[PATCH v9 1/2] i2c: i2c-cortina: added CAxxxx I2C support

Heiko Schocher hs at denx.de
Mon Jun 22 14:15:18 CEST 2020


Hi Alex,

Am 17.06.2020 um 22:09 schrieb Alex Nemirovsky:
> Hi Heiko,

Sorry for the late reply!

> seems that this patch set may have slipped through the cracks.
> Is there anything keeping it from being merged into master?

No, but we are so late in release cycle, so I planned it for the next
merge window!

bye,
Heiko
> 
>> On Jun 1, 2020, at 12:56 PM, Alex Nemirovsky <alex.nemirovsky at cortina-access.com> wrote:
>>
>> From: Arthur Li <arthur.li at cortina-access.com>
>>
>> Add I2C controller support for Cortina Access CAxxxx SoCs
>>
>> Signed-off-by: Arthur Li <arthur.li at cortina-access.com>
>> Signed-off-by: Alex Nemirovsky <alex.nemirovsky at cortina-access.com>
>> CC: Heiko Schocher <hs at denx.de>
>> Reviewed-by: Heiko Schocher <hs at denx.de>
>>
>> ---
>>
>> Changes in v9:
>> - specially include bitops.h and delay.h which
>> were removed from common.h
>>
>> Changes in v8:
>> - No code change
>> - Split out individual driver from Cortina Package 2 patch series
>> to help streamline acceptence into master
>>
>> Changes in v7:
>> - Added additional description info in I2C KConfig
>>
>> Changes in v6:
>> - Add I2C DT binding document
>>
>> Changes in v4:
>> - Utilize standard I2C macros from <i2c.h>
>> - Return ETIMEDOUT in funcs that can timeout
>> - Return i2c_xfer_init() result to caller of i2c_read() if it
>> 	fails within i2c_read() execution
>> - Fix misc. style guide conformance issues
>> - Use printf() to report i2c_xfer() runtime errors
>> 	instead of debug()
>>
>> MAINTAINERS                                  |   4 +
>> doc/device-tree-bindings/i2c/i2c-cortina.txt |  18 ++
>> drivers/i2c/Kconfig                          |   8 +
>> drivers/i2c/Makefile                         |   1 +
>> drivers/i2c/i2c-cortina.c                    | 346 +++++++++++++++++++++++++++
>> drivers/i2c/i2c-cortina.h                    |  87 +++++++
>> 6 files changed, 464 insertions(+)
>> create mode 100644 doc/device-tree-bindings/i2c/i2c-cortina.txt
>> create mode 100644 drivers/i2c/i2c-cortina.c
>> create mode 100644 drivers/i2c/i2c-cortina.h
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 8add9d4..ce70ca9 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -181,6 +181,8 @@ F:	drivers/gpio/cortina_gpio.c
>> F:	drivers/watchdog/cortina_wdt.c
>> F:	drivers/serial/serial_cortina.c
>> F:	drivers/mmc/ca_dw_mmc.c
>> +F:	drivers/i2c/i2c-cortina.c
>> +F:	drivers/i2c/i2c-cortina.h
>>
>> ARM/CZ.NIC TURRIS MOX SUPPORT
>> M:	Marek Behun <marek.behun at nic.cz>
>> @@ -732,6 +734,8 @@ F:	drivers/gpio/cortina_gpio.c
>> F:	drivers/watchdog/cortina_wdt.c
>> F:	drivers/serial/serial_cortina.c
>> F:	drivers/mmc/ca_dw_mmc.c
>> +F:	drivers/i2c/i2c-cortina.c
>> +F:	drivers/i2c/i2c-cortina.h
>>
>> MIPS MSCC
>> M:	Gregory CLEMENT <gregory.clement at bootlin.com>
>> diff --git a/doc/device-tree-bindings/i2c/i2c-cortina.txt b/doc/device-tree-bindings/i2c/i2c-cortina.txt
>> new file mode 100644
>> index 0000000..59d5235
>> --- /dev/null
>> +++ b/doc/device-tree-bindings/i2c/i2c-cortina.txt
>> @@ -0,0 +1,18 @@
>> +* I2C for Cortina platforms
>> +
>> +Required properties :
>> +- compatible : Must be "cortina,ca-i2c"
>> +- reg : Offset and length of the register set for the device
>> +
>> +Recommended properties :
>> +- clock-frequency : desired I2C bus clock frequency in Hz. If not specified,
>> +		    default value is 100000. Possible values are 100000,
>> +		    400000 and 1000000.
