diff options
Diffstat (limited to 'drivers/soc/qcom/smd.c')
| -rw-r--r-- | drivers/soc/qcom/smd.c | 1560 |
1 files changed, 0 insertions, 1560 deletions
diff --git a/drivers/soc/qcom/smd.c b/drivers/soc/qcom/smd.c deleted file mode 100644 index 322034ab9d37..000000000000 --- a/drivers/soc/qcom/smd.c +++ /dev/null @@ -1,1560 +0,0 @@ -/* - * Copyright (c) 2015, Sony Mobile Communications AB. - * Copyright (c) 2012-2013, The Linux Foundation. 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 version 2 and - * only version 2 as published by the Free Software Foundation. - * - * 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/interrupt.h> -#include <linux/io.h> -#include <linux/mfd/syscon.h> -#include <linux/module.h> -#include <linux/of_irq.h> -#include <linux/of_platform.h> -#include <linux/platform_device.h> -#include <linux/regmap.h> -#include <linux/sched.h> -#include <linux/slab.h> -#include <linux/soc/qcom/smd.h> -#include <linux/soc/qcom/smem.h> -#include <linux/wait.h> - -/* - * The Qualcomm Shared Memory communication solution provides point-to-point - * channels for clients to send and receive streaming or packet based data. - * - * Each channel consists of a control item (channel info) and a ring buffer - * pair. The channel info carry information related to channel state, flow - * control and the offsets within the ring buffer. - * - * All allocated channels are listed in an allocation table, identifying the - * pair of items by name, type and remote processor. - * - * Upon creating a new channel the remote processor allocates channel info and - * ring buffer items from the smem heap and populate the allocation table. An - * interrupt is sent to the other end of the channel and a scan for new - * channels should be done. A channel never goes away, it will only change - * state. - * - * The remote processor signals it intent for bring up the communication - * channel by setting the state of its end of the channel to "opening" and - * sends out an interrupt. We detect this change and register a smd device to - * consume the channel. Upon finding a consumer we finish the handshake and the - * channel is up. - * - * Upon closing a channel, the remote processor will update the state of its - * end of the channel and signal us, we will then unregister any attached - * device and close our end of the channel. - * - * Devices attached to a channel can use the qcom_smd_send function to push - * data to the channel, this is done by copying the data into the tx ring - * buffer, updating the pointers in the channel info and signaling the remote - * processor. - * - * The remote processor does the equivalent when it transfer data and upon - * receiving the interrupt we check the channel info for new data and delivers - * this to the attached device. If the device is not ready to receive the data - * we leave it in the ring buffer for now. - */ - -struct smd_channel_info; -struct smd_channel_info_pair; -struct smd_channel_info_word; -struct smd_channel_info_word_pair; - -#define SMD_ALLOC_TBL_COUNT 2 -#define SMD_ALLOC_TBL_SIZE 64 - -/* - * This lists the various smem heap items relevant for the allocation table and - * smd channel entries. - */ -static const struct { - unsigned alloc_tbl_id; - unsigned info_base_id; - unsigned fifo_base_id; -} smem_items[SMD_ALLOC_TBL_COUNT] = { - { - .alloc_tbl_id = 13, - .info_base_id = 14, - .fifo_base_id = 338 - }, - { - .alloc_tbl_id = 266, - .info_base_id = 138, - .fifo_base_id = 202, - }, -}; - -/** - * struct qcom_smd_edge - representing a remote processor - * @dev: device for this edge - * @of_node: of_node handle for information related to this edge - * @edge_id: identifier of this edge - * @remote_pid: identifier of remote processor - * @irq: interrupt for signals on this edge - * @ipc_regmap: regmap handle holding the outgoing ipc register - * @ipc_offset: offset within @ipc_regmap of the register for ipc - * @ipc_bit: bit in the register at @ipc_offset of @ipc_regmap - * @channels: list of all channels detected on this edge - * @channels_lock: guard for modifications of @channels - * @allocated: array of bitmaps representing already allocated channels - * @smem_available: last available amount of smem triggering a channel scan - * @scan_work: work item for discovering new channels - * @state_work: work item for edge state changes - */ -struct qcom_smd_edge { - struct device dev; - - struct device_node *of_node; - unsigned edge_id; - unsigned remote_pid; - - int irq; - - struct regmap *ipc_regmap; - int ipc_offset; - int ipc_bit; - - struct list_head channels; - spinlock_t channels_lock; - - DECLARE_BITMAP(allocated[SMD_ALLOC_TBL_COUNT], SMD_ALLOC_TBL_SIZE); - - unsigned smem_available; - - wait_queue_head_t new_channel_event; - - struct work_struct scan_work; - struct work_struct state_work; -}; - -#define to_smd_edge(d) container_of(d, struct qcom_smd_edge, dev) - -/* - * SMD channel states. - */ -enum smd_channel_state { - SMD_CHANNEL_CLOSED, - SMD_CHANNEL_OPENING, - SMD_CHANNEL_OPENED, - SMD_CHANNEL_FLUSHING, - SMD_CHANNEL_CLOSING, - SMD_CHANNEL_RESET, - SMD_CHANNEL_RESET_OPENING -}; - -/** - * struct qcom_smd_channel - smd channel struct - * @edge: qcom_smd_edge this channel is living on - * @qsdev: reference to a associated smd client device - * @name: name of the channel - * @state: local state of the channel - * @remote_state: remote state of the channel - * @info: byte aligned outgoing/incoming channel info - * @info_word: word aligned outgoing/incoming channel info - * @tx_lock: lock to make writes to the channel mutually exclusive - * @fblockread_event: wakeup event tied to tx fBLOCKREADINTR - * @tx_fifo: pointer to the outgoing ring buffer - * @rx_fifo: pointer to the incoming ring buffer - * @fifo_size: size of each ring buffer - * @bounce_buffer: bounce buffer for reading wrapped packets - * @cb: callback function registered for this channel - * @recv_lock: guard for rx info modifications and cb pointer - * @pkt_size: size of the currently handled packet - * @list: lite entry for @channels in qcom_smd_edge - */ -struct qcom_smd_channel { - struct qcom_smd_edge *edge; - - struct qcom_smd_device *qsdev; - - char *name; - enum smd_channel_state state; - enum smd_channel_state remote_state; - - struct smd_channel_info_pair *info; - struct smd_channel_info_word_pair *info_word; - - struct mutex tx_lock; - wait_queue_head_t fblockread_event; - - void *tx_fifo; - void *rx_fifo; - int fifo_size; - - void *bounce_buffer; - qcom_smd_cb_t cb; - - spinlock_t recv_lock; - - int pkt_size; - - void *drvdata; - - struct list_head list; -}; - -/* - * Format of the smd_info smem items, for byte aligned channels. - */ -struct smd_channel_info { - __le32 state; - u8 fDSR; - u8 fCTS; - u8 fCD; - u8 fRI; - u8 fHEAD; - u8 fTAIL; - u8 fSTATE; - u8 fBLOCKREADINTR; - __le32 tail; - __le32 head; -}; - -struct smd_channel_info_pair { - struct smd_channel_info tx; - struct smd_channel_info rx; -}; - -/* - * Format of the smd_info smem items, for word aligned channels. - */ -struct smd_channel_info_word { - __le32 state; - __le32 fDSR; - __le32 fCTS; - __le32 fCD; - __le32 fRI; - __le32 fHEAD; - __le32 fTAIL; - __le32 fSTATE; - __le32 fBLOCKREADINTR; - __le32 tail; - __le32 head; -}; - -struct smd_channel_info_word_pair { - struct smd_channel_info_word tx; - struct smd_channel_info_word rx; -}; - -#define GET_RX_CHANNEL_FLAG(channel, param) \ - ({ \ - BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u8)); \ - channel->info_word ? \ - le32_to_cpu(channel->info_word->rx.param) : \ - channel->info->rx.param; \ - }) - -#define GET_RX_CHANNEL_INFO(channel, param) \ - ({ \ - BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u32)); \ - le32_to_cpu(channel->info_word ? \ - channel->info_word->rx.param : \ - channel->info->rx.param); \ - }) - -#define SET_RX_CHANNEL_FLAG(channel, param, value) \ - ({ \ - BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u8)); \ - if (channel->info_word) \ - channel->info_word->rx.param = cpu_to_le32(value); \ - else \ - channel->info->rx.param = value; \ - }) - -#define SET_RX_CHANNEL_INFO(channel, param, value) \ - ({ \ - BUILD_BUG_ON(sizeof(channel->info->rx.param) != sizeof(u32)); \ - if (channel->info_word) \ - channel->info_word->rx.param = cpu_to_le32(value); \ - else \ - channel->info->rx.param = cpu_to_le32(value); \ - }) - -#define GET_TX_CHANNEL_FLAG(channel, param) \ - ({ \ - BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u8)); \ - channel->info_word ? \ - le32_to_cpu(channel->info_word->tx.param) : \ - channel->info->tx.param; \ - }) - -#define GET_TX_CHANNEL_INFO(channel, param) \ - ({ \ - BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u32)); \ - le32_to_cpu(channel->info_word ? \ - channel->info_word->tx.param : \ - channel->info->tx.param); \ - }) - -#define SET_TX_CHANNEL_FLAG(channel, param, value) \ - ({ \ - BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u8)); \ - if (channel->info_word) \ - channel->info_word->tx.param = cpu_to_le32(value); \ - else \ - channel->info->tx.param = value; \ - }) - -#define SET_TX_CHANNEL_INFO(channel, param, value) \ - ({ \ - BUILD_BUG_ON(sizeof(channel->info->tx.param) != sizeof(u32)); \ - if (channel->info_word) \ - channel->info_word->tx.param = cpu_to_le32(value); \ - else \ - channel->info->tx.param = cpu_to_le32(value); \ - }) - -/** - * struct qcom_smd_alloc_entry - channel allocation entry - * @name: channel name - * @cid: channel index - * @flags: channel flags and edge id - * @ref_count: reference count of the channel - */ -struct qcom_smd_alloc_entry { - u8 name[20]; - __le32 cid; - __le32 flags; - __le32 ref_count; -} __packed; - -#define SMD_CHANNEL_FLAGS_EDGE_MASK 0xff -#define SMD_CHANNEL_FLAGS_STREAM BIT(8) -#define SMD_CHANNEL_FLAGS_PACKET BIT(9) - -/* - * Each smd packet contains a 20 byte header, with the first 4 being the length - * of the packet. - */ -#define SMD_PACKET_HEADER_LEN 20 - -/* - * Signal the remote processor associated with 'channel'. - */ -static void qcom_smd_signal_channel(struct qcom_smd_channel *channel) -{ - struct qcom_smd_edge *edge = channel->edge; - - regmap_write(edge->ipc_regmap, edge->ipc_offset, BIT(edge->ipc_bit)); -} - -/* - * Initialize the tx channel info - */ -static void qcom_smd_channel_reset(struct qcom_smd_channel *channel) -{ - SET_TX_CHANNEL_INFO(channel, state, SMD_CHANNEL_CLOSED); - SET_TX_CHANNEL_FLAG(channel, fDSR, 0); - SET_TX_CHANNEL_FLAG(channel, fCTS, 0); - SET_TX_CHANNEL_FLAG(channel, fCD, 0); - SET_TX_CHANNEL_FLAG(channel, fRI, 0); - SET_TX_CHANNEL_FLAG(channel, fHEAD, 0); - SET_TX_CHANNEL_FLAG(channel, fTAIL, 0); - SET_TX_CHANNEL_FLAG(channel, fSTATE, 1); - SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 1); - SET_TX_CHANNEL_INFO(channel, head, 0); - SET_RX_CHANNEL_INFO(channel, tail, 0); - - qcom_smd_signal_channel(channel); - - channel->state = SMD_CHANNEL_CLOSED; - channel->pkt_size = 0; -} - -/* - * Set the callback for a channel, with appropriate locking - */ -static void qcom_smd_channel_set_callback(struct qcom_smd_channel *channel, - qcom_smd_cb_t cb) -{ - unsigned long flags; - - spin_lock_irqsave(&channel->recv_lock, flags); - channel->cb = cb; - spin_unlock_irqrestore(&channel->recv_lock, flags); -}; - -/* - * Calculate the amount of data available in the rx fifo - */ -static size_t qcom_smd_channel_get_rx_avail(struct qcom_smd_channel *channel) -{ - unsigned head; - unsigned tail; - - head = GET_RX_CHANNEL_INFO(channel, head); - tail = GET_RX_CHANNEL_INFO(channel, tail); - - return (head - tail) & (channel->fifo_size - 1); -} - -/* - * Set tx channel state and inform the remote processor - */ -static void qcom_smd_channel_set_state(struct qcom_smd_channel *channel, - int state) -{ - struct qcom_smd_edge *edge = channel->edge; - bool is_open = state == SMD_CHANNEL_OPENED; - - if (channel->state == state) - return; - - dev_dbg(&edge->dev, "set_state(%s, %d)\n", channel->name, state); - - SET_TX_CHANNEL_FLAG(channel, fDSR, is_open); - SET_TX_CHANNEL_FLAG(channel, fCTS, is_open); - SET_TX_CHANNEL_FLAG(channel, fCD, is_open); - - SET_TX_CHANNEL_INFO(channel, state, state); - SET_TX_CHANNEL_FLAG(channel, fSTATE, 1); - - channel->state = state; - qcom_smd_signal_channel(channel); -} - -/* - * Copy count bytes of data using 32bit accesses, if that's required. - */ -static void smd_copy_to_fifo(void __iomem *dst, - const void *src, - size_t count, - bool word_aligned) -{ - if (word_aligned) { - __iowrite32_copy(dst, src, count / sizeof(u32)); - } else { - memcpy_toio(dst, src, count); - } -} - -/* - * Copy count bytes of data using 32bit accesses, if that is required. - */ -static void smd_copy_from_fifo(void *dst, - const void __iomem *src, - size_t count, - bool word_aligned) -{ - if (word_aligned) { - __ioread32_copy(dst, src, count / sizeof(u32)); - } else { - memcpy_fromio(dst, src, count); - } -} - -/* - * Read count bytes of data from the rx fifo into buf, but don't advance the - * tail. - */ -static size_t qcom_smd_channel_peek(struct qcom_smd_channel *channel, - void *buf, size_t count) -{ - bool word_aligned; - unsigned tail; - size_t len; - - word_aligned = channel->info_word; - tail = GET_RX_CHANNEL_INFO(channel, tail); - - len = min_t(size_t, count, channel->fifo_size - tail); - if (len) { - smd_copy_from_fifo(buf, - channel->rx_fifo + tail, - len, - word_aligned); - } - - if (len != count) { - smd_copy_from_fifo(buf + len, - channel->rx_fifo, - count - len, - word_aligned); - } - - return count; -} - -/* - * Advance the rx tail by count bytes. - */ -static void qcom_smd_channel_advance(struct qcom_smd_channel *channel, - size_t count) -{ - unsigned tail; - - tail = GET_RX_CHANNEL_INFO(channel, tail); - tail += count; - tail &= (channel->fifo_size - 1); - SET_RX_CHANNEL_INFO(channel, tail, tail); -} - -/* - * Read out a single packet from the rx fifo and deliver it to the device - */ -static int qcom_smd_channel_recv_single(struct qcom_smd_channel *channel) -{ - unsigned tail; - size_t len; - void *ptr; - int ret; - - if (!channel->cb) - return 0; - - tail = GET_RX_CHANNEL_INFO(channel, tail); - - /* Use bounce buffer if the data wraps */ - if (tail + channel->pkt_size >= channel->fifo_size) { - ptr = channel->bounce_buffer; - len = qcom_smd_channel_peek(channel, ptr, channel->pkt_size); - } else { - ptr = channel->rx_fifo + tail; - len = channel->pkt_size; - } - - ret = channel->cb(channel, ptr, len); - if (ret < 0) - return ret; - - /* Only forward the tail if the client consumed the data */ - qcom_smd_channel_advance(channel, len); - - channel->pkt_size = 0; - - return 0; -} - -/* - * Per channel interrupt handling - */ -static bool qcom_smd_channel_intr(struct qcom_smd_channel *channel) -{ - bool need_state_scan = false; - int remote_state; - __le32 pktlen; - int avail; - int ret; - - /* Handle state changes */ - remote_state = GET_RX_CHANNEL_INFO(channel, state); - if (remote_state != channel->remote_state) { - channel->remote_state = remote_state; - need_state_scan = true; - } - /* Indicate that we have seen any state change */ - SET_RX_CHANNEL_FLAG(channel, fSTATE, 0); - - /* Signal waiting qcom_smd_send() about the interrupt */ - if (!GET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR)) - wake_up_interruptible(&channel->fblockread_event); - - /* Don't