diff options
Diffstat (limited to 'drivers/net/can/sja1000/peak_pcmcia.c')
| -rw-r--r-- | drivers/net/can/sja1000/peak_pcmcia.c | 733 |
1 files changed, 733 insertions, 0 deletions
diff --git a/drivers/net/can/sja1000/peak_pcmcia.c b/drivers/net/can/sja1000/peak_pcmcia.c new file mode 100644 index 000000000..ebd5941c3 --- /dev/null +++ b/drivers/net/can/sja1000/peak_pcmcia.c @@ -0,0 +1,733 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2010-2012 Stephane Grosjean <s.grosjean@peak-system.com> + * + * CAN driver for PEAK-System PCAN-PC Card + * Derived from the PCAN project file driver/src/pcan_pccard.c + * Copyright (C) 2006-2010 PEAK System-Technik GmbH + */ +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/interrupt.h> +#include <linux/netdevice.h> +#include <linux/delay.h> +#include <linux/timer.h> +#include <linux/io.h> +#include <pcmcia/cistpl.h> +#include <pcmcia/ds.h> +#include <linux/can.h> +#include <linux/can/dev.h> +#include "sja1000.h" + +MODULE_AUTHOR("Stephane Grosjean <s.grosjean@peak-system.com>"); +MODULE_DESCRIPTION("CAN driver for PEAK-System PCAN-PC Cards"); +MODULE_LICENSE("GPL v2"); + +/* PEAK-System PCMCIA driver name */ +#define PCC_NAME "peak_pcmcia" + +#define PCC_CHAN_MAX 2 + +#define PCC_CAN_CLOCK (16000000 / 2) + +#define PCC_MANF_ID 0x0377 +#define PCC_CARD_ID 0x0001 + +#define PCC_CHAN_SIZE 0x20 +#define PCC_CHAN_OFF(c) ((c) * PCC_CHAN_SIZE) +#define PCC_COMN_OFF (PCC_CHAN_OFF(PCC_CHAN_MAX)) +#define PCC_COMN_SIZE 0x40 + +/* common area registers */ +#define PCC_CCR 0x00 +#define PCC_CSR 0x02 +#define PCC_CPR 0x04 +#define PCC_SPI_DIR 0x06 +#define PCC_SPI_DOR 0x08 +#define PCC_SPI_ADR 0x0a +#define PCC_SPI_IR 0x0c +#define PCC_FW_MAJOR 0x10 +#define PCC_FW_MINOR 0x12 + +/* CCR bits */ +#define PCC_CCR_CLK_16 0x00 +#define PCC_CCR_CLK_10 0x01 +#define PCC_CCR_CLK_21 0x02 +#define PCC_CCR_CLK_8 0x03 +#define PCC_CCR_CLK_MASK PCC_CCR_CLK_8 + +#define PCC_CCR_RST_CHAN(c) (0x01 << ((c) + 2)) +#define PCC_CCR_RST_ALL (PCC_CCR_RST_CHAN(0) | PCC_CCR_RST_CHAN(1)) +#define PCC_CCR_RST_MASK PCC_CCR_RST_ALL + +/* led selection bits */ +#define PCC_LED(c) (1 << (c)) +#define PCC_LED_ALL (PCC_LED(0) | PCC_LED(1)) + +/* led state value */ +#define PCC_LED_ON 0x00 +#define PCC_LED_FAST 0x01 +#define PCC_LED_SLOW 0x02 +#define PCC_LED_OFF 0x03 + +#define PCC_CCR_LED_CHAN(s, c) ((s) << (((c) + 2) << 1)) + +#define PCC_CCR_LED_ON_CHAN(c) PCC_CCR_LED_CHAN(PCC_LED_ON, c) +#define PCC_CCR_LED_FAST_CHAN(c) PCC_CCR_LED_CHAN(PCC_LED_FAST, c) +#define PCC_CCR_LED_SLOW_CHAN(c) PCC_CCR_LED_CHAN(PCC_LED_SLOW, c) +#define PCC_CCR_LED_OFF_CHAN(c) PCC_CCR_LED_CHAN(PCC_LED_OFF, c) +#define PCC_CCR_LED_MASK_CHAN(c) PCC_CCR_LED_OFF_CHAN(c) +#define PCC_CCR_LED_OFF_ALL (PCC_CCR_LED_OFF_CHAN(0) | \ + PCC_CCR_LED_OFF_CHAN(1)) +#define PCC_CCR_LED_MASK PCC_CCR_LED_OFF_ALL + +#define PCC_CCR_INIT (PCC_CCR_CLK_16 | PCC_CCR_RST_ALL | PCC_CCR_LED_OFF_ALL) + +/* CSR bits */ +#define PCC_CSR_SPI_BUSY 0x04 + +/* time waiting for SPI busy (prevent from infinite loop) */ +#define PCC_SPI_MAX_BUSY_WAIT_MS 3 + +/* max count of reading the SPI status register waiting for