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barebox/drivers/i2c/busses/i2c-omap.c

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/*
* TI OMAP I2C master mode driver
*
* Copyright (C) 2003 MontaVista Software, Inc.
* Copyright (C) 2005 Nokia Corporation
* Copyright (C) 2004 - 2007 Texas Instruments.
*
* Originally written by MontaVista Software, Inc.
* Additional contributions by:
* Tony Lindgren <tony@atomide.com>
* Imre Deak <imre.deak@nokia.com>
* Juha Yrjölä <juha.yrjola@solidboot.com>
* Syed Khasim <x0khasim@ti.com>
* Nishant Menon <nm@ti.com>
*
* 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.
*/
#include <clock.h>
#include <common.h>
#include <driver.h>
#include <gpio.h>
#include <init.h>
#include <malloc.h>
#include <types.h>
#include <xfuncs.h>
#include <linux/err.h>
#include <io.h>
#include <i2c/i2c.h>
#include <mach/generic.h>
#include <mach/omap3-clock.h>
/* This will be the driver name */
#define DRIVER_NAME "i2c-omap"
/* I2C Interrupt Enable Register (OMAP_I2C_IE): */
#define OMAP_I2C_IE_XDR (1 << 14) /* TX Buffer drain int enable */
#define OMAP_I2C_IE_RDR (1 << 13) /* RX Buffer drain int enable */
#define OMAP_I2C_IE_XRDY (1 << 4) /* TX data ready int enable */
#define OMAP_I2C_IE_RRDY (1 << 3) /* RX data ready int enable */
#define OMAP_I2C_IE_ARDY (1 << 2) /* Access ready int enable */
#define OMAP_I2C_IE_NACK (1 << 1) /* No ack interrupt enable */
#define OMAP_I2C_IE_AL (1 << 0) /* Arbitration lost int ena */
/* I2C Status Register (OMAP_I2C_STAT): */
#define OMAP_I2C_STAT_XDR (1 << 14) /* TX Buffer draining */
#define OMAP_I2C_STAT_RDR (1 << 13) /* RX Buffer draining */
#define OMAP_I2C_STAT_BB (1 << 12) /* Bus busy */
#define OMAP_I2C_STAT_ROVR (1 << 11) /* Receive overrun */
#define OMAP_I2C_STAT_XUDF (1 << 10) /* Transmit underflow */
#define OMAP_I2C_STAT_AAS (1 << 9) /* Address as slave */
#define OMAP_I2C_STAT_AD0 (1 << 8) /* Address zero */
#define OMAP_I2C_STAT_XRDY (1 << 4) /* Transmit data ready */
#define OMAP_I2C_STAT_RRDY (1 << 3) /* Receive data ready */
#define OMAP_I2C_STAT_ARDY (1 << 2) /* Register access ready */
#define OMAP_I2C_STAT_NACK (1 << 1) /* No ack interrupt enable */
#define OMAP_I2C_STAT_AL (1 << 0) /* Arbitration lost int ena */
/* I2C WE wakeup enable register */
#define OMAP_I2C_WE_XDR_WE (1 << 14) /* TX drain wakup */
#define OMAP_I2C_WE_RDR_WE (1 << 13) /* RX drain wakeup */
#define OMAP_I2C_WE_AAS_WE (1 << 9) /* Address as slave wakeup*/
#define OMAP_I2C_WE_BF_WE (1 << 8) /* Bus free wakeup */
#define OMAP_I2C_WE_STC_WE (1 << 6) /* Start condition wakeup */
#define OMAP_I2C_WE_GC_WE (1 << 5) /* General call wakeup */
#define OMAP_I2C_WE_DRDY_WE (1 << 3) /* TX/RX data ready wakeup */
#define OMAP_I2C_WE_ARDY_WE (1 << 2) /* Reg access ready wakeup */
#define OMAP_I2C_WE_NACK_WE (1 << 1) /* No acknowledgment wakeup */
#define OMAP_I2C_WE_AL_WE (1 << 0) /* Arbitration lost wakeup */
#define OMAP_I2C_WE_ALL (OMAP_I2C_WE_XDR_WE | OMAP_I2C_WE_RDR_WE | \
OMAP_I2C_WE_AAS_WE | OMAP_I2C_WE_BF_WE | \
OMAP_I2C_WE_STC_WE | OMAP_I2C_WE_GC_WE | \
OMAP_I2C_WE_DRDY_WE | OMAP_I2C_WE_ARDY_WE | \
OMAP_I2C_WE_NACK_WE | OMAP_I2C_WE_AL_WE)
/* I2C Buffer Configuration Register (OMAP_I2C_BUF): */