consume any data until we've opened the channel */ - if (channel->state != SMD_CHANNEL_OPENED) - goto out; - - /* Indicate that we've seen the new data */ - SET_RX_CHANNEL_FLAG(channel, fHEAD, 0); - - /* Consume data */ - for (;;) { - avail = qcom_smd_channel_get_rx_avail(channel); - - if (!channel->pkt_size && avail >= SMD_PACKET_HEADER_LEN) { - qcom_smd_channel_peek(channel, &pktlen, sizeof(pktlen)); - qcom_smd_channel_advance(channel, SMD_PACKET_HEADER_LEN); - channel->pkt_size = le32_to_cpu(pktlen); - } else if (channel->pkt_size && avail >= channel->pkt_size) { - ret = qcom_smd_channel_recv_single(channel); - if (ret) - break; - } else { - break; - } - } - - /* Indicate that we have seen and updated tail */ - SET_RX_CHANNEL_FLAG(channel, fTAIL, 1); - - /* Signal the remote that we've consumed the data (if requested) */ - if (!GET_RX_CHANNEL_FLAG(channel, fBLOCKREADINTR)) { - /* Ensure ordering of channel info updates */ - wmb(); - - qcom_smd_signal_channel(channel); - } - -out: - return need_state_scan; -} - -/* - * The edge interrupts are triggered by the remote processor on state changes, - * channel info updates or when new channels are created. - */ -static irqreturn_t qcom_smd_edge_intr(int irq, void *data) -{ - struct qcom_smd_edge *edge = data; - struct qcom_smd_channel *channel; - unsigned available; - bool kick_scanner = false; - bool kick_state = false; - - /* - * Handle state changes or data on each of the channels on this edge - */ - spin_lock(&edge->channels_lock); - list_for_each_entry(channel, &edge->channels, list) { - spin_lock(&channel->recv_lock); - kick_state |= qcom_smd_channel_intr(channel); - spin_unlock(&channel->recv_lock); - } - spin_unlock(&edge->channels_lock); - - /* - * Creating a new channel requires allocating an smem entry, so we only - * have to scan if the amount of available space in smem have changed - * since last scan. - */ - available = qcom_smem_get_free_space(edge->remote_pid); - if (available != edge->smem_available) { - edge->smem_available = available; - kick_scanner = true; - } - - if (kick_scanner) - schedule_work(&edge->scan_work); - if (kick_state) - schedule_work(&edge->state_work); - - return IRQ_HANDLED; -} - -/* - * Delivers any outstanding packets in the rx fifo, can be used after probe of - * the clients to deliver any packets that wasn't delivered before the client - * was setup. - */ -static void qcom_smd_channel_resume(struct qcom_smd_channel *channel) -{ - unsigned long flags; - - spin_lock_irqsave(&channel->recv_lock, flags); - qcom_smd_channel_intr(channel); - spin_unlock_irqrestore(&channel->recv_lock, flags); -} - -/* - * Calculate how much space is available in the tx fifo. - */ -static size_t qcom_smd_get_tx_avail(struct qcom_smd_channel *channel) -{ - unsigned head; - unsigned tail; - unsigned mask = channel->fifo_size - 1; - - head = GET_TX_CHANNEL_INFO(channel, head); - tail = GET_TX_CHANNEL_INFO(channel, tail); - - return mask - ((head - tail) & mask); -} - -/* - * Write count bytes of data into channel, possibly wrapping in the ring buffer - */ -static int qcom_smd_write_fifo(struct qcom_smd_channel *channel, - const void *data, - size_t count) -{ - bool word_aligned; - unsigned head; - size_t len; - - word_aligned = channel->info_word; - head = GET_TX_CHANNEL_INFO(channel, head); - - len = min_t(size_t, count, channel->fifo_size - head); - if (len) { - smd_copy_to_fifo(channel->tx_fifo + head, - data, - len, - word_aligned); - } - - if (len != count) { - smd_copy_to_fifo(channel->tx_fifo, - data + len, - count - len, - word_aligned); - } - - head += count; - head &= (channel->fifo_size - 1); - SET_TX_CHANNEL_INFO(channel, head, head); - - return count; -} - -/** - * qcom_smd_send - write data to smd channel - * @channel: channel handle - * @data: buffer of data to write - * @len: number of bytes to write - * - * This is a blocking write of len bytes into the channel's tx ring buffer and - * signal the remote end. It will sleep until there is enough space available - * in the tx buffer, utilizing the fBLOCKREADINTR signaling mechanism to avoid - * polling. - */ -int qcom_smd_send(struct qcom_smd_channel *channel, const void *data, int len) -{ - __le32 hdr[5] = { cpu_to_le32(len), }; - int tlen = sizeof(hdr) + len; - int ret; - - /* Word aligned channels only accept word size aligned data */ - if (channel->info_word && len % 4) - return -EINVAL; - - /* Reject packets that are too big */ - if (tlen >= channel->fifo_size) - return -EINVAL; - - ret = mutex_lock_interruptible(&channel->tx_lock); - if (ret) - return ret; - - while (qcom_smd_get_tx_avail(channel) < tlen) { - if (channel->state != SMD_CHANNEL_OPENED) { - ret = -EPIPE; - goto out; - } - - SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 0); - - ret = wait_event_interruptible(channel->fblockread_event, - qcom_smd_get_tx_avail(channel) >= tlen || - channel->state != SMD_CHANNEL_OPENED); - if (ret) - goto out; - - SET_TX_CHANNEL_FLAG(channel, fBLOCKREADINTR, 1); - } - - SET_TX_CHANNEL_FLAG(channel, fTAIL, 