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@@ -0,0 +1,407 @@
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+/*
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+ * drivers/i2c/busses/i2c-s6000.c
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+ *
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+ * Description: Driver for S6000 Family I2C Interface
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+ * Copyright (c) 2008 emlix GmbH
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+ * Author: Oskar Schirmer <os@emlix.com>
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+ *
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+ * Partially based on i2c-bfin-twi.c driver by <sonic.zhang@analog.com>
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+ * Copyright (c) 2005-2007 Analog Devices, Inc.
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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 GNU General Public License as published by
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+ * the Free Software Foundation; either version 2 of the License, or
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+ * (at your option) any later version.
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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, write to the Free Software
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+ * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA
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+ */
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+
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+#include <linux/clk.h>
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+#include <linux/err.h>
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+#include <linux/module.h>
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+#include <linux/kernel.h>
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+#include <linux/init.h>
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+#include <linux/delay.h>
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+#include <linux/i2c.h>
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+#include <linux/i2c/s6000.h>
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+#include <linux/timer.h>
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+#include <linux/spinlock.h>
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+#include <linux/completion.h>
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+#include <linux/interrupt.h>
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+#include <linux/platform_device.h>
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+
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+#include <asm/io.h>
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+#include "i2c-s6000.h"
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+
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+#define DRV_NAME "i2c-s6000"
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+
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+#define POLL_TIMEOUT (2 * HZ)
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+
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+struct s6i2c_if {
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+ u8 __iomem *reg; /* memory mapped registers */
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+ int irq;
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+ spinlock_t lock;
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+ struct i2c_msg *msgs; /* messages currently handled */
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+ int msgs_num; /* nb of msgs to do */
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+ int msgs_push; /* nb of msgs read/written */
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+ int msgs_done; /* nb of msgs finally handled */
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+ unsigned push; /* nb of bytes read/written in msg */
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+ unsigned done; /* nb of bytes finally handled */
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+ int timeout_count; /* timeout retries left */
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+ struct timer_list timeout_timer;
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+ struct i2c_adapter adap;
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+ struct completion complete;
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+ struct clk *clk;
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+ struct resource *res;
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+};
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+
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+static inline u16 i2c_rd16(struct s6i2c_if *iface, unsigned n)
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+{
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+ return readw(iface->reg + (n));
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+}
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+
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+static inline void i2c_wr16(struct s6i2c_if *iface, unsigned n, u16 v)
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+{
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+ writew(v, iface->reg + (n));
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+}
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+
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+static inline u32 i2c_rd32(struct s6i2c_if *iface, unsigned n)
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+{
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+ return readl(iface->reg + (n));
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+}
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+
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+static inline void i2c_wr32(struct s6i2c_if *iface, unsigned n, u32 v)
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+{
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+ writel(v, iface->reg + (n));
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+}
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+
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+static struct s6i2c_if s6i2c_if;
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+
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+static void s6i2c_handle_interrupt(struct s6i2c_if *iface)
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+{
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+ if (i2c_rd16(iface, S6_I2C_INTRSTAT) & (1 << S6_I2C_INTR_TXABRT)) {
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+ i2c_rd16(iface, S6_I2C_CLRTXABRT);
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+ i2c_wr16(iface, S6_I2C_INTRMASK, 0);
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+ complete(&iface->complete);
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+ return;
