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v6.8
  1// SPDX-License-Identifier: GPL-2.0+
  2/* Copyright (c) 2015-2016 Quantenna Communications. All rights reserved. */
  3
  4#include <linux/types.h>
  5#include <linux/io.h>
  6
  7#include "shm_ipc.h"
  8
  9#undef pr_fmt
 10#define pr_fmt(fmt)	"qtnfmac shm_ipc: %s: " fmt, __func__
 11
 12static bool qtnf_shm_ipc_has_new_data(struct qtnf_shm_ipc *ipc)
 13{
 14	const u32 flags = readl(&ipc->shm_region->headroom.hdr.flags);
 15
 16	return (flags & QTNF_SHM_IPC_NEW_DATA);
 17}
 18
 19static void qtnf_shm_handle_new_data(struct qtnf_shm_ipc *ipc)
 20{
 21	size_t size;
 22	bool rx_buff_ok = true;
 23	struct qtnf_shm_ipc_region_header __iomem *shm_reg_hdr;
 24
 25	shm_reg_hdr = &ipc->shm_region->headroom.hdr;
 26
 27	size = readw(&shm_reg_hdr->data_len);
 28
 29	if (unlikely(size == 0 || size > QTN_IPC_MAX_DATA_SZ)) {
 30		pr_err("wrong rx packet size: %zu\n", size);
 31		rx_buff_ok = false;
 32	}
 33
 34	if (likely(rx_buff_ok)) {
 35		ipc->rx_packet_count++;
 36		ipc->rx_callback.fn(ipc->rx_callback.arg,
 37				    ipc->shm_region->data, size);
 38	}
 39
 40	writel(QTNF_SHM_IPC_ACK, &shm_reg_hdr->flags);
 41	readl(&shm_reg_hdr->flags); /* flush PCIe write */
 42
 43	ipc->interrupt.fn(ipc->interrupt.arg);
 44}
 45
 46static void qtnf_shm_ipc_irq_work(struct work_struct *work)
 47{
 48	struct qtnf_shm_ipc *ipc = container_of(work, struct qtnf_shm_ipc,
 49						irq_work);
 50
 51	while (qtnf_shm_ipc_has_new_data(ipc))
 52		qtnf_shm_handle_new_data(ipc);
 53}
 54
 55static void qtnf_shm_ipc_irq_inbound_handler(struct qtnf_shm_ipc *ipc)
 56{
 57	u32 flags;
 58
 59	flags = readl(&ipc->shm_region->headroom.hdr.flags);
 60
 61	if (flags & QTNF_SHM_IPC_NEW_DATA)
 62		queue_work(ipc->workqueue, &ipc->irq_work);
 63}
 64
 65static void qtnf_shm_ipc_irq_outbound_handler(struct qtnf_shm_ipc *ipc)
 66{
 67	u32 flags;
 68
 69	if (!READ_ONCE(ipc->waiting_for_ack))
 70		return;
 71
 72	flags = readl(&ipc->shm_region->headroom.hdr.flags);
 73
 74	if (flags & QTNF_SHM_IPC_ACK) {
 75		WRITE_ONCE(ipc->waiting_for_ack, 0);
 76		complete(&ipc->tx_completion);
 77	}
 78}
 79
 80int qtnf_shm_ipc_init(struct qtnf_shm_ipc *ipc,
 81		      enum qtnf_shm_ipc_direction direction,
 82		      struct qtnf_shm_ipc_region __iomem *shm_region,
 83		      struct workqueue_struct *workqueue,
 84		      const struct qtnf_shm_ipc_int *interrupt,
 85		      const struct qtnf_shm_ipc_rx_callback *rx_callback)
 86{
 87	BUILD_BUG_ON(offsetof(struct qtnf_shm_ipc_region, data) !=
 88		     QTN_IPC_REG_HDR_SZ);
 89	BUILD_BUG_ON(sizeof(struct qtnf_shm_ipc_region) > QTN_IPC_REG_SZ);
 90
 91	ipc->shm_region = shm_region;
 92	ipc->direction = direction;
 93	ipc->interrupt = *interrupt;
 94	ipc->rx_callback = *rx_callback;
 95	ipc->tx_packet_count = 0;
 96	ipc->rx_packet_count = 0;
 97	ipc->workqueue = workqueue;
 98	ipc->waiting_for_ack = 0;
 99	ipc->tx_timeout_count = 0;
100
101	switch (direction) {
102	case QTNF_SHM_IPC_OUTBOUND:
