forked from luck/tmp_suning_uos_patched
9ba63c4fa1
Add power I2C support for PXA3xx processors Signed-off-by: Mike Rapoport <mike@compulab.co.il> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
1111 lines
25 KiB
C
1111 lines
25 KiB
C
/*
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* i2c_adap_pxa.c
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*
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* I2C adapter for the PXA I2C bus access.
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*
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* Copyright (C) 2002 Intrinsyc Software Inc.
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* Copyright (C) 2004-2005 Deep Blue Solutions Ltd.
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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 version 2 as
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* published by the Free Software Foundation.
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*
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* History:
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* Apr 2002: Initial version [CS]
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* Jun 2002: Properly seperated algo/adap [FB]
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* Jan 2003: Fixed several bugs concerning interrupt handling [Kai-Uwe Bloem]
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* Jan 2003: added limited signal handling [Kai-Uwe Bloem]
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* Sep 2004: Major rework to ensure efficient bus handling [RMK]
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* Dec 2004: Added support for PXA27x and slave device probing [Liam Girdwood]
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* Feb 2005: Rework slave mode handling [RMK]
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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/i2c.h>
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#include <linux/i2c-id.h>
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#include <linux/init.h>
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#include <linux/time.h>
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#include <linux/sched.h>
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#include <linux/delay.h>
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#include <linux/errno.h>
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#include <linux/interrupt.h>
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#include <linux/i2c-pxa.h>
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#include <linux/platform_device.h>
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#include <linux/err.h>
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#include <linux/clk.h>
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#include <mach/hardware.h>
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#include <asm/irq.h>
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#include <asm/io.h>
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#include <mach/i2c.h>
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#include <mach/pxa-regs.h>
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struct pxa_i2c {
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spinlock_t lock;
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wait_queue_head_t wait;
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struct i2c_msg *msg;
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unsigned int msg_num;
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unsigned int msg_idx;
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unsigned int msg_ptr;
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unsigned int slave_addr;
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struct i2c_adapter adap;
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struct clk *clk;
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#ifdef CONFIG_I2C_PXA_SLAVE
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struct i2c_slave_client *slave;
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#endif
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unsigned int irqlogidx;
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u32 isrlog[32];
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u32 icrlog[32];
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void __iomem *reg_base;
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unsigned int reg_shift;
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unsigned long iobase;
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unsigned long iosize;
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int irq;
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int use_pio;
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};
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#define _IBMR(i2c) ((i2c)->reg_base + (0x0 << (i2c)->reg_shift))
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#define _IDBR(i2c) ((i2c)->reg_base + (0x4 << (i2c)->reg_shift))
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#define _ICR(i2c) ((i2c)->reg_base + (0x8 << (i2c)->reg_shift))
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#define _ISR(i2c) ((i2c)->reg_base + (0xc << (i2c)->reg_shift))
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#define _ISAR(i2c) ((i2c)->reg_base + (0x10 << (i2c)->reg_shift))
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/*
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* I2C Slave mode address
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*/
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#define I2C_PXA_SLAVE_ADDR 0x1
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#ifdef DEBUG
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struct bits {
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u32 mask;
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const char *set;
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const char *unset;
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};
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#define PXA_BIT(m, s, u) { .mask = m, .set = s, .unset = u }
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static inline void
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decode_bits(const char *prefix, const struct bits *bits, int num, u32 val)
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{
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printk("%s %08x: ", prefix, val);
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while (num--) {
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const char *str = val & bits->mask ? bits->set : bits->unset;
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if (str)
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printk("%s ", str);
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bits++;
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}
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}
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static const struct bits isr_bits[] = {
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PXA_BIT(ISR_RWM, "RX", "TX"),
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PXA_BIT(ISR_ACKNAK, "NAK", "ACK"),
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PXA_BIT(ISR_UB, "Bsy", "Rdy"),
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PXA_BIT(ISR_IBB, "BusBsy", "BusRdy"),
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PXA_BIT(ISR_SSD, "SlaveStop", NULL),
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PXA_BIT(ISR_ALD, "ALD", NULL),
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PXA_BIT(ISR_ITE, "TxEmpty", NULL),
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PXA_BIT(ISR_IRF, "RxFull", NULL),
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PXA_BIT(ISR_GCAD, "GenCall", NULL),
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PXA_BIT(ISR_SAD, "SlaveAddr", NULL),
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PXA_BIT(ISR_BED, "BusErr", NULL),
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};
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static void decode_ISR(unsigned int val)
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{
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decode_bits(KERN_DEBUG "ISR", isr_bits, ARRAY_SIZE(isr_bits), val);
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printk("\n");
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}
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static const struct bits icr_bits[] = {
