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u-boot/drivers/i2c/rcar_i2c.c
Tom Rini 83d290c56f SPDX: Convert all of our single license tags to Linux Kernel style 
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>
2018-05-07 09:34:12 -04:00

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// SPDX-License-Identifier: GPL-2.0
/*
* drivers/i2c/rcar_i2c.c
*
* Copyright (C) 2013 Renesas Electronics Corporation
* Copyright (C) 2013 Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
*
* NOTE: This driver should be converted to driver model before June 2017.
* Please see doc/driver-model/i2c-howto.txt for instructions.
*/
#include <common.h>
#include <i2c.h>
#include <asm/io.h>
DECLARE_GLOBAL_DATA_PTR;
struct rcar_i2c {
u32 icscr;
u32 icmcr;
u32 icssr;
u32 icmsr;
u32 icsier;
u32 icmier;
u32 icccr;
u32 icsar;
u32 icmar;
u32 icrxdtxd;
u32 icccr2;
u32 icmpr;
u32 ichpr;
u32 iclpr;
};
#define MCR_MDBS 0x80 /* non-fifo mode switch */
#define MCR_FSCL 0x40 /* override SCL pin */
#define MCR_FSDA 0x20 /* override SDA pin */
#define MCR_OBPC 0x10 /* override pins */
#define MCR_MIE 0x08 /* master if enable */
#define MCR_TSBE 0x04
#define MCR_FSB 0x02 /* force stop bit */
#define MCR_ESG 0x01 /* en startbit gen. */
#define MSR_MASK 0x7f
#define MSR_MNR 0x40 /* nack received */
#define MSR_MAL 0x20 /* arbitration lost */
#define MSR_MST 0x10 /* sent a stop */
#define MSR_MDE 0x08
#define MSR_MDT 0x04
#define MSR_MDR 0x02
#define MSR_MAT 0x01 /* slave addr xfer done */
static const struct rcar_i2c *i2c_dev[CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS] = {
(struct rcar_i2c *)CONFIG_SYS_RCAR_I2C0_BASE,
(struct rcar_i2c *)CONFIG_SYS_RCAR_I2C1_BASE,
(struct rcar_i2c *)CONFIG_SYS_RCAR_I2C2_BASE,
(struct rcar_i2c *)CONFIG_SYS_RCAR_I2C3_BASE,
};
static void rcar_i2c_raw_rw_common(struct rcar_i2c *dev, u8 chip, uint addr)
{
/* set slave address */
writel(chip << 1, &dev->icmar);
/* set register address */
writel(addr, &dev->icrxdtxd);
/* clear status */
writel(0, &dev->icmsr);
/* start master send */
writel(MCR_MDBS | MCR_MIE | MCR_ESG, &dev->icmcr);
while ((readl(&dev->icmsr) & (MSR_MAT | MSR_MDE))
!= (MSR_MAT | MSR_MDE))
udelay(10);
/* clear ESG */
writel(MCR_MDBS | MCR_MIE, &dev->icmcr);
/* start SCLclk */
writel(~(MSR_MAT | MSR_MDE), &dev->icmsr);
while (!(readl(&dev->icmsr) & MSR_MDE))
udelay(10);
}
static void rcar_i2c_raw_rw_finish(struct rcar_i2c *dev)
{
while (!(readl(&dev->icmsr) & MSR_MST))
udelay(10);
writel(0, &dev->icmcr);
}
static int
rcar_i2c_raw_write(struct rcar_i2c *dev, u8 chip, uint addr, u8 *val, int size)
{
rcar_i2c_raw_rw_common(dev, chip, addr);
/* set send date */
writel(*val, &dev->icrxdtxd);
/* start SCLclk */
writel(~MSR_MDE, &dev->icmsr);
while (!(readl(&dev->icmsr) & MSR_MDE))
udelay(10);
/* set stop condition */
writel(MCR_MDBS | MCR_MIE | MCR_FSB, &dev->icmcr);
/* start SCLclk */
writel(~MSR_MDE, &dev->icmsr);
rcar_i2c_raw_rw_finish(dev);
return 0;
}
static u8
rcar_i2c_raw_read(struct rcar_i2c *dev, u8 chip, uint addr)
{
u8 ret;
rcar_i2c_raw_rw_common(dev, chip, addr);
/* set slave address, receive */
writel((chip << 1) | 1, &dev->icmar);
/* start master receive */
writel(MCR_MDBS | MCR_MIE | MCR_ESG, &dev->icmcr);
/* clear status */
writel(0, &dev->icmsr);
while ((readl(&dev->icmsr) & (MSR_MAT | MSR_MDR))
!= (MSR_MAT | MSR_MDR))
udelay(10);
/* clear ESG */
writel(MCR_MDBS | MCR_MIE, &dev->icmcr);
/* prepare stop condition */
writel(MCR_MDBS | MCR_MIE | MCR_FSB, &dev->icmcr);
/* start SCLclk */
writel(~(MSR_MAT | MSR_MDR), &dev->icmsr);
while (!(readl(&dev->icmsr) & MSR_MDR))
