This API is going to be used to configure some pins that are protected for simple modification.
It's not a comprehensive pinctrl driver but can be turned into one when we need this in the future. Now it is planned to be used only in one place. So that's why I decided not to pollute the codebase with a full-blown pinctrl-merrifield nobody will use.
This driver reads corresponding fields in DT and configures pins accordingly.
The "protected" flag is used to distinguish configuration of SCU-owned pins from the ordinary ones.
The code has been adapted from Linux work done by Andy Shevchenko in pinctrl-merrfifield.c
Signed-off-by: Georgii Staroselskii georgii.staroselskii@emlid.com --- arch/x86/cpu/tangier/Makefile | 2 +- arch/x86/cpu/tangier/pinmux.c | 196 ++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 197 insertions(+), 1 deletion(-) create mode 100644 arch/x86/cpu/tangier/pinmux.c
diff --git a/arch/x86/cpu/tangier/Makefile b/arch/x86/cpu/tangier/Makefile index 8274482..68f4a32 100644 --- a/arch/x86/cpu/tangier/Makefile +++ b/arch/x86/cpu/tangier/Makefile @@ -2,5 +2,5 @@ # # Copyright (c) 2017 Intel Corporation
-obj-y += car.o tangier.o sdram.o sysreset.o +obj-y += car.o tangier.o sdram.o sysreset.o pinmux.o obj-$(CONFIG_GENERATE_ACPI_TABLE) += acpi.o diff --git a/arch/x86/cpu/tangier/pinmux.c b/arch/x86/cpu/tangier/pinmux.c new file mode 100644 index 0000000..4a9fc89 --- /dev/null +++ b/arch/x86/cpu/tangier/pinmux.c @@ -0,0 +1,196 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (c) 2018 Emlid Limited + */ + +#include <common.h> +#include <dm.h> +#include <dm/pinctrl.h> +#include <fdtdec.h> +#include <regmap.h> +#include <syscon.h> +#include <asm/cpu.h> +#include <asm/scu.h> +#include <linux/io.h> + +#define BUFCFG_OFFSET 0x100 + +#define MRFLD_FAMILY_LEN 0x400 + +/* These are taken from Linux kernel */ +#define MRFLD_PINMODE_MASK 0x07 + +#define pin_to_bufno(f, p) ((p) - (f)->pin_base) + +struct mrfld_family { + unsigned int family_number; + unsigned int pin_base; + size_t npins; + void __iomem *regs; +}; + +#define MRFLD_FAMILY(b, s, e) \ + { \ + .family_number = (b), \ + .pin_base = (s), \ + .npins = (e) - (s) + 1, \ + } + +/* Now we only support I2C family of pins */ +static struct mrfld_family mrfld_families[] = { + MRFLD_FAMILY(7, 101, 114), +}; + +struct mrfld_pinctrl { + const struct mrfld_family *families; + size_t nfamilies; +}; + +static const struct mrfld_family * +mrfld_get_family(struct mrfld_pinctrl *mp, unsigned int pin) +{ + const struct mrfld_family *family; + unsigned int i; + + for (i = 0; i < mp->nfamilies; i++) { + family = &mp->families[i]; + if (pin >= family->pin_base && + pin < family->pin_base + family->npins) + return family; + } + + pr_err("failed to find family for pin %u\n", pin); + return NULL; +} + +static void __iomem * +mrfld_get_bufcfg(struct mrfld_pinctrl *pinctrl, unsigned int pin) +{ + const struct mrfld_family *family; + unsigned int bufno; + + family = mrfld_get_family(pinctrl, pin); + if (!family) + return NULL; + + bufno = pin_to_bufno(family, pin); + + return family->regs + BUFCFG_OFFSET + bufno * 4; +} + +static void +mrfld_setup_families(void *base_addr, + struct mrfld_family *families, unsigned int nfam) +{ + for (int i = 0; i < nfam; i++) { + struct mrfld_family *family = &families[i]; + + family->regs = base_addr + + family->family_number * MRFLD_FAMILY_LEN; + } +} + +static int mrfld_pinconfig_protected(unsigned int pin, u32 mask, u32 bits) +{ + struct mrfld_pinctrl *pinctrl; + struct udevice *dev; + void __iomem *bufcfg; + u32 v, value; + int ret; + + ret = syscon_get_by_driver_data(X86_SYSCON_PINCONF, &dev); + if (ret) + return ret; + + pinctrl = dev_get_priv(dev); + + bufcfg = mrfld_get_bufcfg(pinctrl, pin); + if (!bufcfg) + return -EINVAL; + + value = readl(bufcfg); + + v = (value & ~mask) | (bits & mask); + + debug("scu: v: 0x%x p: 0x%x bits: %d, mask: %d bufcfg: 0x%p\n", + v, (u32)bufcfg, bits, mask, bufcfg); + + ret = scu_ipc_raw_command(IPCMSG_INDIRECT_WRITE, 0, &v, 4, + NULL, 0, (u32)bufcfg, 0); + if (ret) + pr_err("Failed to set mode via SCU for pin %u (%d)\n", + pin, ret); + + return ret; +} + +static int mrfld_pinctrl_cfg_pin(int pin_node) +{ + bool is_protected; + int pad_offset; + int mode; + u32 mask; + int ret; + + /* For now we only support just protected Family of pins */ + is_protected = fdtdec_get_bool(gd->fdt_blob, pin_node, "protected"); + if (!is_protected) + return -ENOTSUPP; + + pad_offset = fdtdec_get_int(gd->fdt_blob, pin_node, "pad-offset", -1); + if (pad_offset == -1) + return -EINVAL; + + mode = fdtdec_get_int(gd->fdt_blob, pin_node, "mode-func", -1); + if (mode == -1) + return -EINVAL; + + mask = MRFLD_PINMODE_MASK; + + /* We don't support modes not in range 0..7 */ + if (mode & ~mask) + return -ENOTSUPP; + + ret = mrfld_pinconfig_protected(pad_offset, mask, mode); + + return ret; +} + +static int tangier_pinctrl_probe(struct udevice *dev) +{ + void *base_addr = syscon_get_first_range(X86_SYSCON_PINCONF); + struct mrfld_pinctrl *pinctrl = dev_get_priv(dev); + int pin_node; + int ret; + + mrfld_setup_families(base_addr, mrfld_families, + ARRAY_SIZE(mrfld_families)); + + pinctrl->families = mrfld_families; + pinctrl->nfamilies = ARRAY_SIZE(mrfld_families); + + for (pin_node = fdt_first_subnode(gd->fdt_blob, dev_of_offset(dev)); + pin_node > 0; + pin_node = fdt_next_subnode(gd->fdt_blob, pin_node)) { + ret = mrfld_pinctrl_cfg_pin(pin_node); + if (ret) { + pr_err("%s: invalid configuration for the pin %d\n", + __func__, pin_node); + } + } + + return 0; +} + +static const struct udevice_id tangier_pinctrl_match[] = { + { .compatible = "intel,pinctrl-tangier", .data = X86_SYSCON_PINCONF }, + { /* sentinel */ } +}; + +U_BOOT_DRIVER(tangier_pinctrl) = { + .name = "tangier_pinctrl", + .id = UCLASS_SYSCON, + .of_match = tangier_pinctrl_match, + .probe = tangier_pinctrl_probe, + .priv_auto_alloc_size = sizeof(struct mrfld_pinctrl), +};