>> +
>> +Examples :
>> +
>> +	i2c: i2c at f4329120 {
>> +		compatible = "cortina,ca-i2c";
>> +		reg = <0x0 0xf4329120 0x28>;
>> +		clock-frequency = <400000>;
>> +	};
>> diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig
>> index f8b18de..b56e0d9 100644
>> --- a/drivers/i2c/Kconfig
>> +++ b/drivers/i2c/Kconfig
>> @@ -93,6 +93,14 @@ config SYS_I2C_CADENCE
>> 	  Say yes here to select Cadence I2C Host Controller. This controller is
>> 	  e.g. used by Xilinx Zynq.
>>
>> +config SYS_I2C_CA
>> +	tristate "Cortina-Access I2C Controller"
>> +	depends on DM_I2C && CORTINA_PLATFORM
>> +	default n
>> +	help
>> +	  Add support for the Cortina Access I2C host controller.
>> +	  Say yes here to select Cortina-Access I2C Host Controller.
>> +
>> config SYS_I2C_DAVINCI
>> 	bool "Davinci I2C Controller"
>> 	depends on (ARCH_KEYSTONE || ARCH_DAVINCI)
>> diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile
>> index 62935b7..d2b07ce 100644
>> --- a/drivers/i2c/Makefile
>> +++ b/drivers/i2c/Makefile
>> @@ -12,6 +12,7 @@ obj-$(CONFIG_SYS_I2C) += i2c_core.o
>> obj-$(CONFIG_SYS_I2C_ASPEED) += ast_i2c.o
>> obj-$(CONFIG_SYS_I2C_AT91) += at91_i2c.o
>> obj-$(CONFIG_SYS_I2C_CADENCE) += i2c-cdns.o
>> +obj-$(CONFIG_SYS_I2C_CA) += i2c-cortina.o
>> obj-$(CONFIG_SYS_I2C_DAVINCI) += davinci_i2c.o
>> obj-$(CONFIG_SYS_I2C_DW) += designware_i2c.o
>> ifdef CONFIG_DM_PCI
>> diff --git a/drivers/i2c/i2c-cortina.c b/drivers/i2c/i2c-cortina.c
>> new file mode 100644
>> index 0000000..08b812a
>> --- /dev/null
>> +++ b/drivers/i2c/i2c-cortina.c
>> @@ -0,0 +1,346 @@
>> +// SPDX-License-Identifier: GPL-2.0+
>> +/*
>> + * (C) Copyright 2020
>> + * Arthur Li, Cortina Access, arthur.li at cortina-access.com.
