[PATCH v3 3/6] lib: utils/i2c: Add generic I2C configuration library
Alexandre Ghiti
alexandre.ghiti at canonical.com
Tue Nov 9 23:34:11 PST 2021
On Tue, Nov 9, 2021 at 1:41 PM Nikita Shubin <nikita.shubin at maquefel.me> wrote:
>
> From: Nikita Shubin <n.shubin at yadro.com>
>
> Helper library to keep track of registered I2C adapters,
> identified by dts offset, basic send/read functions and
> adapter configuration (enable, set dividers, etc...).
>
> Signed-off-by: Nikita Shubin <n.shubin at yadro.com>
> ---
> v2->v3:
> - dropped configure
> ---
> include/sbi_utils/i2c/i2c.h | 97 +++++++++++++++++++++++++++++++++++++
> lib/utils/i2c/i2c.c | 75 ++++++++++++++++++++++++++++
> lib/utils/i2c/objects.mk | 10 ++++
> 3 files changed, 182 insertions(+)
> create mode 100644 include/sbi_utils/i2c/i2c.h
> create mode 100644 lib/utils/i2c/i2c.c
> create mode 100644 lib/utils/i2c/objects.mk
>
> diff --git a/include/sbi_utils/i2c/i2c.h b/include/sbi_utils/i2c/i2c.h
> new file mode 100644
> index 0000000..09e5f0e
> --- /dev/null
> +++ b/include/sbi_utils/i2c/i2c.h
> @@ -0,0 +1,97 @@
> +/*
> + * SPDX-License-Identifier: BSD-2-Clause
> + *
> + * Copyright (c) 2021 YADRO
> + *
> + * Authors:
> + * Nikita Shubin <nshubin at yadro.com>
> + */
> +
> +#ifndef __I2C_H__
> +#define __I2C_H__
> +
> +#include <sbi/sbi_types.h>
> +#include <sbi/sbi_list.h>
> +
> +/** Representation of a I2C adapter */
> +struct i2c_adapter {
> + /** Pointer to I2C driver owning this I2C adapter */
> + void *driver;
> +
> + /** Uniquie ID of the I2C adapter assigned by the driver */
Still this typo that comes from the GPIO file.
> + int id;
> +
> + /**
> + * Configure I2C adapter
> + *
> + * Enable, set dividers, etc...
> + *
> + * @return 0 on success and negative error code on failure
> + */
> + int (*configure)(struct i2c_adapter *ia);
You drop this in a later patch, maybe you should just not introduce it here.
> +
> + /**
> + * Send buffer to given address, register
> + *
> + * @return 0 on success and negative error code on failure
> + */
> + int (*write)(struct i2c_adapter *ia, uint8_t addr, uint8_t reg,
> + uint8_t *buffer, int len);
> +
> + /**
> + * Read buffer from given address, register
> + *
> + * @return 0 on success and negative error code on failure
> + */
> + int (*read)(struct i2c_adapter *ia, uint8_t addr, uint8_t reg,
> + uint8_t *buffer, int len);
> +
> + /** List */
> + struct sbi_dlist node;
> +};
> +
> +static inline struct i2c_adapter *to_i2c_adapter(struct sbi_dlist *node)
> +{
> + return container_of(node, struct i2c_adapter, node);
> +}
> +
> +/** Find a registered I2C adapter */
> +struct i2c_adapter *i2c_adapter_find(int id);
> +
> +/** Register I2C adapter */
> +int i2c_adapter_add(struct i2c_adapter *ia);
> +
> +/** Un-register I2C adapter */
> +void i2c_adapter_remove(struct i2c_adapter *ia);
> +
> +/** Configure I2C adapter prior to send/read */
> +int i2c_adapter_configure(struct i2c_adapter *ia);
> +
> +/** Send to device on I2C adapter bus */
