+++ /dev/null
-.. SPDX-License-Identifier: GPL-2.0
-
-================
-CAIF SPI porting
-================
-
-CAIF SPI basics
-===============
-
-Running CAIF over SPI needs some extra setup, owing to the nature of SPI.
-Two extra GPIOs have been added in order to negotiate the transfers
-between the master and the slave. The minimum requirement for running
-CAIF over SPI is a SPI slave chip and two GPIOs (more details below).
-Please note that running as a slave implies that you need to keep up
-with the master clock. An overrun or underrun event is fatal.
-
-CAIF SPI framework
-==================
-
-To make porting as easy as possible, the CAIF SPI has been divided in
-two parts. The first part (called the interface part) deals with all
-generic functionality such as length framing, SPI frame negotiation
-and SPI frame delivery and transmission. The other part is the CAIF
-SPI slave device part, which is the module that you have to write if
-you want to run SPI CAIF on a new hardware. This part takes care of
-the physical hardware, both with regard to SPI and to GPIOs.
-
-- Implementing a CAIF SPI device:
-
- - Functionality provided by the CAIF SPI slave device:
-
- In order to implement a SPI device you will, as a minimum,
- need to implement the following
- functions:
-
- ::
-
- int (*init_xfer) (struct cfspi_xfer * xfer, struct cfspi_dev *dev):
-
- This function is called by the CAIF SPI interface to give
- you a chance to set up your hardware to be ready to receive
- a stream of data from the master. The xfer structure contains
- both physical and logical addresses, as well as the total length
- of the transfer in both directions.The dev parameter can be used
- to map to different CAIF SPI slave devices.
-
- ::
-
- void (*sig_xfer) (bool xfer, struct cfspi_dev *dev):
-
- This function is called by the CAIF SPI interface when the output
- (SPI_INT) GPIO needs to change state. The boolean value of the xfer
- variable indicates whether the GPIO should be asserted (HIGH) or
- deasserted (LOW). The dev parameter can be used to map to different CAIF
- SPI slave devices.
-
- - Functionality provided by the CAIF SPI interface:
-
- ::
-
- void (*ss_cb) (bool assert, struct cfspi_ifc *ifc);
-
- This function is called by the CAIF SPI slave device in order to
- signal a change of state of the input GPIO (SS) to the interface.
- Only active edges are mandatory to be reported.
- This function can be called from IRQ context (recommended in order
- not to introduce latency). The ifc parameter should be the pointer
- returned from the platform probe function in the SPI device structure.
-
- ::
-
- void (*xfer_done_cb) (struct cfspi_ifc *ifc);
-
- This function is called by the CAIF SPI slave device in order to
- report that a transfer is completed. This function should only be
- called once both the transmission and the reception are completed.
- This function can be called from IRQ context (recommended in order
- not to introduce latency). The ifc parameter should be the pointer
- returned from the platform probe function in the SPI device structure.
-
- - Connecting the bits and pieces:
-
- - Filling in the SPI slave device structure:
-
- Connect the necessary callback functions.
-
- Indicate clock speed (used to calculate toggle delays).
-
- Chose a suitable name (helps debugging if you use several CAIF
- SPI slave devices).
-
- Assign your private data (can be used to map to your
- structure).
-
- - Filling in the SPI slave platform device structure:
-
- Add name of driver to connect to ("cfspi_sspi").
-
- Assign the SPI slave device structure as platform data.
-
-Padding
-=======
-
-In order to optimize throughput, a number of SPI padding options are provided.
-Padding can be enabled independently for uplink and downlink transfers.
-Padding can be enabled for the head, the tail and for the total frame size.
-The padding needs to be correctly configured on both sides of the link.
-The padding can be changed via module parameters in cfspi_sspi.c or via
-the sysfs directory of the cfspi_sspi driver (before device registration).
-
-- CAIF SPI device template::
-
- /*
- * Copyright (C) ST-Ericsson AB 2010
- * Author: Daniel Martensson / Daniel.Martensson@stericsson.com
- * License terms: GNU General Public License (GPL), version 2.
- *
- */
-
- #include <linux/init.h>
- #include <linux/module.h>
- #include <linux/device.h>
- #include <linux/wait.h>
- #include <linux/interrupt.h>
- #include <linux/dma-mapping.h>
- #include <net/caif/caif_spi.h>
-
- MODULE_LICENSE("GPL");
-
- struct sspi_struct {
- struct cfspi_dev sdev;
- struct cfspi_xfer *xfer;
- };
-
- static struct sspi_struct slave;
- static struct platform_device slave_device;
-
- static irqreturn_t sspi_irq(int irq, void *arg)
- {
- /* You only need to trigger on an edge to the active state of the
- * SS signal. Once a edge is detected, the ss_cb() function should be
- * called with the parameter assert set to true. It is OK
- * (and even advised) to call the ss_cb() function in IRQ context in
- * order not to add any delay. */
-
- return IRQ_HANDLED;
- }
-
- static void sspi_complete(void *context)
- {
- /* Normally the DMA or the SPI framework will call you back
- * in something similar to this. The only thing you need to
- * do is to call the xfer_done_cb() function, providing the pointer
- * to the CAIF SPI interface. It is OK to call this function
- * from IRQ context. */
- }
-
- static int sspi_init_xfer(struct cfspi_xfer *xfer, struct cfspi_dev *dev)
- {
- /* Store transfer info. For a normal implementation you should
- * set up your DMA here and make sure that you are ready to
- * receive the data from the master SPI. */
-
- struct sspi_struct *sspi = (struct sspi_struct *)dev->priv;
-
- sspi->xfer = xfer;
-
- return 0;
- }
-
- void sspi_sig_xfer(bool xfer, struct cfspi_dev *dev)
- {
- /* If xfer is true then you should assert the SPI_INT to indicate to
- * the master that you are ready to receive the data from the master
- * SPI. If xfer is false then you should de-assert SPI_INT to indicate
- * that the transfer is done.
