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dfb86c0d5a
Technologic Systems provides an IP compatible with the SJA1000,
instantiated in an FPGA. Because of some bus widths issue, access to
registers is made through a "window" that works like this:
base + 0x0: address to read/write
base + 0x2: 8-bit register value
This commit adds a new compatible device, "technologic,sja1000", with
read and write functions using the window mechanism.
Signed-off-by: Damien Riegel <damien.riegel@savoirfairelinux.com>
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
329 lines
8 KiB
C
329 lines
8 KiB
C
/*
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* Copyright (C) 2005 Sascha Hauer, Pengutronix
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* Copyright (C) 2007 Wolfgang Grandegger <wg@grandegger.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the version 2 of the GNU General Public License
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* as published by the Free Software Foundation
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, see <http://www.gnu.org/licenses/>.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/interrupt.h>
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#include <linux/netdevice.h>
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#include <linux/delay.h>
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#include <linux/pci.h>
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#include <linux/platform_device.h>
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#include <linux/irq.h>
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#include <linux/can/dev.h>
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#include <linux/can/platform/sja1000.h>
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#include <linux/io.h>
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#include <linux/of.h>
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#include <linux/of_device.h>
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#include <linux/of_irq.h>
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#include "sja1000.h"
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#define DRV_NAME "sja1000_platform"
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#define SP_CAN_CLOCK (16000000 / 2)
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MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
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MODULE_AUTHOR("Wolfgang Grandegger <wg@grandegger.com>");
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MODULE_DESCRIPTION("Socket-CAN driver for SJA1000 on the platform bus");
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MODULE_ALIAS("platform:" DRV_NAME);
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MODULE_LICENSE("GPL v2");
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struct sja1000_of_data {
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size_t priv_sz;
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int (*init)(struct sja1000_priv *priv, struct device_node *of);
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};
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struct technologic_priv {
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spinlock_t io_lock;
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};
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static u8 sp_read_reg8(const struct sja1000_priv *priv, int reg)
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{
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return ioread8(priv->reg_base + reg);
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}
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static void sp_write_reg8(const struct sja1000_priv *priv, int reg, u8 val)
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{
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iowrite8(val, priv->reg_base + reg);
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}
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static u8 sp_read_reg16(const struct sja1000_priv *priv, int reg)
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{
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return ioread8(priv->reg_base + reg * 2);
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}
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static void sp_write_reg16(const struct sja1000_priv *priv, int reg, u8 val)
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{
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iowrite8(val, priv->reg_base + reg * 2);
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}
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static u8 sp_read_reg32(const struct sja1000_priv *priv, int reg)
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{
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return ioread8(priv->reg_base + reg * 4);
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}
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static void sp_write_reg32(const struct sja1000_priv *priv, int reg, u8 val)
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{
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iowrite8(val, priv->reg_base + reg * 4);
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}
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static u8 sp_technologic_read_reg16(const struct sja1000_priv *priv, int reg)
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{
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struct technologic_priv *tp = priv->priv;
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unsigned long flags;
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u8 val;
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spin_lock_irqsave(&tp->io_lock, flags);
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iowrite16(reg, priv->reg_base + 0);
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val = ioread16(priv->reg_base + 2);
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spin_unlock_irqrestore(&tp->io_lock, flags);
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return val;
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}
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static void sp_technologic_write_reg16(const struct sja1000_priv *priv,
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int reg, u8 val)
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{
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struct technologic_priv *tp = priv->priv;
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unsigned long flags;
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spin_lock_irqsave(&tp->io_lock, flags);
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iowrite16(reg, priv->reg_base + 0);
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iowrite16(val, priv->reg_base + 2);
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spin_unlock_irqrestore(&tp->io_lock, flags);
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}
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static int sp_technologic_init(struct sja1000_priv *priv, struct device_node *of)
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{
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struct technologic_priv *tp = priv->priv;
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priv->read_reg = sp_technologic_read_reg16;
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priv->write_reg = sp_technologic_write_reg16;
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spin_lock_init(&tp->io_lock);
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return 0;
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}
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static void sp_populate(struct sja1000_priv *priv,
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struct sja1000_platform_data *pdata,
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unsigned long resource_mem_flags)
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{
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/* The CAN clock frequency is half the oscillator clock frequency */
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priv->can.clock.freq = pdata->osc_freq / 2;
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priv->ocr = pdata->ocr;
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priv->cdr = pdata->cdr;
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switch (resource_mem_flags & IORESOURCE_MEM_TYPE_MASK) {
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case IORESOURCE_MEM_32BIT:
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priv->read_reg = sp_read_reg32;
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priv->write_reg = sp_write_reg32;
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break;
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case IORESOURCE_MEM_16BIT:
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priv->read_reg = sp_read_reg16;
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priv->write_reg = sp_write_reg16;
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break;
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case IORESOURCE_MEM_8BIT:
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default:
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priv->read_reg = sp_read_reg8;
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priv->write_reg = sp_write_reg8;
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break;
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}
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}
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static void sp_populate_of(struct sja1000_priv *priv, struct device_node *of)
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{
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int err;
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u32 prop;
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err = of_property_read_u32(of, "reg-io-width", &prop);
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if (err)
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prop = 1; /* 8 bit is default */
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switch (prop) {
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case 4:
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priv->read_reg = sp_read_reg32;
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priv->write_reg = sp_write_reg32;
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break;
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case 2:
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priv->read_reg = sp_read_reg16;
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priv->write_reg = sp_write_reg16;
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break;