#define OMAP_I2C_BUF_RDMA_EN (1 << 15) /* RX DMA channel enable */
#define OMAP_I2C_BUF_RXFIF_CLR (1 << 14) /* RX FIFO Clear */
#define OMAP_I2C_BUF_XDMA_EN (1 << 7) /* TX DMA channel enable */
#define OMAP_I2C_BUF_TXFIF_CLR (1 << 6) /* TX FIFO Clear */
/* I2C Configuration Register (OMAP_I2C_CON): */
#define OMAP_I2C_CON_EN (1 << 15) /* I2C module enable */
#define OMAP_I2C_CON_BE (1 << 14) /* Big endian mode */
#define OMAP_I2C_CON_OPMODE_HS (1 << 12) /* High Speed support */
#define OMAP_I2C_CON_STB (1 << 11) /* Start byte mode (master) */
#define OMAP_I2C_CON_MST (1 << 10) /* Master/slave mode */
#define OMAP_I2C_CON_TRX (1 << 9) /* TX/RX mode (master only) */
#define OMAP_I2C_CON_XA (1 << 8) /* Expand address */
#define OMAP_I2C_CON_RM (1 << 2) /* Repeat mode (master only) */
#define OMAP_I2C_CON_STP (1 << 1) /* Stop cond (master only) */
#define OMAP_I2C_CON_STT (1 << 0) /* Start condition (master) */
/* I2C SCL time value when Master */
#define OMAP_I2C_SCLL_HSSCLL 8
#define OMAP_I2C_SCLH_HSSCLH 8
/* I2C System Test Register (OMAP_I2C_SYSTEST): */
#ifdef DEBUG
#define OMAP_I2C_SYSTEST_ST_EN (1 << 15) /* System test enable */
#define OMAP_I2C_SYSTEST_FREE (1 << 14) /* Free running mode */
#define OMAP_I2C_SYSTEST_TMODE_MASK (3 << 12) /* Test mode select */
#define OMAP_I2C_SYSTEST_TMODE_SHIFT (12) /* Test mode select */
#define OMAP_I2C_SYSTEST_SCL_I (1 << 3) /* SCL line sense in */
#define OMAP_I2C_SYSTEST_SCL_O (1 << 2) /* SCL line drive out */
#define OMAP_I2C_SYSTEST_SDA_I (1 << 1) /* SDA line sense in */
#define OMAP_I2C_SYSTEST_SDA_O (1 << 0) /* SDA line drive out */
#endif
/* OCP_SYSSTATUS bit definitions */
#define SYSS_RESETDONE_MASK (1 << 0)
/* OCP_SYSCONFIG bit definitions */
#define SYSC_CLOCKACTIVITY_MASK (0x3 << 8)
#define SYSC_SIDLEMODE_MASK (0x3 << 3)
#define SYSC_ENAWAKEUP_MASK (1 << 2)
#define SYSC_SOFTRESET_MASK (1 << 1)
#define SYSC_AUTOIDLE_MASK (1 << 0)
#define SYSC_IDLEMODE_SMART 0x2
#define SYSC_CLOCKACTIVITY_FCLK 0x2
/* Errata definitions */
#define I2C_OMAP_ERRATA_I207 (1 << 0)
#define I2C_OMAP_ERRATA_I462 (1 << 1)
/* i2c driver flags from kernel */
#define OMAP_I2C_FLAG_NO_FIFO BIT(0)
#define OMAP_I2C_FLAG_16BIT_DATA_REG BIT(2)
#define OMAP_I2C_FLAG_BUS_SHIFT_NONE 0
#define OMAP_I2C_FLAG_BUS_SHIFT_1 BIT(7)
#define OMAP_I2C_FLAG_BUS_SHIFT_2 BIT(8)
#define OMAP_I2C_FLAG_BUS_SHIFT__SHIFT 7
/* timeout waiting for the controller to respond */
#define OMAP_I2C_TIMEOUT (1000 * MSECOND) /* ms */
struct omap_i2c_struct {
void *base;
u8 reg_shift;
struct omap_i2c_driver_data *data;
struct resource *ioarea;
u32 fclk_rate;
u32 speed; /* Speed of bus in Khz */
u16 scheme;
u16 cmd_err;
u8 *buf;
u8 *regs;
size_t buf_len;
struct i2c_adapter adapter;
u8 threshold;
u8 fifo_size; /* use as flag and value
* fifo_size==0 implies no fifo
* if set, should be trsh+1
*/
u32 rev;
unsigned b_hw:1; /* bad h/w fixes */
unsigned receiver:1; /* true for receiver mode */
u16 iestate; /* Saved interrupt register */
u16 pscstate;
u16 scllstate;
u16 sclhstate;
u16 bufstate;
u16 syscstate;
u16 westate;
u16 errata;
};
#define to_omap_i2c_struct(a) container_of(a, struct omap_i2c_struct, adapter)
enum {
OMAP_I2C_REV_REG = 0,
OMAP_I2C_IE_REG,
OMAP_I2C_STAT_REG,
OMAP_I2C_IV_REG,