0); - - qcom_smd_write_fifo(channel, hdr, sizeof(hdr)); - qcom_smd_write_fifo(channel, data, len); - - SET_TX_CHANNEL_FLAG(channel, fHEAD, 1); - - /* Ensure ordering of channel info updates */ - wmb(); - - qcom_smd_signal_channel(channel); - -out: - mutex_unlock(&channel->tx_lock); - - return ret; -} -EXPORT_SYMBOL(qcom_smd_send); - -static struct qcom_smd_device *to_smd_device(struct device *dev) -{ - return container_of(dev, struct qcom_smd_device, dev); -} - -static struct qcom_smd_driver *to_smd_driver(struct device *dev) -{ - struct qcom_smd_device *qsdev = to_smd_device(dev); - - return container_of(qsdev->dev.driver, struct qcom_smd_driver, driver); -} - -static int qcom_smd_dev_match(struct device *dev, struct device_driver *drv) -{ - struct qcom_smd_device *qsdev = to_smd_device(dev); - struct qcom_smd_driver *qsdrv = container_of(drv, struct qcom_smd_driver, driver); - const struct qcom_smd_id *match = qsdrv->smd_match_table; - const char *name = qsdev->channel->name; - - if (match) { - while (match->name[0]) { - if (!strcmp(match->name, name)) - return 1; - match++; - } - } - - return of_driver_match_device(dev, drv); -} - -/* - * Helper for opening a channel - */ -static int qcom_smd_channel_open(struct qcom_smd_channel *channel, - qcom_smd_cb_t cb) -{ - size_t bb_size; - - /* - * Packets are maximum 4k, but reduce if the fifo is smaller - */ - bb_size = min(channel->fifo_size, SZ_4K); - channel->bounce_buffer = kmalloc(bb_size, GFP_KERNEL); - if (!channel->bounce_buffer) - return -ENOMEM; - - qcom_smd_channel_set_callback(channel, cb); - qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENING); - qcom_smd_channel_set_state(channel, SMD_CHANNEL_OPENED); - - return 0; -} - -/* - * Helper for closing and resetting a channel - */ -static void qcom_smd_channel_close(struct qcom_smd_channel *channel) -{ - qcom_smd_channel_set_callback(channel, NULL); - - kfree(channel->bounce_buffer); - channel->bounce_buffer = NULL; - - qcom_smd_channel_set_state(channel, SMD_CHANNEL_CLOSED); - qcom_smd_channel_reset(channel); -} - -/* - * Probe the smd client. - * - * The remote side have indicated that it want the channel to be opened, so - * complete the state handshake and probe our client driver. - */ -static int qcom_smd_dev_probe(struct device *dev) -{ - struct qcom_smd_device *qsdev = to_smd_device(dev); - struct qcom_smd_driver *qsdrv = to_smd_driver(dev); - struct qcom_smd_channel *channel = qsdev->channel; - int ret; - - ret = qcom_smd_channel_open(channel, qsdrv->callback); - if (ret) - return ret; - - ret = qsdrv->probe(qsdev); - if (ret) - goto err; - - qcom_smd_channel_resume(channel); - - return 0; - -err: - dev_err(&qsdev->dev, "probe failed\n"); - - qcom_smd_channel_close(channel); - return ret; -} - -/* - * Remove the smd client. - * - * The channel is going away, for some reason, so remove the smd client and - * reset the channel state. - */ -static int qcom_smd_dev_remove(struct device *dev) -{ - struct qcom_smd_device *qsdev = to_smd_device(dev); - struct qcom_smd_driver *qsdrv = to_smd_driver(dev); - struct qcom_smd_channel *channel = qsdev->channel; - - qcom_smd_channel_set_state(channel, SMD_CHANNEL_CLOSING); - - /* - * Make sure we don't race with the code receiving data. - */ - qcom_smd_channel_set_callback(channel, NULL); - - /* Wake up any sleepers in qcom_smd_send() */ - wake_up_interruptible(&channel->fblockread_event); - - /* - * We expect that the client might block in remove() waiting for any - * outstanding calls to qcom_smd_send() to wake up and finish. - */ - if (qsdrv->remove) - qsdrv->remove(qsdev); - - /* The client is now gone, close the primary channel */ - qcom_smd_channel_close(channel); - channel->qsdev = NULL; - - return 0; -} - -static struct bus_type qcom_smd_bus = { - .name = "qcom_smd", - .match = qcom_smd_dev_match, - .probe = qcom_smd_dev_probe, - .remove = qcom_smd_dev_remove, -}; - -/* - * Release function for the qcom_smd_device object. - */ -static void qcom_smd_release_device(struct device *dev) -{ - struct qcom_smd_device *qsdev = to_smd_device(dev); - - kfree(qsdev); -} - -/* - * Finds the device_node for the smd child interested in this channel. - */ -static struct device_node *qcom_smd_match_channel(struct device_node *edge_node, - const char *channel) -{ - struct device_node *child; - const char *name; - const char *key; - int ret; - - for_each_available_child_of_node(edge_node, child) { - key = "qcom,smd-channels"; - ret = of_property_read_string(child, key, &name); - if (ret) - continue; - - if (strcmp(name, channel) == 0) - return child; - } - - return NULL; -} - -/* - * Create a smd client device for channel that is being opened. - */ -static int qcom_smd_create_device(struct qcom_smd_channel *channel) -{ - struct qcom_smd_device *qsdev; - struct qcom_smd_edge *edge = channel->edge; - struct device_node *node; - int ret; - - if (channel->qsdev) - return -EEXIST; - - dev_dbg(&edge->dev, "registering '%s'\n", channel->name); - - qsdev = kzalloc(sizeof(*qsdev), GFP_KERNEL); - if (!qsdev) - return -ENOMEM; - - node = qcom_smd_match_channel(edge->of_node, channel->name); - dev_set_name(&qsdev->dev, "%s.