diff options
author | Eddie James <eajames@linux.vnet.ibm.com> | 2018-07-17 10:31:00 -0500 |
---|---|---|
committer | Wolfram Sang <wsa@the-dreams.de> | 2018-07-21 00:07:07 +0200 |
commit | d6ffb63001167053cc7af889543ca8284beee0dd (patch) | |
tree | 09eff3912a089cf8674981bde61da17d01138e56 | |
parent | 82d41d09743938e5bc399725ad64e12fa968e8ed (diff) |
i2c: Add FSI-attached I2C master algorithm
Add register definitions for FSI-attached I2C master and functions to
access those registers over FSI. Add an FSI driver so that our I2C bus
is probed up during an FSI scan.
Signed-off-by: Eddie James <eajames@linux.vnet.ibm.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Tested-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
-rw-r--r-- | drivers/i2c/busses/Kconfig | 11 | ||||
-rw-r--r-- | drivers/i2c/busses/Makefile | 1 | ||||
-rw-r--r-- | drivers/i2c/busses/i2c-fsi.c | 239 |
3 files changed, 251 insertions, 0 deletions
diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig index e7a4d288c8b7..48b5de7adece 100644 --- a/drivers/i2c/busses/Kconfig +++ b/drivers/i2c/busses/Kconfig @@ -1327,4 +1327,15 @@ config I2C_ZX2967 This driver can also be built as a module. If so, the module will be called i2c-zx2967. +config I2C_FSI + tristate "FSI I2C driver" + depends on FSI + help + Driver for FSI bus attached I2C masters. These are I2C masters that + are connected to the system over an FSI bus, instead of the more + common PCI or MMIO interface. + + This driver can also be built as a module. If so, the module will be + called as i2c-fsi. + endmenu diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile index 5a869144a0c5..4909fd681913 100644 --- a/drivers/i2c/busses/Makefile +++ b/drivers/i2c/busses/Makefile @@ -137,5 +137,6 @@ obj-$(CONFIG_I2C_PCA_ISA) += i2c-pca-isa.o obj-$(CONFIG_I2C_SIBYTE) += i2c-sibyte.o obj-$(CONFIG_I2C_XGENE_SLIMPRO) += i2c-xgene-slimpro.o obj-$(CONFIG_SCx200_ACB) += scx200_acb.o +obj-$(CONFIG_I2C_FSI) += i2c-fsi.o ccflags-$(CONFIG_I2C_DEBUG_BUS) := -DDEBUG diff --git a/drivers/i2c/busses/i2c-fsi.c b/drivers/i2c/busses/i2c-fsi.c new file mode 100644 index 000000000000..3725db1cc1f1 --- /dev/null +++ b/drivers/i2c/busses/i2c-fsi.c @@ -0,0 +1,239 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * FSI-attached I2C master algorithm + * + * Copyright 2018 IBM Corporation + * + * 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. + */ + +#include <linux/bitfield.h> +#include <linux/bitops.h> +#include <linux/device.h> +#include <linux/errno.h> +#include <linux/fsi.h> +#include <linux/i2c.h> +#include <linux/kernel.h> +#include <linux/module.h> + +#define FSI_ENGID_I2C 0x7 + +#define I2C_DEFAULT_CLK_DIV 6 + +/* i2c registers */ +#define I2C_FSI_FIFO 0x00 +#define I2C_FSI_CMD 