- */
-
- struct sspi_struct *sspi = (struct sspi_struct *)dev->priv;
- }
-
- static void sspi_release(struct device *dev)
- {
- /*
- * Here you should release your SPI device resources.
- */
- }
-
- static int __init sspi_init(void)
- {
- /* Here you should initialize your SPI device by providing the
- * necessary functions, clock speed, name and private data. Once
- * done, you can register your device with the
- * platform_device_register() function. This function will return
- * with the CAIF SPI interface initialized. This is probably also
- * the place where you should set up your GPIOs, interrupts and SPI
- * resources. */
-
- int res = 0;
-
- /* Initialize slave device. */
- slave.sdev.init_xfer = sspi_init_xfer;
- slave.sdev.sig_xfer = sspi_sig_xfer;
- slave.sdev.clk_mhz = 13;
- slave.sdev.priv = &slave;
- slave.sdev.name = "spi_sspi";
- slave_device.dev.release = sspi_release;
-
- /* Initialize platform device. */
- slave_device.name = "cfspi_sspi";
- slave_device.dev.platform_data = &slave.sdev;
-
- /* Register platform device. */
- res = platform_device_register(&slave_device);
- if (res) {
- printk(KERN_WARNING "sspi_init: failed to register dev.\n");
- return -ENODEV;
- }
-
- return res;
- }
-
- static void __exit sspi_exit(void)
- {
- platform_device_del(&slave_device);
- }
-
- module_init(sspi_init);
- module_exit(sspi_exit);
+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Copyright (C) ST-Ericsson AB 2010
- * Author: Daniel Martensson
- */
-
-#include <linux/init.h>
-#include <linux/module.h>
-#include <linux/device.h>
-#include <linux/platform_device.h>
-#include <linux/string.h>
-#include <linux/workqueue.h>
-#include <linux/completion.h>
-#include <linux/list.h>
-#include <linux/interrupt.h>
-#include <linux/dma-mapping.h>
-#include <linux/delay.h>
-#include <linux/sched.h>
-#include <linux/debugfs.h>
-#include <linux/if_arp.h>
-#include <net/caif/caif_layer.h>
-#include <net/caif/caif_spi.h>
-
-#ifndef CONFIG_CAIF_SPI_SYNC
-#define FLAVOR "Flavour: Vanilla.\n"
-#else
-#define FLAVOR "Flavour: Master CMD&LEN at start.\n"
-#endif /* CONFIG_CAIF_SPI_SYNC */
-
-MODULE_LICENSE("GPL");
-MODULE_AUTHOR("Daniel Martensson");
-MODULE_DESCRIPTION("CAIF SPI driver");
-
-/* Returns the number of padding bytes for alignment. */
-#define PAD_POW2(x, pow) ((((x)&((pow)-1))==0) ? 0 : (((pow)-((x)&((pow)-1)))))
-
-static bool spi_loop;
-module_param(spi_loop, bool, 0444);
-MODULE_PARM_DESC(spi_loop, "SPI running in loopback mode.");
-
-/* SPI frame alignment. */
-module_param(spi_frm_align, int, 0444);
-MODULE_PARM_DESC(spi_frm_align, "SPI frame alignment.");
-
-/*
- * SPI padding options.
- * Warning: must be a base of 2 (& operation used) and can not be zero !
- */
-module_param(spi_up_head_align, int, 0444);
-MODULE_PARM_DESC(spi_up_head_align, "SPI uplink head alignment.");
-
-module_param(spi_up_tail_align, int, 0444);
-MODULE_PARM_DESC(spi_up_tail_align, "SPI uplink tail alignment.");
-
-module_param(spi_down_head_align, int, 0444);
-MODULE_PARM_DESC(spi_down_head_align, "SPI downlink head alignment.");
-
-module_param(spi_down_tail_align, int, 0444);
-MODULE_PARM_DESC(spi_down_tail_align, "SPI downlink tail alignment.");
-
-#ifdef CONFIG_ARM
-#define BYTE_HEX_FMT "%02X"
-#else
-#define BYTE_HEX_FMT "%02hhX"
-#endif
-
-#define SPI_MAX_PAYLOAD_SIZE 4096
-/*
- * Threshold values for the SPI packet queue. Flowcontrol will be asserted
- * when the number of packets exceeds HIGH_WATER_MARK. It will not be
- * deasserted before the number of packets drops below LOW_WATER_MARK.
- */
-#define LOW_WATER_MARK 100
-#define HIGH_WATER_MARK (LOW_WATER_MARK*5)
-
-#ifndef CONFIG_HAS_DMA
-
-/*
- * We sometimes use UML for debugging, but it cannot handle
- * dma_alloc_coherent so we have to wrap it.