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PXA_BIT(ICR_START, "START", NULL),
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PXA_BIT(ICR_STOP, "STOP", NULL),
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PXA_BIT(ICR_ACKNAK, "ACKNAK", NULL),
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PXA_BIT(ICR_TB, "TB", NULL),
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PXA_BIT(ICR_MA, "MA", NULL),
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PXA_BIT(ICR_SCLE, "SCLE", "scle"),
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PXA_BIT(ICR_IUE, "IUE", "iue"),
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PXA_BIT(ICR_GCD, "GCD", NULL),
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PXA_BIT(ICR_ITEIE, "ITEIE", NULL),
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PXA_BIT(ICR_IRFIE, "IRFIE", NULL),
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PXA_BIT(ICR_BEIE, "BEIE", NULL),
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PXA_BIT(ICR_SSDIE, "SSDIE", NULL),
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PXA_BIT(ICR_ALDIE, "ALDIE", NULL),
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PXA_BIT(ICR_SADIE, "SADIE", NULL),
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PXA_BIT(ICR_UR, "UR", "ur"),
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};
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#ifdef CONFIG_I2C_PXA_SLAVE
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static void decode_ICR(unsigned int val)
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{
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decode_bits(KERN_DEBUG "ICR", icr_bits, ARRAY_SIZE(icr_bits), val);
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printk("\n");
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}
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#endif
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static unsigned int i2c_debug = DEBUG;
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static void i2c_pxa_show_state(struct pxa_i2c *i2c, int lno, const char *fname)
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{
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dev_dbg(&i2c->adap.dev, "state:%s:%d: ISR=%08x, ICR=%08x, IBMR=%02x\n", fname, lno,
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readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
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}
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#define show_state(i2c) i2c_pxa_show_state(i2c, __LINE__, __func__)
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#else
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#define i2c_debug 0
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#define show_state(i2c) do { } while (0)
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#define decode_ISR(val) do { } while (0)
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#define decode_ICR(val) do { } while (0)
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#endif
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#define eedbg(lvl, x...) do { if ((lvl) < 1) { printk(KERN_DEBUG "" x); } } while(0)
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static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret);
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static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id);
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static void i2c_pxa_scream_blue_murder(struct pxa_i2c *i2c, const char *why)
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{
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unsigned int i;
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printk("i2c: error: %s\n", why);
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printk("i2c: msg_num: %d msg_idx: %d msg_ptr: %d\n",
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i2c->msg_num, i2c->msg_idx, i2c->msg_ptr);
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printk("i2c: ICR: %08x ISR: %08x\n"
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"i2c: log: ", readl(_ICR(i2c)), readl(_ISR(i2c)));
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for (i = 0; i < i2c->irqlogidx; i++)
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printk("[%08x:%08x] ", i2c->isrlog[i], i2c->icrlog[i]);
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printk("\n");
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}
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static inline int i2c_pxa_is_slavemode(struct pxa_i2c *i2c)
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{
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return !(readl(_ICR(i2c)) & ICR_SCLE);
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}
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static void i2c_pxa_abort(struct pxa_i2c *i2c)
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{
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unsigned long timeout = jiffies + HZ/4;
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if (i2c_pxa_is_slavemode(i2c)) {
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dev_dbg(&i2c->adap.dev, "%s: called in slave mode\n", __func__);
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return;
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}
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while (time_before(jiffies, timeout) && (readl(_IBMR(i2c)) & 0x1) == 0) {
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unsigned long icr = readl(_ICR(i2c));
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icr &= ~ICR_START;
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icr |= ICR_ACKNAK | ICR_STOP | ICR_TB;
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writel(icr, _ICR(i2c));
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show_state(i2c);
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msleep(1);
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}
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writel(readl(_ICR(i2c)) & ~(ICR_MA | ICR_START | ICR_STOP),
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_ICR(i2c));
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}
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static int i2c_pxa_wait_bus_not_busy(struct pxa_i2c *i2c)
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{
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int timeout = DEF_TIMEOUT;
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while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
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if ((readl(_ISR(i2c)) & ISR_SAD) != 0)
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timeout += 4;
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msleep(2);
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show_state(i2c);
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}
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if (timeout <= 0)
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show_state(i2c);
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return timeout <= 0 ? I2C_RETRY : 0;
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}
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static int i2c_pxa_wait_master(struct pxa_i2c *i2c)
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{
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unsigned long timeout = jiffies + HZ*4;
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while (time_before(jiffies, timeout)) {
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if (i2c_debug > 1)
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dev_dbg(&i2c->adap.dev, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
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__func__, (long)jiffies, readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
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if (readl(_ISR(i2c)) & ISR_SAD) {
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if (i2c_debug > 0)
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dev_dbg(&i2c->adap.dev, "%s: Slave detected\n", __func__);
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goto out;
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}
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/* wait for unit and bus being not busy, and we also do a
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* quick check of the i2c lines themselves to ensure they've
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* gone high...
