--- /dev/null
+/*
+ * drivers/i2c/busses/i2c-s6000.c
+ *
+ * Description: Driver for S6000 Family I2C Interface
+ * Copyright (c) 2008 emlix GmbH
+ * Author: Oskar Schirmer <os@emlix.com>
+ *
+ * Partially based on i2c-bfin-twi.c driver by <sonic.zhang@analog.com>
+ * Copyright (c) 2005-2007 Analog Devices, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/i2c/s6000.h>
+#include <linux/timer.h>
+#include <linux/spinlock.h>
+#include <linux/completion.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+
+#include <asm/io.h>
+#include "i2c-s6000.h"
+
+#define DRV_NAME "i2c-s6000"
+
+#define POLL_TIMEOUT (2 * HZ)
+
+struct s6i2c_if {
+ u8 __iomem *reg; /* memory mapped registers */
+ int irq;
+ spinlock_t lock;
+ struct i2c_msg *msgs; /* messages currently handled */
+ int msgs_num; /* nb of msgs to do */
+ int msgs_push; /* nb of msgs read/written */
+ int msgs_done; /* nb of msgs finally handled */
+ unsigned push; /* nb of bytes read/written in msg */
+ unsigned done; /* nb of bytes finally handled */
+ int timeout_count; /* timeout retries left */
+ struct timer_list timeout_timer;
+ struct i2c_adapter adap;
+ struct completion complete;
+ struct clk *clk;
+ struct resource *res;
+};
+
+static inline u16 i2c_rd16(struct s6i2c_if *iface, unsigned n)
+{
+ return readw(iface->reg + (n));
+}
+
+static inline void i2c_wr16(struct s6i2c_if *iface, unsigned n, u16 v)
+{
+ writew(v, iface->reg + (n));
+}
+
+static inline u32 i2c_rd32(struct s6i2c_if *iface, unsigned n)
+{
+ return readl(iface->reg + (n));
+}
+
+static inline void i2c_wr32(struct s6i2c_if *iface, unsigned n, u32 v)
+{
+ writel(v, iface->reg + (n));
+}
+
+static struct s6i2c_if s6i2c_if;
+
+static void s6i2c_handle_interrupt(struct s6i2c_if *iface)
+{
+ if (i2c_rd16(iface, S6_I2C_INTRSTAT) & (1 << S6_I2C_INTR_TXABRT)) {
+ i2c_rd16(iface, S6_I2C_CLRTXABRT);
+ i2c_wr16(iface, S6_I2C_INTRMASK, 0);
+ complete(&iface->complete);
+ return;
+ }
+ if (iface->msgs_done >= iface->msgs_num) {
+ dev_err(&iface->adap.dev, "s6i2c: spurious I2C irq: %04x\n",
+ i2c_rd16(iface, S6_I2C_INTRSTAT));
+ i2c_wr16(iface, S6_I2C_INTRMASK, 0);
+ return;
+ }
+ while ((iface->msgs_push < iface->msgs_num)
+ && (i2c_rd16(iface, S6_I2C_STATUS) & (1 << S6_I2C_STATUS_TFNF))) {
+ struct i2c_msg *m = &iface->msgs[iface->msgs_push];
+ if (!(m->flags & I2C_M_RD))
+ i2c_wr16(iface, S6_I2C_DATACMD, m->buf[iface->push]);
+ else
+ i2c_wr16(iface, S6_I2C_DATACMD,
+ 1 << S6_I2C_DATACMD_READ);
+ if (++iface->push >= m->len) {
+ iface->push = 0;
+ iface->msgs_push += 1;
+ }
+ }
