[PATCH linux dev-4.10 1/6] drivers: i2c: Add FSI-attached I2C master algorithm
Joel Stanley
joel at jms.id.au
Wed May 10 18:11:59 AEST 2017
On Fri, May 5, 2017 at 5:38 AM, Eddie James <eajames at linux.vnet.ibm.com> wrote:
> From: "Edward A. James" <eajames at us.ibm.com>
>
> Initial startup code for the I2C algorithm to drive the I2C master
> located on POWER CPUs over FSI bus.
>
> Signed-off-by: Edward A. James <eajames at us.ibm.com>
> ---
> drivers/Makefile | 2 +-
> drivers/i2c/busses/Kconfig | 11 ++
> drivers/i2c/busses/Makefile | 1 +
> drivers/i2c/busses/i2c-fsi.c | 275 +++++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 288 insertions(+), 1 deletion(-)
> create mode 100644 drivers/i2c/busses/i2c-fsi.c
>
> diff --git a/drivers/Makefile b/drivers/Makefile
> index 67ce51d..278f109 100644
> --- a/drivers/Makefile
> +++ b/drivers/Makefile
> @@ -105,6 +105,7 @@ obj-$(CONFIG_SERIO) += input/serio/
> obj-$(CONFIG_GAMEPORT) += input/gameport/
> obj-$(CONFIG_INPUT) += input/
> obj-$(CONFIG_RTC_LIB) += rtc/
> +obj-$(CONFIG_FSI) += fsi/
> obj-y += i2c/ media/
> obj-$(CONFIG_PPS) += pps/
> obj-y += ptp/
> @@ -173,4 +174,3 @@ obj-$(CONFIG_STM) += hwtracing/stm/
> obj-$(CONFIG_ANDROID) += android/
> obj-$(CONFIG_NVMEM) += nvmem/
> obj-$(CONFIG_FPGA) += fpga/
> -obj-$(CONFIG_FSI) += fsi/
> diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
> index 7e34901d..0c714e0 100644
> --- a/drivers/i2c/busses/Kconfig
> +++ b/drivers/i2c/busses/Kconfig
> @@ -1245,4 +1245,15 @@ config I2C_OPAL
> This driver can also be built as a module. If so, the module will be
> called as i2c-opal.
>
> +config I2C_FSI
> + tristate "FSI I2C driver"
> + depends on FSI
> + help
> + Driver for FSI bus attached I2C masters. These are I2C masters that
> + are connected to the system over a FSI bus, instead of the more
> + common PCI or MMIO interface.
> +
> + This driver can also be built as a module. If so, the module will be
> + called as i2c-fsi.
> +
> endmenu
> diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
> index 5798b4e..547773b 100644
> --- a/drivers/i2c/busses/Makefile
> +++ b/drivers/i2c/busses/Makefile
> @@ -124,5 +124,6 @@ obj-$(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 0000000..bb12fa9
> --- /dev/null
> +++ b/drivers/i2c/busses/i2c-fsi.c
> @@ -0,0 +1,275 @@
> +/*
> + * Copyright 2017 IBM Corporation
> + *
> + * Eddie James <eajames at us.ibm.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.
> + */
> +
> +#include <linux/fsi.h>
> +#include <linux/i2c.h>
> +#include <linux/jiffies.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/sched.h>
> +#include <linux/semaphore.h>
> +#include <linux/wait.h>
> +
> +#define FSI_ENGID_I2C_FSI 0x7
Is the engine ID something that is part of the FSI spec? If so, we
should put the IDs in the FSI headers.
> +
> +/* Find left shift from first set bit in m */
> +#define MASK_TO_LSH(m) (__builtin_ffsll(m) - 1ULL)
> +
> +/* Extract field m from v */
> +#define GETFIELD(m, v) (((v) & (m)) >> MASK_TO_LSH(m))
> +
> +/* Set field m of v to val */
> +#define SETFIELD(m, v, val) \
> + (((v) & ~(m)) | ((((typeof(v))(val)) << MASK_TO_LSH(m)) & (m)))
My eyes :)
Are these going to be used by all of our FSI drivers? Perhaps we could
get Chris to put them in the common FSI header.