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*/
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if ((readl(_ISR(i2c)) & (ISR_UB | ISR_IBB)) == 0 && readl(_IBMR(i2c)) == 3) {
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if (i2c_debug > 0)
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dev_dbg(&i2c->adap.dev, "%s: done\n", __func__);
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return 1;
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}
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msleep(1);
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}
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if (i2c_debug > 0)
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dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__);
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out:
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return 0;
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}
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static int i2c_pxa_set_master(struct pxa_i2c *i2c)
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{
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if (i2c_debug)
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dev_dbg(&i2c->adap.dev, "setting to bus master\n");
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if ((readl(_ISR(i2c)) & (ISR_UB | ISR_IBB)) != 0) {
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dev_dbg(&i2c->adap.dev, "%s: unit is busy\n", __func__);
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if (!i2c_pxa_wait_master(i2c)) {
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dev_dbg(&i2c->adap.dev, "%s: error: unit busy\n", __func__);
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return I2C_RETRY;
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}
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}
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writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
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return 0;
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}
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#ifdef CONFIG_I2C_PXA_SLAVE
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static int i2c_pxa_wait_slave(struct pxa_i2c *i2c)
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{
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unsigned long timeout = jiffies + HZ*1;
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/* wait for stop */
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show_state(i2c);
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while (time_before(jiffies, timeout)) {
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if (i2c_debug > 1)
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dev_dbg(&i2c->adap.dev, "%s: %ld: ISR=%08x, ICR=%08x, IBMR=%02x\n",
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__func__, (long)jiffies, readl(_ISR(i2c)), readl(_ICR(i2c)), readl(_IBMR(i2c)));
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if ((readl(_ISR(i2c)) & (ISR_UB|ISR_IBB)) == 0 ||
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(readl(_ISR(i2c)) & ISR_SAD) != 0 ||
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(readl(_ICR(i2c)) & ICR_SCLE) == 0) {
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if (i2c_debug > 1)
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dev_dbg(&i2c->adap.dev, "%s: done\n", __func__);
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return 1;
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}
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msleep(1);
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}
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if (i2c_debug > 0)
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dev_dbg(&i2c->adap.dev, "%s: did not free\n", __func__);
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return 0;
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}
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/*
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* clear the hold on the bus, and take of anything else
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* that has been configured
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*/
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static void i2c_pxa_set_slave(struct pxa_i2c *i2c, int errcode)
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{
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show_state(i2c);
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if (errcode < 0) {
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udelay(100); /* simple delay */
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} else {
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/* we need to wait for the stop condition to end */
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/* if we where in stop, then clear... */
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if (readl(_ICR(i2c)) & ICR_STOP) {
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udelay(100);
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writel(readl(_ICR(i2c)) & ~ICR_STOP, _ICR(i2c));
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}
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if (!i2c_pxa_wait_slave(i2c)) {
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dev_err(&i2c->adap.dev, "%s: wait timedout\n",
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__func__);
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return;
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}
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}
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writel(readl(_ICR(i2c)) & ~(ICR_STOP|ICR_ACKNAK|ICR_MA), _ICR(i2c));
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writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
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if (i2c_debug) {
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dev_dbg(&i2c->adap.dev, "ICR now %08x, ISR %08x\n", readl(_ICR(i2c)), readl(_ISR(i2c)));
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decode_ICR(readl(_ICR(i2c)));
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}
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}
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#else
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#define i2c_pxa_set_slave(i2c, err) do { } while (0)
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#endif
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static void i2c_pxa_reset(struct pxa_i2c *i2c)
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{
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pr_debug("Resetting I2C Controller Unit\n");
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/* abort any transfer currently under way */
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i2c_pxa_abort(i2c);
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/* reset according to 9.8 */
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writel(ICR_UR, _ICR(i2c));
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writel(I2C_ISR_INIT, _ISR(i2c));
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writel(readl(_ICR(i2c)) & ~ICR_UR, _ICR(i2c));
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writel(i2c->slave_addr, _ISAR(i2c));
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/* set control register values */
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writel(I2C_ICR_INIT, _ICR(i2c));
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#ifdef CONFIG_I2C_PXA_SLAVE
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dev_info(&i2c->adap.dev, "Enabling slave mode\n");
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writel(readl(_ICR(i2c)) | ICR_SADIE | ICR_ALDIE | ICR_SSDIE, _ICR(i2c));
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#endif
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i2c_pxa_set_slave(i2c, 0);
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/* enable unit */
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writel(readl(_ICR(i2c)) | ICR_IUE, _ICR(i2c));
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udelay(100);
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}
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#ifdef CONFIG_I2C_PXA_SLAVE
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/*
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* PXA I2C Slave mode
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*/
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static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
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{
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if (isr & ISR_BED) {
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/* what should we do here? */
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} else {
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int ret = 0;
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if (i2c->slave != NULL)
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ret = i2c->slave->read(i2c->slave->data);
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writel(ret, _IDBR(i2c));
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writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c)); /* allow next byte */
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}
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}
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static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
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{
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unsigned int byte = readl(_IDBR(i2c));
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if (i2c->slave != NULL)
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i2c->slave->write(i2c->slave->data, byte);
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writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
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}
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static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
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{
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int timeout;
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if (i2c_debug > 0)
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dev_dbg(&i2c->adap.dev, "SAD, mode is slave-%cx\n",
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(isr & ISR_RWM) ? 'r' : 't');
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if (i2c->slave != NULL)
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i2c->slave->event(i2c->slave->data,
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(isr & ISR_RWM) ? I2C_SLAVE_EVENT_START_READ : I2C_SLAVE_EVENT_START_WRITE);
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/*
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* slave could interrupt in the middle of us generating a
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* start condition... if this happens, we'd better back off
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* and stop holding the poor thing up
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*/
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writel(readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP), _ICR(i2c));
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writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
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timeout = 0x10000;
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while (1) {
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if ((readl(_IBMR(i2c)) & 2) == 2)
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break;
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timeout--;
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if (timeout <= 0) {
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dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
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break;
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}
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}
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writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
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}
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static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
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{
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if (i2c_debug > 2)
|
|
dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop)\n");
|
|
|
|
if (i2c->slave != NULL)
|
|
i2c->slave->event(i2c->slave->data, I2C_SLAVE_EVENT_STOP);
|
|
|
|
if (i2c_debug > 2)
|
|
dev_dbg(&i2c->adap.dev, "ISR: SSD (Slave Stop) acked\n");
|
|
|
|
/*
|
|
* If we have a master-mode message waiting,
|
|
* kick it off now that the slave has completed.