0x04 +#define I2C_FSI_MODE 0x08 +#define I2C_FSI_WATER_MARK 0x0C +#define I2C_FSI_INT_MASK 0x10 +#define I2C_FSI_INT_COND 0x14 +#define I2C_FSI_OR_INT_MASK 0x14 +#define I2C_FSI_INTS 0x18 +#define I2C_FSI_AND_INT_MASK 0x18 +#define I2C_FSI_STAT 0x1C +#define I2C_FSI_RESET_I2C 0x1C +#define I2C_FSI_ESTAT 0x20 +#define I2C_FSI_RESET_ERR 0x20 +#define I2C_FSI_RESID_LEN 0x24 +#define I2C_FSI_SET_SCL 0x24 +#define I2C_FSI_PORT_BUSY 0x28 +#define I2C_FSI_RESET_SCL 0x2C +#define I2C_FSI_SET_SDA 0x30 +#define I2C_FSI_RESET_SDA 0x34 + +/* cmd register */ +#define I2C_CMD_WITH_START BIT(31) +#define I2C_CMD_WITH_ADDR BIT(30) +#define I2C_CMD_RD_CONT BIT(29) +#define I2C_CMD_WITH_STOP BIT(28) +#define I2C_CMD_FORCELAUNCH BIT(27) +#define I2C_CMD_ADDR GENMASK(23, 17) +#define I2C_CMD_READ BIT(16) +#define I2C_CMD_LEN GENMASK(15, 0) + +/* mode register */ +#define I2C_MODE_CLKDIV GENMASK(31, 16) +#define I2C_MODE_PORT GENMASK(15, 10) +#define I2C_MODE_ENHANCED BIT(3) +#define I2C_MODE_DIAG BIT(2) +#define I2C_MODE_PACE_ALLOW BIT(1) +#define I2C_MODE_WRAP BIT(0) + +/* watermark register */ +#define I2C_WATERMARK_HI GENMASK(15, 12) +#define I2C_WATERMARK_LO GENMASK(7, 4) + +#define I2C_FIFO_HI_LVL 4 +#define I2C_FIFO_LO_LVL 4 + +/* interrupt register */ +#define I2C_INT_INV_CMD BIT(15) +#define I2C_INT_PARITY BIT(14) +#define I2C_INT_BE_OVERRUN BIT(13) +#define I2C_INT_BE_ACCESS BIT(12) +#define I2C_INT_LOST_ARB BIT(11) +#define I2C_INT_NACK BIT(10) +#define I2C_INT_DAT_REQ BIT(9) +#define I2C_INT_CMD_COMP BIT(8) +#define I2C_INT_STOP_ERR BIT(7) +#define I2C_INT_BUSY BIT(6) +#define I2C_INT_IDLE BIT(5) + +/* status register */ +#define I2C_STAT_INV_CMD BIT(31) +#define I2C_STAT_PARITY BIT(30) +#define I2C_STAT_BE_OVERRUN BIT(29) +#define I2C_STAT_BE_ACCESS BIT(28) +#define I2C_STAT_LOST_ARB BIT(27) +#define I2C_STAT_NACK BIT(26) +#define I2C_STAT_DAT_REQ BIT(25) +#define I2C_STAT_CMD_COMP BIT(24) +#define I2C_STAT_STOP_ERR BIT(23) +#define I2C_STAT_MAX_PORT GENMASK(19, 16) +#define I2C_STAT_ANY_INT BIT(15) +#define I2C_STAT_SCL_IN BIT(11) +#define I2C_STAT_SDA_IN BIT(10) +#define I2C_STAT_PORT_BUSY BIT(9) +#define I2C_STAT_SELF_BUSY BIT(8) +#define I2C_STAT_FIFO_COUNT GENMASK(7, 0) + +#define I2C_STAT_ERR (I2C_STAT_INV_CMD | \ + I2C_STAT_PARITY | \ + I2C_STAT_BE_OVERRUN | \ + I2C_STAT_BE_ACCESS | \ + I2C_STAT_LOST_ARB | \ + I2C_STAT_NACK | \ + I2C_STAT_STOP_ERR) +#define I2C_STAT_ANY_RESP (I2C_STAT_ERR | \ + I2C_STAT_DAT_REQ | \ + I2C_STAT_CMD_COMP) + +/* extended status register */ +#define I2C_ESTAT_FIFO_SZ GENMASK(31, 24) +#define I2C_ESTAT_SCL_IN_SY BIT(15) +#define I2C_ESTAT_SDA_IN_SY BIT(14) +#define I2C_ESTAT_S_SCL BIT(13) +#define I2C_ESTAT_S_SDA BIT(12) +#define I2C_ESTAT_M_SCL BIT(11) +#define I2C_ESTAT_M_SDA