// SPDX-License-Identifier: GPL-2.0-only
-/*
- * CAN bus driver for Microchip 251x/25625 CAN Controller with SPI Interface
+/* CAN bus driver for Microchip 251x/25625 CAN Controller with SPI Interface
*
* MCP2510 support and bug fixes by Christian Pellegrin
* <chripell@evolware.org>
* - Sascha Hauer, Marc Kleine-Budde, Pengutronix
* - Simon Kallweit, intefo AG
* Copyright 2007
- *
- * Your platform definition file should specify something like:
- *
- * static struct mcp251x_platform_data mcp251x_info = {
- * .oscillator_frequency = 8000000,
- * };
- *
- * static struct spi_board_info spi_board_info[] = {
- * {
- * .modalias = "mcp2510",
- * // "mcp2515" or "mcp25625" depending on your controller
- * .platform_data = &mcp251x_info,
- * .irq = IRQ_EINT13,
- * .max_speed_hz = 2*1000*1000,
- * .chip_select = 2,
- * },
- * };
- *
- * Please see mcp251x.h for a description of the fields in
- * struct mcp251x_platform_data.
*/
#include <linux/can/core.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/device.h>
-#include <linux/dma-mapping.h>
#include <linux/freezer.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#define RTS_TXB2 0x04
#define INSTRUCTION_RTS(n) (0x80 | ((n) & 0x07))
-
/* MPC251x registers */
#define CANSTAT 0x0e
#define CANCTRL 0x0f
#define SET_BYTE(val, byte) \
(((val) & 0xff) << ((byte) * 8))
-/*
- * Buffer size required for the largest SPI transfer (i.e., reading a
+/* Buffer size required for the largest SPI transfer (i.e., reading a
* frame)
*/
#define CAN_FRAME_MAX_DATA_LEN 8
#define DEVICE_NAME "mcp251x"
-static int mcp251x_enable_dma; /* Enable SPI DMA. Default: 0 (Off) */
-module_param(mcp251x_enable_dma, int, 0444);
-MODULE_PARM_DESC(mcp251x_enable_dma, "Enable SPI DMA. Default: 0 (Off)");
-
static const struct can_bittiming_const mcp251x_bittiming_const = {
.name = DEVICE_NAME,
.tseg1_min = 3,
u8 *spi_tx_buf;
u8 *spi_rx_buf;
- dma_addr_t spi_tx_dma;
- dma_addr_t spi_rx_dma;
struct sk_buff *tx_skb;
int tx_len;
if (priv->tx_skb || priv->tx_len)
net->stats.tx_errors++;
- if (priv->tx_skb)
- dev_kfree_skb(priv->tx_skb);
+ dev_kfree_skb(priv->tx_skb);
if (priv->tx_len)
can_free_echo_skb(priv->net, 0);
priv->tx_skb = NULL;
priv->tx_len = 0;
}
-/*
- * Note about handling of error return of mcp251x_spi_trans: accessing
+/* Note about handling of error return of mcp251x_spi_trans: accessing
* registers via SPI is not really different conceptually than using
* normal I/O assembler instructions, although it's much more
* complicated from a practical POV. So it's not advisable to always
int ret;
spi_message_init(&m);
-
- if (mcp251x_enable_dma) {
- t.tx_dma = priv->spi_tx_dma;
- t.rx_dma = priv->spi_rx_dma;
- m.is_dma_mapped = 1;
- }
-
spi_message_add_tail(&t, &m);
ret = spi_sync(spi, &m);
return ret;
}
-static u8 mcp251x_read_reg(struct spi_device *spi, uint8_t reg)
+static u8 mcp251x_read_reg(struct spi_device *spi, u8 reg)
{
struct mcp251x_priv *priv = spi_get_drvdata(spi);
u8 val = 0;
return val;
}
-static void mcp251x_read_2regs(struct spi_device *spi, uint8_t reg,
- uint8_t *v1, uint8_t *v2)
+static void mcp251x_read_2regs(struct spi_device *spi, u8 reg, u8 *v1, u8 *v2)
{
struct mcp251x_priv *priv = spi_get_drvdata(spi);
*v2 = priv->spi_rx_buf[3];
}
-static void mcp251x_write_reg(struct spi_device *spi, u8 reg, uint8_t val)
+static void mcp251x_write_reg(struct spi_device *spi, u8 reg, u8 val)
{
struct mcp251x_priv *priv = spi_get_drvdata(spi);
}
static void mcp251x_write_bits(struct spi_device *spi, u8 reg,
- u8 mask, uint8_t val)
+ u8 mask, u8 val)
{
struct mcp251x_priv *priv = spi_get_drvdata(spi);
while (mcp251x_read_reg(spi, CANSTAT) & CANCTRL_REQOP_MASK) {
schedule();
if (time_after(jiffies, timeout)) {
- dev_err(&spi->dev, "MCP251x didn't"
- " enter in normal mode\n");
+ dev_err(&spi->dev, "MCP251x didn't enter in normal mode\n");
return -EBUSY;
}
}
static int mcp251x_hw_reset(struct spi_device *spi)
{
struct mcp251x_priv *priv = spi_get_drvdata(spi);
- u8 reg;
+ unsigned long timeout;
int ret;
/* Wait for oscillator startup timer after power up */
/* Wait for oscillator startup timer after reset */
mdelay(MCP251X_OST_DELAY_MS);
- reg = mcp251x_read_reg(spi, CANSTAT);
- if ((reg & CANCTRL_REQOP_MASK) != CANCTRL_REQOP_CONF)
- return -ENODEV;
-
+ /* Wait for reset to finish */
+ timeout = jiffies + HZ;
+ while ((mcp251x_read_reg(spi, CANSTAT) & CANCTRL_REQOP_MASK) !=
+ CANCTRL_REQOP_CONF) {
+ usleep_range(MCP251X_OST_DELAY_MS * 1000,
+ MCP251X_OST_DELAY_MS * 1000 * 2);
+
+ if (time_after(jiffies, timeout)) {
+ dev_err(&spi->dev,
+ "MCP251x didn't enter in conf mode after reset\n");
+ return -EBUSY;
+ }
+ }
return 0;
}
* (The MCP2515/25625 does this automatically.)