>> + */
>> +
>> +#include <common.h>
>> +#include <i2c.h>
>> +#include <asm/io.h>
>> +#include <dm.h>
>> +#include <mapmem.h>
>> +#include "i2c-cortina.h"
>> +
>> +static void set_speed(struct i2c_regs *regs, int i2c_spd)
>> +{
>> +	union ca_biw_cfg i2c_cfg;
>> +
>> +	i2c_cfg.wrd = readl(&regs->i2c_cfg);
>> +	i2c_cfg.bf.core_en = 0;
>> +	writel(i2c_cfg.wrd, &regs->i2c_cfg);
>> +
>> +	switch (i2c_spd) {
>> +	case IC_SPEED_MODE_FAST_PLUS:
>> +		i2c_cfg.bf.prer = CORTINA_PER_IO_FREQ /
>> +				  (5 * I2C_SPEED_FAST_PLUS_RATE) - 1;
>> +		break;
>> +
>> +	case IC_SPEED_MODE_STANDARD:
>> +		i2c_cfg.bf.prer = CORTINA_PER_IO_FREQ /
>> +				  (5 * I2C_SPEED_STANDARD_RATE) - 1;
>> +		break;
>> +
>> +	case IC_SPEED_MODE_FAST:
>> +	default:
>> +		i2c_cfg.bf.prer = CORTINA_PER_IO_FREQ /
>> +				  (5 * I2C_SPEED_FAST_RATE) - 1;
>> +		break;
>> +	}
>> +
>> +	i2c_cfg.bf.core_en = 1;
>> +	writel(i2c_cfg.wrd, &regs->i2c_cfg);
>> +}
>> +
>> +static int ca_i2c_set_bus_speed(struct udevice *bus, unsigned int speed)
>> +{
>> +	struct ca_i2c *priv = dev_get_priv(bus);
>> +	int i2c_spd;
>> +
>> +	if (speed >= I2C_SPEED_FAST_PLUS_RATE) {
>> +		i2c_spd = IC_SPEED_MODE_FAST_PLUS;
>> +		priv->speed = I2C_SPEED_FAST_PLUS_RATE;
>> +	} else if (speed >= I2C_SPEED_FAST_RATE) {
>> +		i2c_spd = IC_SPEED_MODE_FAST;
>> +		priv->speed = I2C_SPEED_FAST_RATE;
>> +	} else {
>> +		i2c_spd = IC_SPEED_MODE_STANDARD;
>> +		priv->speed = I2C_SPEED_STANDARD_RATE;
>> +	}
>> +
>> +	set_speed(priv->regs, i2c_spd);
>> +
>> +	return 0;
>> +}
>> +
>> +static int ca_i2c_get_bus_speed(struct udevice *bus)
>> +{
>> +	struct ca_i2c *priv = dev_get_priv(bus);
>> +
>> +	return priv->speed;
>> +}
>> +
>> +static void ca_i2c_init(struct i2c_regs *regs)
>> +{
>> +	union ca_biw_cfg i2c_cfg;
>> +
>> +	i2c_cfg.wrd = readl(&regs->i2c_cfg);
>> +	i2c_cfg.bf.core_en = 0;
>> +	i2c_cfg.bf.biw_soft_reset = 1;
>> +	writel(i2c_cfg.wrd, &regs->i2c_cfg);
>> +	mdelay(10);
>> +	i2c_cfg.bf.biw_soft_reset = 0;
>> +	writel(i2c_cfg.wrd, &regs->i2c_cfg);
>> +
>> +	set_speed(regs, IC_SPEED_MODE_STANDARD);
>> +
>> +	i2c_cfg.wrd = readl(&regs->i2c_cfg);
>> +	i2c_cfg.bf.core_en = 1;
>> +	writel(i2c_cfg.wrd, &regs->i2c_cfg);
>> +}
>> +
>> +static int i2c_wait_complete(struct i2c_regs *regs)
>> +{
>> +	union ca_biw_ctrl i2c_ctrl;
>> +	unsigned long start_time_bb = get_timer(0);
>> +
>> +	i2c_ctrl.wrd = readl(&regs->i2c_ctrl);
>> +
>> +	while (i2c_ctrl.bf.biwdone == 0) {
>> +		i2c_ctrl.wrd = readl(&regs->i2c_ctrl);
>> +
>> +		if (get_timer(start_time_bb) >
>> +		   (unsigned long)(I2C_BYTE_TO_BB)) {
>> +			printf("%s not done!!!\n", __func__);
