diff options
Diffstat (limited to 'drivers/net/can/spi/mcp251x.c')
| -rw-r--r-- | drivers/net/can/spi/mcp251x.c | 187 |
1 files changed, 62 insertions, 125 deletions
diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c index 12358f06d194..bee9f7b8dad6 100644 --- a/drivers/net/can/spi/mcp251x.c +++ b/drivers/net/can/spi/mcp251x.c @@ -1,6 +1,5 @@ // 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> @@ -18,26 +17,6 @@ * - 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> @@ -48,15 +27,13 @@ #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> #include <linux/kernel.h> #include <linux/module.h> #include <linux/netdevice.h> -#include <linux/of.h> -#include <linux/of_device.h> +#include <linux/property.h> #include <linux/platform_device.h> #include <linux/slab.h> #include <linux/spi/spi.h> @@ -75,7 +52,6 @@ #define RTS_TXB2 0x04 #define INSTRUCTION_RTS(n) (0x80 | ((n) & 0x07)) - /* MPC251x registers */ #define CANSTAT 0x0e #define CANCTRL 0x0f @@ -191,8 +167,7 @@ #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 @@ -205,10 +180,6 @@ #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, @@ -237,8 +208,6 @@ struct mcp251x_priv { 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; @@ -274,16 +243,14 @@ static void mcp251x_clean(struct net_device *net) 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 @@ -308,13 +275,6 @@ static int mcp251x_spi_trans(struct spi_device *spi, int len) 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); @@ -323,7 +283,7 @@ static int mcp251x_spi_trans(struct spi_device *spi, int len) 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; @@ -337,8 +297,7 @@ static u8 mcp251x_read_reg(struct spi_device *spi, uint8_t reg) 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); @@ -351,7 +310,7 @@ static void mcp251x_read_2regs(struct spi_device *spi, uint8_t reg, *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); @@ -363,7 +322,7 @@ static void mcp251x_write_reg(struct spi_device *spi, u8 reg, uint8_t val) } 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); @@ -565,8 +524,7 @@ static int mcp251x_set_normal_mode(struct spi_device *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; } } @@ -612,7 +570,7 @@ static int mcp251x_setup(struct net_device *net, struct spi_device *spi) 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 */ @@ -626,10 +584,19 @@ static int mcp251x_hw_reset(struct spi_device *spi) /* 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; } @@ -799,7 +766,8 @@ static irqreturn_t mcp251x_can_ist(int irq, void *dev_id) * (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 */ @@ -900,7 +868,6 @@ static irqreturn_t mcp251x_can_ist(int irq, void *dev_id) } netif_wake_queue(net); } - } mutex_unlock(&priv->mcp_lock); return IRQ_HANDLED; @@ -910,7 +877,7 @@ static int mcp251x_open(struct net_device *net) { 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); @@ -926,8 +893,12 @@ static int mcp251x_open(struct net_device *net) priv->tx_skb = NULL; priv->tx_len = 0; + if (!dev_fwnode(&spi->dev)) + 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; @@ -1014,23 +985,20 @@ MODULE_DEVICE_TABLE(spi, mcp251x_id_table); static int mcp251x_can_probe(struct spi_device *spi) { - const struct of_device_id *of_id = of_match_device(mcp251x_of_match, - &spi->dev); + const void *match = device_get_match_data(&spi->dev); struct mcp251x_platform_data *pdata = dev_get_platdata(&spi->dev); struct net_device *net; struct mcp251x_priv *priv; struct clk *clk; int freq, ret; - clk = devm_clk_get(&spi->dev, NULL); - if (IS_ERR(clk)) { - if (pdata) - freq = pdata->oscillator_frequency; - else - return PTR_ERR(clk); - } else { - freq = clk_get_rate(clk); - } + clk = devm_clk_get_optional(&spi->dev, NULL); + if (IS_ERR(clk)) + return PTR_ERR(clk); + + freq = clk_get_rate(clk); + if (freq == 0 && pdata) + freq = pdata->oscillator_frequency; /* Sanity check */ if (freq < 1000000 || freq > 25000000) @@ -1041,11 +1009,9 @@ static int mcp251x_can_probe(struct spi_device *spi) if (!net) return -ENOMEM; - if (!IS_ERR(clk)) { - ret = clk_prepare_enable(clk); - if (ret) - goto out_free; - } + ret = clk_prepare_enable(clk); + if (ret) + goto out_free; net->netdev_ops = &mcp251x_netdev_ops; net->flags |= IFF_ECHO; @@ -1056,8 +1022,8 @@ static int mcp251x_can_probe(struct spi_device *spi) priv->can.clock.freq = freq / 2; priv->can.ctrlmode_supported = CAN_CTRLMODE_3_SAMPLES | CAN_CTRLMODE_LOOPBACK | CAN_CTRLMODE_LISTENONLY; - if (of_id) - priv->model = (enum mcp251x_model)of_id->data; + if (match) + priv->model = (enum mcp251x_model)match; else priv->model = spi_get_device_id(spi)->driver_data; priv->net = net; @@ -1090,43 +1056,18 @@ static int mcp251x_can_probe(struct spi_device *spi) 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); @@ -1135,7 +1076,8 @@ static int mcp251x_can_probe(struct spi_device *spi) 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; } @@ -1154,8 +1096,7 @@ error_probe: mcp251x_power_enable(priv->power, 0); out_clk: - if (!IS_ERR(clk)) - clk_disable_unprepare(clk); + clk_disable_unprepare(clk); out_free: free_candev(net); @@ -1173,8 +1114,7 @@ static int mcp251x_can_remove(struct spi_device *spi) mcp251x_power_enable(priv->power, 0); - if (!IS_ERR(priv->clk)) - clk_disable_unprepare(priv->clk); + clk_disable_unprepare(priv->clk); free_candev(net); @@ -1189,8 +1129,7 @@ static int __maybe_unused mcp251x_can_suspend(struct device *dev) 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)) { @@ -1203,10 +1142,8 @@ static int __maybe_unused mcp251x_can_suspend(struct device *dev) priv->after_suspend = AFTER_SUSPEND_DOWN; } - if (!IS_ERR_OR_NULL(priv->power)) { - regulator_disable(priv->power); - priv->after_suspend |= AFTER_SUSPEND_POWER; - } + mcp251x_power_enable(priv->power, 0); + priv->after_suspend |= AFTER_SUSPEND_POWER; return 0; } |