%s", - edge->of_node->name, - node ? node->name : channel->name); - - qsdev->dev.parent = &edge->dev; - qsdev->dev.bus = &qcom_smd_bus; - qsdev->dev.release = qcom_smd_release_device; - qsdev->dev.of_node = node; - - qsdev->channel = channel; - - channel->qsdev = qsdev; - - ret = device_register(&qsdev->dev); - if (ret) { - dev_err(&edge->dev, "device_register failed: %d\n", ret); - put_device(&qsdev->dev); - } - - return ret; -} - -/* - * Destroy a smd client device for a channel that's going away. - */ -static void qcom_smd_destroy_device(struct qcom_smd_channel *channel) -{ - struct device *dev; - - BUG_ON(!channel->qsdev); - - dev = &channel->qsdev->dev; - - device_unregister(dev); - of_node_put(dev->of_node); - put_device(dev); -} - -/** - * qcom_smd_driver_register - register a smd driver - * @qsdrv: qcom_smd_driver struct - */ -int qcom_smd_driver_register(struct qcom_smd_driver *qsdrv) -{ - qsdrv->driver.bus = &qcom_smd_bus; - return driver_register(&qsdrv->driver); -} -EXPORT_SYMBOL(qcom_smd_driver_register); - -void *qcom_smd_get_drvdata(struct qcom_smd_channel *channel) -{ - return channel->drvdata; -} -EXPORT_SYMBOL(qcom_smd_get_drvdata); - -void qcom_smd_set_drvdata(struct qcom_smd_channel *channel, void *data) -{ - channel->drvdata = data; -} -EXPORT_SYMBOL(qcom_smd_set_drvdata); - -/** - * qcom_smd_driver_unregister - unregister a smd driver - * @qsdrv: qcom_smd_driver struct - */ -void qcom_smd_driver_unregister(struct qcom_smd_driver *qsdrv) -{ - driver_unregister(&qsdrv->driver); -} -EXPORT_SYMBOL(qcom_smd_driver_unregister); - -static struct qcom_smd_channel * -qcom_smd_find_channel(struct qcom_smd_edge *edge, const char *name) -{ - struct qcom_smd_channel *channel; - struct qcom_smd_channel *ret = NULL; - unsigned long flags; - unsigned state; - - spin_lock_irqsave(&edge->channels_lock, flags); - list_for_each_entry(channel, &edge->channels, list) { - if (strcmp(channel->name, name)) - continue; - - state = GET_RX_CHANNEL_INFO(channel, state); - if (state != SMD_CHANNEL_OPENING && - state != SMD_CHANNEL_OPENED) - continue; - - ret = channel; - break; - } - spin_unlock_irqrestore(&edge->channels_lock, flags); - - return ret; -} - -/** - * qcom_smd_open_channel() - claim additional channels on the same edge - * @sdev: smd_device handle - * @name: channel name - * @cb: callback method to use for incoming data - * - * Returns a channel handle on success, or -EPROBE_DEFER if the channel isn't - * ready. - * - * Any channels returned must be closed with a call to qcom_smd_close_channel() - */ -struct qcom_smd_channel *qcom_smd_open_channel(struct qcom_smd_channel *parent, - const char *name, - qcom_smd_cb_t cb) -{ - struct qcom_smd_channel *channel; - struct qcom_smd_device *sdev = parent->qsdev; - struct qcom_smd_edge *edge = parent->edge; - int ret; - - /* Wait up to HZ for the channel to appear */ - ret = wait_event_interruptible_timeout(edge->new_channel_event, - (channel = qcom_smd_find_channel(edge, name)) != NULL, - HZ); - if (!ret) - return ERR_PTR(-ETIMEDOUT); - - if (channel->state != SMD_CHANNEL_CLOSED) { - dev_err(&sdev->dev, "channel %s is busy\n", channel->name); - return ERR_PTR(-EBUSY); - } - - channel->qsdev = sdev; - ret = qcom_smd_channel_open(channel, cb); - if (ret) { - channel->qsdev = NULL; - return ERR_PTR(ret); - } - - return channel; -} -EXPORT_SYMBOL(qcom_smd_open_channel); - -/** - * qcom_smd_close_channel() - close an additionally opened channel - * @channel: channel handle, returned by qcom_smd_open_channel() - */ -void qcom_smd_close_channel(struct qcom_smd_channel *channel) -{ - qcom_smd_channel_close(channel); - channel->qsdev = NULL; -} -EXPORT_SYMBOL(qcom_smd_close_channel); - -/* - * Allocate the qcom_smd_channel object for a newly found smd channel, - * retrieving and validating the smem items involved. - */ -static struct qcom_smd_channel *qcom_smd_create_channel(struct qcom_smd_edge *edge, - unsigned smem_info_item, - unsigned smem_fifo_item, - char *name) -{ - struct qcom_smd_channel *channel; - size_t fifo_size; - size_t info_size; - void *fifo_base; - void *info; - int ret; - - channel = devm_kzalloc(&edge->dev, sizeof(*channel), GFP_KERNEL); - if (!channel) - return ERR_PTR(-ENOMEM); - - channel->edge = edge; - channel->name = devm_kstrdup(&edge->dev, name, GFP_KERNEL); - if (!channel->name) - return ERR_PTR(-ENOMEM); - - mutex_init(&channel->tx_lock); - spin_lock_init(&channel->recv_lock); - init_waitqueue_head(&channel->fblockread_event); - - info = qcom_smem_get(edge->remote_pid, smem_info_item, &info_size); - if (IS_ERR(info)) { - ret = PTR_ERR(info); - goto free_name_and_channel; - } - - /* - * Use the size of the item to figure out which channel info struct to - * use. - */ - if (info_size == 2 * sizeof(struct smd_channel_info_word)) { - channel->info_word = info; - } else if (info_size == 2 * sizeof(struct smd_channel_info)) { - channel->info = info; - } else { - dev_err(&edge->dev, - "channel info of size %zu not