*/
if (mcp251x_is_2510(spi))
- mcp251x_write_bits(spi, CANINTF, CANINTF_RX0IF, 0x00);
+ mcp251x_write_bits(spi, CANINTF,
+ CANINTF_RX0IF, 0x00);
}
/* receive buffer 1 */
}
netif_wake_queue(net);
}
-
}
mutex_unlock(&priv->mcp_lock);
return IRQ_HANDLED;
{
struct mcp251x_priv *priv = netdev_priv(net);
struct spi_device *spi = priv->spi;
- unsigned long flags = IRQF_ONESHOT | IRQF_TRIGGER_FALLING;
+ unsigned long flags = 0;
int ret;
ret = open_candev(net);
priv->tx_skb = NULL;
priv->tx_len = 0;
+ if (!spi->dev.of_node)
+ flags = IRQF_TRIGGER_FALLING;
+
ret = request_threaded_irq(spi->irq, NULL, mcp251x_can_ist,
- flags | IRQF_ONESHOT, DEVICE_NAME, priv);
+ flags | IRQF_ONESHOT, dev_name(&spi->dev),
+ priv);
if (ret) {
dev_err(&spi->dev, "failed to acquire irq %d\n", spi->irq);
goto out_close;
priv->spi = spi;
mutex_init(&priv->mcp_lock);
- /* If requested, allocate DMA buffers */
- if (mcp251x_enable_dma) {
- spi->dev.coherent_dma_mask = ~0;
-
- /*
- * Minimum coherent DMA allocation is PAGE_SIZE, so allocate
- * that much and share it between Tx and Rx DMA buffers.
- */
- priv->spi_tx_buf = dmam_alloc_coherent(&spi->dev,
- PAGE_SIZE,
- &priv->spi_tx_dma,
- GFP_DMA);
-
- if (priv->spi_tx_buf) {
- priv->spi_rx_buf = (priv->spi_tx_buf + (PAGE_SIZE / 2));
- priv->spi_rx_dma = (dma_addr_t)(priv->spi_tx_dma +
- (PAGE_SIZE / 2));
- } else {
- /* Fall back to non-DMA */
- mcp251x_enable_dma = 0;
- }
+ priv->spi_tx_buf = devm_kzalloc(&spi->dev, SPI_TRANSFER_BUF_LEN,
+ GFP_KERNEL);
+ if (!priv->spi_tx_buf) {
+ ret = -ENOMEM;
+ goto error_probe;
}
- /* Allocate non-DMA buffers */
- if (!mcp251x_enable_dma) {
- priv->spi_tx_buf = devm_kzalloc(&spi->dev, SPI_TRANSFER_BUF_LEN,
- GFP_KERNEL);
- if (!priv->spi_tx_buf) {
- ret = -ENOMEM;
- goto error_probe;
- }
- priv->spi_rx_buf = devm_kzalloc(&spi->dev, SPI_TRANSFER_BUF_LEN,
- GFP_KERNEL);
- if (!priv->spi_rx_buf) {
- ret = -ENOMEM;
- goto error_probe;
- }
+ priv->spi_rx_buf = devm_kzalloc(&spi->dev, SPI_TRANSFER_BUF_LEN,
+ GFP_KERNEL);
+ if (!priv->spi_rx_buf) {
+ ret = -ENOMEM;
+ goto error_probe;
}
SET_NETDEV_DEV(net, &spi->dev);
ret = mcp251x_hw_probe(spi);
if (ret) {
if (ret == -ENODEV)
- dev_err(&spi->dev, "Cannot initialize MCP%x. Wrong wiring?\n", priv->model);
+ dev_err(&spi->dev, "Cannot initialize MCP%x. Wrong wiring?\n",
+ priv->model);
goto error_probe;
}
priv->force_quit = 1;
disable_irq(spi->irq);
- /*
- * Note: at this point neither IST nor workqueues are running.
+ /* Note: at this point neither IST nor workqueues are running.
* open/stop cannot be called anyway so locking is not needed
*/
if (netif_running(net)) {
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