+ do {
+ struct i2c_msg *m = &iface->msgs[iface->msgs_done];
+ if (!(m->flags & I2C_M_RD)) {
+ if (iface->msgs_done < iface->msgs_push)
+ iface->msgs_done += 1;
+ else
+ break;
+ } else if (i2c_rd16(iface, S6_I2C_STATUS)
+ & (1 << S6_I2C_STATUS_RFNE)) {
+ m->buf[iface->done] = i2c_rd16(iface, S6_I2C_DATACMD);
+ if (++iface->done >= m->len) {
+ iface->done = 0;
+ iface->msgs_done += 1;
+ }
+ } else{
+ break;
+ }
+ } while (iface->msgs_done < iface->msgs_num);
+ if (iface->msgs_done >= iface->msgs_num) {
+ i2c_wr16(iface, S6_I2C_INTRMASK, 1 << S6_I2C_INTR_TXABRT);
+ complete(&iface->complete);
+ } else if (iface->msgs_push >= iface->msgs_num) {
+ i2c_wr16(iface, S6_I2C_INTRMASK, (1 << S6_I2C_INTR_TXABRT) |
+ (1 << S6_I2C_INTR_RXFULL));
+ } else {
+ i2c_wr16(iface, S6_I2C_INTRMASK, (1 << S6_I2C_INTR_TXABRT) |
+ (1 << S6_I2C_INTR_TXEMPTY) |
+ (1 << S6_I2C_INTR_RXFULL));
+ }
+}
+
+static irqreturn_t s6i2c_interrupt_entry(int irq, void *dev_id)
+{
+ struct s6i2c_if *iface = dev_id;
+ if (!(i2c_rd16(iface, S6_I2C_STATUS) & ((1 << S6_I2C_INTR_RXUNDER)
+ | (1 << S6_I2C_INTR_RXOVER)
+ | (1 << S6_I2C_INTR_RXFULL)
+ | (1 << S6_I2C_INTR_TXOVER)
+ | (1 << S6_I2C_INTR_TXEMPTY)
+ | (1 << S6_I2C_INTR_RDREQ)
+ | (1 << S6_I2C_INTR_TXABRT)
+ | (1 << S6_I2C_INTR_RXDONE)
+ | (1 << S6_I2C_INTR_ACTIVITY)
+ | (1 << S6_I2C_INTR_STOPDET)
+ | (1 << S6_I2C_INTR_STARTDET)
+ | (1 << S6_I2C_INTR_GENCALL))))
+ return IRQ_NONE;
+
+ spin_lock(&iface->lock);
+ del_timer(&iface->timeout_timer);
+ s6i2c_handle_interrupt(iface);
+ spin_unlock(&iface->lock);
+ return IRQ_HANDLED;
+}
+
+static void s6i2c_timeout(unsigned long data)
+{
+ struct s6i2c_if *iface = (struct s6i2c_if *)data;
+ unsigned long flags;
+
+ spin_lock_irqsave(&iface->lock, flags);
+ s6i2c_handle_interrupt(iface);
+ if (--iface->timeout_count > 0) {
+ iface->timeout_timer.expires = jiffies + POLL_TIMEOUT;
+ add_timer(&iface->timeout_timer);
+ } else {
+ complete(&iface->complete);
+ i2c_wr16(iface, S6_I2C_INTRMASK, 0);
+ }
+ spin_unlock_irqrestore(&iface->lock, flags);
+}
+
+static int s6i2c_master_xfer(struct i2c_adapter *adap,
+ struct i2c_msg *msgs, int num)
+{
+ struct s6i2c_if *iface = adap->algo_data;
+ int i;
+ if (num == 0)
+ return 0;
+ if (i2c_rd16(iface, S6_I2C_STATUS) & (1 << S6_I2C_STATUS_ACTIVITY))
+ yield();
+ i2c_wr16(iface, S6_I2C_INTRMASK, 0);
+ i2c_rd16(iface, S6_I2C_CLRINTR);
+ for (i = 0; i < num; i++) {
+ if (msgs[i].flags & I2C_M_TEN) {
+ dev_err(&adap->dev,
+ "s6i2c: 10 bits addr not supported\n");
+ return -EINVAL;
+ }
+ if (msgs[i].len == 0) {
