diff options
| author | Nikita Shubin <n.shubin@yadro.com> | 2021-11-10 12:42:27 +0300 |
|---|---|---|
| committer | Anup Patel <anup@brainfault.org> | 2021-11-12 10:17:50 +0530 |
| commit | 2c964a2e159880c921a33f51f493a3a257d4bfce (patch) | |
| tree | 4ac136ab46da0560e7049eb67950420184d985d7 | |
| parent | 1d462e039782e49d2a96a776e50b7478d87b228d (diff) | |
lib: utils/i2c: Add generic I2C configuration library
Helper library to keep track of registered I2C adapters,
identified by dts offset, basic send/read functions and
adapter configuration (enable, set dividers, etc...).
Tested-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Tested-by: Alexandre Ghiti <alexandre.ghiti@canonical.com>
Signed-off-by: Nikita Shubin <n.shubin@yadro.com>
| -rw-r--r-- | include/sbi_utils/i2c/i2c.h | 85 | ||||
| -rw-r--r-- | lib/utils/i2c/i2c.c | 75 | ||||
| -rw-r--r-- | lib/utils/i2c/objects.mk | 10 |
3 files changed, 170 insertions, 0 deletions
diff --git a/include/sbi_utils/i2c/i2c.h b/include/sbi_utils/i2c/i2c.h new file mode 100644 index 0000000..5a70364 --- /dev/null +++ b/include/sbi_utils/i2c/i2c.h @@ -0,0 +1,85 @@ +/* + * SPDX-License-Identifier: BSD-2-Clause + * + * Copyright (c) 2021 YADRO + * + * Authors: + * Nikita Shubin <n.shubin@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; + + /** Unique ID of the I2C adapter assigned by the driver */ + int id; + + /** + * 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); + +/** 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..6be4e24 --- /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 <n.shubin@yadro.com> + * + * derivate: lib/utils/gpio/gpio.c + * Authors: + * Anup Patel <anup.patel@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..894f618 --- /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 <n.shubin@yadro.com> +# + +libsbiutils-objs-y += i2c/i2c.o |