103		ipc->irq_handler = qtnf_shm_ipc_irq_outbound_handler;
104		break;
105	case QTNF_SHM_IPC_INBOUND:
106		ipc->irq_handler = qtnf_shm_ipc_irq_inbound_handler;
107		break;
108	default:
109		return -EINVAL;
110	}
111
112	INIT_WORK(&ipc->irq_work, qtnf_shm_ipc_irq_work);
113	init_completion(&ipc->tx_completion);
114
115	return 0;
116}
117
118void qtnf_shm_ipc_free(struct qtnf_shm_ipc *ipc)
119{
120	complete_all(&ipc->tx_completion);
121}
122
123int qtnf_shm_ipc_send(struct qtnf_shm_ipc *ipc, const u8 *buf, size_t size)
124{
125	int ret = 0;
126	struct qtnf_shm_ipc_region_header __iomem *shm_reg_hdr;
127
128	shm_reg_hdr = &ipc->shm_region->headroom.hdr;
129
130	if (unlikely(size > QTN_IPC_MAX_DATA_SZ))
131		return -E2BIG;
132
133	ipc->tx_packet_count++;
134
135	writew(size, &shm_reg_hdr->data_len);
136	memcpy_toio(ipc->shm_region->data, buf, size);
137
138	/* sync previous writes before proceeding */
139	dma_wmb();
140
141	WRITE_ONCE(ipc->waiting_for_ack, 1);
142
143	/* sync previous memory write before announcing new data ready */
144	wmb();
145
146	writel(QTNF_SHM_IPC_NEW_DATA, &shm_reg_hdr->flags);
147	readl(&shm_reg_hdr->flags); /* flush PCIe write */
148
149	ipc->interrupt.fn(ipc->interrupt.arg);
150
151	if (!wait_for_completion_timeout(&ipc->tx_completion,
152					 QTN_SHM_IPC_ACK_TIMEOUT)) {
153		ret = -ETIMEDOUT;
154		ipc->tx_timeout_count++;
155		pr_err("TX ACK timeout\n");
156	}
157
158	/* now we're not waiting for ACK even in case of timeout */
159	WRITE_ONCE(ipc->waiting_for_ack, 0);
160
161	return ret;
162}
v5.4
  1// SPDX-License-Identifier: GPL-2.0+
  2/* Copyright (c) 2015-2016 Quantenna Communications. All rights reserved. */
  3
  4#include <linux/types.h>
  5#include <linux/io.h>
  6
  7#include "shm_ipc.h"
  8
  9#undef pr_fmt
 10#define pr_fmt(fmt)	"qtnfmac shm_ipc: %s: " fmt, __func__
 11
 12static bool qtnf_shm_ipc_has_new_data(struct qtnf_shm_ipc *ipc)
 13{
 14	const u32 flags = readl(&ipc->shm_region->headroom.hdr.flags);
 15
 16	return (flags & QTNF_SHM_IPC_NEW_DATA);
 17}
 18
 19static void qtnf_shm_handle_new_data(struct qtnf_shm_ipc *ipc)
 20{
 21	size_t size;
 22	bool rx_buff_ok = true;
 23	struct qtnf_shm_ipc_region_header __iomem *shm_reg_hdr;
 24
 25	shm_reg_hdr = &ipc->shm_region->headroom.hdr;
 26
 27	size = readw(&shm_reg_hdr->data_len);
 28
 29	if (unlikely(size == 0 || size > QTN_IPC_MAX_DATA_SZ)) {
 30		pr_err("wrong rx packet size: %zu\n", size);
 31		rx_buff_ok = false;
 32	}
 33
 34	if (likely(rx_buff_ok)) {
 35		ipc->rx_packet_count++;
 36		ipc->rx_callback.fn(ipc->rx_callback.arg,
 37				    ipc->shm_region->data, size);
 38	}
 39
 40	writel(QTNF_SHM_IPC_ACK, &shm_reg_hdr->flags);
 41	readl(&shm_reg_hdr->flags); /* flush PCIe write */
 42
 43	ipc->interrupt.fn(ipc->interrupt.arg);
 44}
 45
 46static void qtnf_shm_ipc_irq_work(struct work_struct *work)
 47{
 48	struct qtnf_shm_ipc *ipc = container_of(work, struct qtnf_shm_ipc,
 49						irq_work);
 50
 51	while (qtnf_shm_ipc_has_new_data(ipc))
 52		qtnf_shm_handle_new_data(ipc);