>> +			return -ETIMEDOUT;
>> +		}
>> +	}
>> +
>> +	/* Clear done bit */
>> +	writel(i2c_ctrl.wrd, &regs->i2c_ctrl);
>> +
>> +	return 0;
>> +}
>> +
>> +static void i2c_setaddress(struct i2c_regs *regs, unsigned int i2c_addr,
>> +			   int write_read)
>> +{
>> +	writel(i2c_addr | write_read, &regs->i2c_txr);
>> +
>> +	writel(BIW_CTRL_START | BIW_CTRL_WRITE,
>> +	       &regs->i2c_ctrl);
>> +
>> +	i2c_wait_complete(regs);
>> +}
>> +
>> +static int i2c_wait_for_bus_busy(struct i2c_regs *regs)
>> +{
>> +	union ca_biw_ack i2c_ack;
>> +	unsigned long start_time_bb = get_timer(0);
>> +
>> +	i2c_ack.wrd = readl(&regs->i2c_ack);
>> +
>> +	while (i2c_ack.bf.biw_busy) {
>> +		i2c_ack.wrd = readl(&regs->i2c_ack);
>> +
>> +		if (get_timer(start_time_bb) >
>> +		   (unsigned long)(I2C_BYTE_TO_BB)) {
>> +			printf("%s: timeout!\n", __func__);
>> +			return -ETIMEDOUT;
>> +		}
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int i2c_xfer_init(struct i2c_regs *regs, uint8_t chip, uint addr,
>> +			 int alen, int write_read)
>> +{
>> +	int addr_len = alen;
>> +
>> +	if (i2c_wait_for_bus_busy(regs))
>> +		return 1;
>> +
>> +	/* First cycle must write addr + offset */
>> +	chip = ((chip & 0x7F) << 1);
>> +	if (alen == 0 && write_read == I2C_CMD_RD)
>> +		i2c_setaddress(regs, chip, I2C_CMD_RD);
>> +	else
>> +		i2c_setaddress(regs, chip, I2C_CMD_WT);
>> +
>> +	while (alen) {
>> +		alen--;
>> +		writel(addr, &regs->i2c_txr);
>> +		if (write_read == I2C_CMD_RD)
>> +			writel(BIW_CTRL_WRITE | BIW_CTRL_STOP,
>> +			       &regs->i2c_ctrl);
>> +		else
>> +			writel(BIW_CTRL_WRITE, &regs->i2c_ctrl);
>> +		i2c_wait_complete(regs);
>> +	}
>> +
>> +	/* Send address again with Read flag if it's read command */
>> +	if (write_read == I2C_CMD_RD && addr_len > 0)
>> +		i2c_setaddress(regs, chip, I2C_CMD_RD);
>> +
>> +	return 0;
>> +}
>> +
>> +static int i2c_xfer_finish(struct i2c_regs *regs)
>> +{
>> +	/* Dummy read makes bus free */
>> +	writel(BIW_CTRL_READ | BIW_CTRL_STOP, &regs->i2c_ctrl);
>> +	i2c_wait_complete(regs);
>> +
>> +	if (i2c_wait_for_bus_busy(regs)) {
>> +		printf("Timed out waiting for bus\n");
>> +		return -ETIMEDOUT;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int ca_i2c_read(struct i2c_regs *regs, uint8_t chip, uint addr,
>> +		       int alen, uint8_t *buffer, int len)
>> +{
>> +	unsigned long start_time_rx;
>> +	int rc = 0;
>> +
>> +	rc = i2c_xfer_init(regs, chip, addr, alen, I2C_CMD_RD);
>> +	if (rc)
>> +		return rc;
>> +
>> +	start_time_rx = get_timer(0);
>> +	while (len) {
>> +		/* ACK_IN is ack value to send during read.
>> +		 * ack high only on the very last byte!