+ dev_err(&adap->dev,
+ "s6i2c: zero length message not supported\n");
+ return -EINVAL;
+ }
+ if (msgs[i].addr != msgs[0].addr) {
+ dev_err(&adap->dev,
+ "s6i2c: multiple xfer cannot change target\n");
+ return -EINVAL;
+ }
+ }
+
+ iface->msgs = msgs;
+ iface->msgs_num = num;
+ iface->msgs_push = 0;
+ iface->msgs_done = 0;
+ iface->push = 0;
+ iface->done = 0;
+ iface->timeout_count = 10;
+ i2c_wr16(iface, S6_I2C_TAR, msgs[0].addr);
+ i2c_wr16(iface, S6_I2C_ENABLE, 1);
+ i2c_wr16(iface, S6_I2C_INTRMASK, (1 << S6_I2C_INTR_TXEMPTY) |
+ (1 << S6_I2C_INTR_TXABRT));
+
+ iface->timeout_timer.expires = jiffies + POLL_TIMEOUT;
+ add_timer(&iface->timeout_timer);
+ wait_for_completion(&iface->complete);
+ del_timer_sync(&iface->timeout_timer);
+ while (i2c_rd32(iface, S6_I2C_TXFLR) > 0)
+ schedule();
+ while (i2c_rd16(iface, S6_I2C_STATUS) & (1 << S6_I2C_STATUS_ACTIVITY))
+ schedule();
+
+ i2c_wr16(iface, S6_I2C_INTRMASK, 0);
+ i2c_wr16(iface, S6_I2C_ENABLE, 0);
+ return iface->msgs_done;
+}
+
+static u32 s6i2c_functionality(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static struct i2c_algorithm s6i2c_algorithm = {
+ .master_xfer = s6i2c_master_xfer,
+ .functionality = s6i2c_functionality,
+};
+
+static u16 __devinit nanoseconds_on_clk(struct s6i2c_if *iface, u32 ns)
+{
+ u32 dividend = ((clk_get_rate(iface->clk) / 1000) * ns) / 1000000;
+ if (dividend > 0xffff)
+ return 0xffff;
+ return dividend;
+}
+
+static int __devinit s6i2c_probe(struct platform_device *dev)
+{
+ struct s6i2c_if *iface = &s6i2c_if;
+ struct i2c_adapter *p_adap;
+ const char *clock;
+ int bus_num, rc;
+ spin_lock_init(&iface->lock);
+ init_completion(&iface->complete);
+ iface->irq = platform_get_irq(dev, 0);
+ if (iface->irq < 0) {
+ rc = iface->irq;
+ goto err_out;
+ }
+ iface->res = platform_get_resource(dev, IORESOURCE_MEM, 0);
+ if (!iface->res) {
+ rc = -ENXIO;
+ goto err_out;
+ }
+ iface->res = request_mem_region(iface->res->start,
+ resource_size(iface->res),
+ dev->dev.bus_id);
+ if (!iface->res) {
+ rc = -EBUSY;
+ goto err_out;
+ }
+ iface->reg = ioremap_nocache(iface->res->start,
+ resource_size(iface->res));
+ if (!iface->reg) {
+ rc = -ENOMEM;
+ goto err_reg;
+ }
+
+ clock = 0;
+ bus_num = -1;
+ if (dev->dev.platform_data) {
+ struct s6_i2c_platform_data *pdata = dev->dev.platform_data;
+ bus_num = pdata->bus_num;
+ clock = pdata->clock;
+ }
+ iface->clk = clk_get(&dev->dev, clock);
+ if (IS_ERR(iface->clk)) {
+ rc = PTR_ERR(iface->clk);
+ goto err_map;
+ }
+ rc = clk_enable(iface->clk);
+ if (rc < 0)
+ goto err_clk_put;