OMAP_I2C_WE_REG,
OMAP_I2C_SYSS_REG,
OMAP_I2C_BUF_REG,
OMAP_I2C_CNT_REG,
OMAP_I2C_DATA_REG,
OMAP_I2C_SYSC_REG,
OMAP_I2C_CON_REG,
OMAP_I2C_OA_REG,
OMAP_I2C_SA_REG,
OMAP_I2C_PSC_REG,
OMAP_I2C_SCLL_REG,
OMAP_I2C_SCLH_REG,
OMAP_I2C_SYSTEST_REG,
OMAP_I2C_BUFSTAT_REG,
/* only on OMAP4430 */
OMAP_I2C_IP_V2_REVNB_LO,
OMAP_I2C_IP_V2_REVNB_HI,
OMAP_I2C_IP_V2_IRQSTATUS_RAW,
OMAP_I2C_IP_V2_IRQENABLE_SET,
OMAP_I2C_IP_V2_IRQENABLE_CLR,
};
static const u8 reg_map_ip_v1[] = {
[OMAP_I2C_REV_REG] = 0x00,
[OMAP_I2C_IE_REG] = 0x01,
[OMAP_I2C_STAT_REG] = 0x02,
[OMAP_I2C_IV_REG] = 0x03,
[OMAP_I2C_WE_REG] = 0x03,
[OMAP_I2C_SYSS_REG] = 0x04,
[OMAP_I2C_BUF_REG] = 0x05,
[OMAP_I2C_CNT_REG] = 0x06,
[OMAP_I2C_DATA_REG] = 0x07,
[OMAP_I2C_SYSC_REG] = 0x08,
[OMAP_I2C_CON_REG] = 0x09,
[OMAP_I2C_OA_REG] = 0x0a,
[OMAP_I2C_SA_REG] = 0x0b,
[OMAP_I2C_PSC_REG] = 0x0c,
[OMAP_I2C_SCLL_REG] = 0x0d,
[OMAP_I2C_SCLH_REG] = 0x0e,
[OMAP_I2C_SYSTEST_REG] = 0x0f,
[OMAP_I2C_BUFSTAT_REG] = 0x10,
};
static const u8 reg_map_ip_v2[] = {
[OMAP_I2C_REV_REG] = 0x04,
[OMAP_I2C_IE_REG] = 0x2c,
[OMAP_I2C_STAT_REG] = 0x28,
[OMAP_I2C_IV_REG] = 0x34,
[OMAP_I2C_WE_REG] = 0x34,
[OMAP_I2C_SYSS_REG] = 0x90,
[OMAP_I2C_BUF_REG] = 0x94,
[OMAP_I2C_CNT_REG] = 0x98,
[OMAP_I2C_DATA_REG] = 0x9c,
[OMAP_I2C_SYSC_REG] = 0x10,
[OMAP_I2C_CON_REG] = 0xa4,
[OMAP_I2C_OA_REG] = 0xa8,
[OMAP_I2C_SA_REG] = 0xac,
[OMAP_I2C_PSC_REG] = 0xb0,
[OMAP_I2C_SCLL_REG] = 0xb4,
[OMAP_I2C_SCLH_REG] = 0xb8,
[OMAP_I2C_SYSTEST_REG] = 0xbc,
[OMAP_I2C_BUFSTAT_REG] = 0xc0,
[OMAP_I2C_IP_V2_REVNB_LO] = 0x00,
[OMAP_I2C_IP_V2_REVNB_HI] = 0x04,
[OMAP_I2C_IP_V2_IRQSTATUS_RAW] = 0x24,
[OMAP_I2C_IP_V2_IRQENABLE_SET] = 0x2c,
[OMAP_I2C_IP_V2_IRQENABLE_CLR] = 0x30,
};
struct omap_i2c_driver_data {
u32 flags;
u32 fclk_rate;
};
static struct omap_i2c_driver_data omap3_data = {
.flags = OMAP_I2C_FLAG_BUS_SHIFT_2,
.fclk_rate = 96000,
};
static struct omap_i2c_driver_data omap4_data = {
.flags = OMAP_I2C_FLAG_BUS_SHIFT_NONE,
.fclk_rate = 96000,
};
static struct omap_i2c_driver_data am33xx_data = {
.flags = OMAP_I2C_FLAG_BUS_SHIFT_NONE,
.fclk_rate = 48000,
};
static struct omap_i2c_driver_data omap4_of_data = {
.flags = OMAP_I2C_FLAG_BUS_SHIFT_NONE,
.fclk_rate = 0,
};
static inline void omap_i2c_write_reg(struct omap_i2c_struct *i2c_omap,
int reg, u16 val)
{
__raw_writew(val, i2c_omap->base +
(i2c_omap->regs[reg] << i2c_omap->reg_shift));
}
static inline u16 omap_i2c_read_reg(struct omap_i2c_struct *i2c_omap, int reg)
{
return __raw_readw(i2c_omap->base +
(i2c_omap->regs[reg] << i2c_omap->reg_shift));
}
static void __omap_i2c_init(struct omap_i2c_struct *dev)
{
omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, 0);
/* Setup clock prescaler to obtain approx 12MHz I2C module clock: */
omap_i2c_write_reg(dev, OMAP_I2C_PSC_REG, dev->pscstate);
/* SCL low and high time values */
omap_i2c_write_reg(dev, OMAP_I2C_SCLL_REG, dev->scllstate);
omap_i2c_write_reg(dev, OMAP_I2C_SCLH_REG, dev->sclhstate);
if (dev->rev >= OMAP_I2C_REV_ON_3430_3530)
omap_i2c_write_reg(dev, OMAP_I2C_WE_REG, dev->westate);
/* Take the I2C module out of reset: */
omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
/*
* Don't write to this register if the IE state is 0 as it can
* cause deadlock.