a change */ +/* (prevent from infinite loop) */ +#define PCC_WRITE_MAX_LOOP 1000 + +/* max nb of int handled by that isr in one shot (prevent from infinite loop) */ +#define PCC_ISR_MAX_LOOP 10 + +/* EEPROM chip instruction set */ +/* note: EEPROM Read/Write instructions include A8 bit */ +#define PCC_EEP_WRITE(a) (0x02 | (((a) & 0x100) >> 5)) +#define PCC_EEP_READ(a) (0x03 | (((a) & 0x100) >> 5)) +#define PCC_EEP_WRDI 0x04 /* EEPROM Write Disable */ +#define PCC_EEP_RDSR 0x05 /* EEPROM Read Status Register */ +#define PCC_EEP_WREN 0x06 /* EEPROM Write Enable */ + +/* EEPROM Status Register bits */ +#define PCC_EEP_SR_WEN 0x02 /* EEPROM SR Write Enable bit */ +#define PCC_EEP_SR_WIP 0x01 /* EEPROM SR Write In Progress bit */ + +/* + * The board configuration is probably following: + * RX1 is connected to ground. + * TX1 is not connected. + * CLKO is not connected. + * Setting the OCR register to 0xDA is a good idea. + * This means normal output mode, push-pull and the correct polarity. + */ +#define PCC_OCR (OCR_TX0_PUSHPULL | OCR_TX1_PUSHPULL) + +/* + * In the CDR register, you should set CBP to 1. + * You will probably also want to set the clock divider value to 7 + * (meaning direct oscillator output) because the second SJA1000 chip + * is driven by the first one CLKOUT output. + */ +#define PCC_CDR (CDR_CBP | CDR_CLKOUT_MASK) + +struct pcan_channel { + struct net_device *netdev; + unsigned long prev_rx_bytes; + unsigned long prev_tx_bytes; +}; + +/* PCAN-PC Card private structure */ +struct pcan_pccard { + struct pcmcia_device *pdev; + int chan_count; + struct pcan_channel channel[PCC_CHAN_MAX]; + u8 ccr; + u8 fw_major; + u8 fw_minor; + void __iomem *ioport_addr; + struct timer_list led_timer; +}; + +static struct pcmcia_device_id pcan_table[] = { + PCMCIA_DEVICE_MANF_CARD(PCC_MANF_ID, PCC_CARD_ID), + PCMCIA_DEVICE_NULL, +}; + +MODULE_DEVICE_TABLE(pcmcia, pcan_table); + +static void pcan_set_leds(struct pcan_pccard *card, u8 mask, u8 state); + +/* + * start timer which controls leds state + */ +static void pcan_start_led_timer(struct pcan_pccard *card) +{ + if (!timer_pending(&card->led_timer)) + mod_timer(&card->led_timer, jiffies + HZ); +} + +/* + * stop the timer which controls leds state + */ +static void pcan_stop_led_timer(struct pcan_pccard *card) +{ + del_timer_sync(&card->led_timer); +} + +/* + * read a sja1000 register + */ +static u8 pcan_read_canreg(const struct sja1000_priv *priv, int port) +{ + return ioread8(priv->reg_base + port); +} + +/* + * write a sja1000 register + */ +static void pcan_write_canreg(const struct sja1000_priv *priv, int port, u8 v) +{ + struct pcan_pccard *card = priv->priv; + int c = (priv->reg_base - card->ioport_addr) / PCC_CHAN_SIZE; + + /* sja1000 register changes control the leds state */ + if (port == SJA1000_MOD) + switch (v) { + case MOD_RM: + /* Reset Mode: set led on */ + pcan_set_leds(card, PCC_LED(c), PCC_LED_ON); + break; + case 0x00: + /* Normal Mode: led slow blinking and start led timer */ + pcan_set_leds(card, PCC_LED(c), PCC_LED_SLOW); + pcan_start_led_timer(card); + break; + default: + break; + } + + iowrite8(v, priv->reg_base + port); +} + +/* + * read a register from the common area + */ +static u8 pcan_read_reg(struct pcan_pccard *card, int port) +{ + return ioread8(card->ioport_addr + PCC_COMN_OFF + port); +} + +/* + * write a register into the common area + */ +static void pcan_write_reg(struct pcan_pccard *card, int port, u8 v) +{ + /* cache ccr value */ + if (port == PCC_CCR) { + if (card->ccr == v) + return; + card->ccr = v; + } + + iowrite8(v, card->ioport_addr + PCC_COMN_OFF + port); +} + +/* + * check whether the card is present by checking its fw version numbers + * against values read at probing time. + */ +static inline int pcan_pccard_present(struct pcan_pccard *card) +{ + return ((pcan_read_reg(card, PCC_FW_MAJOR) == card->fw_major) && + (pcan_read_reg(card, PCC_FW_MINOR) == card->fw_minor)); +} + +/* + * wait for SPI engine while it is busy + */ +static int pcan_wait_spi_busy(struct pcan_pccard *card) +{ + unsigned long timeout = jiffies + + msecs_to_jiffies(PCC_SPI_MAX_BUSY_WAIT_MS) + 1; + + /* be sure to read status at least once after sleeping */ + while (pcan_read_reg(card, PCC_CSR) & PCC_CSR_SPI_BUSY) { + if (time_after(jiffies, timeout)) + return -EBUSY; + schedule(); + } + + return 0; +} + +/* + * write data in device eeprom + */ +static int pcan_write_eeprom(struct pcan_pccard *card, u16 addr, u8 v) +{ + u8 status; + int err, i; + + /* write instruction enabling write */ + pcan_write_reg(card, PCC_SPI_IR, PCC_EEP_WREN); + err = pcan_wait_spi_busy(card); + if (err) + goto we_spi_err; + + /* wait until write enabled */ + for (i = 0; i < PCC_WRITE_MAX_LOOP; i++) { + /* write instruction reading the status register */ + pcan_write_reg(card, PCC_SPI_IR, PCC_EEP_RDSR); + err = pcan_wait_spi_busy(card); + if (err) + goto we_spi_err; + + /* get status register value and check write enable bit */ + status = pcan_read_reg(card, PCC_SPI_DIR); + if (status & PCC_EEP_SR_WEN) + break; + } + + if (i >= PCC_WRITE_MAX_LOOP) { + dev_err(&card->pdev->dev, + "stop waiting to be allowed to write in eeprom\n"); + return -EIO; + } + + /* set address and data */ + pcan_write_reg(card, PCC_SPI_ADR, addr & 0xff); + pcan_write_reg(card, PCC_SPI_DOR, v); + + /* + * write instruction with bit[3] set according to address value: + * if addr refers to upper half of the memory array: bit[3] = 1 + */ + pcan_write_reg(card, PCC_SPI_IR, PCC_EEP_WRITE(addr)); + err = pcan_wait_spi_busy(card); + if (err) + goto we_spi_err; + + /* wait while write in progress */ + for (i = 0; i < PCC_WRITE_MAX_LOOP; i++) { + /* write instruction reading the status register */ + pcan_write_reg(card, PCC_SPI_IR, PCC_EEP_RDSR); + err = pcan_wait_spi_busy(card); + if (err) + goto we_spi_err; + + /* get status register value and check write in progress bit */ + status = pcan_read_reg(card, PCC_SPI_DIR); + if (!