- */
-static inline void *dma_alloc(struct cfspi *cfspi, dma_addr_t *daddr)
-{
- return kmalloc(SPI_DMA_BUF_LEN, GFP_KERNEL);
-}
-
-static inline void dma_free(struct cfspi *cfspi, void *cpu_addr,
- dma_addr_t handle)
-{
- kfree(cpu_addr);
-}
-
-#else
-
-static inline void *dma_alloc(struct cfspi *cfspi, dma_addr_t *daddr)
-{
- return dma_alloc_coherent(&cfspi->pdev->dev, SPI_DMA_BUF_LEN, daddr,
- GFP_KERNEL);
-}
-
-static inline void dma_free(struct cfspi *cfspi, void *cpu_addr,
- dma_addr_t handle)
-{
- dma_free_coherent(&cfspi->pdev->dev, SPI_DMA_BUF_LEN, cpu_addr, handle);
-}
-#endif /* CONFIG_HAS_DMA */
-
-#ifdef CONFIG_DEBUG_FS
-
-#define DEBUGFS_BUF_SIZE 4096
-
-static struct dentry *dbgfs_root;
-
-static inline void driver_debugfs_create(void)
-{
- dbgfs_root = debugfs_create_dir(cfspi_spi_driver.driver.name, NULL);
-}
-
-static inline void driver_debugfs_remove(void)
-{
- debugfs_remove(dbgfs_root);
-}
-
-static inline void dev_debugfs_rem(struct cfspi *cfspi)
-{
- debugfs_remove(cfspi->dbgfs_frame);
- debugfs_remove(cfspi->dbgfs_state);
- debugfs_remove(cfspi->dbgfs_dir);
-}
-
-static ssize_t dbgfs_state(struct file *file, char __user *user_buf,
- size_t count, loff_t *ppos)
-{
- char *buf;
- int len = 0;
- ssize_t size;
- struct cfspi *cfspi = file->private_data;
-
- buf = kzalloc(DEBUGFS_BUF_SIZE, GFP_KERNEL);
- if (!buf)
- return 0;
-
- /* Print out debug information. */
- len += scnprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
- "CAIF SPI debug information:\n");
-
- len += scnprintf((buf + len), (DEBUGFS_BUF_SIZE - len), FLAVOR);
-
- len += scnprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
- "STATE: %d\n", cfspi->dbg_state);
- len += scnprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
- "Previous CMD: 0x%x\n", cfspi->pcmd);
- len += scnprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
- "Current CMD: 0x%x\n", cfspi->cmd);
- len += scnprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
- "Previous TX len: %d\n", cfspi->tx_ppck_len);
- len += scnprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
- "Previous RX len: %d\n", cfspi->rx_ppck_len);
- len += scnprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
- "Current TX len: %d\n", cfspi->tx_cpck_len);
- len += scnprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
- "Current RX len: %d\n", cfspi->rx_cpck_len);
- len += scnprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
- "Next TX len: %d\n", cfspi->tx_npck_len);
- len += scnprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
- "Next RX len: %d\n", cfspi->rx_npck_len);
-
- if (len > DEBUGFS_BUF_SIZE)
- len = DEBUGFS_BUF_SIZE;
-
- size = simple_read_from_buffer(user_buf, count, ppos, buf, len);
- kfree(buf);
-
- return size;
-}
-
-static ssize_t print_frame(char *buf, size_t size, char *frm,
- size_t count, size_t cut)
-{
- int len = 0;
- int i;
- for (i = 0; i < count; i++) {
- len += scnprintf((buf + len), (size - len),
- "[0x" BYTE_HEX_FMT "]",
- frm[i]);
- if ((i == cut) && (count > (cut * 2))) {
- /* Fast forward. */
- i = count - cut;
- len += scnprintf((buf + len), (size - len),
- "--- %zu bytes skipped ---\n",
- count - (cut * 2));
- }
-
- if ((!(i % 10)) && i) {
- len += scnprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
- "\n");
- }
- }
- len += scnprintf((buf + len), (DEBUGFS_BUF_SIZE - len), "\n");
- return len;
-}
-
-static ssize_t dbgfs_frame(struct file *file, char __user *user_buf,
- size_t count, loff_t *ppos)
-{
- char *buf;
- int len = 0;
- ssize_t size;
- struct cfspi *cfspi;
-
- cfspi = file->private_data;
- buf = kzalloc(DEBUGFS_BUF_SIZE, GFP_KERNEL);
- if (!buf)
- return 0;
-
- /* Print out debug information. */
- len += scnprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
- "Current frame:\n");
-
- len += scnprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
- "Tx data (Len: %d):\n", cfspi->tx_cpck_len);
-
- len += print_frame((buf + len), (DEBUGFS_BUF_SIZE - len),
- cfspi->xfer.va_tx[0],
- (cfspi->tx_cpck_len + SPI_CMD_SZ), 100);
-
- len += scnprintf((buf + len), (DEBUGFS_BUF_SIZE - len),
- "Rx data (Len: %d):\n", cfspi->rx_cpck_len);
-
- len += print_frame((buf + len), (DEBUGFS_BUF_SIZE - len),
- cfspi->xfer.va_rx,
- (cfspi->rx_cpck_len + SPI_CMD_SZ), 100);
-
- size = simple_read_from_buffer(user_buf, count, ppos, buf, len);
- kfree(buf);
-
- return size;
-}
-
-static const struct file_operations dbgfs_state_fops = {
- .open = simple_open,
- .read = dbgfs_state,
- .owner = THIS_MODULE
-};
-
-static const struct file_operations dbgfs_frame_fops = {
- .open = simple_open,
- .read = dbgfs_frame,
- .owner = THIS_MODULE
-};
-
-static inline void dev_debugfs_add(struct cfspi *cfspi)
-{
- cfspi->dbgfs_dir = debugfs_create_dir(cfspi->pdev->name, dbgfs_root);