*/
if (dev->iestate)
omap_i2c_write_reg(dev, OMAP_I2C_IE_REG, dev->iestate);
}
static int omap_i2c_reset(struct omap_i2c_struct *dev)
{
uint64_t start;
u16 sysc;
if (dev->rev >= OMAP_I2C_OMAP1_REV_2) {
sysc = omap_i2c_read_reg(dev, OMAP_I2C_SYSC_REG);
/* Disable I2C controller before soft reset */
omap_i2c_write_reg(dev, OMAP_I2C_CON_REG,
omap_i2c_read_reg(dev, OMAP_I2C_CON_REG) &
~(OMAP_I2C_CON_EN));
omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, SYSC_SOFTRESET_MASK);
/* For some reason we need to set the EN bit before the
* reset done bit gets set. */
omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
start = get_time_ns();
while (!(omap_i2c_read_reg(dev, OMAP_I2C_SYSS_REG) &
SYSS_RESETDONE_MASK)) {
if (is_timeout(start, OMAP_I2C_TIMEOUT)) {
dev_warn(&dev->adapter.dev, "timeout waiting "
"for controller reset\n");
return -ETIMEDOUT;
}
mdelay(1000);
}
/* SYSC register is cleared by the reset; rewrite it */
omap_i2c_write_reg(dev, OMAP_I2C_SYSC_REG, sysc);
}
return 0;
}
static int omap_i2c_init(struct omap_i2c_struct *i2c_omap)
{
u16 psc = 0, scll = 0, sclh = 0, buf = 0;
u16 fsscll = 0, fssclh = 0, hsscll = 0, hssclh = 0;
uint64_t start;
unsigned long internal_clk = 0;
struct omap_i2c_driver_data *i2c_data = i2c_omap->data;
if (i2c_omap->rev >= OMAP_I2C_OMAP1_REV_2) {
/* Disable I2C controller before soft reset */
omap_i2c_write_reg(i2c_omap, OMAP_I2C_CON_REG,
omap_i2c_read_reg(i2c_omap, OMAP_I2C_CON_REG) &
~(OMAP_I2C_CON_EN));
omap_i2c_write_reg(i2c_omap, OMAP_I2C_SYSC_REG, SYSC_SOFTRESET_MASK);
/* For some reason we need to set the EN bit before the
* reset done bit gets set. */
start = get_time_ns();
omap_i2c_write_reg(i2c_omap, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
while (!(omap_i2c_read_reg(i2c_omap, OMAP_I2C_SYSS_REG) &
SYSS_RESETDONE_MASK)) {
if (is_timeout(start, MSECOND)) {
dev_warn(&i2c_omap->adapter.dev, "timeout waiting "
"for controller reset\n");
return -ETIMEDOUT;
}
mdelay(1);
}
/* SYSC register is cleared by the reset; rewrite it */
if (i2c_omap->rev == OMAP_I2C_REV_ON_2430) {
omap_i2c_write_reg(i2c_omap, OMAP_I2C_SYSC_REG,
SYSC_AUTOIDLE_MASK);
} else if (i2c_omap->rev >= OMAP_I2C_REV_ON_3430_3530) {
i2c_omap->syscstate = SYSC_AUTOIDLE_MASK;
i2c_omap->syscstate |= SYSC_ENAWAKEUP_MASK;
i2c_omap->syscstate |= (SYSC_IDLEMODE_SMART <<
__ffs(SYSC_SIDLEMODE_MASK));
i2c_omap->syscstate |= (SYSC_CLOCKACTIVITY_FCLK <<
__ffs(SYSC_CLOCKACTIVITY_MASK));
omap_i2c_write_reg(i2c_omap, OMAP_I2C_SYSC_REG,
i2c_omap->syscstate);
/*
* Enabling all wakup sources to stop I2C freezing on
* WFI instruction.
* REVISIT: Some wkup sources might not be needed.
*/
i2c_omap->westate = OMAP_I2C_WE_ALL;
omap_i2c_write_reg(i2c_omap, OMAP_I2C_WE_REG, i2c_omap->westate);
}
}
omap_i2c_write_reg(i2c_omap, OMAP_I2C_CON_REG, 0);
/*
* HSI2C controller internal clk rate should be 19.2 Mhz for
* HS and for all modes on 2430. On 34xx we can use lower rate
* to get longer filter period for better noise suppression.
* The filter is iclk (fclk for HS) period.
*/
if (i2c_omap->speed > 400)
internal_clk = 19200;
else if (i2c_omap->speed > 100)
internal_clk = 9600;
else
internal_clk = 4000;
/* Compute prescaler divisor */
psc = i2c_omap->fclk_rate / internal_clk;
psc = psc - 1;
/* If configured for High Speed */
if (i2c_omap->speed > 400) {
unsigned long scl;
/* For first phase of HS mode */
scl = internal_clk / 400;
fsscll = scl - (scl / 3) - 7;
fssclh = (scl / 3) - 5;
/* For second phase of HS mode */
scl = i2c_data->fclk_rate / i2c_omap->speed;
hsscll = scl - (scl / 3) - 7;
hssclh = (scl / 3) - 5;
} else if (i2c_omap->speed > 100) {
unsigned long scl;
/* Fast mode */
scl = internal_clk / i2c_omap->speed;
fsscll = scl - (scl / 3) - 7;
fssclh = (scl / 3) - 5;
} else {
/* Standard mode */
fsscll = internal_clk / (i2c_omap->speed * 2) - 7;
fssclh = internal_clk / (i2c_omap->speed * 2) - 5;
}
scll = (hsscll << OMAP_I2C_SCLL_HSSCLL) | fsscll;
sclh = (hssclh << OMAP_I2C_SCLH_HSSCLH) | fssclh;
/* Setup clock prescaler to obtain approx 12MHz I2C module clock: */
omap_i2c_write_reg(i2c_omap, OMAP_I2C_PSC_REG, psc);
/* SCL low and high time values */
omap_i2c_write_reg(i2c_omap, OMAP_I2C_SCLL_REG, scll);
omap_i2c_write_reg(i2c_omap, OMAP_I2C_SCLH_REG, sclh);
if (i2c_omap->fifo_size) {
/* Note: setup required fifo size - 1. RTRSH and XTRSH */
buf = (i2c_omap->fifo_size - 1) << 8 | OMAP_I2C_BUF_RXFIF_CLR |
(i2c_omap->fifo_size - 1) | OMAP_I2C_BUF_TXFIF_CLR;
omap_i2c_write_reg(i2c_omap, OMAP_I2C_BUF_REG, buf);
}
/* Take the I2C module out of reset: */
omap_i2c_write_reg(i2c_omap, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
/* Enable interrupts */
i2c_omap->iestate = (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY |
OMAP_I2C_IE_ARDY | OMAP_I2C_IE_NACK |
OMAP_I2C_IE_AL) | ((i2c_omap->fifo_size) ?