(status & PCC_EEP_SR_WIP)) + break; + } + + if (i >= PCC_WRITE_MAX_LOOP) { + dev_err(&card->pdev->dev, + "stop waiting for write in eeprom to complete\n"); + return -EIO; + } + + /* write instruction disabling write */ + pcan_write_reg(card, PCC_SPI_IR, PCC_EEP_WRDI); + err = pcan_wait_spi_busy(card); + if (err) + goto we_spi_err; + + return 0; + +we_spi_err: + dev_err(&card->pdev->dev, + "stop waiting (spi engine always busy) err %d\n", err); + + return err; +} + +static void pcan_set_leds(struct pcan_pccard *card, u8 led_mask, u8 state) +{ + u8 ccr = card->ccr; + int i; + + for (i = 0; i < card->chan_count; i++) + if (led_mask & PCC_LED(i)) { + /* clear corresponding led bits in ccr */ + ccr &= ~PCC_CCR_LED_MASK_CHAN(i); + /* then set new bits */ + ccr |= PCC_CCR_LED_CHAN(state, i); + } + + /* real write only if something has changed in ccr */ + pcan_write_reg(card, PCC_CCR, ccr); +} + +/* + * enable/disable CAN connectors power + */ +static inline void pcan_set_can_power(struct pcan_pccard *card, int onoff) +{ + int err; + + err = pcan_write_eeprom(card, 0, !!onoff); + if (err) + dev_err(&card->pdev->dev, + "failed setting power %s to can connectors (err %d)\n", + (onoff) ? "on" : "off", err); +} + +/* + * set leds state according to channel activity + */ +static void pcan_led_timer(struct timer_list *t) +{ + struct pcan_pccard *card = from_timer(card, t, led_timer); + struct net_device *netdev; + int i, up_count = 0; + u8 ccr; + + ccr = card->ccr; + for (i = 0; i < card->chan_count; i++) { + /* default is: not configured */ + ccr &= ~PCC_CCR_LED_MASK_CHAN(i); + ccr |= PCC_CCR_LED_ON_CHAN(i); + + netdev = card->channel[i].netdev; + if (!netdev || !(netdev->flags & IFF_UP)) + continue; + + up_count++; + + /* no activity (but configured) */ + ccr &= ~PCC_CCR_LED_MASK_CHAN(i); + ccr |= PCC_CCR_LED_SLOW_CHAN(i); + + /* if bytes counters changed, set fast blinking led */ + if (netdev->stats.rx_bytes != card->channel[i].prev_rx_bytes) { + card->channel[i].prev_rx_bytes = netdev->stats.rx_bytes; + ccr &= ~PCC_CCR_LED_MASK_CHAN(i); + ccr |= PCC_CCR_LED_FAST_CHAN(i); + } + if (netdev->stats.tx_bytes != card->channel[i].prev_tx_bytes) { + card->channel[i].prev_tx_bytes = netdev->stats.tx_bytes; + ccr &= ~PCC_CCR_LED_MASK_CHAN(i); + ccr |= PCC_CCR_LED_FAST_CHAN(i); + } + } + + /* write the new leds state */ + pcan_write_reg(card, PCC_CCR, ccr); + + /* restart timer (except if no more configured channels) */ + if (up_count) + mod_timer(&card->led_timer, jiffies + HZ); +} + +/* + * interrupt service routine + */ +static irqreturn_t pcan_isr(int irq, void *dev_id) +{ + struct pcan_pccard *card = dev_id; + int irq_handled; + + /* prevent from infinite loop */ + for (irq_handled = 0; irq_handled < PCC_ISR_MAX_LOOP; irq_handled++) { + /* handle shared interrupt and next loop */ + int nothing_to_handle = 1; + int i; + + /* check interrupt for each channel */ + for (i = 0; i < card->chan_count; i++) { + struct net_device *netdev; + + /* + * check whether the card is present before calling + * sja1000_interrupt() to speed up hotplug detection + */ + if (!pcan_pccard_present(card)) { + /* card unplugged during isr */ + return IRQ_NONE; + } + + /* + * should check whether all or SJA1000_MAX_IRQ + * interrupts have been handled: loop again to be sure. + */ + netdev = card->channel[i].netdev; + if (netdev && + sja1000_interrupt(irq, netdev) == IRQ_HANDLED) + nothing_to_handle = 0; + } + + if (nothing_to_handle) + break; + } + + return (irq_handled) ? IRQ_HANDLED : IRQ_NONE; +} + +/* + * free all resources used by the channels and switch off leds and can power + */ +static void pcan_free_channels(struct pcan_pccard *card) +{ + int i; + u8 led_mask = 0; + + for (i = 0; i < card->chan_count; i++) { + struct net_device *netdev; + char name[IFNAMSIZ]; + + led_mask |= PCC_LED(i); + + netdev = card->channel[i].netdev; + if (!netdev) + continue; + + strscpy(name, netdev->name, IFNAMSIZ); + + unregister_sja1000dev(netdev); + + free_sja1000dev(netdev); + + dev_info(&card->pdev->dev, "%s removed\n", name); + } + + /* do it only if device not removed */ + if (pcan_pccard_present(card)) { + pcan_set_leds(card, led_mask, PCC_LED_OFF); + pcan_set_can_power(card, 0); + } +} + +/* + * check if a CAN controller is present at the specified location + */ +static inline int pcan_channel_present(struct sja1000_priv *priv) +{ + /* make sure SJA1000 is in reset mode */ + pcan_write_canreg(priv, SJA1000_MOD, 1); + pcan_write_canreg(priv, SJA1000_CDR, CDR_PELICAN); + + /* read reset-values */ + if (pcan_read_canreg(priv, SJA1000_CDR) == CDR_PELICAN) + return 1; + + return 0; +} + +static int pcan_add_channels(struct pcan_pccard *card) +{ + struct pcmcia_device *pdev = card->pdev; + int i, err = 0; + u8 ccr = PCC_CCR_INIT; + + /* init common registers (reset channels and leds off) */ + card->ccr = ~ccr; + pcan_write_reg(card, PCC_CCR, ccr); + + /* wait 2ms before unresetting channels */ + usleep_range(2000, 3000); + + ccr &= ~PCC_CCR_RST_ALL; + pcan_write_reg(card, PCC_CCR, ccr); + + /* create one network device per channel detected */ + for (i = 0; i < ARRAY_SIZE(card->channel); i++) { + struct net_device *netdev; + struct sja1000_priv *priv; + + netdev = alloc_sja1000dev(0); + if (!netdev) { + err = -ENOMEM; + break; + } + + /* update linkages */ + priv = netdev_priv(netdev); + priv->priv = card; + SET_NETDEV_DEV(netdev, &pdev->dev); + netdev->dev_id = i; + + priv->irq_flags = IRQF_SHARED; + netdev->irq = pdev->irq; + priv->reg_base = card->ioport_addr + PCC_CHAN_OFF(i); + + /* check if channel is present */ + if (!pcan_channel_present(priv)) { + dev_err(&pdev->dev, "channel %d not present\n", i); + free_sja1000dev(netdev); + continue; + } + + priv->read_reg = pcan_read_canreg; + priv->write_reg = pcan_write_canreg; + priv->can.clock.freq = PCC_CAN_CLOCK; + priv->ocr = PCC_OCR; + priv->cdr = PCC_CDR; + + /* Neither a slave device distributes the clock */ + if (i > 0) + priv->cdr |= CDR_CLK_OFF; + + priv->flags |= SJA1000_CUSTOM_IRQ_HANDLER; + + /* register SJA1000 device */ + err = register_sja1000dev(netdev); + if (err) { + free_sja1000dev(netdev); + continue; + } + + card->channel[i].netdev = netdev; + card->chan_count++; + + /* set corresponding led on in the new ccr */ + ccr &= ~PCC_CCR_LED_OFF_CHAN(i); + + dev_info(&pdev->dev, + "%s on channel %d at 0x%p irq %d\n", + netdev->name, i, priv->reg_base, pdev->irq); + } + + /* write new ccr (change leds state) */ + pcan_write_reg(card, PCC_CCR, ccr); + + return err; +} + +static int pcan_conf_check(struct