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rt-thread-official/bsp/fh8620/libraries/driverlib/fh_i2c.c

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/*
* This file is part of FH8620 BSP for RT-Thread distribution.
*
* Copyright (c) 2016 Shanghai Fullhan Microelectronics Co., Ltd.
* All rights reserved
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Visit http://www.fullhan.com to get contact with Fullhan.
*
* Change Logs:
* Date Author Notes
*/
#include "inc/fh_driverlib.h"
int I2C_WaitMasterIdle(struct fh_i2c_obj *i2c_obj)
{
UINT32 reg;
int timeout = 200; //20 ms
while (GET_REG(i2c_obj->base + OFFSET_I2C_STATUS) & DW_IC_STATUS_MASTER_ACTIVITY)
{
if(timeout < 0)
{
rt_kprintf( "ERROR: %s, timeout waiting for master not active, txflr: 0x%x, rxflr: 0x%x, stat: 0x%x\n",
__func__, I2C_GetReceiveFifoLevel(i2c_obj), I2C_GetTransmitFifoLevel(i2c_obj), GET_REG(i2c_obj->base + OFFSET_I2C_INTR_STAT));
return -RT_ETIMEOUT;
}
timeout--;
udelay(100);
}
return 0;
}
int I2C_WaitDeviceIdle(struct fh_i2c_obj *i2c_obj)
{
UINT32 reg;
int timeout = 2000; //200 ms
while (GET_REG(i2c_obj->base + OFFSET_I2C_STATUS) & DW_IC_STATUS_ACTIVITY)
{
if(timeout < 0)
{
rt_kprintf( "ERROR: %s, timeout waiting for device not active\n", __func__);
return -RT_ETIMEOUT;
}
timeout--;
udelay(100);
}
return 0;
}
static inline UINT32 I2C_CalcSclHcnt(UINT32 ic_clk, UINT32 tSYMBOL, UINT32 tf, int cond, int offset)
{
/*
* DesignWare I2C core doesn't seem to have solid strategy to meet
* the tHD;STA timing spec. Configuring _HCNT based on tHIGH spec
* will result in violation of the tHD;STA spec.
*/
if (cond)
/*
* Conditional expression:
*
* IC_[FS]S_SCL_HCNT + (1+4+3) >= IC_CLK * tHIGH
*
* This is based on the DW manuals, and represents an ideal
* configuration. The resulting I2C bus speed will be
* faster than any of the others.
*
* If your hardware is free from tHD;STA issue, try this one.
*/
return (ic_clk * tSYMBOL + 5000) / 10000 - 8 + offset;
else
/*
* Conditional expression:
*
* IC_[FS]S_SCL_HCNT + 3 >= IC_CLK * (tHD;STA + tf)
*
* This is just experimental rule; the tHD;STA period turned
* out to be proportinal to (_HCNT + 3). With this setting,
* we could meet both tHIGH and tHD;STA timing specs.
*
* If unsure, you'd better to take this alternative.
*
* The reason why we need to take into account "tf" here,
* is the same as described in i2c_fh_scl_lcnt().
*/
return (ic_clk * (tSYMBOL + tf) + 5000) / 10000 - 3 + offset;
}
static inline UINT32 I2C_CalcSclLcnt(UINT32 ic_clk, UINT32 tLOW, UINT32 tf, int offset)
{
/*
* Conditional expression:
*
* IC_[FS]S_SCL_LCNT + 1 >= IC_CLK * (tLOW + tf)
*
* DW I2C core starts counting the SCL CNTs for the LOW period
* of the SCL clock (tLOW) as soon as it pulls the SCL line.
* In order to meet the tLOW timing spec, we need to take into
* account the fall time of SCL signal (tf). Default tf value
* should be 0.3 us, for safety.
*/
return ((ic_clk * (tLOW + tf) + 5000) / 10000) - 1 + offset;
}
static int I2C_SetSpeedCount(struct fh_i2c_obj *i2c_obj)
{
UINT32 hcnt, lcnt;
/* set standard and fast speed count for high/low periods */
/* Standard-mode */
hcnt = I2C_CalcSclHcnt(i2c_obj->input_clock,
40, /* tHD;STA = tHIGH = 4.0 us */
3, /* tf = 0.3 us */
0, /* 0: DW default, 1: Ideal */
0); /* No offset */
lcnt = I2C_CalcSclLcnt(i2c_obj->input_clock,
47, /* tLOW = 4.7 us */
3, /* tf = 0.3 us */
0); /* No offset */
SET_REG(i2c_obj->base + OFFSET_I2C_SS_SCL_HCNT, hcnt);
SET_REG(i2c_obj->base + OFFSET_I2C_SS_SCL_LCNT, lcnt);
/* Fast-mode */
hcnt = I2C_CalcSclHcnt(i2c_obj->input_clock,
6, /* tHD;STA = tHIGH = 0.6 us */
3, /* tf = 0.3 us */
0, /* 0: DW default, 1: Ideal */
0); /* No offset */
lcnt = I2C_CalcSclLcnt(i2c_obj->input_clock,
13, /* tLOW = 1.3 us */
3, /* tf = 0.3 us */
0); /* No offset */
SET_REG(i2c_obj->base + OFFSET_I2C_FS_SCL_HCNT, hcnt);
SET_REG(i2c_obj->base + OFFSET_I2C_FS_SCL_LCNT, lcnt);
return 0;
}
UINT32 I2C_ClearAndGetInterrupts(struct fh_i2c_obj *i2c_obj)
{
UINT32 stat;
/*
* The IC_INTR_STAT register just indicates "enabled" interrupts.
