diff options
| -rw-r--r-- | drivers/soc/Kconfig | 1 | ||||
| -rw-r--r-- | drivers/soc/Makefile | 1 | ||||
| -rw-r--r-- | drivers/soc/samsung/Kconfig | 23 | ||||
| -rw-r--r-- | drivers/soc/samsung/Makefile | 3 | ||||
| -rw-r--r-- | drivers/soc/samsung/exynos-usi.c | 208 |
5 files changed, 236 insertions, 0 deletions
diff --git a/drivers/soc/Kconfig b/drivers/soc/Kconfig index 85dac9de78a..03433bc0e6d 100644 --- a/drivers/soc/Kconfig +++ b/drivers/soc/Kconfig @@ -40,6 +40,7 @@ config SOC_XILINX_VERSAL_NET This allows other drivers to verify the SoC familiy & revision using matching SoC attributes. +source "drivers/soc/samsung/Kconfig" source "drivers/soc/ti/Kconfig" endmenu diff --git a/drivers/soc/Makefile b/drivers/soc/Makefile index 84385650d46..610bf816d40 100644 --- a/drivers/soc/Makefile +++ b/drivers/soc/Makefile @@ -2,6 +2,7 @@ # # Makefile for the U-Boot SOC specific device drivers. +obj-$(CONFIG_SOC_SAMSUNG) += samsung/ obj-$(CONFIG_SOC_TI) += ti/ obj-$(CONFIG_SOC_DEVICE) += soc-uclass.o obj-$(CONFIG_SOC_DEVICE_TI_K3) += soc_ti_k3.o diff --git a/drivers/soc/samsung/Kconfig b/drivers/soc/samsung/Kconfig new file mode 100644 index 00000000000..ffb87fe7931 --- /dev/null +++ b/drivers/soc/samsung/Kconfig @@ -0,0 +1,23 @@ +# SPDX-License-Identifier: GPL-2.0+ + +menuconfig SOC_SAMSUNG + bool "Samsung SoC drivers support" + +if SOC_SAMSUNG + +config EXYNOS_USI + bool "Exynos USI (Universal Serial Interface) driver" + depends on ARCH_EXYNOS + select MISC + select REGMAP + select SYSCON + help + Enable support for USI block. USI (Universal Serial Interface) is an + IP-core found in modern Samsung Exynos SoCs, like Exynos850 and + ExynosAutoV9. USI block can be configured to provide one of the + following serial protocols: UART, SPI or High Speed I2C. + + This driver allows one to configure USI for desired protocol, which + is usually done in USI node in Device Tree. + +endif diff --git a/drivers/soc/samsung/Makefile b/drivers/soc/samsung/Makefile new file mode 100644 index 00000000000..833ac073fbf --- /dev/null +++ b/drivers/soc/samsung/Makefile @@ -0,0 +1,3 @@ +# SPDX-License-Identifier: GPL-2.0+ + +obj-$(CONFIG_EXYNOS_USI) += exynos-usi.o diff --git a/drivers/soc/samsung/exynos-usi.c b/drivers/soc/samsung/exynos-usi.c new file mode 100644 index 00000000000..b746a7838e1 --- /dev/null +++ b/drivers/soc/samsung/exynos-usi.c @@ -0,0 +1,208 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2023 Linaro Ltd. + * Author: Sam Protsenko <semen.protsenko@linaro.org> + * + * Samsung Exynos USI driver (Universal Serial Interface). + */ + +#include <dm.h> +#include <dm/device_compat.h> +#include <errno.h> +#include <regmap.h> +#include <syscon.h> +#include <asm/io.h> +#include <linux/bitops.h> +#include <linux/delay.h> +#include <linux/err.h> + +#include <dt-bindings/soc/samsung,exynos-usi.h> + +/* USIv2: System Register: SW_CONF register bits */ +#define USI_V2_SW_CONF_NONE 0x0 +#define USI_V2_SW_CONF_UART BIT(0) +#define USI_V2_SW_CONF_SPI BIT(1) +#define USI_V2_SW_CONF_I2C BIT(2) +#define USI_V2_SW_CONF_MASK (USI_V2_SW_CONF_UART | USI_V2_SW_CONF_SPI | \ + USI_V2_SW_CONF_I2C) + +/* USIv2: USI register offsets */ +#define USI_CON 0x04 +#define USI_OPTION 0x08 + +/* USIv2: USI register bits */ +#define USI_CON_RESET BIT(0) +#define USI_OPTION_CLKREQ_ON BIT(1) +#define USI_OPTION_CLKSTOP_ON BIT(2) + +enum exynos_usi_ver { + USI_VER2 = 2, +}; + +struct exynos_usi_variant { + enum exynos_usi_ver ver; /* USI IP-core version */ + unsigned int sw_conf_mask; /* SW_CONF mask for all protocols */ + size_t min_mode; /* first index in exynos_usi_modes[] */ + size_t max_mode; /* last index in exynos_usi_modes[] */ +}; + +struct exynos_usi { + void __iomem *regs; /* USI register map */ + + size_t mode; /* current USI SW_CONF mode index */ + bool clkreq_on; /* always provide clock to IP */ + + /* System Register */ + struct regmap *sysreg; /* System