udelay(10);
/* get receive data */
ret = (u8)readl(&dev->icrxdtxd);
/* start SCLclk */
writel(~MSR_MDR, &dev->icmsr);
rcar_i2c_raw_rw_finish(dev);
return ret;
}
/*
* SCL = iicck / (20 + SCGD * 8 + F[(ticf + tr + intd) * iicck])
* iicck : I2C internal clock < 20 MHz
* ticf : I2C SCL falling time: 35 ns
* tr : I2C SCL rising time: 200 ns
* intd : LSI internal delay: I2C0: 50 ns I2C1-3: 5
* F[n] : n rounded up to an integer
*/
static u32 rcar_clock_gen(int i2c_no, u32 bus_speed)
{
u32 iicck, f, scl, scgd;
u32 intd = 5;
int bit = 0, cdf_width = 3;
for (bit = 0; bit < (1 << cdf_width); bit++) {
iicck = CONFIG_HP_CLK_FREQ / (1 + bit);
if (iicck < 20000000)
break;
}
if (bit > (1 << cdf_width)) {
puts("rcar-i2c: Can not get CDF\n");
return 0;
}
if (i2c_no == 0)
intd = 50;
f = (35 + 200 + intd) * (iicck / 1000000000);
for (scgd = 0; scgd < 0x40; scgd++) {
scl = iicck / (20 + (scgd * 8) + f);
if (scl <= bus_speed)
break;
}
if (scgd > 0x40) {
puts("rcar-i2c: Can not get SDGB\n");
return 0;
}
debug("%s: scl: %d\n", __func__, scl);
debug("%s: bit %x\n", __func__, bit);
debug("%s: scgd %x\n", __func__, scgd);
debug("%s: iccr %x\n", __func__, (scgd << (cdf_width) | bit));
return scgd << (cdf_width) | bit;
}
static void
rcar_i2c_init(struct i2c_adapter *adap, int speed, int slaveadd)
{
struct rcar_i2c *dev = (struct rcar_i2c *)i2c_dev[adap->hwadapnr];
u32 icccr = 0;
/* No i2c support prior to relocation */
if (!(gd->flags & GD_FLG_RELOC))
return;
/*
* reset slave mode.
* slave mode is not used on this driver
*/
writel(0, &dev->icsier);
writel(0, &dev->icsar);
writel(0, &dev->icscr);
writel(0, &dev->icssr);
/* reset master mode */
writel(0, &dev->icmier);
writel(0, &dev->icmcr);
writel(0, &dev->icmsr);
writel(0, &dev->icmar);
icccr = rcar_clock_gen(adap->hwadapnr, adap->speed);
if (icccr == 0)
puts("I2C: Init failed\n");
else
writel(icccr, &dev->icccr);
}
static int rcar_i2c_read(struct i2c_adapter *adap, uint8_t chip,
uint addr, int alen, u8 *data, int len)
{
struct rcar_i2c *dev = (struct rcar_i2c *)i2c_dev[adap->hwadapnr];
int i;
for (i = 0; i < len; i++)
data[i] = rcar_i2c_raw_read(dev, chip, addr + i);
return 0;
}
static int rcar_i2c_write(struct i2c_adapter *adap, uint8_t chip, uint addr,
int alen, u8 *data, int len)
{
struct rcar_i2c *dev = (struct rcar_i2c *)i2c_dev[adap->hwadapnr];
return rcar_i2c_raw_write(dev, chip, addr, data, len);
}
static int
rcar_i2c_probe(struct i2c_adapter *adap, u8 dev)
{
return rcar_i2c_read(adap, dev, 0, 0, NULL, 0);
}
static unsigned int rcar_i2c_set_bus_speed(struct i2c_adapter *adap,
unsigned int speed)
{
struct rcar_i2c *dev = (struct rcar_i2c *)i2c_dev[adap->hwadapnr];
u32 icccr;
int ret = 0;
rcar_i2c_raw_rw_finish(dev);
icccr = rcar_clock_gen(adap->hwadapnr, speed);
if (icccr == 0) {
puts("I2C: Init failed\n");
ret = -1;
} else {
writel(icccr, &dev->icccr);
}
return ret;
}
/*
* Register RCAR i2c adapters
*/
U_BOOT_I2C_ADAP_COMPLETE(rcar_0, rcar_i2c_init, rcar_i2c_probe, rcar_i2c_read,
rcar_i2c_write, rcar_i2c_set_bus_speed,
CONFIG_SYS_RCAR_I2C0_SPEED, 0, 0)
U_BOOT_I2C_ADAP_COMPLETE(rcar_1, rcar_i2c_init, rcar_i2c_probe, rcar_i2c_read,
rcar_i2c_write, rcar_i2c_set_bus_speed,
CONFIG_SYS_RCAR_I2C1_SPEED, 0, 1)
U_BOOT_I2C_ADAP_COMPLETE(rcar_2, rcar_i2c_init, rcar_i2c_probe, rcar_i2c_read,
rcar_i2c_write, rcar_i2c_set_bus_speed,
CONFIG_SYS_RCAR_I2C2_SPEED, 0, 2)
U_BOOT_I2C_ADAP_COMPLETE(rcar_3, rcar_i2c_init, rcar_i2c_probe, rcar_i2c_read,
rcar_i2c_write, rcar_i2c_set_bus_speed,
CONFIG_SYS_RCAR_I2C3_SPEED, 0, 3)
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