+ init_timer(&iface->timeout_timer);
+ iface->timeout_timer.function = s6i2c_timeout;
+ iface->timeout_timer.data = (unsigned long)iface;
+
+ p_adap = &iface->adap;
+ strlcpy(p_adap->name, dev->name, sizeof(p_adap->name));
+ p_adap->algo = &s6i2c_algorithm;
+ p_adap->algo_data = iface;
+ p_adap->nr = bus_num;
+ p_adap->class = 0;
+ p_adap->dev.parent = &dev->dev;
+ i2c_wr16(iface, S6_I2C_INTRMASK, 0);
+ rc = request_irq(iface->irq, s6i2c_interrupt_entry,
+ IRQF_SHARED, dev->name, iface);
+ if (rc) {
+ dev_err(&p_adap->dev, "s6i2c: cant get IRQ %d\n", iface->irq);
+ goto err_clk_dis;
+ }
+
+ i2c_wr16(iface, S6_I2C_ENABLE, 0);
+ udelay(1);
+ i2c_wr32(iface, S6_I2C_SRESET, 1 << S6_I2C_SRESET_IC_SRST);
+ i2c_wr16(iface, S6_I2C_CLRTXABRT, 1);
+ i2c_wr16(iface, S6_I2C_CON,
+ (1 << S6_I2C_CON_MASTER) |
+ (S6_I2C_CON_SPEED_NORMAL << S6_I2C_CON_SPEED) |
+ (0 << S6_I2C_CON_10BITSLAVE) |
+ (0 << S6_I2C_CON_10BITMASTER) |
+ (1 << S6_I2C_CON_RESTARTENA) |
+ (1 << S6_I2C_CON_SLAVEDISABLE));
+ i2c_wr16(iface, S6_I2C_SSHCNT, nanoseconds_on_clk(iface, 4000));
+ i2c_wr16(iface, S6_I2C_SSLCNT, nanoseconds_on_clk(iface, 4700));
+ i2c_wr16(iface, S6_I2C_FSHCNT, nanoseconds_on_clk(iface, 600));
+ i2c_wr16(iface, S6_I2C_FSLCNT, nanoseconds_on_clk(iface, 1300));
+ i2c_wr16(iface, S6_I2C_RXTL, 0);
+ i2c_wr16(iface, S6_I2C_TXTL, 0);
+
+ platform_set_drvdata(dev, iface);
+ if (bus_num < 0)
+ rc = i2c_add_adapter(p_adap);
+ else
+ rc = i2c_add_numbered_adapter(p_adap);
+ if (rc)
+ goto err_irq_free;
+ return 0;
+
+err_irq_free:
+ free_irq(iface->irq, iface);
+err_clk_dis:
+ clk_disable(iface->clk);
+err_clk_put:
+ clk_put(iface->clk);
+err_map:
+ iounmap(iface->reg);
+err_reg:
+ release_mem_region(iface->res->start,
+ resource_size(iface->res));
+err_out:
+ return rc;
+}
+
+static int __devexit s6i2c_remove(struct platform_device *pdev)
+{
+ struct s6i2c_if *iface = platform_get_drvdata(pdev);
+ i2c_wr16(iface, S6_I2C_ENABLE, 0);
+ platform_set_drvdata(pdev, NULL);
+ i2c_del_adapter(&iface->adap);
+ free_irq(iface->irq, iface);
+ clk_disable(iface->clk);
+ clk_put(iface->clk);
+ iounmap(iface->reg);
+ release_mem_region(iface->res->start,
+ resource_size(iface->res));
+ return 0;
+}
+
+static struct platform_driver s6i2c_driver = {
+ .probe = s6i2c_probe,
+ .remove = __devexit_p(s6i2c_remove),
+ .driver = {
+ .name = DRV_NAME,
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init s6i2c_init(void)
+{
+ pr_info("I2C: S6000 I2C driver\n");
+ return platform_driver_register(&s6i2c_driver);
+}
+
+static void __exit s6i2c_exit(void)