- cfspi->dbgfs_state = debugfs_create_file("state", 0444,
- cfspi->dbgfs_dir, cfspi,
- &dbgfs_state_fops);
- cfspi->dbgfs_frame = debugfs_create_file("frame", 0444,
- cfspi->dbgfs_dir, cfspi,
- &dbgfs_frame_fops);
-}
-
-inline void cfspi_dbg_state(struct cfspi *cfspi, int state)
-{
- cfspi->dbg_state = state;
-};
-#else
-
-static inline void driver_debugfs_create(void)
-{
-}
-
-static inline void driver_debugfs_remove(void)
-{
-}
-
-static inline void dev_debugfs_add(struct cfspi *cfspi)
-{
-}
-
-static inline void dev_debugfs_rem(struct cfspi *cfspi)
-{
-}
-
-inline void cfspi_dbg_state(struct cfspi *cfspi, int state)
-{
-}
-#endif /* CONFIG_DEBUG_FS */
-
-static LIST_HEAD(cfspi_list);
-static spinlock_t cfspi_list_lock;
-
-/* SPI uplink head alignment. */
-static ssize_t up_head_align_show(struct device_driver *driver, char *buf)
-{
- return sprintf(buf, "%d\n", spi_up_head_align);
-}
-
-static DRIVER_ATTR_RO(up_head_align);
-
-/* SPI uplink tail alignment. */
-static ssize_t up_tail_align_show(struct device_driver *driver, char *buf)
-{
- return sprintf(buf, "%d\n", spi_up_tail_align);
-}
-
-static DRIVER_ATTR_RO(up_tail_align);
-
-/* SPI downlink head alignment. */
-static ssize_t down_head_align_show(struct device_driver *driver, char *buf)
-{
- return sprintf(buf, "%d\n", spi_down_head_align);
-}
-
-static DRIVER_ATTR_RO(down_head_align);
-
-/* SPI downlink tail alignment. */
-static ssize_t down_tail_align_show(struct device_driver *driver, char *buf)
-{
- return sprintf(buf, "%d\n", spi_down_tail_align);
-}
-
-static DRIVER_ATTR_RO(down_tail_align);
-
-/* SPI frame alignment. */
-static ssize_t frame_align_show(struct device_driver *driver, char *buf)
-{
- return sprintf(buf, "%d\n", spi_frm_align);
-}
-
-static DRIVER_ATTR_RO(frame_align);
-
-int cfspi_xmitfrm(struct cfspi *cfspi, u8 *buf, size_t len)
-{
- u8 *dst = buf;
- caif_assert(buf);
-
- if (cfspi->slave && !cfspi->slave_talked)
- cfspi->slave_talked = true;
-
- do {
- struct sk_buff *skb;
- struct caif_payload_info *info;
- int spad = 0;
- int epad;
-
- skb = skb_dequeue(&cfspi->chead);
- if (!skb)
- break;
-
- /*
- * Calculate length of frame including SPI padding.
- * The payload position is found in the control buffer.
- */
- info = (struct caif_payload_info *)&skb->cb;
-
- /*
- * Compute head offset i.e. number of bytes to add to
- * get the start of the payload aligned.
- */
- if (spi_up_head_align > 1) {
- spad = 1 + PAD_POW2((info->hdr_len + 1), spi_up_head_align);
- *dst = (u8)(spad - 1);
- dst += spad;
- }
-
- /* Copy in CAIF frame. */
- skb_copy_bits(skb, 0, dst, skb->len);
- dst += skb->len;
- cfspi->ndev->stats.tx_packets++;
- cfspi->ndev->stats.tx_bytes += skb->len;
-
- /*
- * Compute tail offset i.e. number of bytes to add to
- * get the complete CAIF frame aligned.
- */
- epad = PAD_POW2((skb->len + spad), spi_up_tail_align);
- dst += epad;
-
- dev_kfree_skb(skb);
-
- } while ((dst - buf) < len);
-
- return dst - buf;
-}
-
-int cfspi_xmitlen(struct cfspi *cfspi)
-{
- struct sk_buff *skb = NULL;
- int frm_len = 0;
- int pkts = 0;
-
- /*
- * Decommit previously committed frames.
- * skb_queue_splice_tail(&cfspi->chead,&cfspi->qhead)
- */
- while (skb_peek(&cfspi->chead)) {
- skb = skb_dequeue_tail(&cfspi->chead);
- skb_queue_head(&cfspi->qhead, skb);
- }
-
- do {
- struct caif_payload_info *info = NULL;
- int spad = 0;
- int epad = 0;
-
- skb = skb_dequeue(&cfspi->qhead);
- if (!skb)
- break;
-
- /*
- * Calculate length of frame including SPI padding.
- * The payload position is found in the control buffer.
- */
- info = (struct caif_payload_info *)&skb->cb;
-
- /*
- * Compute head offset i.e. number of bytes to add to
- * get the start of the payload aligned.
- */
- if (spi_up_head_align > 1)
- spad = 1 + PAD_POW2((info->hdr_len + 1), spi_up_head_align);
-
- /*
- * Compute tail offset i.e. number of bytes to add to
- * get the complete CAIF frame aligned.
- */
- epad = PAD_POW2((skb->len + spad), spi_up_tail_align);
-
- if ((skb->len + spad + epad + frm_len) <= CAIF_MAX_SPI_FRAME) {
- skb_queue_tail(&cfspi->chead, skb);
- pkts++;
- frm_len += skb->len + spad + epad;
- } else {
- /* Put back packet. */
- skb_queue_head(&cfspi->qhead, skb);
- break;
- }
- } while (pkts <= CAIF_MAX_SPI_PKTS);
-
- /*
- * Send flow on if previously sent flow off
- * and now go below the low water mark
- */
- if (cfspi->flow_off_sent && cfspi->qhead.qlen < cfspi->qd_low_mark &&
- cfspi->cfdev.flowctrl) {
- cfspi->flow_off_sent = 0;
- cfspi->cfdev.flowctrl(cfspi->ndev, 1);
- }
-
- return frm_len;
-}
-
-static void cfspi_ss_cb(bool assert, struct cfspi_ifc *ifc)
-{
- struct cfspi *cfspi = (struct cfspi *)ifc->priv;
-
- /*
- * The slave device is the master on the link. Interrupts before the
- * slave has transmitted are considered spurious.