BIT(10) +#define I2C_ESTAT_HI_WATER BIT(9) +#define I2C_ESTAT_LO_WATER BIT(8) +#define I2C_ESTAT_PORT_BUSY BIT(7) +#define I2C_ESTAT_SELF_BUSY BIT(6) +#define I2C_ESTAT_VERSION GENMASK(4, 0) + +struct fsi_i2c_master { + struct fsi_device *fsi; + u8 fifo_size; +}; + +static int fsi_i2c_read_reg(struct fsi_device *fsi, unsigned int reg, + u32 *data) +{ + int rc; + __be32 data_be; + + rc = fsi_device_read(fsi, reg, &data_be, sizeof(data_be)); + if (rc) + return rc; + + *data = be32_to_cpu(data_be); + + return 0; +} + +static int fsi_i2c_write_reg(struct fsi_device *fsi, unsigned int reg, + u32 *data) +{ + __be32 data_be = cpu_to_be32p(data); + + return fsi_device_write(fsi, reg, &data_be, sizeof(data_be)); +} + +static int fsi_i2c_dev_init(struct fsi_i2c_master *i2c) +{ + int rc; + u32 mode = I2C_MODE_ENHANCED, extended_status, watermark; + u32 interrupt = 0; + + /* since we use polling, disable interrupts */ + rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_INT_MASK, &interrupt); + if (rc) + return rc; + + mode |= FIELD_PREP(I2C_MODE_CLKDIV, I2C_DEFAULT_CLK_DIV); + rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_MODE, &mode); + if (rc) + return rc; + + rc = fsi_i2c_read_reg(i2c->fsi, I2C_FSI_ESTAT, &extended_status); + if (rc) + return rc; + + i2c->fifo_size = FIELD_GET(I2C_ESTAT_FIFO_SZ, extended_status); + watermark = FIELD_PREP(I2C_WATERMARK_HI, + i2c->fifo_size - I2C_FIFO_HI_LVL); + watermark |= FIELD_PREP(I2C_WATERMARK_LO, I2C_FIFO_LO_LVL); + + return fsi_i2c_write_reg(i2c->fsi, I2C_FSI_WATER_MARK, &watermark); +} + +static int fsi_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, + int num) +{ + return -EOPNOTSUPP; +} + +static u32 fsi_i2c_functionality(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | I2C_FUNC_PROTOCOL_MANGLING | + I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SMBUS_BLOCK_DATA; +} + +static const struct i2c_algorithm fsi_i2c_algorithm = { + .master_xfer = fsi_i2c_xfer, + .functionality = fsi_i2c_functionality, +}; + +static int fsi_i2c_probe(struct device *dev) +{ + struct fsi_i2c_master *i2c; + int rc; + + i2c = devm_kzalloc(dev, sizeof(*i2c), GFP_KERNEL); + if (!i2c) + return -ENOMEM; + + i2c->fsi = to_fsi_dev(dev); + + rc = fsi_i2c_dev_init(i2c); + if (rc) + return rc; + + dev_set_drvdata(dev, i2c); + + return 0; +} + +static const struct fsi_device_id fsi_i2c_ids[] = { + { FSI_ENGID_I2C, FSI_VERSION_ANY }, + { } +}; + +static struct fsi_driver fsi_i2c_driver = { + .id_table = fsi_i2c_ids, + .drv = { + .name = "i2c-fsi", + .bus = &fsi_bus_type, + .probe = fsi_i2c_probe, + }, +}; + +module_fsi_driver(fsi_i2c_driver); + +MODULE_AUTHOR("Eddie James <eajames@us.ibm.com>"); +MODULE_DESCRIPTION("FSI attached I2C master"); +MODULE_LICENSE("GPL"); |