } + + return ret; +} + +#ifdef CONFIG_COMPAT + +struct rp1_pio_sm_xfer_data_args_compat { + uint16_t sm; + uint16_t dir; + uint16_t data_bytes; + compat_uptr_t data; +}; + +struct rp1_pio_sm_xfer_data32_args_compat { + uint16_t sm; + uint16_t dir; + uint32_t data_bytes; + compat_uptr_t data; +}; + +struct rp1_access_hw_args_compat { + uint32_t addr; + uint32_t len; + compat_uptr_t data; +}; + +#define PIO_IOC_SM_XFER_DATA_COMPAT \ + _IOW(PIO_IOC_MAGIC, 1, struct rp1_pio_sm_xfer_data_args_compat) +#define PIO_IOC_SM_XFER_DATA32_COMPAT \ + _IOW(PIO_IOC_MAGIC, 2, struct rp1_pio_sm_xfer_data32_args_compat) +#define PIO_IOC_READ_HW_COMPAT _IOW(PIO_IOC_MAGIC, 8, struct rp1_access_hw_args_compat) +#define PIO_IOC_WRITE_HW_COMPAT _IOW(PIO_IOC_MAGIC, 9, struct rp1_access_hw_args_compat) + +static long rp1_pio_compat_ioctl(struct file *filp, unsigned int ioctl_num, + unsigned long ioctl_param) +{ + struct rp1_pio_client *client = filp->private_data; + + switch (ioctl_num) { + case PIO_IOC_SM_XFER_DATA_COMPAT: + { + struct rp1_pio_sm_xfer_data_args_compat compat_param; + struct rp1_pio_sm_xfer_data_args param; + + if (copy_from_user(&compat_param, compat_ptr(ioctl_param), sizeof(compat_param))) + return -EFAULT; + param.sm = compat_param.sm; + param.dir = compat_param.dir; + param.data_bytes = compat_param.data_bytes; + param.data = compat_ptr(compat_param.data); + return rp1_pio_sm_xfer_data_user(client, ¶m); + } + case PIO_IOC_SM_XFER_DATA32_COMPAT: + { + struct rp1_pio_sm_xfer_data32_args_compat compat_param; + struct rp1_pio_sm_xfer_data32_args param; + + if (copy_from_user(&compat_param, compat_ptr(ioctl_param), sizeof(compat_param))) + return -EFAULT; + param.sm = compat_param.sm; + param.dir = compat_param.dir; + param.data_bytes = compat_param.data_bytes; + param.data = compat_ptr(compat_param.data); + return rp1_pio_sm_xfer_data32_user(client, ¶m); + } + + case PIO_IOC_READ_HW_COMPAT: + case PIO_IOC_WRITE_HW_COMPAT: + { + struct rp1_access_hw_args_compat compat_param; + struct rp1_access_hw_args param; + + if (copy_from_user(&compat_param, compat_ptr(ioctl_param), sizeof(compat_param))) + return -EFAULT; + param.addr = compat_param.addr; + param.len = compat_param.len; + param.data = compat_ptr(compat_param.data); + if (ioctl_num == PIO_IOC_READ_HW_COMPAT) + return rp1_pio_read_hw(client, ¶m); + else + return rp1_pio_write_hw(client, ¶m); + } + default: + return rp1_pio_ioctl(filp, ioctl_num, ioctl_param); + } +} +#else +#define rp1_pio_compat_ioctl NULL +#endif + +const struct file_operations rp1_pio_fops = { + .owner = THIS_MODULE, + .open = rp1_pio_file_open, + .release = rp1_pio_file_release, + .unlocked_ioctl = rp1_pio_ioctl, + .compat_ioctl = rp1_pio_compat_ioctl, +}; + +static int rp1_pio_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct resource *ioresource; + struct rp1_pio_device *pio; + struct rp1_firmware *fw; + uint32_t op_count = 0; + uint32_t op_base = 0; + struct