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+ }
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+ if (iface->msgs_done >= iface->msgs_num) {
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+ dev_err(&iface->adap.dev, "s6i2c: spurious I2C irq: %04x\n",
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+ i2c_rd16(iface, S6_I2C_INTRSTAT));
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+ i2c_wr16(iface, S6_I2C_INTRMASK, 0);
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+ return;
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+ }
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+ while ((iface->msgs_push < iface->msgs_num)
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+ && (i2c_rd16(iface, S6_I2C_STATUS) & (1 << S6_I2C_STATUS_TFNF))) {
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+ struct i2c_msg *m = &iface->msgs[iface->msgs_push];
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+ if (!(m->flags & I2C_M_RD))
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+ i2c_wr16(iface, S6_I2C_DATACMD, m->buf[iface->push]);
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+ else
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+ i2c_wr16(iface, S6_I2C_DATACMD,
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+ 1 << S6_I2C_DATACMD_READ);
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+ if (++iface->push >= m->len) {
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+ iface->push = 0;
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+ iface->msgs_push += 1;
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+ }
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+ }
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+ do {
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+ struct i2c_msg *m = &iface->msgs[iface->msgs_done];
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+ if (!(m->flags & I2C_M_RD)) {
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+ if (iface->msgs_done < iface->msgs_push)
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+ iface->msgs_done += 1;
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+ else
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+ break;
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+ } else if (i2c_rd16(iface, S6_I2C_STATUS)
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+ & (1 << S6_I2C_STATUS_RFNE)) {
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+ m->buf[iface->done] = i2c_rd16(iface, S6_I2C_DATACMD);
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+ if (++iface->done >= m->len) {
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+ iface->done = 0;
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+ iface->msgs_done += 1;
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+ }
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+ } else{
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+ break;
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+ }
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+ } while (iface->msgs_done < iface->msgs_num);
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+ if (iface->msgs_done >= iface->msgs_num) {
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+ i2c_wr16(iface, S6_I2C_INTRMASK, 1 << S6_I2C_INTR_TXABRT);
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+ complete(&iface->complete);
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+ } else if (iface->msgs_push >= iface->msgs_num) {
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+ i2c_wr16(iface, S6_I2C_INTRMASK, (1 << S6_I2C_INTR_TXABRT) |
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+ (1 << S6_I2C_INTR_RXFULL));
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+ } else {
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+ i2c_wr16(iface, S6_I2C_INTRMASK, (1 << S6_I2C_INTR_TXABRT) |
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+ (1 << S6_I2C_INTR_TXEMPTY) |
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+ (1 << S6_I2C_INTR_RXFULL));
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+ }
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+}
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+
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+static irqreturn_t s6i2c_interrupt_entry(int irq, void *dev_id)
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+{
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+ struct s6i2c_if *iface = dev_id;
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+ if (!(i2c_rd16(iface, S6_I2C_STATUS) & ((1 << S6_I2C_INTR_RXUNDER)
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+ | (1 << S6_I2C_INTR_RXOVER)
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+ | (1 << S6_I2C_INTR_RXFULL)
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+ | (1 << S6_I2C_INTR_TXOVER)
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+ | (1 << S6_I2C_INTR_TXEMPTY)
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+ | (1 << S6_I2C_INTR_RDREQ)
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+ | (1 << S6_I2C_INTR_TXABRT)
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+ | (1 << S6_I2C_INTR_RXDONE)
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+ | (1 << S6_I2C_INTR_ACTIVITY)
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+ | (1 << S6_I2C_INTR_STOPDET)
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+ | (1 << S6_I2C_INTR_STARTDET)
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+ | (1 << S6_I2C_INTR_GENCALL))))
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+ return IRQ_NONE;
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+
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+ spin_lock(&iface->lock);
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+ del_timer(&iface->timeout_timer);
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+ s6i2c_handle_interrupt(iface);
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+ spin_unlock(&iface->lock);
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+ return IRQ_HANDLED;
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+}
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+
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+static void s6i2c_timeout(unsigned long data)
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+{
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+ struct s6i2c_if *iface = (struct s6i2c_if *)data;
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+ unsigned long flags;
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+
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+ spin_lock_irqsave(&iface->lock, flags);
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+ s6i2c_handle_interrupt(iface);
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+ if (--iface->timeout_count > 0) {
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+ iface->timeout_timer.expires = jiffies + POLL_TIMEOUT;