pcmcia_device *pdev, void *priv_data) +{ + pdev->resource[0]->flags &= ~IO_DATA_PATH_WIDTH; + pdev->resource[0]->flags |= IO_DATA_PATH_WIDTH_8; /* only */ + pdev->io_lines = 10; + + /* This reserves IO space but doesn't actually enable it */ + return pcmcia_request_io(pdev); +} + +/* + * free all resources used by the device + */ +static void pcan_free(struct pcmcia_device *pdev) +{ + struct pcan_pccard *card = pdev->priv; + + if (!card) + return; + + free_irq(pdev->irq, card); + pcan_stop_led_timer(card); + + pcan_free_channels(card); + + ioport_unmap(card->ioport_addr); + + kfree(card); + pdev->priv = NULL; +} + +/* + * setup PCMCIA socket and probe for PEAK-System PC-CARD + */ +static int pcan_probe(struct pcmcia_device *pdev) +{ + struct pcan_pccard *card; + int err; + + pdev->config_flags |= CONF_ENABLE_IRQ | CONF_AUTO_SET_IO; + + err = pcmcia_loop_config(pdev, pcan_conf_check, NULL); + if (err) { + dev_err(&pdev->dev, "pcmcia_loop_config() error %d\n", err); + goto probe_err_1; + } + + if (!pdev->irq) { + dev_err(&pdev->dev, "no irq assigned\n"); + err = -ENODEV; + goto probe_err_1; + } + + err = pcmcia_enable_device(pdev); + if (err) { + dev_err(&pdev->dev, "pcmcia_enable_device failed err=%d\n", + err); + goto probe_err_1; + } + + card = kzalloc(sizeof(struct pcan_pccard), GFP_KERNEL); + if (!card) { + err = -ENOMEM; + goto probe_err_2; + } + + card->pdev = pdev; + pdev->priv = card; + + /* sja1000 api uses iomem */ + card->ioport_addr = ioport_map(pdev->resource[0]->start, + resource_size(pdev->resource[0])); + if (!card->ioport_addr) { + dev_err(&pdev->dev, "couldn't map io port into io memory\n"); + err = -ENOMEM; + goto probe_err_3; + } + card->fw_major = pcan_read_reg(card, PCC_FW_MAJOR); + card->fw_minor = pcan_read_reg(card, PCC_FW_MINOR); + + /* display board name and firmware version */ + dev_info(&pdev->dev, "PEAK-System pcmcia card %s fw %d.%d\n", + pdev->prod_id[1] ? pdev->prod_id[1] : "PCAN-PC Card", + card->fw_major, card->fw_minor); + + /* detect available channels */ + pcan_add_channels(card); + if (!card->chan_count) { + err = -ENOMEM; + goto probe_err_4; + } + + /* init the timer which controls the leds */ + timer_setup(&card->led_timer, pcan_led_timer, 0); + + /* request the given irq */ + err = request_irq(pdev->irq, &pcan_isr, IRQF_SHARED, PCC_NAME, card); + if (err) { + dev_err(&pdev->dev, "couldn't request irq%d\n", pdev->irq); + goto probe_err_5; + } + + /* power on the connectors */ + pcan_set_can_power(card, 1); + + return 0; + +probe_err_5: + /* unregister can devices from network */ + pcan_free_channels(card); + +probe_err_4: + ioport_unmap(card->ioport_addr); + +probe_err_3: + kfree(card); + pdev->priv = NULL; + +probe_err_2: + pcmcia_disable_device(pdev); + +probe_err_1: + return err; +} + +/* + * release claimed resources + */ +static void pcan_remove(struct pcmcia_device *pdev) +{ + pcan_free(pdev); + pcmcia_disable_device(pdev); +} + +static struct pcmcia_driver pcan_driver = { + .name = PCC_NAME, + .probe = pcan_probe, + .remove = pcan_remove, + .id_table = pcan_table, +}; +module_pcmcia_driver(pcan_driver); |