- */
- if (cfspi->slave && !cfspi->slave_talked) {
- printk(KERN_WARNING "CFSPI: Spurious SS interrupt.\n");
- return;
- }
-
- if (!in_interrupt())
- spin_lock(&cfspi->lock);
- if (assert) {
- set_bit(SPI_SS_ON, &cfspi->state);
- set_bit(SPI_XFER, &cfspi->state);
- } else {
- set_bit(SPI_SS_OFF, &cfspi->state);
- }
- if (!in_interrupt())
- spin_unlock(&cfspi->lock);
-
- /* Wake up the xfer thread. */
- if (assert)
- wake_up_interruptible(&cfspi->wait);
-}
-
-static void cfspi_xfer_done_cb(struct cfspi_ifc *ifc)
-{
- struct cfspi *cfspi = (struct cfspi *)ifc->priv;
-
- /* Transfer done, complete work queue */
- complete(&cfspi->comp);
-}
-
-static netdev_tx_t cfspi_xmit(struct sk_buff *skb, struct net_device *dev)
-{
- struct cfspi *cfspi = NULL;
- unsigned long flags;
- if (!dev)
- return -EINVAL;
-
- cfspi = netdev_priv(dev);
-
- skb_queue_tail(&cfspi->qhead, skb);
-
- spin_lock_irqsave(&cfspi->lock, flags);
- if (!test_and_set_bit(SPI_XFER, &cfspi->state)) {
- /* Wake up xfer thread. */
- wake_up_interruptible(&cfspi->wait);
- }
- spin_unlock_irqrestore(&cfspi->lock, flags);
-
- /* Send flow off if number of bytes is above high water mark */
- if (!cfspi->flow_off_sent &&
- cfspi->qhead.qlen > cfspi->qd_high_mark &&
- cfspi->cfdev.flowctrl) {
- cfspi->flow_off_sent = 1;
- cfspi->cfdev.flowctrl(cfspi->ndev, 0);
- }
-
- return NETDEV_TX_OK;
-}
-
-int cfspi_rxfrm(struct cfspi *cfspi, u8 *buf, size_t len)
-{
- u8 *src = buf;
-
- caif_assert(buf != NULL);
-
- do {
- int res;
- struct sk_buff *skb = NULL;
- int spad = 0;
- int epad = 0;
- int pkt_len = 0;
-
- /*
- * Compute head offset i.e. number of bytes added to
- * get the start of the payload aligned.
- */
- if (spi_down_head_align > 1) {
- spad = 1 + *src;
- src += spad;
- }
-
- /* Read length of CAIF frame (little endian). */
- pkt_len = *src;
- pkt_len |= ((*(src+1)) << 8) & 0xFF00;
- pkt_len += 2; /* Add FCS fields. */
-
- /* Get a suitable caif packet and copy in data. */
-
- skb = netdev_alloc_skb(cfspi->ndev, pkt_len + 1);
- caif_assert(skb != NULL);
-
- skb_put_data(skb, src, pkt_len);
- src += pkt_len;
-
- skb->protocol = htons(ETH_P_CAIF);
- skb_reset_mac_header(skb);
-
- /*
- * Push received packet up the stack.
- */
- if (!spi_loop)
- res = netif_rx_ni(skb);
- else
- res = cfspi_xmit(skb, cfspi->ndev);
-
- if (!res) {
- cfspi->ndev->stats.rx_packets++;
- cfspi->ndev->stats.rx_bytes += pkt_len;
- } else
- cfspi->ndev->stats.rx_dropped++;
-
- /*
- * Compute tail offset i.e. number of bytes added to
- * get the complete CAIF frame aligned.
- */
- epad = PAD_POW2((pkt_len + spad), spi_down_tail_align);
- src += epad;
- } while ((src - buf) < len);
-
- return src - buf;
-}
-
-static int cfspi_open(struct net_device *dev)
-{
- netif_wake_queue(dev);
- return 0;
-}
-
-static int cfspi_close(struct net_device *dev)
-{
- netif_stop_queue(dev);
- return 0;
-}
-
-static int cfspi_init(struct net_device *dev)
-{
- int res = 0;
- struct cfspi *cfspi = netdev_priv(dev);
-
- /* Set flow info. */
- cfspi->flow_off_sent = 0;
- cfspi->qd_low_mark = LOW_WATER_MARK;
- cfspi->qd_high_mark = HIGH_WATER_MARK;
-
- /* Set slave info. */
- if (!strncmp(cfspi_spi_driver.driver.name, "cfspi_sspi", 10)) {
- cfspi->slave = true;
- cfspi->slave_talked = false;
- } else {
- cfspi->slave = false;
- cfspi->slave_talked = false;
- }
-
- /* Allocate DMA buffers. */
- cfspi->xfer.va_tx[0] = dma_alloc(cfspi, &cfspi->xfer.pa_tx[0]);
- if (!cfspi->xfer.va_tx[0]) {
- res = -ENODEV;
- goto err_dma_alloc_tx_0;
- }
-
- cfspi->xfer.va_rx = dma_alloc(cfspi, &cfspi->xfer.pa_rx);
-
- if (!cfspi->xfer.va_rx) {
- res = -ENODEV;
- goto err_dma_alloc_rx;
- }
-
- /* Initialize the work queue. */
- INIT_WORK(&cfspi->work, cfspi_xfer);
-
- /* Initialize spin locks. */
- spin_lock_init(&cfspi->lock);
-
- /* Initialize flow control state. */
- cfspi->flow_stop = false;
-
- /* Initialize wait queue. */
- init_waitqueue_head(&cfspi->wait);
-
- /* Create work thread. */
- cfspi->wq = create_singlethread_workqueue(dev->name);
- if (!cfspi->wq) {
- printk(KERN_WARNING "CFSPI: failed to create work queue.\n");
- res = -ENODEV;
- goto err_create_wq;
- }
-
- /* Initialize work queue. */
- init_completion(&cfspi->comp);
-
- /* Create debugfs entries. */
- dev_debugfs_add(cfspi);
-
- /* Set up the ifc. */