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+ add_timer(&iface->timeout_timer);
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+ } else {
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+ complete(&iface->complete);
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+ i2c_wr16(iface, S6_I2C_INTRMASK, 0);
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+ }
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+ spin_unlock_irqrestore(&iface->lock, flags);
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+}
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+
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+static int s6i2c_master_xfer(struct i2c_adapter *adap,
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+ struct i2c_msg *msgs, int num)
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+{
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+ struct s6i2c_if *iface = adap->algo_data;
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+ int i;
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+ if (num == 0)
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+ return 0;
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+ if (i2c_rd16(iface, S6_I2C_STATUS) & (1 << S6_I2C_STATUS_ACTIVITY))
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+ yield();
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+ i2c_wr16(iface, S6_I2C_INTRMASK, 0);
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+ i2c_rd16(iface, S6_I2C_CLRINTR);
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+ for (i = 0; i < num; i++) {
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+ if (msgs[i].flags & I2C_M_TEN) {
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+ dev_err(&adap->dev,
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+ "s6i2c: 10 bits addr not supported\n");
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+ return -EINVAL;
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+ }
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+ if (msgs[i].len == 0) {
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+ dev_err(&adap->dev,
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+ "s6i2c: zero length message not supported\n");
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+ return -EINVAL;
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+ }
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+ if (msgs[i].addr != msgs[0].addr) {
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+ dev_err(&adap->dev,
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+ "s6i2c: multiple xfer cannot change target\n");
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+ return -EINVAL;
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+ }
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+ }
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+
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+ iface->msgs = msgs;
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+ iface->msgs_num = num;
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+ iface->msgs_push = 0;
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+ iface->msgs_done = 0;
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+ iface->push = 0;
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+ iface->done = 0;
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+ iface->timeout_count = 10;
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+ i2c_wr16(iface, S6_I2C_TAR, msgs[0].addr);
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+ i2c_wr16(iface, S6_I2C_ENABLE, 1);
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+ i2c_wr16(iface, S6_I2C_INTRMASK, (1 << S6_I2C_INTR_TXEMPTY) |
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+ (1 << S6_I2C_INTR_TXABRT));
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+
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+ iface->timeout_timer.expires = jiffies + POLL_TIMEOUT;
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+ add_timer(&iface->timeout_timer);
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+ wait_for_completion(&iface->complete);
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+ del_timer_sync(&iface->timeout_timer);
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+ while (i2c_rd32(iface, S6_I2C_TXFLR) > 0)
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+ schedule();
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+ while (i2c_rd16(iface, S6_I2C_STATUS) & (1 << S6_I2C_STATUS_ACTIVITY))
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+ schedule();
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+
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+ i2c_wr16(iface, S6_I2C_INTRMASK, 0);
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+ i2c_wr16(iface, S6_I2C_ENABLE, 0);
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+ return iface->msgs_done;
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+}
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+
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+static u32 s6i2c_functionality(struct i2c_adapter *adap)
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+{
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+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
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+}
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+
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+static struct i2c_algorithm s6i2c_algorithm = {
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+ .master_xfer = s6i2c_master_xfer,
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+ .functionality = s6i2c_functionality,
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+};
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+
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+static u16 __devinit nanoseconds_on_clk(struct s6i2c_if *iface, u32 ns)
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+{
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+ u32 dividend = ((clk_get_rate(iface->clk) / 1000) * ns) / 1000000;
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+ if (dividend > 0xffff)
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+ return 0xffff;
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+ return dividend;
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+}
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+
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+static int __devinit s6i2c_probe(struct platform_device *dev)
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+{
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+ struct s6i2c_if *iface = &s6i2c_if;
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+ struct i2c_adapter *p_adap;
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+ const char *clock;
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+ int bus_num, rc;
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+ spin_lock_init(&iface->lock);