|
|
*/
|
|
if (i2c->msg)
|
|
i2c_pxa_master_complete(i2c, I2C_RETRY);
|
|
}
|
|
#else
|
|
static void i2c_pxa_slave_txempty(struct pxa_i2c *i2c, u32 isr)
|
|
{
|
|
if (isr & ISR_BED) {
|
|
/* what should we do here? */
|
|
} else {
|
|
writel(0, _IDBR(i2c));
|
|
writel(readl(_ICR(i2c)) | ICR_TB, _ICR(i2c));
|
|
}
|
|
}
|
|
|
|
static void i2c_pxa_slave_rxfull(struct pxa_i2c *i2c, u32 isr)
|
|
{
|
|
writel(readl(_ICR(i2c)) | ICR_TB | ICR_ACKNAK, _ICR(i2c));
|
|
}
|
|
|
|
static void i2c_pxa_slave_start(struct pxa_i2c *i2c, u32 isr)
|
|
{
|
|
int timeout;
|
|
|
|
/*
|
|
* slave could interrupt in the middle of us generating a
|
|
* start condition... if this happens, we'd better back off
|
|
* and stop holding the poor thing up
|
|
*/
|
|
writel(readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP), _ICR(i2c));
|
|
writel(readl(_ICR(i2c)) | ICR_TB | ICR_ACKNAK, _ICR(i2c));
|
|
|
|
timeout = 0x10000;
|
|
|
|
while (1) {
|
|
if ((readl(_IBMR(i2c)) & 2) == 2)
|
|
break;
|
|
|
|
timeout--;
|
|
|
|
if (timeout <= 0) {
|
|
dev_err(&i2c->adap.dev, "timeout waiting for SCL high\n");
|
|
break;
|
|
}
|
|
}
|
|
|
|
writel(readl(_ICR(i2c)) & ~ICR_SCLE, _ICR(i2c));
|
|
}
|
|
|
|
static void i2c_pxa_slave_stop(struct pxa_i2c *i2c)
|
|
{
|
|
if (i2c->msg)
|
|
i2c_pxa_master_complete(i2c, I2C_RETRY);
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
* PXA I2C Master mode
|
|
*/
|
|
|
|
static inline unsigned int i2c_pxa_addr_byte(struct i2c_msg *msg)
|
|
{
|
|
unsigned int addr = (msg->addr & 0x7f) << 1;
|
|
|
|
if (msg->flags & I2C_M_RD)
|
|
addr |= 1;
|
|
|
|
return addr;
|
|
}
|
|
|
|
static inline void i2c_pxa_start_message(struct pxa_i2c *i2c)
|
|
{
|
|
u32 icr;
|
|
|
|
/*
|
|
* Step 1: target slave address into IDBR
|
|
*/
|
|
writel(i2c_pxa_addr_byte(i2c->msg), _IDBR(i2c));
|
|
|
|
/*
|
|
* Step 2: initiate the write.
|
|
*/
|
|
icr = readl(_ICR(i2c)) & ~(ICR_STOP | ICR_ALDIE);
|
|
writel(icr | ICR_START | ICR_TB, _ICR(i2c));
|
|
}
|
|
|
|
static inline void i2c_pxa_stop_message(struct pxa_i2c *i2c)
|
|
{
|
|
u32 icr;
|
|
|
|
/*
|
|
* Clear the STOP and ACK flags
|
|
*/
|
|
icr = readl(_ICR(i2c));
|
|
icr &= ~(ICR_STOP | ICR_ACKNAK);
|
|
writel(icr, _ICR(i2c));
|
|
}
|
|
|
|
static int i2c_pxa_pio_set_master(struct pxa_i2c *i2c)
|
|
{
|
|
/* make timeout the same as for interrupt based functions */
|
|
long timeout = 2 * DEF_TIMEOUT;
|
|
|
|
/*
|
|
* Wait for the bus to become free.