* Ths unmasked raw version of interrupt status bits are available
* in the IC_RAW_INTR_STAT register.
*
* That is,
* stat = readl(IC_INTR_STAT);
* equals to,
* stat = readl(IC_RAW_INTR_STAT) & readl(IC_INTR_MASK);
*
* The raw version might be useful for debugging purposes.
*/
stat = GET_REG(i2c_obj->base + OFFSET_I2C_INTR_STAT);
/*
* Do not use the IC_CLR_INTR register to clear interrupts, or
* you'll miss some interrupts, triggered during the period from
* readl(IC_INTR_STAT) to readl(IC_CLR_INTR).
*
* Instead, use the separately-prepared IC_CLR_* registers.
*/
if (stat & DW_IC_INTR_RX_UNDER)
GET_REG(i2c_obj->base + OFFSET_I2C_CLR_RX_UNDER);
if (stat & DW_IC_INTR_RX_OVER)
GET_REG(i2c_obj->base + OFFSET_I2C_CLR_RX_OVER);
if (stat & DW_IC_INTR_TX_OVER)
GET_REG(i2c_obj->base + OFFSET_I2C_CLR_TX_OVER);
if (stat & DW_IC_INTR_RD_REQ)
GET_REG(i2c_obj->base + OFFSET_I2C_CLR_RD_REQ);
if (stat & DW_IC_INTR_TX_ABRT)
{
/*
* The IC_TX_ABRT_SOURCE register is cleared whenever
* the IC_CLR_TX_ABRT is read. Preserve it beforehand.
*/
i2c_obj->abort_source = GET_REG(i2c_obj->base + OFFSET_I2C_TX_ABRT_SOURCE);
GET_REG(i2c_obj->base + OFFSET_I2C_CLR_TX_ABRT);
}
if (stat & DW_IC_INTR_RX_DONE)
GET_REG(i2c_obj->base + OFFSET_I2C_CLR_RX_DONE);
if (stat & DW_IC_INTR_ACTIVITY)
GET_REG(i2c_obj->base + OFFSET_I2C_CLR_ACTIVITY);
if (stat & DW_IC_INTR_STOP_DET)
GET_REG(i2c_obj->base + OFFSET_I2C_CLR_STOP_DET);
if (stat & DW_IC_INTR_START_DET)
GET_REG(i2c_obj->base + OFFSET_I2C_CLR_START_DET);
if (stat & DW_IC_INTR_GEN_CALL)
GET_REG(i2c_obj->base + OFFSET_I2C_CLR_GEN_CALL);
return stat;
}
int I2C_HandleTxAbort(struct fh_i2c_obj *i2c_obj)
{
unsigned long abort_source = i2c_obj->abort_source;
int i;
if (abort_source & DW_IC_TX_ABRT_NOACK)
{
//for_each_set_bit(i, &abort_source, ARRAY_SIZE(abort_sources))
// rt_kprintf( "%s: %s\n", __func__, abort_sources[i]);
return 0;
}
//for_each_set_bit(i, &abort_source, ARRAY_SIZE(abort_sources))
// rt_kprintf( "%s: %s\n", __func__, abort_sources[i]);
rt_kprintf("%s: abort_sources 0x%x\n", __func__, abort_sources);
if (abort_source & DW_IC_TX_ARB_LOST)
return 0;
else if (abort_source & DW_IC_TX_ABRT_GCALL_READ)
return 0; /* wrong msgs[] data */
else
return 0;
}
void I2C_Init(struct fh_i2c_obj *i2c_obj)
{
UINT32 ic_con;
UINT32 param0 = GET_REG(i2c_obj->base + OFFSET_I2C_COMP_PARAM1);
I2C_WaitMasterIdle(i2c_obj);
I2C_Enable(i2c_obj, RT_FALSE);
I2C_SetSpeedCount(i2c_obj);
i2c_obj->config.tx_fifo_depth = ((param0 >> 16) & 0xff) + 1;
i2c_obj->config.rx_fifo_depth = ((param0 >> 8) & 0xff) + 1;
/* Configure Tx/Rx FIFO threshold levels */
SET_REG(i2c_obj->base + OFFSET_I2C_TX_TL, i2c_obj->config.tx_fifo_depth - 1);
SET_REG(i2c_obj->base + OFFSET_I2C_RX_TL, 0);
/* configure the i2c master */
ic_con = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
/*OFFSET_I2C_CON_RESTART_EN |*/ DW_IC_CON_SPEED_FAST; //DW_IC_CON_SPEED_STD;
SET_REG( i2c_obj->base + OFFSET_I2C_CON, ic_con);
}
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