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+ init_completion(&iface->complete);
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+ iface->irq = platform_get_irq(dev, 0);
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+ if (iface->irq < 0) {
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+ rc = iface->irq;
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+ goto err_out;
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+ }
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+ iface->res = platform_get_resource(dev, IORESOURCE_MEM, 0);
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+ if (!iface->res) {
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+ rc = -ENXIO;
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+ goto err_out;
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+ }
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+ iface->res = request_mem_region(iface->res->start,
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+ resource_size(iface->res),
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+ dev->dev.bus_id);
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+ if (!iface->res) {
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+ rc = -EBUSY;
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+ goto err_out;
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+ }
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+ iface->reg = ioremap_nocache(iface->res->start,
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+ resource_size(iface->res));
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+ if (!iface->reg) {
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+ rc = -ENOMEM;
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+ goto err_reg;
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+ }
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+
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+ clock = 0;
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+ bus_num = -1;
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+ if (dev->dev.platform_data) {
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+ struct s6_i2c_platform_data *pdata = dev->dev.platform_data;
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+ bus_num = pdata->bus_num;
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+ clock = pdata->clock;
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+ }
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+ iface->clk = clk_get(&dev->dev, clock);
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+ if (IS_ERR(iface->clk)) {
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+ rc = PTR_ERR(iface->clk);
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+ goto err_map;
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+ }
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+ rc = clk_enable(iface->clk);
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+ if (rc < 0)
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+ goto err_clk_put;
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+ init_timer(&iface->timeout_timer);
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+ iface->timeout_timer.function = s6i2c_timeout;
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+ iface->timeout_timer.data = (unsigned long)iface;
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+
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+ p_adap = &iface->adap;
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+ strlcpy(p_adap->name, dev->name, sizeof(p_adap->name));
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+ p_adap->algo = &s6i2c_algorithm;
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+ p_adap->algo_data = iface;
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+ p_adap->nr = bus_num;
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+ p_adap->class = 0;
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+ p_adap->dev.parent = &dev->dev;
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+ i2c_wr16(iface, S6_I2C_INTRMASK, 0);
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+ rc = request_irq(iface->irq, s6i2c_interrupt_entry,
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+ IRQF_SHARED, dev->name, iface);
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+ if (rc) {
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+ dev_err(&p_adap->dev, "s6i2c: cant get IRQ %d\n", iface->irq);
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+ goto err_clk_dis;
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+ }
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+
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+ i2c_wr16(iface, S6_I2C_ENABLE, 0);
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+ udelay(1);
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+ i2c_wr32(iface, S6_I2C_SRESET, 1 << S6_I2C_SRESET_IC_SRST);
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+ i2c_wr16(iface, S6_I2C_CLRTXABRT, 1);
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+ i2c_wr16(iface, S6_I2C_CON,
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+ (1 << S6_I2C_CON_MASTER) |
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+ (S6_I2C_CON_SPEED_NORMAL << S6_I2C_CON_SPEED) |
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+ (0 << S6_I2C_CON_10BITSLAVE) |
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+ (0 << S6_I2C_CON_10BITMASTER) |
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+ (1 << S6_I2C_CON_RESTARTENA) |
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+ (1 << S6_I2C_CON_SLAVEDISABLE));
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+ i2c_wr16(iface, S6_I2C_SSHCNT, nanoseconds_on_clk(iface, 4000));
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+ i2c_wr16(iface, S6_I2C_SSLCNT, nanoseconds_on_clk(iface, 4700));
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+ i2c_wr16(iface, S6_I2C_FSHCNT, nanoseconds_on_clk(iface, 600));
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+ i2c_wr16(iface, S6_I2C_FSLCNT, nanoseconds_on_clk(iface, 1300));
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+ i2c_wr16(iface, S6_I2C_RXTL, 0);
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+ i2c_wr16(iface, S6_I2C_TXTL, 0);
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+
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+ platform_set_drvdata(dev, iface);
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+ if (bus_num < 0)
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+ rc = i2c_add_adapter(p_adap);
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+ else
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+ rc = i2c_add_numbered_adapter(p_adap);
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+ if (rc)
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+ 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);
|
Oskar Schirmer