|
|
*/
|
|
while (timeout-- && readl(_ISR(i2c)) & (ISR_IBB | ISR_UB)) {
|
|
udelay(1000);
|
|
show_state(i2c);
|
|
}
|
|
|
|
if (timeout <= 0) {
|
|
show_state(i2c);
|
|
dev_err(&i2c->adap.dev,
|
|
"i2c_pxa: timeout waiting for bus free\n");
|
|
return I2C_RETRY;
|
|
}
|
|
|
|
/*
|
|
* Set master mode.
|
|
*/
|
|
writel(readl(_ICR(i2c)) | ICR_SCLE, _ICR(i2c));
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int i2c_pxa_do_pio_xfer(struct pxa_i2c *i2c,
|
|
struct i2c_msg *msg, int num)
|
|
{
|
|
unsigned long timeout = 500000; /* 5 seconds */
|
|
int ret = 0;
|
|
|
|
ret = i2c_pxa_pio_set_master(i2c);
|
|
if (ret)
|
|
goto out;
|
|
|
|
i2c->msg = msg;
|
|
i2c->msg_num = num;
|
|
i2c->msg_idx = 0;
|
|
i2c->msg_ptr = 0;
|
|
i2c->irqlogidx = 0;
|
|
|
|
i2c_pxa_start_message(i2c);
|
|
|
|
while (timeout-- && i2c->msg_num > 0) {
|
|
i2c_pxa_handler(0, i2c);
|
|
udelay(10);
|
|
}
|
|
|
|
i2c_pxa_stop_message(i2c);
|
|
|
|
/*
|
|
* We place the return code in i2c->msg_idx.
|
|
*/
|
|
ret = i2c->msg_idx;
|
|
|
|
out:
|
|
if (timeout == 0)
|
|
i2c_pxa_scream_blue_murder(i2c, "timeout");
|
|
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* We are protected by the adapter bus mutex.
|
|
*/
|
|
static int i2c_pxa_do_xfer(struct pxa_i2c *i2c, struct i2c_msg *msg, int num)
|
|
{
|
|
long timeout;
|
|
int ret;
|
|
|
|
/*
|
|
* Wait for the bus to become free.
|
|
*/
|
|
ret = i2c_pxa_wait_bus_not_busy(i2c);
|
|
if (ret) {
|
|
dev_err(&i2c->adap.dev, "i2c_pxa: timeout waiting for bus free\n");
|
|
goto out;
|
|
}
|
|
|
|
/*
|
|
* Set master mode.
|
|
*/
|
|
ret = i2c_pxa_set_master(i2c);
|
|
if (ret) {
|
|
dev_err(&i2c->adap.dev, "i2c_pxa_set_master: error %d\n", ret);
|
|
goto out;
|
|
}
|
|
|
|
spin_lock_irq(&i2c->lock);
|
|
|
|
i2c->msg = msg;
|
|
i2c->msg_num = num;
|
|
i2c->msg_idx = 0;
|
|
i2c->msg_ptr = 0;
|
|
i2c->irqlogidx = 0;
|
|
|
|
i2c_pxa_start_message(i2c);
|
|
|
|
spin_unlock_irq(&i2c->lock);
|
|
|
|
/*
|
|
* The rest of the processing occurs in the interrupt handler.
|
|
*/
|
|
timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
|
|
i2c_pxa_stop_message(i2c);
|
|
|
|
/*
|
|
* We place the return code in i2c->msg_idx.
|
|
*/
|
|
ret = i2c->msg_idx;
|
|
|
|
if (timeout == 0)
|
|
i2c_pxa_scream_blue_murder(i2c, "timeout");
|
|
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static int i2c_pxa_pio_xfer(struct i2c_adapter *adap,
|
|
struct i2c_msg msgs[], int num)
|
|
{
|
|
struct pxa_i2c *i2c = adap->algo_data;
|
|
int ret, i;
|
|
|
|
/* If the I2C controller is disabled we need to reset it
|
|
(probably due to a suspend/resume destroying state). We do
|
|
this here as we can then avoid worrying about resuming the
|
|
controller before its users. */
|
|
if (!(readl(_ICR(i2c)) & ICR_IUE))
|
|
i2c_pxa_reset(i2c);
|
|
|
|
for (i = adap->retries; i >= 0; i--) {
|
|
ret = i2c_pxa_do_pio_xfer(i2c, msgs, num);
|
|
if (ret != I2C_RETRY)
|
|
goto out;
|
|
|
|
if (i2c_debug)
|
|
dev_dbg(&adap->dev, "Retrying transmission\n");
|
|
udelay(100);
|
|
}
|
|
i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
|
|
ret = -EREMOTEIO;
|
|
out:
|
|
i2c_pxa_set_slave(i2c, ret);
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
* i2c_pxa_master_complete - complete the message and wake up.
|
|
*/
|
|
static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret)
|
|
{
|
|
i2c->msg_ptr = 0;
|
|
i2c->msg = NULL;
|
|
i2c->msg_idx ++;
|
|
i2c->msg_num = 0;
|
|
if (ret)
|
|
i2c->msg_idx = ret;
|
|
if (!i2c->use_pio)
|
|
wake_up(&i2c->wait);
|
|
}
|
|
|
|
static void i2c_pxa_irq_txempty(struct pxa_i2c *i2c, u32 isr)
|
|
{
|
|
u32 icr = readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB);
|
|
|
|
again:
|
|
/*
|
|
* If ISR_ALD is set, we lost arbitration.
