[U-Boot] [PATCH 2/4] x86: tangier: pinmux: add API to configure protected pins
Bin Meng
bmeng.cn at gmail.com
Tue Sep 4 04:37:56 UTC 2018
Hi Georgii,
On Mon, Sep 3, 2018 at 11:07 PM Georgii Staroselskii
<georgii.staroselskii at emlid.com> wrote:
>
> 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 polute 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 at emlid.com>
> ---
> arch/x86/cpu/tangier/Makefile | 2 +-
> arch/x86/cpu/tangier/pinmux.c | 188 ++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 189 insertions(+), 1 deletion(-)
> create mode 100644 arch/x86/cpu/tangier/pinmux.c
>
Basically this looks good to me, except several styling issues below:
> 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..c59b63c
> --- /dev/null
> +++ b/arch/x86/cpu/tangier/pinmux.c
> @@ -0,0 +1,188 @@
> +// 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, \
> + }
> +
> +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)
CHECK: Alignment should match open parenthesis
> + return family;
> + }
> +
> + printf("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)
WARNING: line over 80 characters
> +{
> + for (int i = 0; i < nfam; i++) {
> + struct mrfld_family *family = &families[i];
> +
> + family->regs = base_addr + family->family_number * MRFLD_FAMILY_LEN;
WARNING: line over 80 characters
> + }
> +}
> +
> +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);
CHECK: Alignment should match open parenthesis
> +
> + 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);
WARNING: line over 80 characters
> +
> + return ret;
> +}
nits: needs a blank line here
> +static int mrfld_pinctrl_cfg_pin(int pin_node)
> +{
> + bool is_protected;
> + int pad_offset;
> + int mode;
> + int ret;
> +
> + 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;
> +
> + if (mode != 1)
> + return -ENOTSUPP;
> +
> + u32 mask = MRFLD_PINMODE_MASK;
> +
> + 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 != 0) {
> + pr_err("%s: invalid configuration for the pin %d\n",
> + __func__, pin_node);
CHECK: Alignment should match open parenthesis
> + }
> + }
> +
> + 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),
> +};
> --
Regards,
Bin
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