>> +		 */
>> +		if (len == 1)
>> +			writel(BIW_CTRL_READ | BIW_CTRL_ACK_IN | BIW_CTRL_STOP,
>> +			       &regs->i2c_ctrl);
>> +		else
>> +			writel(BIW_CTRL_READ, &regs->i2c_ctrl);
>> +
>> +		rc = i2c_wait_complete(regs);
>> +		udelay(1);
>> +
>> +		if (rc == 0) {
>> +			*buffer++ =
>> +				(uchar) readl(&regs->i2c_rxr);
>> +			len--;
>> +			start_time_rx = get_timer(0);
>> +
>> +		} else if (get_timer(start_time_rx) > I2C_BYTE_TO) {
>> +			return -ETIMEDOUT;
>> +		}
>> +	}
>> +	i2c_xfer_finish(regs);
>> +	return rc;
>> +}
>> +
>> +static int ca_i2c_write(struct i2c_regs *regs, uint8_t chip, uint addr,
>> +			int alen, uint8_t *buffer, int len)
>> +{
>> +	int rc, nb = len;
>> +	unsigned long start_time_tx;
>> +
>> +	rc = i2c_xfer_init(regs, chip, addr, alen, I2C_CMD_WT);
>> +	if (rc)
>> +		return rc;
>> +
>> +	start_time_tx = get_timer(0);
>> +	while (len) {
>> +		writel(*buffer, &regs->i2c_txr);
>> +		if (len == 1)
>> +			writel(BIW_CTRL_WRITE | BIW_CTRL_STOP,
>> +			       &regs->i2c_ctrl);
>> +		else
>> +			writel(BIW_CTRL_WRITE, &regs->i2c_ctrl);
>> +
>> +		rc = i2c_wait_complete(regs);
>> +
>> +		if (rc == 0) {
>> +			len--;
>> +			buffer++;
>> +			start_time_tx = get_timer(0);
>> +		} else if (get_timer(start_time_tx) > (nb * I2C_BYTE_TO)) {
>> +			return -ETIMEDOUT;
>> +		}
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static int ca_i2c_probe_chip(struct udevice *bus, uint chip_addr,
>> +			     uint chip_flags)
>> +{
>> +	struct ca_i2c *priv = dev_get_priv(bus);
>> +	int ret;
>> +	u32 tmp;
>> +
>> +	/* Try to read the first location of the chip */
>> +	ret = ca_i2c_read(priv->regs, chip_addr, 0, 1, (uchar *)&tmp, 1);
>> +	if (ret)
>> +		ca_i2c_init(priv->regs);
>> +
>> +	return ret;
>> +}
>> +
>> +static int ca_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs)
>> +{
>> +	struct ca_i2c *priv = dev_get_priv(bus);
>> +	int ret;
>> +
>> +	debug("i2c_xfer: %d messages\n", nmsgs);
>> +	for (; nmsgs > 0; nmsgs--, msg++) {
>> +		debug("i2c_xfer: chip=0x%x, len=0x%x\n", msg->addr, msg->len);
>> +		if (msg->flags & I2C_M_RD)
>> +			ret = ca_i2c_read(priv->regs, msg->addr, 0, 0,
>> +					  msg->buf, msg->len);
>> +		else
>> +			ret = ca_i2c_write(priv->regs, msg->addr, 0, 0,
>> +					   msg->buf, msg->len);
>> +
>> +		if (ret) {
>> +			printf("i2c_xfer: %s error\n",
>> +			       msg->flags & I2C_M_RD ? "read" : "write");
>> +			return ret;
>> +		}
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +static const struct dm_i2c_ops ca_i2c_ops = {
>> +	.xfer		= ca_i2c_xfer,
>> +	.probe_chip	= ca_i2c_probe_chip,
>> +	.set_bus_speed	= ca_i2c_set_bus_speed,
>> +	.get_bus_speed	= ca_i2c_get_bus_speed,
>> +};
>> +
>> +static const struct udevice_id ca_i2c_ids[] = {
>> +	{ .compatible = "cortina,ca-i2c", },
>> +	{ }
>> +};
>> +
>> +static int ca_i2c_probe(struct udevice *bus)
>> +{
>> +	struct ca_i2c *priv = dev_get_priv(bus);
>> +
>> +	ca_i2c_init(priv->regs);
>> +