|
|
*/
|
|
if (isr & ISR_ALD) {
|
|
/*
|
|
* Do we need to do anything here? The PXA docs
|
|
* are vague about what happens.
|
|
*/
|
|
i2c_pxa_scream_blue_murder(i2c, "ALD set");
|
|
|
|
/*
|
|
* We ignore this error. We seem to see spurious ALDs
|
|
* for seemingly no reason. If we handle them as I think
|
|
* they should, we end up causing an I2C error, which
|
|
* is painful for some systems.
|
|
*/
|
|
return; /* ignore */
|
|
}
|
|
|
|
if (isr & ISR_BED) {
|
|
int ret = BUS_ERROR;
|
|
|
|
/*
|
|
* I2C bus error - either the device NAK'd us, or
|
|
* something more serious happened. If we were NAK'd
|
|
* on the initial address phase, we can retry.
|
|
*/
|
|
if (isr & ISR_ACKNAK) {
|
|
if (i2c->msg_ptr == 0 && i2c->msg_idx == 0)
|
|
ret = I2C_RETRY;
|
|
else
|
|
ret = XFER_NAKED;
|
|
}
|
|
i2c_pxa_master_complete(i2c, ret);
|
|
} else if (isr & ISR_RWM) {
|
|
/*
|
|
* Read mode. We have just sent the address byte, and
|
|
* now we must initiate the transfer.
|
|
*/
|
|
if (i2c->msg_ptr == i2c->msg->len - 1 &&
|
|
i2c->msg_idx == i2c->msg_num - 1)
|
|
icr |= ICR_STOP | ICR_ACKNAK;
|
|
|
|
icr |= ICR_ALDIE | ICR_TB;
|
|
} else if (i2c->msg_ptr < i2c->msg->len) {
|
|
/*
|
|
* Write mode. Write the next data byte.
|
|
*/
|
|
writel(i2c->msg->buf[i2c->msg_ptr++], _IDBR(i2c));
|
|
|
|
icr |= ICR_ALDIE | ICR_TB;
|
|
|
|
/*
|
|
* If this is the last byte of the last message, send
|
|
* a STOP.
|
|
*/
|
|
if (i2c->msg_ptr == i2c->msg->len &&
|
|
i2c->msg_idx == i2c->msg_num - 1)
|
|
icr |= ICR_STOP;
|
|
} else if (i2c->msg_idx < i2c->msg_num - 1) {
|
|
/*
|
|
* Next segment of the message.
|
|
*/
|
|
i2c->msg_ptr = 0;
|
|
i2c->msg_idx ++;
|
|
i2c->msg++;
|
|
|
|
/*
|
|
* If we aren't doing a repeated start and address,
|
|
* go back and try to send the next byte. Note that
|
|
* we do not support switching the R/W direction here.
|
|
*/
|
|
if (i2c->msg->flags & I2C_M_NOSTART)
|
|
goto again;
|
|
|
|
/*
|
|
* Write the next address.
|
|
*/
|
|
writel(i2c_pxa_addr_byte(i2c->msg), _IDBR(i2c));
|
|
|
|
/*
|
|
* And trigger a repeated start, and send the byte.
|
|
*/
|
|
icr &= ~ICR_ALDIE;
|
|
icr |= ICR_START | ICR_TB;
|
|
} else {
|
|
if (i2c->msg->len == 0) {
|
|
/*
|
|
* Device probes have a message length of zero
|
|
* and need the bus to be reset before it can
|
|
* be used again.
|
|
*/
|
|
i2c_pxa_reset(i2c);
|
|
}
|
|
i2c_pxa_master_complete(i2c, 0);
|
|
}
|
|
|
|
i2c->icrlog[i2c->irqlogidx-1] = icr;
|
|
|
|
writel(icr, _ICR(i2c));
|
|
show_state(i2c);
|
|
}
|
|
|
|
static void i2c_pxa_irq_rxfull(struct pxa_i2c *i2c, u32 isr)
|
|
{
|
|
u32 icr = readl(_ICR(i2c)) & ~(ICR_START|ICR_STOP|ICR_ACKNAK|ICR_TB);
|
|
|
|
/*
|
|
* Read the byte.
|
|
*/
|
|
i2c->msg->buf[i2c->msg_ptr++] = readl(_IDBR(i2c));
|
|
|
|
if (i2c->msg_ptr < i2c->msg->len) {
|
|
/*
|
|
* If this is the last byte of the last
|
|
* message, send a STOP.