supported\n", info_size); - ret = -EINVAL; - goto free_name_and_channel; - } - - fifo_base = qcom_smem_get(edge->remote_pid, smem_fifo_item, &fifo_size); - if (IS_ERR(fifo_base)) { - ret = PTR_ERR(fifo_base); - goto free_name_and_channel; - } - - /* The channel consist of a rx and tx fifo of equal size */ - fifo_size /= 2; - - dev_dbg(&edge->dev, "new channel '%s' info-size: %zu fifo-size: %zu\n", - name, info_size, fifo_size); - - channel->tx_fifo = fifo_base; - channel->rx_fifo = fifo_base + fifo_size; - channel->fifo_size = fifo_size; - - qcom_smd_channel_reset(channel); - - return channel; - -free_name_and_channel: - devm_kfree(&edge->dev, channel->name); - devm_kfree(&edge->dev, channel); - - return ERR_PTR(ret); -} - -/* - * Scans the allocation table for any newly allocated channels, calls - * qcom_smd_create_channel() to create representations of these and add - * them to the edge's list of channels. - */ -static void qcom_channel_scan_worker(struct work_struct *work) -{ - struct qcom_smd_edge *edge = container_of(work, struct qcom_smd_edge, scan_work); - struct qcom_smd_alloc_entry *alloc_tbl; - struct qcom_smd_alloc_entry *entry; - struct qcom_smd_channel *channel; - unsigned long flags; - unsigned fifo_id; - unsigned info_id; - int tbl; - int i; - u32 eflags, cid; - - for (tbl = 0; tbl < SMD_ALLOC_TBL_COUNT; tbl++) { - alloc_tbl = qcom_smem_get(edge->remote_pid, - smem_items[tbl].alloc_tbl_id, NULL); - if (IS_ERR(alloc_tbl)) - continue; - - for (i = 0; i < SMD_ALLOC_TBL_SIZE; i++) { - entry = &alloc_tbl[i]; - eflags = le32_to_cpu(entry->flags); - if (test_bit(i, edge->allocated[tbl])) - continue; - - if (entry->ref_count == 0) - continue; - - if (!entry->name[0]) - continue; - - if (!(eflags & SMD_CHANNEL_FLAGS_PACKET)) - continue; - - if ((eflags & SMD_CHANNEL_FLAGS_EDGE_MASK) != edge->edge_id) - continue; - - cid = le32_to_cpu(entry->cid); - info_id = smem_items[tbl].info_base_id + cid; - fifo_id = smem_items[tbl].fifo_base_id + cid; - - channel = qcom_smd_create_channel(edge, info_id, fifo_id, entry->name); - if (IS_ERR(channel)) - continue; - - spin_lock_irqsave(&edge->channels_lock, flags); - list_add(&channel->list, &edge->channels); - spin_unlock_irqrestore(&edge->channels_lock, flags); - - dev_dbg(&edge->dev, "new channel found: '%s'\n", channel->name); - set_bit(i, edge->allocated[tbl]); - - wake_up_interruptible(&edge->new_channel_event); - } - } - - schedule_work(&edge->state_work); -} - -/* - * This per edge worker scans smem for any new channels and register these. It - * then scans all registered channels for state changes that should be handled - * by creating or destroying smd client devices for the registered channels. - * - * LOCKING: edge->channels_lock only needs to cover the list operations, as the - * worker is killed before any channels are deallocated - */ -static void qcom_channel_state_worker(struct work_struct *work) -{ - struct qcom_smd_channel *channel; - struct qcom_smd_edge *edge = container_of(work, - struct qcom_smd_edge, - state_work); - unsigned remote_state; - unsigned long flags; - - /* - * Register a device for any closed channel where the remote processor - * is showing interest in opening the channel. - */ - spin_lock_irqsave(&edge->channels_lock, flags); - list_for_each_entry(channel, &edge->channels, list) { - if (channel->state != SMD_CHANNEL_CLOSED) - continue; - - remote_state = GET_RX_CHANNEL_INFO(channel, state); - if (remote_state != SMD_CHANNEL_OPENING && - remote_state != SMD_CHANNEL_OPENED) - continue; - - spin_unlock_irqrestore(&edge->channels_lock, flags); - qcom_smd_create_device(channel); - spin_lock_irqsave(&edge->channels_lock, flags); - } - - /* - * Unregister the device for any channel that is opened where the - * remote processor is closing the channel. - */ - list_for_each_entry(channel, &edge->channels, list) { - if (channel->state != SMD_CHANNEL_OPENING && - channel->state != SMD_CHANNEL_OPENED) - continue; - - remote_state = GET_RX_CHANNEL_INFO(channel, state); - if (remote_state == SMD_CHANNEL_OPENING || - remote_state == SMD_CHANNEL_OPENED) - continue; - - spin_unlock_irqrestore(&edge->channels_lock, flags); - qcom_smd_destroy_device(channel); - spin_lock_irqsave(&edge->channels_lock, flags); - } - spin_unlock_irqrestore(&edge->channels_lock, flags); -} - -/* - * Parses an of_node describing an edge. - */ -static int qcom_smd_parse_edge(struct device *dev, - struct device_node *node, - struct qcom_smd_edge *edge) -{ - struct device_node *syscon_np; - const char *key; - int irq; - int ret; - - INIT_LIST_HEAD(&edge->channels); - spin_lock_init(&edge->channels_lock); - - INIT_WORK(&edge->scan_work, qcom_channel_scan_worker); - INIT_WORK(&edge->state_work, qcom_channel_state_worker); - - edge->of_node = of_node_get(node); - - key = "qcom,smd-edge"; - ret = of_property_read_u32(node, key, &edge->edge_id); - if (ret) { - dev_err(dev, "edge missing %s property\n", key); - return -EINVAL; - } - - edge->remote_pid = QCOM_SMEM_HOST_ANY; - key = "qcom,remote-pid"; - of_property_read_u32(node, key, &edge->remote_pid); - - syscon_np = of_parse_phandle(node, "qcom,ipc", 0); - if (!syscon_np) { - dev_err(dev, "no qcom,ipc node\n"); - return -ENODEV; - } - - edge->ipc_regmap = syscon_node_to_regmap(syscon_np); - if (IS_ERR(edge->ipc_regmap)) - return PTR_ERR(edge->ipc_regmap); - - key = "qcom,ipc"; - ret = of_property_read_u32_index(node, key, 1, &edge->ipc_offset); - if (ret < 0) { - dev_err(dev, "no offset in %s\n", key); - return -EINVAL; - } - - ret = of_property_read_u32_index(node, key, 2, &edge->ipc_bit); - if (ret < 0) { - dev_err(dev, "no bit in %s\n", key); - return -EINVAL; - } - - irq = irq_of_parse_and_map(node, 0); - if (irq < 0) { - dev_err(dev, "required smd interrupt missing\n"); - return -EINVAL; - } - - ret = devm_request_irq(dev, irq, - qcom_smd_edge_intr, IRQF_TRIGGER_RISING, - node->name, edge); - if (ret) { - dev_err(dev, "failed to request smd irq\n"); - return ret; - } - - edge->irq = irq; - - return 0; -} - -/* - * Release function for an edge. - * Reset the state of each associated channel and free the edge context. - */ -static void qcom_smd_edge_release(struct device *dev) -{ - struct qcom_smd_channel *channel; - struct qcom_smd_edge *edge = to_smd_edge(dev); - - list_for_each_entry(channel, &edge->channels, list) { - SET_RX_CHANNEL_INFO(channel, state, SMD_CHANNEL_CLOSED); - SET_RX_CHANNEL_INFO(channel, head, 0); - SET_RX_CHANNEL_INFO(channel, tail, 0); - } - - kfree(edge); -} - -/** - * qcom_smd_register_edge() - register an edge based on an device_node - * @parent: parent device for the edge - * @node: device_node describing the edge - * - * Returns an edge reference, or negative ERR_PTR() on failure. - */ -struct qcom_smd_edge *qcom_smd_register_edge(struct device *parent, - struct device_node *node) -{ - struct qcom_smd_edge *edge; - int ret; - - edge = kzalloc(sizeof(*edge), GFP_KERNEL); - if (!edge) - return ERR_PTR(-ENOMEM); - - init_waitqueue_head(&edge->new_channel_event); - - edge->dev.parent = parent; - edge->dev.release = qcom_smd_edge_release; - dev_set_name(&edge->dev, "%s:%s", dev_name(parent), node->name); - ret = device_register(&edge->dev); - if (ret) { - pr_err("failed to register smd edge\n"); - return ERR_PTR(ret); - } - - ret = qcom_smd_parse_edge(&edge->dev, node, edge); - if (ret) { - dev_err(&edge->dev, "failed to parse smd edge\n"); - goto unregister_dev; - } - - schedule_work(&edge->scan_work); - - return edge; - -unregister_dev: - put_device(&edge->dev); - return ERR_PTR(ret); -} -EXPORT_SYMBOL(qcom_smd_register_edge); - -static int qcom_smd_remove_device(struct device *dev, void *data) -{ - device_unregister(dev); - of_node_put(dev->of_node); - put_device(dev); - - return 0; -} - -/** - * qcom_smd_unregister_edge() - release an edge and its children - * @edge: edge reference acquired from qcom_smd_register_edge - */ -int qcom_smd_unregister_edge(struct qcom_smd_edge *edge) -{ - int ret; - - disable_irq(edge->irq); - cancel_work_sync(&edge->scan_work); - cancel_work_sync(&edge->state_work); - - ret = device_for_each_child(&edge->dev, NULL, qcom_smd_remove_device); - if (ret) - dev_warn(&edge->dev, "can't remove smd device: %d\n", ret); - - device_unregister(&edge->dev); - - return 0; -} -EXPORT_SYMBOL(qcom_smd_unregister_edge); - -static int qcom_smd_probe(struct platform_device *pdev) -{ - struct device_node *node; - void *p; - - /* Wait for smem */ - p = qcom_smem_get(QCOM_SMEM_HOST_ANY, smem_items[0].alloc_tbl_id, NULL); - if (PTR_ERR(p) == -EPROBE_DEFER) - return PTR_ERR(p); - - for_each_available_child_of_node(pdev->dev.of_node, node) - qcom_smd_register_edge(&pdev->dev, node); - - return 0; -} - -static int qcom_smd_remove_edge(struct device *dev, void *data) -{ - struct qcom_smd_edge *edge = to_smd_edge(dev); - - return qcom_smd_unregister_edge(edge); -} - -/* - * Shut down all smd clients by making sure that each edge stops processing - * events and scanning for new channels, then call destroy on the devices. - */ -static int qcom_smd_remove(struct platform_device *pdev) -{ - int ret; - - ret = device_for_each_child(&pdev->dev, NULL, qcom_smd_remove_edge); - if (ret) - dev_warn(&pdev->dev, "can't remove smd device: %d\n", ret); - - return ret; -} - -static const struct of_device_id qcom_smd_of_match[] = { - { .compatible = "qcom,smd" }, - {} -}; -MODULE_DEVICE_TABLE(of, qcom_smd_of_match); - -static struct platform_driver qcom_smd_driver = { - .probe = qcom_smd_probe, - .remove = qcom_smd_remove, - .driver = { - .name = "qcom-smd", - .of_match_table = qcom_smd_of_match, - }, -}; - -static int __init qcom_smd_init(void) -{ - int ret; - - ret = bus_register(&qcom_smd_bus); - if (ret) { - pr_err("failed to register smd bus: %d\n", ret); - return ret; - } - - return platform_driver_register(&qcom_smd_driver); -} -postcore_initcall(qcom_smd_init); - -static void __exit qcom_smd_exit(void) -{ - platform_driver_unregister(&qcom_smd_driver); - bus_unregister(&qcom_smd_bus); -} -module_exit(qcom_smd_exit); - -MODULE_AUTHOR("Bjorn Andersson <bjorn.andersson@sonymobile.com>"); -MODULE_DESCRIPTION("Qualcomm Shared Memory Driver"); -MODULE_LICENSE("GPL v2"); |