>> +	return 0;
>> +}
>> +
>> +static int ca_i2c_ofdata_to_platdata(struct udevice *bus)
>> +{
>> +	struct ca_i2c *priv = dev_get_priv(bus);
>> +
>> +	priv->regs = map_sysmem(dev_read_addr(bus), sizeof(struct i2c_regs));
>> +	if (!priv->regs) {
>> +		printf("I2C: base address is invalid\n");
>> +		return -EINVAL;
>> +	}
>> +
>> +	return 0;
>> +}
>> +
>> +U_BOOT_DRIVER(i2c_cortina) = {
>> +	.name	= "i2c_cortina",
>> +	.id	= UCLASS_I2C,
>> +	.of_match = ca_i2c_ids,
>> +	.ofdata_to_platdata = ca_i2c_ofdata_to_platdata,
>> +	.probe	= ca_i2c_probe,
>> +	.priv_auto_alloc_size = sizeof(struct ca_i2c),
>> +	.ops	= &ca_i2c_ops,
>> +	.flags  = DM_FLAG_PRE_RELOC,
>> +};
>> diff --git a/drivers/i2c/i2c-cortina.h b/drivers/i2c/i2c-cortina.h
>> new file mode 100644
>> index 0000000..7e406b5
>> --- /dev/null
>> +++ b/drivers/i2c/i2c-cortina.h
>> @@ -0,0 +1,87 @@
>> +/* SPDX-License-Identifier: GPL-2.0+ */
>> +/*
>> + * (C) Copyright 2019
>> + * Cortina Access, <www.cortina-access.com>
>> + */
>> +
>> +#ifndef __CA_I2C_H_
>> +#define __CA_I2C_H_
>> +
>> +#include <linux/bitops.h>
>> +#include <linux/delay.h>
>> +
>> +#if !defined(__ASSEMBLER__) && !defined(__ASSEMBLY__)
>> +struct i2c_regs {
>> +	u32 i2c_cfg;
>> +	u32 i2c_ctrl;
>> +	u32 i2c_txr;
>> +	u32 i2c_rxr;
>> +	u32 i2c_ack;
>> +	u32 i2c_ie0;
>> +	u32 i2c_int0;
>> +	u32 i2c_ie1;
>> +	u32 i2c_int1;
>> +	u32 i2c_stat;
>> +};
>> +
>> +union ca_biw_cfg {
>> +	struct biw_cfg {
>> +		u32 core_en		: 1;
>> +		u32 biw_soft_reset	: 1;
>> +		u32 busywait_en		: 1;
>> +		u32 stretch_en		: 1;
>> +		u32 arb_en		: 1;
>> +		u32 clksync_en		: 1;
>> +		u32 rsrvd1		: 2;
>> +		u32 spike_cnt		: 4;
>> +		u32 rsrvd2		: 4;
>> +		u32 prer		: 16;
>> +	} bf;
>> +	unsigned int wrd;
>> +};
>> +
>> +union ca_biw_ctrl {
>> +	struct biw_ctrl {
>> +		u32 biwdone	: 1;
>> +		u32 rsrvd1	: 2;
>> +		u32 ack_in	: 1;
>> +		u32 write	: 1;
>> +		u32 read	: 1;
>> +		u32 stop	: 1;
>> +		u32 start	: 1;
>> +		u32 rsrvd2	: 24;
>> +	} bf;
>> +	unsigned int wrd;
>> +};
>> +
>> +union ca_biw_ack {
>> +	struct biw_ack {
>> +		u32 al		:1;
>> +		u32 biw_busy	:1;
>> +		u32 ack_out	:1;
>> +		u32 rsrvd1	:29;
>> +	} bf;
>> +	unsigned int wrd;
>> +};
>> +#endif /* !__ASSEMBLER__*/
>> +
>> +struct ca_i2c {
>> +	struct i2c_regs *regs;
>> +	unsigned int speed;
>> +};
>> +
>> +#define I2C_CMD_WT			0
>> +#define I2C_CMD_RD			1
>> +
>> +#define BIW_CTRL_DONE		BIT(0)
>> +#define BIW_CTRL_ACK_IN		BIT(3)
>> +#define BIW_CTRL_WRITE		BIT(4)
>> +#define BIW_CTRL_READ		BIT(5)
>> +#define BIW_CTRL_STOP		BIT(6)
>> +#define BIW_CTRL_START		BIT(7)
>> +
>> +#define I2C_BYTE_TO		(CONFIG_SYS_HZ / 500)
>> +#define I2C_STOPDET_TO		(CONFIG_SYS_HZ / 500)
>> +#define I2C_BYTE_TO_BB		(10)
>> +
>> +#endif							/* __CA_I2C_H_ */
>> -- 
>> 2.7.4
>>
> 

-- 
DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: +49-8142-66989-52   Fax: +49-8142-66989-80   Email: hs at denx.de


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