On Sat, Jan 25, 2020 at 05:52:57PM +0530, Amit Singh Tomar wrote:
The simplest and most generic form of a reset controller just exposes multiple MMIO registers, where each bit toggles a separate reset line. Add a generic driver to describe this kind of reset controller.
This is used on the Action Semi S700, for instance, but also by other SoCs.
Why not name it as reset-simple as linux kernel?
Signed-off-by: Amit Singh Tomar amittomer25@gmail.com [Andre: make more generic, let it cover multiple registers, slight rework] Signed-off-by: Andre Przywara andre.przywara@arm.com
Changes since v2: * Newly added patch, not there in v2/v1.
drivers/reset/Kconfig | 6 +++ drivers/reset/Makefile | 1 + drivers/reset/reset-generic.c | 111 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 118 insertions(+) create mode 100644 drivers/reset/reset-generic.c
diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig index 75ccd65..1cdc159 100644 --- a/drivers/reset/Kconfig +++ b/drivers/reset/Kconfig @@ -12,6 +12,12 @@ config DM_RESET although driving such reset isgnals using GPIOs may be more appropriate in this case.
+config GENERIC_RESET
bool "Generic Reset controller driver"depends on DM_RESEThelpSupport Generic reset controller.config SANDBOX_RESET bool "Enable the sandbox reset test driver" depends on DM_MAILBOX && SANDBOX diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile index 0a044d5..5e027a1 100644 --- a/drivers/reset/Makefile +++ b/drivers/reset/Makefile @@ -4,6 +4,7 @@ #
obj-$(CONFIG_DM_RESET) += reset-uclass.o +obj-$(CONFIG_GENERIC_RESET) += reset-generic.o obj-$(CONFIG_SANDBOX_MBOX) += sandbox-reset.o obj-$(CONFIG_SANDBOX_MBOX) += sandbox-reset-test.o obj-$(CONFIG_STI_RESET) += sti-reset.o diff --git a/drivers/reset/reset-generic.c b/drivers/reset/reset-generic.c new file mode 100644 index 0000000..9c45087 --- /dev/null +++ b/drivers/reset/reset-generic.c @@ -0,0 +1,111 @@ +/*
- Copyright (C) 2017 Amit Singh Tomar amittomer25@gmail.com
- SPDX-License-Identifier: GPL-2.0+
- */
+#include <common.h> +#include <dm.h> +#include <errno.h> +#include <reset-uclass.h> +#include <linux/bitops.h> +#include <linux/io.h> +#include <linux/sizes.h>
+DECLARE_GLOBAL_DATA_PTR;
+struct generic_reset_priv {
- void __iomem *membase;
- int max_reset;
+};
+#define BITS_PER_BYTE 8 +static int generic_reset_toggle(struct reset_ctl *rst, bool assert) +{
- struct generic_reset_priv *priv = dev_get_priv(rst->dev);
- int reg_width = sizeof(u32);
- int bank, offset;
- u32 reg;
- if (rst->id >= priv->max_reset)
return -EINVAL;- bank = rst->id / (reg_width * BITS_PER_BYTE);
- offset = rst->id % (reg_width * BITS_PER_BYTE);
- reg = readl(priv->membase + (bank * reg_width));
- if (assert)
writel(reg & ~BIT(offset), priv->membase + (bank * reg_width));- else
writel(reg | BIT(offset), priv->membase + (bank * reg_width));- return 0;
+}
+static int generic_reset_assert(struct reset_ctl *rst) +{
- return generic_reset_toggle(rst, true);
+}
+static int generic_reset_deassert(struct reset_ctl *rst) +{
- return generic_reset_toggle(rst, false);
+}
+static int generic_reset_free(struct reset_ctl *rst) +{
- return 0;
+}
+static int generic_reset_request(struct reset_ctl *rst) +{
- struct generic_reset_priv *priv = dev_get_priv(rst->dev);
- if (rst->id >= priv->max_reset)
return -EINVAL;- return generic_reset_assert(rst);
+}
+struct reset_ops generic_reset_reset_ops = {
- .free = generic_reset_free,
- .request = generic_reset_request,
- .rst_assert = generic_reset_assert,
- .rst_deassert = generic_reset_deassert,
+};
+static const struct udevice_id generic_reset_ids[] = {
- { .compatible = "generic-reset" },
- { .compatible = "actions,s700-reset" },
No need of S700 specific compatible here. Linux kernel dts also doesn't require it.
Thanks, Mani
- { }
+};
+static int generic_reset_probe(struct udevice *dev) +{
- struct generic_reset_priv *priv = dev_get_priv(dev);
- fdt_addr_t addr;
- fdt_size_t size;
- addr = devfdt_get_addr_size_index(dev, 0, &size);
- if (addr == FDT_ADDR_T_NONE)
return -EINVAL;- priv->max_reset = dev_read_u32_default(dev, "num-resets", -1);
- if (priv->max_reset == -1)
priv->max_reset = size * BITS_PER_BYTE;- priv->membase = devm_ioremap(dev, addr, size);
- if (!priv->membase)
return -EFAULT;- return 0;
+}
+U_BOOT_DRIVER(generic_reset) = {
- .name = "generic_reset",
- .id = UCLASS_RESET,
- .of_match = generic_reset_ids,
- .ops = &generic_reset_reset_ops,
- .probe = generic_reset_probe,
- .priv_auto_alloc_size = sizeof(struct generic_reset_priv),
+};
2.7.4