- cfspi->ifc.ss_cb = cfspi_ss_cb;
- cfspi->ifc.xfer_done_cb = cfspi_xfer_done_cb;
- cfspi->ifc.priv = cfspi;
-
- /* Add CAIF SPI device to list. */
- spin_lock(&cfspi_list_lock);
- list_add_tail(&cfspi->list, &cfspi_list);
- spin_unlock(&cfspi_list_lock);
-
- /* Schedule the work queue. */
- queue_work(cfspi->wq, &cfspi->work);
-
- return 0;
-
- err_create_wq:
- dma_free(cfspi, cfspi->xfer.va_rx, cfspi->xfer.pa_rx);
- err_dma_alloc_rx:
- dma_free(cfspi, cfspi->xfer.va_tx[0], cfspi->xfer.pa_tx[0]);
- err_dma_alloc_tx_0:
- return res;
-}
-
-static void cfspi_uninit(struct net_device *dev)
-{
- struct cfspi *cfspi = netdev_priv(dev);
-
- /* Remove from list. */
- spin_lock(&cfspi_list_lock);
- list_del(&cfspi->list);
- spin_unlock(&cfspi_list_lock);
-
- cfspi->ndev = NULL;
- /* Free DMA buffers. */
- dma_free(cfspi, cfspi->xfer.va_rx, cfspi->xfer.pa_rx);
- dma_free(cfspi, cfspi->xfer.va_tx[0], cfspi->xfer.pa_tx[0]);
- set_bit(SPI_TERMINATE, &cfspi->state);
- wake_up_interruptible(&cfspi->wait);
- destroy_workqueue(cfspi->wq);
- /* Destroy debugfs directory and files. */
- dev_debugfs_rem(cfspi);
- return;
-}
-
-static const struct net_device_ops cfspi_ops = {
- .ndo_open = cfspi_open,
- .ndo_stop = cfspi_close,
- .ndo_init = cfspi_init,
- .ndo_uninit = cfspi_uninit,
- .ndo_start_xmit = cfspi_xmit
-};
-
-static void cfspi_setup(struct net_device *dev)
-{
- struct cfspi *cfspi = netdev_priv(dev);
- dev->features = 0;
- dev->netdev_ops = &cfspi_ops;
- dev->type = ARPHRD_CAIF;
- dev->flags = IFF_NOARP | IFF_POINTOPOINT;
- dev->priv_flags |= IFF_NO_QUEUE;
- dev->mtu = SPI_MAX_PAYLOAD_SIZE;
- dev->needs_free_netdev = true;
- skb_queue_head_init(&cfspi->qhead);
- skb_queue_head_init(&cfspi->chead);
- cfspi->cfdev.link_select = CAIF_LINK_HIGH_BANDW;
- cfspi->cfdev.use_frag = false;
- cfspi->cfdev.use_stx = false;
- cfspi->cfdev.use_fcs = false;
- cfspi->ndev = dev;
-}
-
-int cfspi_spi_probe(struct platform_device *pdev)
-{
- struct cfspi *cfspi = NULL;
- struct net_device *ndev;
- struct cfspi_dev *dev;
- int res;
- dev = (struct cfspi_dev *)pdev->dev.platform_data;
-
- if (!dev)
- return -ENODEV;
-
- ndev = alloc_netdev(sizeof(struct cfspi), "cfspi%d",
- NET_NAME_UNKNOWN, cfspi_setup);
- if (!ndev)
- return -ENOMEM;
-
- cfspi = netdev_priv(ndev);
- netif_stop_queue(ndev);
- cfspi->ndev = ndev;
- cfspi->pdev = pdev;
-
- /* Assign the SPI device. */
- cfspi->dev = dev;
- /* Assign the device ifc to this SPI interface. */
- dev->ifc = &cfspi->ifc;
-
- /* Register network device. */
- res = register_netdev(ndev);
- if (res) {
- printk(KERN_ERR "CFSPI: Reg. error: %d.\n", res);
- goto err_net_reg;
- }
- return res;
-
- err_net_reg:
- free_netdev(ndev);
-
- return res;
-}
-
-int cfspi_spi_remove(struct platform_device *pdev)
-{
- /* Everything is done in cfspi_uninit(). */
- return 0;
-}
-
-static void __exit cfspi_exit_module(void)
-{
- struct list_head *list_node;
- struct list_head *n;
- struct cfspi *cfspi = NULL;
-
- list_for_each_safe(list_node, n, &cfspi_list) {
- cfspi = list_entry(list_node, struct cfspi, list);
- unregister_netdev(cfspi->ndev);
- }
-
- /* Destroy sysfs files. */
- driver_remove_file(&cfspi_spi_driver.driver,
- &driver_attr_up_head_align);
- driver_remove_file(&cfspi_spi_driver.driver,
- &driver_attr_up_tail_align);
- driver_remove_file(&cfspi_spi_driver.driver,
- &driver_attr_down_head_align);
- driver_remove_file(&cfspi_spi_driver.driver,
- &driver_attr_down_tail_align);
- driver_remove_file(&cfspi_spi_driver.driver, &driver_attr_frame_align);
- /* Unregister platform driver. */
- platform_driver_unregister(&cfspi_spi_driver);
- /* Destroy debugfs root directory. */
- driver_debugfs_remove();
-}
-
-static int __init cfspi_init_module(void)
-{
- int result;
-
- /* Initialize spin lock. */
- spin_lock_init(&cfspi_list_lock);
-
- /* Register platform driver. */
- result = platform_driver_register(&cfspi_spi_driver);
- if (result) {
- printk(KERN_ERR "Could not register platform SPI driver.\n");
- goto err_dev_register;
- }
-
- /* Create sysfs files. */
- result =
- driver_create_file(&cfspi_spi_driver.driver,
- &driver_attr_up_head_align);
- if (result) {
- printk(KERN_ERR "Sysfs creation failed 1.\n");
- goto err_create_up_head_align;
- }
-
- result =
- driver_create_file(&cfspi_spi_driver.driver,