device *cdev; + char dev_name[16]; + void *p; + int ret; + int i; + + /* Run-time check for a build-time misconfiguration */ + for (i = 0; i < ARRAY_SIZE(ioctl_handlers); i++) { + struct handler_info *hdlr = &ioctl_handlers[i]; + + if (WARN_ON(hdlr->argsize > MAX_ARG_SIZE)) + return -EINVAL; + } + + pdev->id = of_alias_get_id(pdev->dev.of_node, "pio"); + if (pdev->id < 0) + return dev_err_probe(dev, pdev->id, "alias is missing\n"); + + fw = devm_rp1_firmware_get(dev, dev->of_node); + if (IS_ERR_OR_NULL(fw)) + return dev_err_probe(dev, -ENOENT, "failed to contact RP1 firmware\n"); + ret = rp1_firmware_get_feature(fw, FOURCC_PIO, &op_base, &op_count); + if (ret < 0) + return ret; + + pio = devm_kzalloc(&pdev->dev, sizeof(*pio), GFP_KERNEL); + if (!pio) + return -ENOMEM; + + platform_set_drvdata(pdev, pio); + pio->fw_pio_base = op_base; + pio->fw_pio_count = op_count; + pio->pdev = pdev; + pio->fw = fw; + spin_lock_init(&pio->lock); + mutex_init(&pio->instr_mutex); + + p = devm_platform_get_and_ioremap_resource(pdev, 0, &ioresource); + if (IS_ERR(p)) + return PTR_ERR(p); + + pio->phys_addr = ioresource->start; + + ret = alloc_chrdev_region(&pio->dev_num, 0, 1, DRIVER_NAME); + if (ret < 0) { + dev_err(dev, "alloc_chrdev_region failed (rc=%d)\n", ret); + goto out_err; + } + + pio->dev_class = class_create(DRIVER_NAME); + if (IS_ERR(pio->dev_class)) { + ret = PTR_ERR(pio->dev_class); + dev_err(dev, "class_create failed (err %d)\n", ret); + goto out_unregister; + } + + cdev_init(&pio->cdev, &rp1_pio_fops); + ret = cdev_add(&pio->cdev, pio->dev_num, 1); + if (ret) { + dev_err(dev, "cdev_add failed (err %d)\n", ret); + goto out_class_destroy; + } + + sprintf(dev_name, "pio%d", pdev->id); + cdev = device_create(pio->dev_class, NULL, pio->dev_num, NULL, dev_name); + if (IS_ERR(cdev)) { + ret = PTR_ERR(cdev); + dev_err(dev, "%s: device_create failed (err %d)\n", __func__, ret); + goto out_cdev_del; + } + + g_pio = pio; + + dev_info(dev, "Created instance as %s\n", dev_name); + return 0; + +out_cdev_del: + cdev_del(&pio->cdev); + +out_class_destroy: + class_destroy(pio->dev_class); + +out_unregister: + unregister_chrdev_region(pio->dev_num, 1); + +out_err: + return ret; +} + +static void rp1_pio_remove(struct platform_device *pdev) +{ + struct rp1_pio_device *pio = platform_get_drvdata(pdev); + + /* There should be no clients */ + + if (g_pio == pio) + g_pio = NULL; +} + +static const struct of_device_id rp1_pio_ids[] = { + { .compatible = "raspberrypi,rp1-pio" }, + { } +}; +MODULE_DEVICE_TABLE(of, rp1_pio_ids); + +static struct platform_driver rp1_pio_driver = { + .driver = { + .name = "rp1-pio", + .of_match_table = of_match_ptr(rp1_pio_ids), + }, + .probe = rp1_pio_probe, + .remove = rp1_pio_remove, + .shutdown = rp1_pio_remove, +}; + +module_platform_driver(rp1_pio_driver); + +MODULE_DESCRIPTION("PIO controller driver for Raspberry Pi RP1"); +MODULE_AUTHOR("Phil Elwell"); +MODULE_LICENSE("GPL"); |