Register map */ + unsigned int sw_conf; /* SW_CONF register offset in sysreg */ + + const struct exynos_usi_variant *data; +}; + +struct exynos_usi_mode { + const char *name; /* mode name */ + unsigned int val; /* mode register value */ +}; + +static const struct exynos_usi_mode exynos_usi_modes[] = { + [USI_V2_NONE] = { .name = "none", .val = USI_V2_SW_CONF_NONE }, + [USI_V2_UART] = { .name = "uart", .val = USI_V2_SW_CONF_UART }, + [USI_V2_SPI] = { .name = "spi", .val = USI_V2_SW_CONF_SPI }, + [USI_V2_I2C] = { .name = "i2c", .val = USI_V2_SW_CONF_I2C }, +}; + +static const struct exynos_usi_variant exynos850_usi_data = { + .ver = USI_VER2, + .sw_conf_mask = USI_V2_SW_CONF_MASK, + .min_mode = USI_V2_NONE, + .max_mode = USI_V2_I2C, +}; + +static const struct udevice_id exynos_usi_ids[] = { + { + .compatible = "samsung,exynos850-usi", + .data = (ulong)&exynos850_usi_data, + }, + { } /* sentinel */ +}; + +/** + * exynos_usi_set_sw_conf - Set USI block configuration mode + * @dev: Driver object + * + * Select underlying serial protocol (UART/SPI/I2C) in USI IP-core as specified + * in @usi.mode. + * + * Return: 0 on success, or negative error code on failure. + */ +static int exynos_usi_set_sw_conf(struct udevice *dev) +{ + struct exynos_usi *usi = dev_get_priv(dev); + size_t mode = usi->mode; + unsigned int val; + int ret; + + if (mode < usi->data->min_mode || mode > usi->data->max_mode) + return -EINVAL; + + val = exynos_usi_modes[mode].val; + ret = regmap_update_bits(usi->sysreg, usi->sw_conf, + usi->data->sw_conf_mask, val); + if (ret) + return ret; + + dev_dbg(dev, "protocol: %s\n", exynos_usi_modes[mode].name); + + return 0; +} + +/** + * exynos_usi_enable - Initialize USI block + * @usi: USI driver object + * + * USI IP-core start state is "reset" (on startup and after CPU resume). This + * routine enables the USI block by clearing the reset flag. It also configures + * HWACG behavior (needed e.g. for UART Rx). It should be performed before + * underlying protocol becomes functional. + */ +static void exynos_usi_enable(const struct exynos_usi *usi) +{ + u32 val; + + /* Enable USI block */ + val = readl(usi->regs + USI_CON); + val &= ~USI_CON_RESET; + writel(val, usi->regs + USI_CON); + udelay(1); + + /* Continuously provide the clock to USI IP w/o gating */ + if (usi->clkreq_on) { + val = readl(usi->regs + USI_OPTION); + val &= ~USI_OPTION_CLKSTOP_ON; + val |= USI_OPTION_CLKREQ_ON; + writel(val, usi->regs + USI_OPTION); + } +} + +static int exynos_usi_configure(struct udevice *dev) +{ + struct exynos_usi *usi = dev_get_priv(dev); + int ret; + + ret = exynos_usi_set_sw_conf(dev); + if (ret) + return ret; + + if (usi->data->ver == USI_VER2) + exynos_usi_enable(usi); + + return 0; +} + +static int exynos_usi_of_to_plat(struct udevice *dev) +{ + struct exynos_usi *usi = dev_get_priv(dev); + ofnode node = dev_ofnode(dev); + int ret; + u32 mode; + + usi->data = (struct exynos_usi_variant *)dev_get_driver_data(dev); + if (usi->data->ver == USI_VER2) { + usi->regs = dev_read_addr_ptr(dev); + if (!usi->regs) + return -ENODEV; + } + + ret = ofnode_read_u32(node, "samsung,mode", &mode); + if (ret) + return ret; + if (mode < usi->data->min_mode || mode > usi->data->max_mode) + return -EINVAL; + usi->mode = mode; + + usi->sysreg = syscon_regmap_lookup_by_phandle(dev, "samsung,sysreg"); + if (IS_ERR(usi->sysreg)) + return PTR_ERR(usi->sysreg); + + ret = ofnode_read_u32_index(node, "samsung,sysreg", 1, &usi->sw_conf); + if (ret) + return ret; + + usi->clkreq_on = ofnode_read_bool(node, "samsung,clkreq-on"); + + return 0; +} + +static int exynos_usi_probe(struct udevice *dev) +{ + return exynos_usi_configure(dev); +} + +U_BOOT_DRIVER(exynos_usi) = { + .name = "exynos-usi", + .id = UCLASS_MISC, + .of_match = exynos_usi_ids, + .of_to_plat = exynos_usi_of_to_plat, + .probe = exynos_usi_probe, + .priv_auto = sizeof(struct exynos_usi), +}; |