(OMAP_I2C_IE_RDR | OMAP_I2C_IE_XDR) : 0);
omap_i2c_write_reg(i2c_omap, OMAP_I2C_IE_REG, i2c_omap->iestate);
i2c_omap->pscstate = psc;
i2c_omap->scllstate = scll;
i2c_omap->sclhstate = sclh;
i2c_omap->bufstate = buf;
__omap_i2c_init(i2c_omap);
return 0;
}
/*
* Waiting on Bus Busy
*/
static int omap_i2c_wait_for_bb(struct i2c_adapter *adapter)
{
uint64_t start;
struct omap_i2c_struct *i2c_omap = to_omap_i2c_struct(adapter);
start = get_time_ns();
while (omap_i2c_read_reg(i2c_omap, OMAP_I2C_STAT_REG) & OMAP_I2C_STAT_BB) {
if (is_timeout(start, MSECOND)) {
dev_warn(&adapter->dev, "timeout waiting for bus ready\n");
return -ETIMEDOUT;
}
}
return 0;
}
static inline void
omap_i2c_complete_cmd(struct omap_i2c_struct *dev, u16 err)
{
dev->cmd_err |= err;
}
static inline void
omap_i2c_ack_stat(struct omap_i2c_struct *i2c_omap, u16 stat)
{
omap_i2c_write_reg(i2c_omap, OMAP_I2C_STAT_REG, stat);
}
static int errata_omap3_i462(struct omap_i2c_struct *dev)
{
unsigned long timeout = 10000;
u16 stat;
do {
stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
if (stat & OMAP_I2C_STAT_XUDF)
break;
if (stat & (OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) {
omap_i2c_ack_stat(dev, (OMAP_I2C_STAT_XRDY |
OMAP_I2C_STAT_XDR));
if (stat & OMAP_I2C_STAT_NACK) {
dev->cmd_err |= OMAP_I2C_STAT_NACK;
omap_i2c_ack_stat(dev, OMAP_I2C_STAT_NACK);
}
if (stat & OMAP_I2C_STAT_AL) {
dev_err(&dev->adapter.dev, "Arbitration lost\n");
dev->cmd_err |= OMAP_I2C_STAT_AL;
omap_i2c_ack_stat(dev, OMAP_I2C_STAT_AL);
}
return -EIO;
}
} while (--timeout);
if (!timeout) {
dev_err(&dev->adapter.dev, "timeout waiting on XUDF bit\n");
return 0;
}
return 0;
}
static void omap_i2c_receive_data(struct omap_i2c_struct *dev, u8 num_bytes,
bool is_rdr)
{
u16 w;
while (num_bytes--) {
w = omap_i2c_read_reg(dev, OMAP_I2C_DATA_REG);
*dev->buf++ = w;
dev->buf_len--;
/*
* Data reg in 2430, omap3 and
* omap4 is 8 bit wide
*/
if (dev->data->flags & OMAP_I2C_FLAG_16BIT_DATA_REG) {
*dev->buf++ = w >> 8;
dev->buf_len--;
}
}
}
static inline void i2c_omap_errata_i207(struct omap_i2c_struct *dev, u16 stat)
{
/*
* I2C Errata(Errata Nos. OMAP2: 1.67, OMAP3: 1.8)
* Not applicable for OMAP4.
* Under certain rare conditions, RDR could be set again
* when the bus is busy, then ignore the interrupt and
* clear the interrupt.
*/
if (stat & OMAP_I2C_STAT_RDR) {
/* Step 1: If RDR is set, clear it */
omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RDR);
/* Step 2: */
if (!(omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG)
& OMAP_I2C_STAT_BB)) {
/* Step 3: */
if (omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG)
& OMAP_I2C_STAT_RDR) {
omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RDR);
dev_dbg(&dev->adapter.dev, "RDR when bus is busy.\n");
}
}
}
}
static int omap_i2c_transmit_data(struct omap_i2c_struct *dev, u8 num_bytes,
bool is_xdr)
{
u16 w;
while (num_bytes--) {
w = *dev->buf++;
dev->buf_len--;
/*
* Data reg in 2430, omap3 and
* omap4 is 8 bit wide
*/
if (dev->data->flags & OMAP_I2C_FLAG_16BIT_DATA_REG) {
w |= *dev->buf++ << 8;
dev->buf_len--;
}
if (dev->errata & I2C_OMAP_ERRATA_I462) {
int ret;
ret = errata_omap3_i462(dev);
if (ret < 0)
return ret;
}
omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
}
return 0;
}
static int
omap_i2c_isr(struct omap_i2c_struct *dev)
{
u16 bits;
u16 stat;
int err = 0, count = 0;
do {
bits = omap_i2c_read_reg(dev, OMAP_I2C_IE_REG);
stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
stat &= bits;
/* If we're in receiver mode, ignore XDR/XRDY */
if (dev->receiver)
stat &= ~(OMAP_I2C_STAT_XDR | OMAP_I2C_STAT_XRDY);
else
stat &= ~(OMAP_I2C_STAT_RDR | OMAP_I2C_STAT_RRDY);
if (!stat) {
/* my work here is done */
goto out;
}
dev_dbg(&dev->adapter.dev, "IRQ (ISR = 0x%04x)\n", stat);
if (count++ == 100) {
dev_warn(&dev->adapter.dev, "Too much work in one IRQ\n");
break;
}
if (stat & OMAP_I2C_STAT_NACK) {
err |= OMAP_I2C_STAT_NACK;
omap_i2c_ack_stat(dev, OMAP_I2C_STAT_NACK);
break;
}
if (stat & OMAP_I2C_STAT_AL) {
dev_err(&dev->adapter.dev, "Arbitration lost\n");
err |= OMAP_I2C_STAT_AL;