+{
+ platform_driver_unregister(&s6i2c_driver);
+}
+
+MODULE_DESCRIPTION("I2C-Bus adapter routines for S6000 I2C");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRV_NAME);
+
+subsys_initcall(s6i2c_init);
+module_exit(s6i2c_exit);
--- /dev/null
+/*
+ * drivers/i2c/busses/i2c-s6000.h
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2008 Emlix GmbH <info@emlix.com>
+ * Author: Oskar Schirmer <os@emlix.com>
+ */
+
+#ifndef __DRIVERS_I2C_BUSSES_I2C_S6000_H
+#define __DRIVERS_I2C_BUSSES_I2C_S6000_H
+
+#define S6_I2C_CON 0x000
+#define S6_I2C_CON_MASTER 0
+#define S6_I2C_CON_SPEED 1
+#define S6_I2C_CON_SPEED_NORMAL 1
+#define S6_I2C_CON_SPEED_FAST 2
+#define S6_I2C_CON_SPEED_MASK 3
+#define S6_I2C_CON_10BITSLAVE 3
+#define S6_I2C_CON_10BITMASTER 4
+#define S6_I2C_CON_RESTARTENA 5
+#define S6_I2C_CON_SLAVEDISABLE 6
+#define S6_I2C_TAR 0x004
+#define S6_I2C_TAR_GCORSTART 10
+#define S6_I2C_TAR_SPECIAL 11
+#define S6_I2C_SAR 0x008
+#define S6_I2C_HSMADDR 0x00C
+#define S6_I2C_DATACMD 0x010
+#define S6_I2C_DATACMD_READ 8
+#define S6_I2C_SSHCNT 0x014
+#define S6_I2C_SSLCNT 0x018
+#define S6_I2C_FSHCNT 0x01C
+#define S6_I2C_FSLCNT 0x020
+#define S6_I2C_INTRSTAT 0x02C
+#define S6_I2C_INTRMASK 0x030
+#define S6_I2C_RAWINTR 0x034
+#define S6_I2C_INTR_RXUNDER 0
+#define S6_I2C_INTR_RXOVER 1
+#define S6_I2C_INTR_RXFULL 2
+#define S6_I2C_INTR_TXOVER 3
+#define S6_I2C_INTR_TXEMPTY 4
+#define S6_I2C_INTR_RDREQ 5
+#define S6_I2C_INTR_TXABRT 6
+#define S6_I2C_INTR_RXDONE 7
+#define S6_I2C_INTR_ACTIVITY 8
+#define S6_I2C_INTR_STOPDET 9
+#define S6_I2C_INTR_STARTDET 10
+#define S6_I2C_INTR_GENCALL 11
+#define S6_I2C_RXTL 0x038
+#define S6_I2C_TXTL 0x03C
+#define S6_I2C_CLRINTR 0x040
+#define S6_I2C_CLRRXUNDER 0x044
+#define S6_I2C_CLRRXOVER 0x048
+#define S6_I2C_CLRTXOVER 0x04C
+#define S6_I2C_CLRRDREQ 0x050
+#define S6_I2C_CLRTXABRT 0x054
+#define S6_I2C_CLRRXDONE 0x058
+#define S6_I2C_CLRACTIVITY 0x05C
+#define S6_I2C_CLRSTOPDET 0x060
+#define S6_I2C_CLRSTARTDET 0x064
+#define S6_I2C_CLRGENCALL 0x068
+#define S6_I2C_ENABLE 0x06C
+#define S6_I2C_STATUS 0x070
+#define S6_I2C_STATUS_ACTIVITY 0
+#define S6_I2C_STATUS_TFNF 1
+#define S6_I2C_STATUS_TFE 2
+#define S6_I2C_STATUS_RFNE 3
+#define S6_I2C_STATUS_RFF 4
+#define S6_I2C_TXFLR 0x074
+#define S6_I2C_RXFLR 0x078
+#define S6_I2C_SRESET 0x07C
+#define S6_I2C_SRESET_IC_SRST 0
+#define S6_I2C_SRESET_IC_MASTER_SRST 1
+#define S6_I2C_SRESET_IC_SLAVE_SRST 2
+#define S6_I2C_TXABRTSOURCE 0x080
+
+#endif
projects / platform / kernel / linux-rpi.git / commitdiff