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case 1: /* fallthrough */
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default:
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priv->read_reg = sp_read_reg8;
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priv->write_reg = sp_write_reg8;
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}
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err = of_property_read_u32(of, "nxp,external-clock-frequency", &prop);
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if (!err)
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priv->can.clock.freq = prop / 2;
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else
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priv->can.clock.freq = SP_CAN_CLOCK; /* default */
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err = of_property_read_u32(of, "nxp,tx-output-mode", &prop);
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if (!err)
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priv->ocr |= prop & OCR_MODE_MASK;
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else
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priv->ocr |= OCR_MODE_NORMAL; /* default */
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err = of_property_read_u32(of, "nxp,tx-output-config", &prop);
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if (!err)
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priv->ocr |= (prop << OCR_TX_SHIFT) & OCR_TX_MASK;
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else
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priv->ocr |= OCR_TX0_PULLDOWN; /* default */
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err = of_property_read_u32(of, "nxp,clock-out-frequency", &prop);
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if (!err && prop) {
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u32 divider = priv->can.clock.freq * 2 / prop;
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if (divider > 1)
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priv->cdr |= divider / 2 - 1;
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else
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priv->cdr |= CDR_CLKOUT_MASK;
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} else {
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priv->cdr |= CDR_CLK_OFF; /* default */
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}
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if (!of_property_read_bool(of, "nxp,no-comparator-bypass"))
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priv->cdr |= CDR_CBP; /* default */
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}
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static struct sja1000_of_data technologic_data = {
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.priv_sz = sizeof(struct technologic_priv),
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.init = sp_technologic_init,
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};
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static const struct of_device_id sp_of_table[] = {
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{ .compatible = "nxp,sja1000", .data = NULL, },
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{ .compatible = "technologic,sja1000", .data = &technologic_data, },
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{ /* sentinel */ },
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};
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MODULE_DEVICE_TABLE(of, sp_of_table);
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static int sp_probe(struct platform_device *pdev)
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{
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int err, irq = 0;
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void __iomem *addr;
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struct net_device *dev;
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struct sja1000_priv *priv;
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struct resource *res_mem, *res_irq = NULL;
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struct sja1000_platform_data *pdata;
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struct device_node *of = pdev->dev.of_node;
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const struct of_device_id *of_id;
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const struct sja1000_of_data *of_data = NULL;
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size_t priv_sz = 0;
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pdata = dev_get_platdata(&pdev->dev);
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if (!pdata && !of) {
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dev_err(&pdev->dev, "No platform data provided!\n");
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return -ENODEV;
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}
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res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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if (!res_mem)
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return -ENODEV;
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if (!devm_request_mem_region(&pdev->dev, res_mem->start,
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resource_size(res_mem), DRV_NAME))
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return -EBUSY;
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addr = devm_ioremap_nocache(&pdev->dev, res_mem->start,
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resource_size(res_mem));
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if (!addr)
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return -ENOMEM;
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if (of)
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irq = irq_of_parse_and_map(of, 0);
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else
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res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
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if (!irq && !res_irq)
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return -ENODEV;
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of_id = of_match_device(sp_of_table, &pdev->dev);
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if (of_id && of_id->data) {
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of_data = of_id->data;
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priv_sz = of_data->priv_sz;
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}
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dev = alloc_sja1000dev(priv_sz);
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if (!dev)
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return -ENOMEM;
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priv = netdev_priv(dev);
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if (res_irq) {
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irq = res_irq->start;
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priv->irq_flags = res_irq->flags & IRQF_TRIGGER_MASK;
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if (res_irq->flags & IORESOURCE_IRQ_SHAREABLE)
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priv->irq_flags |= IRQF_SHARED;
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} else {
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priv->irq_flags = IRQF_SHARED;
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}
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dev->irq = irq;
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priv->reg_base = addr;
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if (of) {
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sp_populate_of(priv, of);
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if (of_data && of_data->init) {
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err = of_data->init(priv, of);
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if (err)
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goto exit_free;
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}
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} else {
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sp_populate(priv, pdata, res_mem->flags);
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}
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platform_set_drvdata(pdev, dev);
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SET_NETDEV_DEV(dev, &pdev->dev);
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err = register_sja1000dev(dev);
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if (err) {
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dev_err(&pdev->dev, "registering %s failed (err=%d)\n",
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DRV_NAME, err);
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goto exit_free;
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}
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dev_info(&pdev->dev, "%s device registered (reg_base=%p, irq=%d)\n",
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DRV_NAME, priv->reg_base, dev->irq);
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return 0;
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exit_free:
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free_sja1000dev(dev);
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return err;
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}
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static int sp_remove(struct platform_device *pdev)
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{
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struct net_device *dev = platform_get_drvdata(pdev);
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unregister_sja1000dev(dev);
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free_sja1000dev(dev);
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return 0;
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}
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static struct platform_driver sp_driver = {
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.probe = sp_probe,
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.remove = sp_remove,
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.driver = {
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.name = DRV_NAME,
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.of_match_table = sp_of_table,
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},
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};
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module_platform_driver(sp_driver);
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