omap_i2c_ack_stat(dev, OMAP_I2C_STAT_AL);
break;
}
/*
* ProDB0017052: Clear ARDY bit twice
*/
if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK |
OMAP_I2C_STAT_AL)) {
omap_i2c_ack_stat(dev, (OMAP_I2C_STAT_RRDY |
OMAP_I2C_STAT_RDR |
OMAP_I2C_STAT_XRDY |
OMAP_I2C_STAT_XDR |
OMAP_I2C_STAT_ARDY));
break;
}
if (stat & OMAP_I2C_STAT_RDR) {
u8 num_bytes = 1;
if (dev->fifo_size)
num_bytes = dev->buf_len;
omap_i2c_receive_data(dev, num_bytes, true);
if (dev->errata & I2C_OMAP_ERRATA_I207)
i2c_omap_errata_i207(dev, stat);
omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RDR);
continue;
}
if (stat & OMAP_I2C_STAT_RRDY) {
u8 num_bytes = 1;
if (dev->threshold)
num_bytes = dev->threshold;
omap_i2c_receive_data(dev, num_bytes, false);
omap_i2c_ack_stat(dev, OMAP_I2C_STAT_RRDY);
continue;
}
if (stat & OMAP_I2C_STAT_XDR) {
u8 num_bytes = 1;
int ret;
if (dev->fifo_size)
num_bytes = dev->buf_len;
ret = omap_i2c_transmit_data(dev, num_bytes, true);
if (ret < 0)
break;
omap_i2c_ack_stat(dev, OMAP_I2C_STAT_XDR);
continue;
}
if (stat & OMAP_I2C_STAT_XRDY) {
u8 num_bytes = 1;
int ret;
if (dev->threshold)
num_bytes = dev->threshold;
ret = omap_i2c_transmit_data(dev, num_bytes, false);
if (ret < 0)
break;
omap_i2c_ack_stat(dev, OMAP_I2C_STAT_XRDY);
continue;
}
if (stat & OMAP_I2C_STAT_ROVR) {
dev_err(&dev->adapter.dev, "Receive overrun\n");
err |= OMAP_I2C_STAT_ROVR;
omap_i2c_ack_stat(dev, OMAP_I2C_STAT_ROVR);
break;
}
if (stat & OMAP_I2C_STAT_XUDF) {
dev_err(&dev->adapter.dev, "Transmit underflow\n");
err |= OMAP_I2C_STAT_XUDF;
omap_i2c_ack_stat(dev, OMAP_I2C_STAT_XUDF);
break;
}
} while (stat);
omap_i2c_complete_cmd(dev, err);
return 0;
out:
return -EBUSY;
}
static void omap_i2c_resize_fifo(struct omap_i2c_struct *dev, u8 size,
bool is_rx)
{
u16 buf;
if (dev->data->flags & OMAP_I2C_FLAG_NO_FIFO)
return;
/*
* Set up notification threshold based on message size. We're doing
* this to try and avoid draining feature as much as possible. Whenever
* we have big messages to transfer (bigger than our total fifo size)
* then we might use draining feature to transfer the remaining bytes.
*/
dev->threshold = clamp(size, (u8) 1, dev->fifo_size);
buf = omap_i2c_read_reg(dev, OMAP_I2C_BUF_REG);
if (is_rx) {
/* Clear RX Threshold */
buf &= ~(0x3f << 8);
buf |= ((dev->threshold - 1) << 8) | OMAP_I2C_BUF_RXFIF_CLR;
} else {
/* Clear TX Threshold */
buf &= ~0x3f;
buf |= (dev->threshold - 1) | OMAP_I2C_BUF_TXFIF_CLR;
}
omap_i2c_write_reg(dev, OMAP_I2C_BUF_REG, buf);
if (dev->rev < OMAP_I2C_REV_ON_3630)
dev->b_hw = 1; /* Enable hardware fixes */
}
/*
* Low level master read/write transaction.
*/
static int omap_i2c_xfer_msg(struct i2c_adapter *adapter,
struct i2c_msg *msg, int stop)
{
struct omap_i2c_struct *i2c_omap = to_omap_i2c_struct(adapter);
uint64_t start;
u16 con;
u16 w;
int ret = 0;
dev_dbg(&adapter->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n",
msg->addr, msg->len, msg->flags, stop);
if (msg->len == 0)
return -EINVAL;
i2c_omap->receiver = !!(msg->flags & I2C_M_RD);
omap_i2c_resize_fifo(i2c_omap, msg->len, i2c_omap->receiver);
omap_i2c_write_reg(i2c_omap, OMAP_I2C_SA_REG, msg->addr);
/* REVISIT: Could the STB bit of I2C_CON be used with probing? */
i2c_omap->buf = msg->buf;
i2c_omap->buf_len = msg->len;
/* make sure writes to dev->buf_len are ordered */
barrier();
omap_i2c_write_reg(i2c_omap, OMAP_I2C_CNT_REG, i2c_omap->buf_len);
/* Clear the FIFO Buffers */
w = omap_i2c_read_reg(i2c_omap, OMAP_I2C_BUF_REG);
w |= OMAP_I2C_BUF_RXFIF_CLR | OMAP_I2C_BUF_TXFIF_CLR;
omap_i2c_write_reg(i2c_omap, OMAP_I2C_BUF_REG, w);
i2c_omap->cmd_err = 0;
w = OMAP_I2C_CON_EN | OMAP_I2C_CON_MST | OMAP_I2C_CON_STT;
/* High speed configuration */
if (i2c_omap->speed > 400)
w |= OMAP_I2C_CON_OPMODE_HS;
if (msg->flags & I2C_M_STOP)
stop = 1;
if (msg->flags & I2C_M_TEN)
w |= OMAP_I2C_CON_XA;
if (!(msg->flags & I2C_M_RD))
w |= OMAP_I2C_CON_TRX;
if (!i2c_omap->b_hw && stop)
w |= OMAP_I2C_CON_STP;
omap_i2c_write_reg(i2c_omap, OMAP_I2C_CON_REG, w);
/*
* Don't write stt and stp together on some hardware.
