diff options
| -rw-r--r-- | lib/utils/i2c/Kconfig | 4 | ||||
| -rw-r--r-- | lib/utils/i2c/fdt_i2c_spacemit.c | 220 | ||||
| -rw-r--r-- | lib/utils/i2c/objects.mk | 3 | ||||
| -rw-r--r-- | platform/generic/configs/defconfig | 1 |
4 files changed, 228 insertions, 0 deletions
diff --git a/lib/utils/i2c/Kconfig b/lib/utils/i2c/Kconfig index 7fa32fcf..bdaaff62 100644 --- a/lib/utils/i2c/Kconfig +++ b/lib/utils/i2c/Kconfig @@ -14,6 +14,10 @@ config FDT_I2C_SIFIVE bool "SiFive I2C FDT driver" default n +config FDT_I2C_SPACEMIT + bool "SpacemiT I2C FDT driver" + default n + config FDT_I2C_DW bool "Synopsys Designware I2C FDT driver" select I2C_DW diff --git a/lib/utils/i2c/fdt_i2c_spacemit.c b/lib/utils/i2c/fdt_i2c_spacemit.c new file mode 100644 index 00000000..9009b6b6 --- /dev/null +++ b/lib/utils/i2c/fdt_i2c_spacemit.c @@ -0,0 +1,220 @@ +/* + * SPDX-License-Identifier: BSD-2-Clause + * + * Copyright (c) 2026 Aurelien Jarno + * + * Authors: + * Aurelien Jarno <[email protected]> + */ + +#include <sbi/riscv_io.h> +#include <sbi/sbi_error.h> +#include <sbi/sbi_heap.h> +#include <sbi/sbi_timer.h> +#include <sbi_utils/fdt/fdt_helper.h> +#include <sbi_utils/i2c/fdt_i2c.h> + +/* Controller registers */ +#define ICR_OFFSET 0x00 /* I2C control register */ +#define IDBR_OFFSET 0x0c /* I2C data buffer register */ + +/* Control register bits */ +#define ICR_START BIT(0) /* start */ +#define ICR_STOP BIT(1) /* stop */ +#define ICR_ACKNAK BIT(2) /* ACK(0) or NAK(1) */ +#define ICR_TB BIT(3) /* transfer byte */ +#define ICR_UR BIT(10) /* unit reset */ +#define ICR_SCLE BIT(13) /* SCL enable */ +#define ICR_IUE BIT(14) /* unit enable */ + +/* Timing */ +#define I2C_RESET_US 10 +#define I2C_TIMEOUT_US 1000 + +struct spacemit_i2c_adapter { + unsigned long base; + struct i2c_adapter adapter; +}; + +static inline void spacemit_i2c_set_reg(struct spacemit_i2c_adapter *adap, + uint8_t reg, uint32_t val) +{ + writel(val, (void *)adap->base + reg); +} + +static inline uint32_t spacemit_i2c_get_reg(struct spacemit_i2c_adapter *adap, + uint32_t reg) +{ + return readl((void *)adap->base + reg); +} + +static void spacemit_i2c_reset(struct spacemit_i2c_adapter *adap) +{ + /* disable unit */ + spacemit_i2c_set_reg(adap, ICR_OFFSET, 0); + sbi_timer_udelay(I2C_RESET_US); + + /* reset unit */ + spacemit_i2c_set_reg(adap, ICR_OFFSET, ICR_UR); + sbi_timer_udelay(I2C_RESET_US); + + /* clear reset and enable unit and SCL */ + spacemit_i2c_set_reg(adap, ICR_OFFSET, ICR_IUE | ICR_SCLE); +} + +static int spacemit_i2c_wait_xfer_done(struct spacemit_i2c_adapter *adap) +{ + for (int i = 0; i < I2C_TIMEOUT_US; i++) { + uint32_t val = spacemit_i2c_get_reg(adap, ICR_OFFSET); + + if (!(val & ICR_TB)) + return 0; + + sbi_timer_udelay(1); + }; + + return SBI_ETIMEDOUT; +} + +static void spacemit_i2c_start_xfer(struct spacemit_i2c_adapter *adap, + uint32_t ctrl) +{ + const uint32_t ctrl_mask = ICR_START | ICR_STOP | ICR_ACKNAK; + uint32_t val; + + val = spacemit_i2c_get_reg(adap, ICR_OFFSET); + val &= ~ctrl_mask; + val |= (ctrl & ctrl_mask); + val |= ICR_TB; + + spacemit_i2c_set_reg(adap, ICR_OFFSET, val); +} + +static int spacemit_i2c_xfer_write(struct spacemit_i2c_adapter *adap, + uint8_t byte, uint32_t ctrl) +{ + spacemit_i2c_set_reg(adap, IDBR_OFFSET, byte); + spacemit_i2c_start_xfer(adap, ctrl); + + return spacemit_i2c_wait_xfer_done(adap); +} + +static int spacemit_i2c_xfer_read(struct spacemit_i2c_adapter *adap, + uint8_t *byte, uint32_t ctrl) +{ + int rc; + + spacemit_i2c_start_xfer(adap, ctrl); + + rc = spacemit_i2c_wait_xfer_done(adap); + if (rc) + return rc; + + *byte = spacemit_i2c_get_reg(adap, IDBR_OFFSET); + return 0; +} + +static int spacemit_i2c_adapter_write(struct i2c_adapter *ia, uint8_t addr, + uint8_t reg, uint8_t *buffer, int len) +{ + struct spacemit_i2c_adapter *adap = + container_of(ia, struct spacemit_i2c_adapter, adapter); + int rc; + + /* reset controller to a known state */ + spacemit_i2c_reset(adap); + + /* send device address (in write mode) */ + rc = spacemit_i2c_xfer_write(adap, addr << 1, ICR_START); + if (rc) + return rc; + + /* send register + data bytes */ + for (int i = 0; i < len + 1; i++) { + uint32_t ctrl = (i == len) ? ICR_STOP : 0; + uint8_t byte = (i == 0) ? reg : buffer[i - 1]; + + rc = spacemit_i2c_xfer_write(adap, byte, ctrl); + if (rc) + return rc; + } + + return 0; +} + +static int spacemit_i2c_adapter_read(struct i2c_adapter *ia, uint8_t addr, + uint8_t reg, uint8_t *buffer, int len) +{ + struct spacemit_i2c_adapter *adap = + container_of(ia, struct spacemit_i2c_adapter, adapter); + int rc; + + /* reset controller to a known state */ + spacemit_i2c_reset(adap); + + /* send device address (in write mode) */ + rc = spacemit_i2c_xfer_write(adap, addr << 1, ICR_START); + if (rc) + return rc; + + /* send register */ + rc = spacemit_i2c_xfer_write(adap, reg, 0); + if (rc) + return rc; + + /* repeated start and send device address (in read mode) */ + rc = spacemit_i2c_xfer_write(adap, (addr << 1) | 1, ICR_START); + if (rc) + return rc; + + /* read data bytes */ + for (int i = 0; i < len; i++) { + uint32_t ctrl = (i == len - 1) ? (ICR_ACKNAK | ICR_STOP) : 0; + + rc = spacemit_i2c_xfer_read(adap, &buffer[i], ctrl); + if (rc) + return rc; + } + + return 0; +} + +static int spacemit_i2c_init(const void *fdt, int nodeoff, + const struct fdt_match *match) +{ + struct spacemit_i2c_adapter *adapter; + uint64_t base; + int rc; + + adapter = sbi_zalloc(sizeof(*adapter)); + if (!adapter) + return SBI_ENOMEM; + + rc = fdt_get_node_addr_size(fdt, nodeoff, 0, &base, NULL); + if (rc) { + sbi_free(adapter); + return rc; + } + + adapter->base = base; + adapter->adapter.id = nodeoff; + adapter->adapter.write = spacemit_i2c_adapter_write; + adapter->adapter.read = spacemit_i2c_adapter_read; + rc = i2c_adapter_add(&adapter->adapter); + if (rc) { + sbi_free(adapter); + return rc; + } + + return 0; +} + +static const struct fdt_match spacemit_i2c_match[] = { + { .compatible = "spacemit,k1-i2c" }, + { }, +}; + +const struct fdt_driver fdt_i2c_adapter_spacemit = { + .match_table = spacemit_i2c_match, + .init = spacemit_i2c_init, +}; diff --git a/lib/utils/i2c/objects.mk b/lib/utils/i2c/objects.mk index d34d6648..91ac17ec 100644 --- a/lib/utils/i2c/objects.mk +++ b/lib/utils/i2c/objects.mk @@ -15,6 +15,9 @@ libsbiutils-objs-$(CONFIG_FDT_I2C) += i2c/fdt_i2c_adapter_drivers.carray.o carray-fdt_i2c_adapter_drivers-$(CONFIG_FDT_I2C_SIFIVE) += fdt_i2c_adapter_sifive libsbiutils-objs-$(CONFIG_FDT_I2C_SIFIVE) += i2c/fdt_i2c_sifive.o +carray-fdt_i2c_adapter_drivers-$(CONFIG_FDT_I2C_SPACEMIT) += fdt_i2c_adapter_spacemit +libsbiutils-objs-$(CONFIG_FDT_I2C_SPACEMIT) += i2c/fdt_i2c_spacemit.o + carray-fdt_i2c_adapter_drivers-$(CONFIG_FDT_I2C_DW) += fdt_i2c_adapter_dw libsbiutils-objs-$(CONFIG_FDT_I2C_DW) += i2c/fdt_i2c_dw.o diff --git a/platform/generic/configs/defconfig b/platform/generic/configs/defconfig index 800f3f14..91f59a33 100644 --- a/platform/generic/configs/defconfig +++ b/platform/generic/configs/defconfig @@ -32,6 +32,7 @@ CONFIG_FDT_HSM_RPMI=y CONFIG_FDT_HSM_SIFIVE_TMC0=y CONFIG_FDT_I2C=y CONFIG_FDT_I2C_SIFIVE=y +CONFIG_FDT_I2C_SPACEMIT=y CONFIG_FDT_I2C_DW=y CONFIG_FDT_IPI=y CONFIG_FDT_IPI_MSWI=y |