|
|
*/
|
|
if (i2c->msg_ptr == i2c->msg->len - 1)
|
|
icr |= ICR_STOP | ICR_ACKNAK;
|
|
|
|
icr |= ICR_ALDIE | ICR_TB;
|
|
} else {
|
|
i2c_pxa_master_complete(i2c, 0);
|
|
}
|
|
|
|
i2c->icrlog[i2c->irqlogidx-1] = icr;
|
|
|
|
writel(icr, _ICR(i2c));
|
|
}
|
|
|
|
static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id)
|
|
{
|
|
struct pxa_i2c *i2c = dev_id;
|
|
u32 isr = readl(_ISR(i2c));
|
|
|
|
if (i2c_debug > 2 && 0) {
|
|
dev_dbg(&i2c->adap.dev, "%s: ISR=%08x, ICR=%08x, IBMR=%02x\n",
|
|
__func__, isr, readl(_ICR(i2c)), readl(_IBMR(i2c)));
|
|
decode_ISR(isr);
|
|
}
|
|
|
|
if (i2c->irqlogidx < ARRAY_SIZE(i2c->isrlog))
|
|
i2c->isrlog[i2c->irqlogidx++] = isr;
|
|
|
|
show_state(i2c);
|
|
|
|
/*
|
|
* Always clear all pending IRQs.
|
|
*/
|
|
writel(isr & (ISR_SSD|ISR_ALD|ISR_ITE|ISR_IRF|ISR_SAD|ISR_BED), _ISR(i2c));
|
|
|
|
if (isr & ISR_SAD)
|
|
i2c_pxa_slave_start(i2c, isr);
|
|
if (isr & ISR_SSD)
|
|
i2c_pxa_slave_stop(i2c);
|
|
|
|
if (i2c_pxa_is_slavemode(i2c)) {
|
|
if (isr & ISR_ITE)
|
|
i2c_pxa_slave_txempty(i2c, isr);
|
|
if (isr & ISR_IRF)
|
|
i2c_pxa_slave_rxfull(i2c, isr);
|
|
} else if (i2c->msg) {
|
|
if (isr & ISR_ITE)
|
|
i2c_pxa_irq_txempty(i2c, isr);
|
|
if (isr & ISR_IRF)
|
|
i2c_pxa_irq_rxfull(i2c, isr);
|
|
} else {
|
|
i2c_pxa_scream_blue_murder(i2c, "spurious irq");
|
|
}
|
|
|
|
return IRQ_HANDLED;
|
|
}
|
|
|
|
|
|
static int i2c_pxa_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
|
|
{
|
|
struct pxa_i2c *i2c = adap->algo_data;
|
|
int ret, i;
|
|
|
|
/* If the I2C controller is disabled we need to reset it (probably due
|
|
to a suspend/resume destroying state). We do this here as we can then
|
|
avoid worrying about resuming the controller before its users. */
|
|
if (!(readl(_ICR(i2c)) & ICR_IUE))
|
|
i2c_pxa_reset(i2c);
|
|
|
|
for (i = adap->retries; i >= 0; i--) {
|
|
ret = i2c_pxa_do_xfer(i2c, msgs, num);
|
|
if (ret != I2C_RETRY)
|
|
goto out;
|
|
|
|
if (i2c_debug)
|
|
dev_dbg(&adap->dev, "Retrying transmission\n");
|
|
udelay(100);
|
|
}
|
|
i2c_pxa_scream_blue_murder(i2c, "exhausted retries");
|
|
ret = -EREMOTEIO;
|
|
out:
|
|
i2c_pxa_set_slave(i2c, ret);
|
|
return ret;
|
|
}
|
|
|
|
static u32 i2c_pxa_functionality(struct i2c_adapter *adap)
|
|
{
|
|
return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
|
|
}
|
|
|
|
static const struct i2c_algorithm i2c_pxa_algorithm = {
|
|
.master_xfer = i2c_pxa_xfer,
|
|
.functionality = i2c_pxa_functionality,
|
|
};
|
|
|
|
static const struct i2c_algorithm i2c_pxa_pio_algorithm = {
|
|
.master_xfer = i2c_pxa_pio_xfer,
|
|
.functionality = i2c_pxa_functionality,
|
|
};
|
|
|
|
#define res_len(r) ((r)->end - (r)->start + 1)
|
|
static int i2c_pxa_probe(struct platform_device *dev)
|
|
{
|
|
struct pxa_i2c *i2c;
|
|
struct resource *res;
|
|
struct i2c_pxa_platform_data *plat = dev->dev.platform_data;
|
|
int ret;
|
|
int irq;
|
|
|
|
res = platform_get_resource(dev, IORESOURCE_MEM, 0);
|
|
irq = platform_get_irq(dev, 0);
|
|
if (res == NULL || irq < 0)
|
|
return -ENODEV;
|
|
|
|
if (!request_mem_region(res->start, res_len(res), res->name))
|
|
return -ENOMEM;
|
|
|
|
i2c = kzalloc(sizeof(struct pxa_i2c), GFP_KERNEL);
|
|
if (!i2c) {
|
|
ret = -ENOMEM;
|
|
goto emalloc;
|
|
}
|
|
|
|
i2c->adap.owner = THIS_MODULE;
|
|
i2c->adap.retries = 5;
|
|
|
|
spin_lock_init(&i2c->lock);
|
|
init_waitqueue_head(&i2c->wait);
|
|
|
|
/*
|
|
* If "dev->id" is negative we consider it as zero.