*/
if (i2c_omap->b_hw && stop) {
start = get_time_ns();
con = omap_i2c_read_reg(i2c_omap, OMAP_I2C_CON_REG);
while (con & OMAP_I2C_CON_STT) {
con = omap_i2c_read_reg(i2c_omap, OMAP_I2C_CON_REG);
/* Let the user know if i2c is in a bad state */
if (is_timeout(start, MSECOND)) {
dev_err(&adapter->dev, "controller timed out "
"waiting for start condition to finish\n");
return -ETIMEDOUT;
}
}
w |= OMAP_I2C_CON_STP;
w &= ~OMAP_I2C_CON_STT;
omap_i2c_write_reg(i2c_omap, OMAP_I2C_CON_REG, w);
}
/*
* REVISIT: We should abort the transfer on signals, but the bus goes
* into arbitration and we're currently unable to recover from it.
*/
start = get_time_ns();
ret = omap_i2c_isr(i2c_omap);
while (ret){
ret = omap_i2c_isr(i2c_omap);
if (is_timeout(start, OMAP_I2C_TIMEOUT)) {
dev_err(&adapter->dev,
"timed out on polling for "
"open i2c message handling\n");
omap_i2c_reset(i2c_omap);
__omap_i2c_init(i2c_omap);
return -ETIMEDOUT;
}
}
if (likely(!i2c_omap->cmd_err))
return 0;
/* We have an error */
if (i2c_omap->cmd_err & (OMAP_I2C_STAT_AL | OMAP_I2C_STAT_ROVR |
OMAP_I2C_STAT_XUDF)) {
omap_i2c_reset(i2c_omap);
__omap_i2c_init(i2c_omap);
return -EIO;
}
if (i2c_omap->cmd_err & OMAP_I2C_STAT_NACK) {
if (msg->flags & I2C_M_IGNORE_NAK)
return 0;
w = omap_i2c_read_reg(i2c_omap, OMAP_I2C_CON_REG);
w |= OMAP_I2C_CON_STP;
omap_i2c_write_reg(i2c_omap, OMAP_I2C_CON_REG, w);
return -EREMOTEIO;
}
return -EIO;
}
static void omap_i2c_unidle(struct omap_i2c_struct *i2c_omap)
{
__omap_i2c_init(i2c_omap);
}
static void omap_i2c_idle(struct omap_i2c_struct *i2c_omap)
{
u16 iv;
i2c_omap->iestate = omap_i2c_read_reg(i2c_omap, OMAP_I2C_IE_REG);
/* Barebox driver don't need to clear interrupts here */
/* omap_i2c_write_reg(i2c_omap, OMAP_I2C_IE_REG, 0); */
if (i2c_omap->rev < OMAP_I2C_OMAP1_REV_2) {
/* Read clears */
iv = omap_i2c_read_reg(i2c_omap, OMAP_I2C_IV_REG);
} else {
omap_i2c_write_reg(i2c_omap, OMAP_I2C_STAT_REG,
i2c_omap->iestate);
/* Flush posted write before the i2c_omap->idle store occurs */
omap_i2c_read_reg(i2c_omap, OMAP_I2C_STAT_REG);
}
}
/*
* Prepare controller for a transaction and call omap_i2c_xfer_msg
* to do the work during IRQ processing.
*/
static int
omap_i2c_xfer(struct i2c_adapter *adapter, struct i2c_msg msgs[], int num)
{
struct omap_i2c_struct *i2c_omap = to_omap_i2c_struct(adapter);
int i;
int r;
omap_i2c_unidle(i2c_omap);
r = omap_i2c_wait_for_bb(adapter);
if (r < 0)
goto out;
for (i = 0; i < num; i++) {
r = omap_i2c_xfer_msg(adapter, &msgs[i], (i == (num - 1)));
if (r != 0)
break;
}
if (r == 0)
r = num;
omap_i2c_wait_for_bb(adapter);
out:
omap_i2c_idle(i2c_omap);
return r;
}
#define OMAP_I2C_SCHEME(rev) ((rev & 0xc000) >> 14)
#define OMAP_I2C_REV_SCHEME_0_MAJOR(rev) (rev >> 4)
#define OMAP_I2C_REV_SCHEME_0_MINOR(rev) (rev & 0xf)
#define OMAP_I2C_REV_SCHEME_1_MAJOR(rev) ((rev & 0x0700) >> 7)
#define OMAP_I2C_REV_SCHEME_1_MINOR(rev) (rev & 0x1f)
#define OMAP_I2C_SCHEME_0 0
#define OMAP_I2C_SCHEME_1 1
static int __init
i2c_omap_probe(struct device_d *pdev)
{
struct omap_i2c_struct *i2c_omap;
struct omap_i2c_driver_data *i2c_data;
int r;
u32 speed = 0;
u32 rev;
u16 minor, major;
i2c_omap = kzalloc(sizeof(struct omap_i2c_struct), GFP_KERNEL);
if (!i2c_omap) {
r = -ENOMEM;
goto err_free_mem;
}
r = dev_get_drvdata(pdev, (unsigned long *)&i2c_data);
if (r)
return r;
i2c_omap->data = i2c_data;
i2c_omap->reg_shift = (i2c_data->flags >>
OMAP_I2C_FLAG_BUS_SHIFT__SHIFT) & 3;
if (pdev->platform_data != NULL)
speed = *(u32 *)pdev->platform_data;
else
speed = 100; /* Default speed */
i2c_omap->speed = speed;
i2c_omap->base = dev_request_mem_region(pdev, 0);
/*
* Read the Rev hi bit-[15:14] ie scheme this is 1 indicates ver2.