> +
> +#define I2C_DEFAULT_CLK_DIV 6
> +#define I2C_DEFAULT_CLK 333333
> +
> +/* 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 0x80000000
> +#define I2C_CMD_WITH_ADDR 0x40000000
> +#define I2C_CMD_RD_CONT 0x20000000
> +#define I2C_CMD_WITH_STOP 0x10000000
> +#define I2C_CMD_FORCELAUNCH 0x08000000
> +#define I2C_CMD_ADDR 0x00fe0000
> +#define I2C_CMD_READ 0x00010000
> +#define I2C_CMD_LEN 0x0000ffff
> +
> +/* mode register */
> +#define I2C_MODE_CLKDIV 0xffff0000
> +#define I2C_MODE_PORT 0x0000fc00
> +#define I2C_MODE_ENHANCED 0x00000008
> +#define I2C_MODE_DIAG 0x00000004
> +#define I2C_MODE_PACE_ALLOW 0x00000002
> +#define I2C_MODE_WRAP 0x00000001
> +
> +/* watermark register */
> +#define I2C_WATERMARK_HI 0x0000f000
> +#define I2C_WATERMARK_LO 0x000000f0
> +
> +#define I2C_FIFO_HI_LVL 4
> +#define I2C_FIFO_LO_LVL 4
> +
> +/* interrupt register */
> +#define I2C_INT_INV_CMD 0x00008000
> +#define I2C_INT_PARITY 0x00004000
> +#define I2C_INT_BE_OVERRUN 0x00002000
> +#define I2C_INT_BE_ACCESS 0x00001000
> +#define I2C_INT_LOST_ARB 0x00000800
> +#define I2C_INT_NACK 0x00000400
> +#define I2C_INT_DAT_REQ 0x00000200
> +#define I2C_INT_CMD_COMP 0x00000100
> +#define I2C_INT_STOP_ERR 0x00000080
> +#define I2C_INT_BUSY 0x00000040
> +#define I2C_INT_IDLE 0x00000020
> +
> +#define I2C_INT_ENABLE 0x0000ff80
> +#define I2C_INT_ERR 0x0000fcc0
> +
> +/* status register */
> +#define I2C_STAT_INV_CMD 0x80000000
> +#define I2C_STAT_PARITY 0x40000000
> +#define I2C_STAT_BE_OVERRUN 0x20000000
> +#define I2C_STAT_BE_ACCESS 0x10000000
> +#define I2C_STAT_LOST_ARB 0x08000000
> +#define I2C_STAT_NACK 0x04000000
> +#define I2C_STAT_DAT_REQ 0x02000000
> +#define I2C_STAT_CMD_COMP 0x01000000
> +#define I2C_STAT_STOP_ERR 0x00800000
> +#define I2C_STAT_MAX_PORT 0x000f0000
> +#define I2C_STAT_ANY_INT 0x00008000
> +#define I2C_STAT_SCL_IN 0x00000800
> +#define I2C_STAT_SDA_IN 0x00000400
> +#define I2C_STAT_PORT_BUSY 0x00000200
> +#define I2C_STAT_SELF_BUSY 0x00000100
> +#define I2C_STAT_FIFO_COUNT 0x000000ff
> +
> +#define I2C_STAT_ERR 0xfc800000
> +#define I2C_STAT_ANY_RESP 0xff800000
> +
> +/* extended status register */
> +#define I2C_ESTAT_FIFO_SZ 0xff000000
> +#define I2C_ESTAT_SCL_IN_SY 0x00008000
> +#define I2C_ESTAT_SDA_IN_SY 0x00004000
> +#define I2C_ESTAT_S_SCL 0x00002000
> +#define I2C_ESTAT_S_SDA 0x00001000
> +#define I2C_ESTAT_M_SCL 0x00000800
> +#define I2C_ESTAT_M_SDA 0x00000400
> +#define I2C_ESTAT_HI_WATER 0x00000200
> +#define I2C_ESTAT_LO_WATER 0x00000100
> +#define I2C_ESTAT_PORT_BUSY 0x00000080
> +#define I2C_ESTAT_SELF_BUSY 0x00000040
> +#define I2C_ESTAT_VERSION 0x0000001f
> +
> +struct fsi_i2c_master {
> + struct fsi_device *fsi;
> + u8 fifo_size;
> + unsigned long clk;
> +};
> +
> +static int fsi_i2c_read_reg(struct fsi_device *fsi, unsigned int reg,
> + u32 *data)
> +{
> + int rc;
> + u32 _data;
Not a fan of the underscores. Perhaps raw_data?