- &driver_attr_up_tail_align);
- if (result) {
- printk(KERN_ERR "Sysfs creation failed 2.\n");
- goto err_create_up_tail_align;
- }
-
- result =
- driver_create_file(&cfspi_spi_driver.driver,
- &driver_attr_down_head_align);
- if (result) {
- printk(KERN_ERR "Sysfs creation failed 3.\n");
- goto err_create_down_head_align;
- }
-
- result =
- driver_create_file(&cfspi_spi_driver.driver,
- &driver_attr_down_tail_align);
- if (result) {
- printk(KERN_ERR "Sysfs creation failed 4.\n");
- goto err_create_down_tail_align;
- }
-
- result =
- driver_create_file(&cfspi_spi_driver.driver,
- &driver_attr_frame_align);
- if (result) {
- printk(KERN_ERR "Sysfs creation failed 5.\n");
- goto err_create_frame_align;
- }
- driver_debugfs_create();
- return result;
-
- err_create_frame_align:
- driver_remove_file(&cfspi_spi_driver.driver,
- &driver_attr_down_tail_align);
- err_create_down_tail_align:
- driver_remove_file(&cfspi_spi_driver.driver,
- &driver_attr_down_head_align);
- err_create_down_head_align:
- driver_remove_file(&cfspi_spi_driver.driver,
- &driver_attr_up_tail_align);
- err_create_up_tail_align:
- driver_remove_file(&cfspi_spi_driver.driver,
- &driver_attr_up_head_align);
- err_create_up_head_align:
- platform_driver_unregister(&cfspi_spi_driver);
- err_dev_register:
- return result;
-}
-
-module_init(cfspi_init_module);
-module_exit(cfspi_exit_module);
+++ /dev/null
-// SPDX-License-Identifier: GPL-2.0-only
-/*
- * Copyright (C) ST-Ericsson AB 2010
- * Author: Daniel Martensson
- */
-#include <linux/module.h>
-#include <linux/device.h>
-#include <linux/platform_device.h>
-#include <linux/string.h>
-#include <linux/semaphore.h>
-#include <linux/workqueue.h>
-#include <linux/completion.h>
-#include <linux/list.h>
-#include <linux/interrupt.h>
-#include <linux/dma-mapping.h>
-#include <linux/delay.h>
-#include <linux/sched.h>
-#include <linux/debugfs.h>
-#include <net/caif/caif_spi.h>
-
-#ifndef CONFIG_CAIF_SPI_SYNC
-#define SPI_DATA_POS 0
-static inline int forward_to_spi_cmd(struct cfspi *cfspi)
-{
- return cfspi->rx_cpck_len;
-}
-#else
-#define SPI_DATA_POS SPI_CMD_SZ
-static inline int forward_to_spi_cmd(struct cfspi *cfspi)
-{
- return 0;
-}
-#endif
-
-int spi_frm_align = 2;
-
-/*
- * SPI padding options.
- * Warning: must be a base of 2 (& operation used) and can not be zero !
- */
-int spi_up_head_align = 1 << 1;
-int spi_up_tail_align = 1 << 0;
-int spi_down_head_align = 1 << 2;
-int spi_down_tail_align = 1 << 1;
-
-#ifdef CONFIG_DEBUG_FS
-static inline void debugfs_store_prev(struct cfspi *cfspi)
-{
- /* Store previous command for debugging reasons.*/
- cfspi->pcmd = cfspi->cmd;
- /* Store previous transfer. */
- cfspi->tx_ppck_len = cfspi->tx_cpck_len;
- cfspi->rx_ppck_len = cfspi->rx_cpck_len;
-}
-#else
-static inline void debugfs_store_prev(struct cfspi *cfspi)
-{
-}
-#endif
-
-void cfspi_xfer(struct work_struct *work)
-{
- struct cfspi *cfspi;
- u8 *ptr = NULL;
- unsigned long flags;
- int ret;
- cfspi = container_of(work, struct cfspi, work);
-
- /* Initialize state. */
- cfspi->cmd = SPI_CMD_EOT;
-
- for (;;) {
-
- cfspi_dbg_state(cfspi, CFSPI_STATE_WAITING);
-
- /* Wait for master talk or transmit event. */
- wait_event_interruptible(cfspi->wait,
- test_bit(SPI_XFER, &cfspi->state) ||
- test_bit(SPI_TERMINATE, &cfspi->state));
-
- if (test_bit(SPI_TERMINATE, &cfspi->state))
- return;
-
-#if CFSPI_DBG_PREFILL
- /* Prefill buffers for easier debugging. */
- memset(cfspi->xfer.va_tx, 0xFF, SPI_DMA_BUF_LEN);
- memset(cfspi->xfer.va_rx, 0xFF, SPI_DMA_BUF_LEN);
-#endif /* CFSPI_DBG_PREFILL */
-
- cfspi_dbg_state(cfspi, CFSPI_STATE_AWAKE);
-
- /* Check whether we have a committed frame. */
- if (cfspi->tx_cpck_len) {
- int len;
-
- cfspi_dbg_state(cfspi, CFSPI_STATE_FETCH_PKT);
-
- /* Copy committed SPI frames after the SPI indication. */
- ptr = (u8 *) cfspi->xfer.va_tx;
- ptr += SPI_IND_SZ;
- len = cfspi_xmitfrm(cfspi, ptr, cfspi->tx_cpck_len);
- WARN_ON(len != cfspi->tx_cpck_len);
- }
-
- cfspi_dbg_state(cfspi, CFSPI_STATE_GET_NEXT);
-
- /* Get length of next frame to commit. */
- cfspi->tx_npck_len = cfspi_xmitlen(cfspi);
-
- WARN_ON(cfspi->tx_npck_len > SPI_DMA_BUF_LEN);
-
- /*
- * Add indication and length at the beginning of the frame,
- * using little endian.