* On omap1/3/2 Offset 4 is IE Reg the bit [15:14] is 0 at reset.
* Also since the omap_i2c_read_reg uses reg_map_ip_* a
* raw_readw is done.
*/
rev = __raw_readw(i2c_omap->base + 0x04);
i2c_omap->scheme = OMAP_I2C_SCHEME(rev);
switch (i2c_omap->scheme) {
case OMAP_I2C_SCHEME_0:
i2c_omap->regs = (u8 *)reg_map_ip_v1;
i2c_omap->rev = omap_i2c_read_reg(i2c_omap, OMAP_I2C_REV_REG);
minor = OMAP_I2C_REV_SCHEME_0_MAJOR(i2c_omap->rev);
major = OMAP_I2C_REV_SCHEME_0_MAJOR(i2c_omap->rev);
break;
case OMAP_I2C_SCHEME_1:
/* FALLTHROUGH */
default:
i2c_omap->regs = (u8 *)reg_map_ip_v2;
rev = (rev << 16) |
omap_i2c_read_reg(i2c_omap, OMAP_I2C_IP_V2_REVNB_LO);
minor = OMAP_I2C_REV_SCHEME_1_MINOR(rev);
major = OMAP_I2C_REV_SCHEME_1_MAJOR(rev);
i2c_omap->rev = rev;
}
i2c_omap->errata = 0;
if (i2c_omap->rev >= OMAP_I2C_REV_ON_2430 &&
i2c_omap->rev < OMAP_I2C_REV_ON_4430_PLUS)
i2c_omap->errata |= I2C_OMAP_ERRATA_I207;
if (i2c_omap->rev <= OMAP_I2C_REV_ON_3430_3530)
i2c_omap->errata |= I2C_OMAP_ERRATA_I462;
if (!(i2c_data->flags & OMAP_I2C_FLAG_NO_FIFO)) {
u16 s;
/* Set up the fifo size - Get total size */
s = (omap_i2c_read_reg(i2c_omap, OMAP_I2C_BUFSTAT_REG) >> 14)
& 0x3;
i2c_omap->fifo_size = 0x8 << s;
/*
* Set up notification threshold as half the total available
* size. This is to ensure that we can handle the status on int
* call back latencies.
*/
i2c_omap->fifo_size = (i2c_omap->fifo_size / 2);
if (i2c_omap->rev < OMAP_I2C_REV_ON_3630)
i2c_omap->b_hw = 1; /* Enable hardware fixes */
}
i2c_omap->fclk_rate = i2c_data->fclk_rate;
if (!i2c_omap->fclk_rate)
of_property_read_u32(pdev->device_node, "clock-frequency",
&i2c_omap->fclk_rate);
/* reset ASAP, clearing any IRQs */
omap_i2c_init(i2c_omap);
dev_info(pdev, "bus %d rev%d.%d at %d kHz\n",
pdev->id, major, minor, i2c_omap->speed);
omap_i2c_idle(i2c_omap);
i2c_omap->adapter.master_xfer = omap_i2c_xfer,
i2c_omap->adapter.nr = pdev->id;
i2c_omap->adapter.dev.parent = pdev;
i2c_omap->adapter.dev.device_node = pdev->device_node;
/* i2c device drivers may be active on return from add_adapter() */
r = i2c_add_numbered_adapter(&i2c_omap->adapter);
if (r) {
dev_err(pdev, "failure adding adapter\n");
goto err_unuse_clocks;
}
return 0;
err_unuse_clocks:
omap_i2c_write_reg(i2c_omap, OMAP_I2C_CON_REG, 0);
omap_i2c_idle(i2c_omap);
err_free_mem:
kfree(i2c_omap);
return r;
}
static struct platform_device_id omap_i2c_ids[] = {
{
.name = "i2c-omap3",
.driver_data = (unsigned long)&omap3_data,
}, {
.name = "i2c-omap4",
.driver_data = (unsigned long)&omap4_data,
}, {
.name = "i2c-am33xx",
.driver_data = (unsigned long)&am33xx_data,
}, {
/* sentinel */
},
};
static __maybe_unused struct of_device_id omap_spi_dt_ids[] = {
{
.compatible = "ti,omap3-i2c",
.data = (unsigned long)&omap3_data,
}, {
.compatible = "ti,omap4-i2c",
.data = (unsigned long)&omap4_of_data,
}, {
/* sentinel */
}
};
static struct driver_d omap_i2c_driver = {
.probe = i2c_omap_probe,
.name = DRIVER_NAME,
.id_table = omap_i2c_ids,
.of_compatible = DRV_OF_COMPAT(omap_spi_dt_ids),
};
device_platform_driver(omap_i2c_driver);
MODULE_AUTHOR("MontaVista Software, Inc. (and others)");
MODULE_DESCRIPTION("TI OMAP I2C bus adapter");
MODULE_LICENSE("GPL");
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