> +int i2c_adapter_write(struct i2c_adapter *ia, uint8_t addr, uint8_t reg,
> + uint8_t *buffer, int len);
> +
> +/** Read from device on I2C adapter bus */
> +int i2c_adapter_read(struct i2c_adapter *ia, uint8_t addr, uint8_t reg,
> + uint8_t *buffer, int len);
> +
> +static inline int i2c_adapter_reg_write(struct i2c_adapter *ia, uint8_t addr,
> + uint8_t reg, uint8_t val)
> +{
> + return i2c_adapter_write(ia, addr, reg, &val, 1);
> +}
> +
> +static inline int i2c_adapter_reg_read(struct i2c_adapter *ia, uint8_t addr,
> + uint8_t reg, uint8_t *val)
> +{
> + uint8_t buf;
> + int ret = i2c_adapter_read(ia, addr, reg, &buf, 1);
> +
> + if (ret)
> + return ret;
> +
> + *val = buf;
> + return 0;
> +}
> +
> +#endif
> diff --git a/lib/utils/i2c/i2c.c b/lib/utils/i2c/i2c.c
> new file mode 100644
> index 0000000..1f5072c
> --- /dev/null
> +++ b/lib/utils/i2c/i2c.c
> @@ -0,0 +1,75 @@
> +/*
> + * SPDX-License-Identifier: BSD-2-Clause
> + *
> + * Copyright (c) 2021 YADRO
> + *
> + * Authors:
> + * Nikita Shubin <nshubin at yadro.com>
> + *
> + * derivate: lib/utils/gpio/gpio.c
> + * Authors:
> + * Anup Patel <anup.patel at wdc.com>
> + */
> +
> +#include <sbi/sbi_error.h>
> +#include <sbi_utils/i2c/i2c.h>
> +
> +static SBI_LIST_HEAD(i2c_adapters_list);
> +
> +struct i2c_adapter *i2c_adapter_find(int id)
> +{
> + struct sbi_dlist *pos;
> +
> + sbi_list_for_each(pos, &(i2c_adapters_list)) {
> + struct i2c_adapter *adap = to_i2c_adapter(pos);
> +
> + if (adap->id == id)
> + return adap;
> + }
> +
> + return NULL;
> +}
> +
> +int i2c_adapter_add(struct i2c_adapter *ia)
> +{
> + if (!ia)
> + return SBI_EINVAL;
> +
> + if (i2c_adapter_find(ia->id))
> + return SBI_EALREADY;
> +
> + sbi_list_add(&(ia->node), &(i2c_adapters_list));
> +
> + return 0;
> +}
> +
> +void i2c_adapter_remove(struct i2c_adapter *ia)
> +{
> + if (!ia)
> + return;
> +
> + sbi_list_del(&(ia->node));
> +}
> +
> +int i2c_adapter_write(struct i2c_adapter *ia, uint8_t addr, uint8_t reg,
> + uint8_t *buffer, int len)
> +{
> + if (!ia)
> + return SBI_EINVAL;
> + if (!ia->write)
> + return SBI_ENOSYS;
> +
> + return ia->write(ia, addr, reg, buffer, len);
> +}
> +
> +
> +int i2c_adapter_read(struct i2c_adapter *ia, uint8_t addr, uint8_t reg,
> + uint8_t *buffer, int len)
> +{
> + if (!ia)
> + return SBI_EINVAL;
> + if (!ia->read)
> + return SBI_ENOSYS;
> +
> + return ia->read(ia, addr, reg, buffer, len);
> +}
> diff --git a/lib/utils/i2c/objects.mk b/lib/utils/i2c/objects.mk
> new file mode 100644
> index 0000000..16a70da
> --- /dev/null
> +++ b/lib/utils/i2c/objects.mk
> @@ -0,0 +1,10 @@
> +#
> +# SPDX-License-Identifier: BSD-2-Clause
> +#
> +# Copyright (c) 2021 YADRO
> +#
> +# Authors:
> +# Nikita Shubin <nshubin at yadro.com>
> +#
> +
> +libsbiutils-objs-y += i2c/i2c.o
> --
> 2.31.1
>
Otherwise, this looks good to me:
Reviewed-by: Alexandre Ghiti <alexandre.ghiti at canonical.com>
Tested-by: Alexandre Ghiti <alexandre.ghiti at canonical.com>
Thanks!
Alex
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