 53}
 54
 55static void qtnf_shm_ipc_irq_inbound_handler(struct qtnf_shm_ipc *ipc)
 56{
 57	u32 flags;
 58
 59	flags = readl(&ipc->shm_region->headroom.hdr.flags);
 60
 61	if (flags & QTNF_SHM_IPC_NEW_DATA)
 62		queue_work(ipc->workqueue, &ipc->irq_work);
 63}
 64
 65static void qtnf_shm_ipc_irq_outbound_handler(struct qtnf_shm_ipc *ipc)
 66{
 67	u32 flags;
 68
 69	if (!READ_ONCE(ipc->waiting_for_ack))
 70		return;
 71
 72	flags = readl(&ipc->shm_region->headroom.hdr.flags);
 73
 74	if (flags & QTNF_SHM_IPC_ACK) {
 75		WRITE_ONCE(ipc->waiting_for_ack, 0);
 76		complete(&ipc->tx_completion);
 77	}
 78}
 79
 80int qtnf_shm_ipc_init(struct qtnf_shm_ipc *ipc,
 81		      enum qtnf_shm_ipc_direction direction,
 82		      struct qtnf_shm_ipc_region __iomem *shm_region,
 83		      struct workqueue_struct *workqueue,
 84		      const struct qtnf_shm_ipc_int *interrupt,
 85		      const struct qtnf_shm_ipc_rx_callback *rx_callback)
 86{
 87	BUILD_BUG_ON(offsetof(struct qtnf_shm_ipc_region, data) !=
 88		     QTN_IPC_REG_HDR_SZ);
 89	BUILD_BUG_ON(sizeof(struct qtnf_shm_ipc_region) > QTN_IPC_REG_SZ);
 90
 91	ipc->shm_region = shm_region;
 92	ipc->direction = direction;
 93	ipc->interrupt = *interrupt;
 94	ipc->rx_callback = *rx_callback;
 95	ipc->tx_packet_count = 0;
 96	ipc->rx_packet_count = 0;
 97	ipc->workqueue = workqueue;
 98	ipc->waiting_for_ack = 0;
 99	ipc->tx_timeout_count = 0;
100
101	switch (direction) {
102	case QTNF_SHM_IPC_OUTBOUND:
103		ipc->irq_handler = qtnf_shm_ipc_irq_outbound_handler;
104		break;
105	case QTNF_SHM_IPC_INBOUND:
106		ipc->irq_handler = qtnf_shm_ipc_irq_inbound_handler;
107		break;
108	default:
109		return -EINVAL;
110	}
111
112	INIT_WORK(&ipc->irq_work, qtnf_shm_ipc_irq_work);
113	init_completion(&ipc->tx_completion);
114
115	return 0;
116}
117
118void qtnf_shm_ipc_free(struct qtnf_shm_ipc *ipc)
119{
120	complete_all(&ipc->tx_completion);
121}
122
123int qtnf_shm_ipc_send(struct qtnf_shm_ipc *ipc, const u8 *buf, size_t size)
124{
125	int ret = 0;
126	struct qtnf_shm_ipc_region_header __iomem *shm_reg_hdr;
127
128	shm_reg_hdr = &ipc->shm_region->headroom.hdr;
129
130	if (unlikely(size > QTN_IPC_MAX_DATA_SZ))
131		return -E2BIG;
132
133	ipc->tx_packet_count++;
134
135	writew(size, &shm_reg_hdr->data_len);
136	memcpy_toio(ipc->shm_region->data, buf, size);
137
138	/* sync previous writes before proceeding */
139	dma_wmb();
140
141	WRITE_ONCE(ipc->waiting_for_ack, 1);
142
143	/* sync previous memory write before announcing new data ready */
144	wmb();
145
146	writel(QTNF_SHM_IPC_NEW_DATA, &shm_reg_hdr->flags);
147	readl(&shm_reg_hdr->flags); /* flush PCIe write */
148
149	ipc->interrupt.fn(ipc->interrupt.arg);
150
151	if (!wait_for_completion_timeout(&ipc->tx_completion,
152					 QTN_SHM_IPC_ACK_TIMEOUT)) {
153		ret = -ETIMEDOUT;
154		ipc->tx_timeout_count++;
155		pr_err("TX ACK timeout\n");
156	}
157
158	/* now we're not waiting for ACK even in case of timeout */
159	WRITE_ONCE(ipc->waiting_for_ack, 0);
160
161	return ret;
162}