/* * 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 * * This program is free software; you can redistribute it and/or modify * it under the terms of the version 2 of the GNU General Public License * 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/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"); MODULE_SUPPORTED_DEVICE("PEAK PCAN-PC Card"); /* 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 == REG_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(unsigned long arg) { struct pcan_pccard *card = (struct pcan_pccard *)arg; 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; strncpy(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, REG_MOD, 1); pcan_write_canreg(priv, REG_CDR, CDR_PELICAN); /* read reset-values */ if (pcan_read_canreg(priv, REG_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 */ mdelay(2); 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); 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 firware 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 */ init_timer(&card->led_timer); card->led_timer.function = pcan_led_timer; card->led_timer.data = (unsigned long)card; /* 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, }; static int __init pcan_init(void) { return pcmcia_register_driver(&pcan_driver); } module_init(pcan_init); static void __exit pcan_exit(void) { pcmcia_unregister_driver(&pcan_driver); } module_exit(pcan_exit);