|
|
* The reason to do so is to avoid sysfs names that only make
|
|
* sense when there are multiple adapters.
|
|
*/
|
|
i2c->adap.nr = dev->id != -1 ? dev->id : 0;
|
|
snprintf(i2c->adap.name, sizeof(i2c->adap.name), "pxa_i2c-i2c.%u",
|
|
i2c->adap.nr);
|
|
|
|
i2c->clk = clk_get(&dev->dev, "I2CCLK");
|
|
if (IS_ERR(i2c->clk)) {
|
|
ret = PTR_ERR(i2c->clk);
|
|
goto eclk;
|
|
}
|
|
|
|
i2c->reg_base = ioremap(res->start, res_len(res));
|
|
if (!i2c->reg_base) {
|
|
ret = -EIO;
|
|
goto eremap;
|
|
}
|
|
i2c->reg_shift = (cpu_is_pxa3xx() && (dev->id == 1)) ? 0 : 1;
|
|
|
|
i2c->iobase = res->start;
|
|
i2c->iosize = res_len(res);
|
|
|
|
i2c->irq = irq;
|
|
|
|
i2c->slave_addr = I2C_PXA_SLAVE_ADDR;
|
|
|
|
#ifdef CONFIG_I2C_PXA_SLAVE
|
|
if (plat) {
|
|
i2c->slave_addr = plat->slave_addr;
|
|
i2c->slave = plat->slave;
|
|
}
|
|
#endif
|
|
|
|
clk_enable(i2c->clk);
|
|
|
|
if (plat) {
|
|
i2c->adap.class = plat->class;
|
|
i2c->use_pio = plat->use_pio;
|
|
}
|
|
|
|
if (i2c->use_pio) {
|
|
i2c->adap.algo = &i2c_pxa_pio_algorithm;
|
|
} else {
|
|
i2c->adap.algo = &i2c_pxa_algorithm;
|
|
ret = request_irq(irq, i2c_pxa_handler, IRQF_DISABLED,
|
|
i2c->adap.name, i2c);
|
|
if (ret)
|
|
goto ereqirq;
|
|
}
|
|
|
|
i2c_pxa_reset(i2c);
|
|
|
|
i2c->adap.algo_data = i2c;
|
|
i2c->adap.dev.parent = &dev->dev;
|
|
|
|
ret = i2c_add_numbered_adapter(&i2c->adap);
|
|
if (ret < 0) {
|
|
printk(KERN_INFO "I2C: Failed to add bus\n");
|
|
goto eadapt;
|
|
}
|
|
|
|
platform_set_drvdata(dev, i2c);
|
|
|
|
#ifdef CONFIG_I2C_PXA_SLAVE
|
|
printk(KERN_INFO "I2C: %s: PXA I2C adapter, slave address %d\n",
|
|
i2c->adap.dev.bus_id, i2c->slave_addr);
|
|
#else
|
|
printk(KERN_INFO "I2C: %s: PXA I2C adapter\n",
|
|
i2c->adap.dev.bus_id);
|
|
#endif
|
|
return 0;
|
|
|
|
eadapt:
|
|
if (!i2c->use_pio)
|
|
free_irq(irq, i2c);
|
|
ereqirq:
|
|
clk_disable(i2c->clk);
|
|
iounmap(i2c->reg_base);
|
|
eremap:
|
|
clk_put(i2c->clk);
|
|
eclk:
|
|
kfree(i2c);
|
|
emalloc:
|
|
release_mem_region(res->start, res_len(res));
|
|
return ret;
|
|
}
|
|
|
|
static int __exit i2c_pxa_remove(struct platform_device *dev)
|
|
{
|
|
struct pxa_i2c *i2c = platform_get_drvdata(dev);
|
|
|
|
platform_set_drvdata(dev, NULL);
|
|
|
|
i2c_del_adapter(&i2c->adap);
|
|
if (!i2c->use_pio)
|
|
free_irq(i2c->irq, i2c);
|
|
|
|
clk_disable(i2c->clk);
|
|
clk_put(i2c->clk);
|
|
|
|
iounmap(i2c->reg_base);
|
|
release_mem_region(i2c->iobase, i2c->iosize);
|
|
kfree(i2c);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static struct platform_driver i2c_pxa_driver = {
|
|
.probe = i2c_pxa_probe,
|
|
.remove = __exit_p(i2c_pxa_remove),
|
|
.driver = {
|
|
.name = "pxa2xx-i2c",
|
|
.owner = THIS_MODULE,
|
|
},
|
|
};
|
|
|
|
static int __init i2c_adap_pxa_init(void)
|
|
{
|
|
return platform_driver_register(&i2c_pxa_driver);
|
|
}
|
|
|
|
static void __exit i2c_adap_pxa_exit(void)
|
|
{
|
|
platform_driver_unregister(&i2c_pxa_driver);
|
|
}
|
|
|
|
MODULE_LICENSE("GPL");
|
|
MODULE_ALIAS("platform:pxa2xx-i2c");
|
|
|
|
subsys_initcall(i2c_adap_pxa_init);
|
|
module_exit(i2c_adap_pxa_exit);
|