> +
> + rc = fsi_device_read(fsi, reg, &_data, sizeof(_data));
> + if (rc)
> + return rc;
> +
> + *data = be32_to_cpu(_data);
> +
> + return 0;
> +}
> +
> +static int fsi_i2c_write_reg(struct fsi_device *fsi, unsigned int reg,
> + u32 *data)
> +{
> + u32 _data = cpu_to_be32(*data);
> +
> + return fsi_device_write(fsi, reg, &_data, sizeof(_data));
It would be nice if the FSI api checked that you were passing it data
in the correct endiannes.
> +}
> +
> +static unsigned long fsi_i2c_get_clk_div(struct fsi_i2c_master *i2c)
> +{
> + unsigned long clk_div = I2C_DEFAULT_CLK_DIV;
> +
> + return clk_div;
> +}
A bit of overkill. You could just use the #define where you need it.
> +
> +static int fsi_i2c_dev_init(struct fsi_i2c_master *i2c)
> +{
> + int rc;
> + unsigned long clk_div;
> + u32 mode = I2C_MODE_ENHANCED, extended_status, watermark = 0;
> + 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;
> +
> + clk_div = fsi_i2c_get_clk_div(i2c);
> + mode = SETFIELD(I2C_MODE_CLKDIV, mode, 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 = GETFIELD(I2C_ESTAT_FIFO_SZ, extended_status);
> + watermark = SETFIELD(I2C_WATERMARK_HI, watermark,
> + i2c->fifo_size - I2C_FIFO_HI_LVL);
> + watermark = SETFIELD(I2C_WATERMARK_LO, watermark,
> + I2C_FIFO_LO_LVL);
> +
> + rc = fsi_i2c_write_reg(i2c->fsi, I2C_FSI_WATER_MARK, &watermark);
> +
> + return rc;
> +}
> +
> +static int fsi_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
> + int num)
> +{
> + return -ENOSYS;
> +}
> +
> +static u32 fsi_i2c_functionality(struct i2c_adapter *adap)
> +{
> + return I2C_FUNC_I2C | I2C_FUNC_PROTOCOL_MANGLING | I2C_FUNC_10BIT_ADDR;
> +}
> +
> +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;
> + u32 clk;
> +
> + i2c = devm_kzalloc(dev, sizeof(*i2c), GFP_KERNEL);
> + if (!i2c)
> + return -ENOMEM;
> +
> + i2c->fsi = to_fsi_dev(dev);
> + i2c->clk = I2C_DEFAULT_CLK;
> +
> + if (dev->of_node) {
> + if (!of_property_read_u32(dev->of_node, "clock-frequency",
> + &clk))
> + i2c->clk = clk;
> + }
> +
> + 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, FSI_VERSION_ANY },
> + { 0 }
> +};
> +
> +static struct fsi_driver fsi_i2c_driver = {
> + .id_table = fsi_i2c_ids,
> + .drv = {
> + .name = "i2c_master_fsi",
> + .bus = &fsi_bus_type,
> + .probe = fsi_i2c_probe,
> + },
> +};
> +
> +static int fsi_i2c_init(void)
> +{
> + return fsi_driver_register(&fsi_i2c_driver);
> +}
> +
> +static void fsi_i2c_exit(void)
> +{
> + fsi_driver_unregister(&fsi_i2c_driver);
> +}
> +
> +module_init(fsi_i2c_init);
> +module_exit(fsi_i2c_exit);
Please use module_fsi_driver() instead.
> +
> +MODULE_AUTHOR("Eddie James <eajames at us.ibm.com>");
> +MODULE_DESCRIPTION("FSI attached I2C master");
> +MODULE_LICENSE("GPL");
> --
> 1.8.3.1
>
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