diff options
Diffstat (limited to 'drivers/net/wireless/quantenna/qtnfmac/shm_ipc.c')
| -rw-r--r-- | drivers/net/wireless/quantenna/qtnfmac/shm_ipc.c | 176 |
1 files changed, 176 insertions, 0 deletions
diff --git a/drivers/net/wireless/quantenna/qtnfmac/shm_ipc.c b/drivers/net/wireless/quantenna/qtnfmac/shm_ipc.c new file mode 100644 index 000000000..aa106dd0a --- /dev/null +++ b/drivers/net/wireless/quantenna/qtnfmac/shm_ipc.c @@ -0,0 +1,176 @@ +/* + * Copyright (c) 2015-2016 Quantenna Communications, Inc. + * All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + */ + +#include <linux/types.h> +#include <linux/io.h> + +#include "shm_ipc.h" + +#undef pr_fmt +#define pr_fmt(fmt) "qtnfmac shm_ipc: %s: " fmt, __func__ + +static bool qtnf_shm_ipc_has_new_data(struct qtnf_shm_ipc *ipc) +{ + const u32 flags = readl(&ipc->shm_region->headroom.hdr.flags); + + return (flags & QTNF_SHM_IPC_NEW_DATA); +} + +static void qtnf_shm_handle_new_data(struct qtnf_shm_ipc *ipc) +{ + size_t size; + bool rx_buff_ok = true; + struct qtnf_shm_ipc_region_header __iomem *shm_reg_hdr; + + shm_reg_hdr = &ipc->shm_region->headroom.hdr; + + size = readw(&shm_reg_hdr->data_len); + + if (unlikely(size == 0 || size > QTN_IPC_MAX_DATA_SZ)) { + pr_err("wrong rx packet size: %zu\n", size); + rx_buff_ok = false; + } else { + memcpy_fromio(ipc->rx_data, ipc->shm_region->data, size); + } + + writel(QTNF_SHM_IPC_ACK, &shm_reg_hdr->flags); + readl(&shm_reg_hdr->flags); /* flush PCIe write */ + + ipc->interrupt.fn(ipc->interrupt.arg); + + if (likely(rx_buff_ok)) { + ipc->rx_packet_count++; + ipc->rx_callback.fn(ipc->rx_callback.arg, ipc->rx_data, size); + } +} + +static void qtnf_shm_ipc_irq_work(struct work_struct *work) +{ + struct qtnf_shm_ipc *ipc = container_of(work, struct qtnf_shm_ipc, + irq_work); + + while (qtnf_shm_ipc_has_new_data(ipc)) + qtnf_shm_handle_new_data(ipc); +} + +static void qtnf_shm_ipc_irq_inbound_handler(struct qtnf_shm_ipc *ipc) +{ + u32 flags; + + flags = readl(&ipc->shm_region->headroom.hdr.flags); + + if (flags & QTNF_SHM_IPC_NEW_DATA) + queue_work(ipc->workqueue, &ipc->irq_work); +} + +static void qtnf_shm_ipc_irq_outbound_handler(struct qtnf_shm_ipc *ipc) +{ + u32 flags; + + if (!READ_ONCE(ipc->waiting_for_ack)) + return; + + flags = readl(&ipc->shm_region->headroom.hdr.flags); + + if (flags & QTNF_SHM_IPC_ACK) { + WRITE_ONCE(ipc->waiting_for_ack, 0); + complete(&ipc->tx_completion); + } +} + +int qtnf_shm_ipc_init(struct qtnf_shm_ipc *ipc, + enum qtnf_shm_ipc_direction direction, + struct qtnf_shm_ipc_region __iomem *shm_region, + struct workqueue_struct *workqueue, + const struct qtnf_shm_ipc_int *interrupt, + const struct qtnf_shm_ipc_rx_callback *rx_callback) +{ + BUILD_BUG_ON(offsetof(struct qtnf_shm_ipc_region, data) != + QTN_IPC_REG_HDR_SZ); + BUILD_BUG_ON(sizeof(struct qtnf_shm_ipc_region) > QTN_IPC_REG_SZ); + + ipc->shm_region = shm_region; + ipc->direction = direction; + ipc->interrupt = *interrupt; + ipc->rx_callback = *rx_callback; + ipc->tx_packet_count = 0; + ipc->rx_packet_count = 0; + ipc->workqueue = workqueue; + ipc->waiting_for_ack = 0; + ipc->tx_timeout_count = 0; + + switch (direction) { + case QTNF_SHM_IPC_OUTBOUND: + ipc->irq_handler = qtnf_shm_ipc_irq_outbound_handler; + break; + case QTNF_SHM_IPC_INBOUND: + ipc->irq_handler = qtnf_shm_ipc_irq_inbound_handler; + break; + default: + return -EINVAL; + } + + INIT_WORK(&ipc->irq_work, qtnf_shm_ipc_irq_work); + init_completion(&ipc->tx_completion); + + return 0; +} + +void qtnf_shm_ipc_free(struct qtnf_shm_ipc *ipc) +{ + complete_all(&ipc->tx_completion); +} + +int qtnf_shm_ipc_send(struct qtnf_shm_ipc *ipc, const u8 *buf, size_t size) +{ + int ret = 0; + struct qtnf_shm_ipc_region_header __iomem *shm_reg_hdr; + + shm_reg_hdr = &ipc->shm_region->headroom.hdr; + + if (unlikely(size > QTN_IPC_MAX_DATA_SZ)) + return -E2BIG; + + ipc->tx_packet_count++; + + writew(size, &shm_reg_hdr->data_len); + memcpy_toio(ipc->shm_region->data, buf, size); + + /* sync previous writes before proceeding */ + dma_wmb(); + + WRITE_ONCE(ipc->waiting_for_ack, 1); + + /* sync previous memory write before announcing new data ready */ + wmb(); + + writel(QTNF_SHM_IPC_NEW_DATA, &shm_reg_hdr->flags); + readl(&shm_reg_hdr->flags); /* flush PCIe write */ + + ipc->interrupt.fn(ipc->interrupt.arg); + + if (!wait_for_completion_timeout(&ipc->tx_completion, + QTN_SHM_IPC_ACK_TIMEOUT)) { + ret = -ETIMEDOUT; + ipc->tx_timeout_count++; + pr_err("TX ACK timeout\n"); + } + + /* now we're not waiting for ACK even in case of timeout */ + WRITE_ONCE(ipc->waiting_for_ack, 0); + + return ret; +} |