- */
- ptr = (u8 *) cfspi->xfer.va_tx;
- *ptr++ = SPI_CMD_IND;
- *ptr++ = (SPI_CMD_IND & 0xFF00) >> 8;
- *ptr++ = cfspi->tx_npck_len & 0x00FF;
- *ptr++ = (cfspi->tx_npck_len & 0xFF00) >> 8;
-
- /* Calculate length of DMAs. */
- cfspi->xfer.tx_dma_len = cfspi->tx_cpck_len + SPI_IND_SZ;
- cfspi->xfer.rx_dma_len = cfspi->rx_cpck_len + SPI_CMD_SZ;
-
- /* Add SPI TX frame alignment padding, if necessary. */
- if (cfspi->tx_cpck_len &&
- (cfspi->xfer.tx_dma_len % spi_frm_align)) {
-
- cfspi->xfer.tx_dma_len += spi_frm_align -
- (cfspi->xfer.tx_dma_len % spi_frm_align);
- }
-
- /* Add SPI RX frame alignment padding, if necessary. */
- if (cfspi->rx_cpck_len &&
- (cfspi->xfer.rx_dma_len % spi_frm_align)) {
-
- cfspi->xfer.rx_dma_len += spi_frm_align -
- (cfspi->xfer.rx_dma_len % spi_frm_align);
- }
-
- cfspi_dbg_state(cfspi, CFSPI_STATE_INIT_XFER);
-
- /* Start transfer. */
- ret = cfspi->dev->init_xfer(&cfspi->xfer, cfspi->dev);
- WARN_ON(ret);
-
- cfspi_dbg_state(cfspi, CFSPI_STATE_WAIT_ACTIVE);
-
- /*
- * TODO: We might be able to make an assumption if this is the
- * first loop. Make sure that minimum toggle time is respected.
- */
- udelay(MIN_TRANSITION_TIME_USEC);
-
- cfspi_dbg_state(cfspi, CFSPI_STATE_SIG_ACTIVE);
-
- /* Signal that we are ready to receive data. */
- cfspi->dev->sig_xfer(true, cfspi->dev);
-
- cfspi_dbg_state(cfspi, CFSPI_STATE_WAIT_XFER_DONE);
-
- /* Wait for transfer completion. */
- wait_for_completion(&cfspi->comp);
-
- cfspi_dbg_state(cfspi, CFSPI_STATE_XFER_DONE);
-
- if (cfspi->cmd == SPI_CMD_EOT) {
- /*
- * Clear the master talk bit. A xfer is always at
- * least two bursts.
- */
- clear_bit(SPI_SS_ON, &cfspi->state);
- }
-
- cfspi_dbg_state(cfspi, CFSPI_STATE_WAIT_INACTIVE);
-
- /* Make sure that the minimum toggle time is respected. */
- if (SPI_XFER_TIME_USEC(cfspi->xfer.tx_dma_len,
- cfspi->dev->clk_mhz) <
- MIN_TRANSITION_TIME_USEC) {
-
- udelay(MIN_TRANSITION_TIME_USEC -
- SPI_XFER_TIME_USEC
- (cfspi->xfer.tx_dma_len, cfspi->dev->clk_mhz));
- }
-
- cfspi_dbg_state(cfspi, CFSPI_STATE_SIG_INACTIVE);
-
- /* De-assert transfer signal. */
- cfspi->dev->sig_xfer(false, cfspi->dev);
-
- /* Check whether we received a CAIF packet. */
- if (cfspi->rx_cpck_len) {
- int len;
-
- cfspi_dbg_state(cfspi, CFSPI_STATE_DELIVER_PKT);
-
- /* Parse SPI frame. */
- ptr = ((u8 *)(cfspi->xfer.va_rx + SPI_DATA_POS));
-
- len = cfspi_rxfrm(cfspi, ptr, cfspi->rx_cpck_len);
- WARN_ON(len != cfspi->rx_cpck_len);
- }
-
- /* Check the next SPI command and length. */
- ptr = (u8 *) cfspi->xfer.va_rx;
-
- ptr += forward_to_spi_cmd(cfspi);
-
- cfspi->cmd = *ptr++;
- cfspi->cmd |= ((*ptr++) << 8) & 0xFF00;
- cfspi->rx_npck_len = *ptr++;
- cfspi->rx_npck_len |= ((*ptr++) << 8) & 0xFF00;
-
- WARN_ON(cfspi->rx_npck_len > SPI_DMA_BUF_LEN);
- WARN_ON(cfspi->cmd > SPI_CMD_EOT);
-
- debugfs_store_prev(cfspi);
-
- /* Check whether the master issued an EOT command. */
- if (cfspi->cmd == SPI_CMD_EOT) {
- /* Reset state. */
- cfspi->tx_cpck_len = 0;
- cfspi->rx_cpck_len = 0;
- } else {
- /* Update state. */
- cfspi->tx_cpck_len = cfspi->tx_npck_len;
- cfspi->rx_cpck_len = cfspi->rx_npck_len;
- }
-
- /*
- * Check whether we need to clear the xfer bit.
- * Spin lock needed for packet insertion.
- * Test and clear of different bits
- * are not supported.
- */
- spin_lock_irqsave(&cfspi->lock, flags);
- if (cfspi->cmd == SPI_CMD_EOT && !cfspi_xmitlen(cfspi)
- && !test_bit(SPI_SS_ON, &cfspi->state))
- clear_bit(SPI_XFER, &cfspi->state);
-
- spin_unlock_irqrestore(&cfspi->lock, flags);
- }
-}
-
-struct platform_driver cfspi_spi_driver = {
- .probe = cfspi_spi_probe,
- .remove = cfspi_spi_remove,
- .driver = {
- .name = "cfspi_sspi",
- .owner = THIS_MODULE,
- },
-};
projects / linux-2.6-microblaze.git / commitdiff