Messages in this thread | | | Date | Tue, 9 Aug 2022 10:06:35 -0700 | Subject | Re: [PATCH v1] regmap: add generic indirect regmap support | From | Russ Weight <> |
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On 6/6/22 18:37, Tianfei Zhang wrote: > From: Matthew Gerlach <matthew.gerlach@linux.intel.com> > > This patch adds support for regmap APIs that are intended to be used by > the drivers of some devices which support generic indirect register access, > for example PMCI (Platform Management Control Interface) device, HSSI > (High Speed Serial Interface) device in FPGA. > > Signed-off-by: Matthew Gerlach <matthew.gerlach@linux.intel.com> > Signed-off-by: Tianfei Zhang <tianfei.zhang@intel.com> > --- > drivers/base/regmap/Kconfig | 3 + > drivers/base/regmap/Makefile | 1 + > .../base/regmap/regmap-indirect-register.c | 133 ++++++++++++++++++ > include/linux/regmap.h | 12 ++ > 4 files changed, 149 insertions(+) > create mode 100644 drivers/base/regmap/regmap-indirect-register.c > > diff --git a/drivers/base/regmap/Kconfig b/drivers/base/regmap/Kconfig > index 159bac6c5046..4ea590604f8d 100644 > --- a/drivers/base/regmap/Kconfig > +++ b/drivers/base/regmap/Kconfig > @@ -65,3 +65,6 @@ config REGMAP_I3C > config REGMAP_SPI_AVMM > tristate > depends on SPI > + > +config REGMAP_INDIRECT_REGISTER > + tristate > diff --git a/drivers/base/regmap/Makefile b/drivers/base/regmap/Makefile > index 11facb32a027..504a32b79d8c 100644 > --- a/drivers/base/regmap/Makefile > +++ b/drivers/base/regmap/Makefile > @@ -20,3 +20,4 @@ obj-$(CONFIG_REGMAP_SCCB) += regmap-sccb.o > obj-$(CONFIG_REGMAP_I3C) += regmap-i3c.o > obj-$(CONFIG_REGMAP_SPI_AVMM) += regmap-spi-avmm.o > obj-$(CONFIG_REGMAP_MDIO) += regmap-mdio.o > +obj-$(CONFIG_REGMAP_INDIRECT_REGISTER) += regmap-indirect-register.o > diff --git a/drivers/base/regmap/regmap-indirect-register.c b/drivers/base/regmap/regmap-indirect-register.c > new file mode 100644 > index 000000000000..0b748e48bd87 > --- /dev/null > +++ b/drivers/base/regmap/regmap-indirect-register.c > @@ -0,0 +1,133 @@ > +// SPDX-License-Identifier: GPL-2.0 > +// > +// Indirect Register Access. > +// > +// Copyright (C) 2022 Intel Corporation, Inc. > + > +#include <linux/device.h> > +#include <linux/module.h> > +#include <linux/regmap.h> > + > +#define INDIRECT_CMD_OFF 0x0 > +#define INDIRECT_CMD_RD BIT(0) > +#define INDIRECT_CMD_WR BIT(1) > +#define INDIRECT_CMD_ACK BIT(2) > + > +#define INDIRECT_ADDR_OFF 0x4 > +#define INDIRECT_RD_OFF 0x8 > +#define INDIRECT_WR_OFF 0xc > + > +#define INDIRECT_INT_US 1 > +#define INDIRECT_TIMEOUT_US 10000 > + > +struct indirect_ctx { > + void __iomem *base; > + struct device *dev; > +}; > + > +static int indirect_bus_clr_cmd(struct indirect_ctx *ctx) > +{ > + unsigned int cmd; > + int ret; > + > + writel(0, ctx->base + INDIRECT_CMD_OFF); > + ret = readl_poll_timeout((ctx->base + INDIRECT_CMD_OFF), cmd, > + (!cmd), INDIRECT_INT_US, INDIRECT_TIMEOUT_US); > + if (ret) > + dev_err(ctx->dev, "%s timed out on clearing cmd 0x%xn", __func__, cmd); The line-return in the above dev_err() is missing a forward slash: \n
- Russ > + > + return ret; > +} > + > +static int indirect_bus_reg_read(void *context, unsigned int reg, > + unsigned int *val) > +{ > + struct indirect_ctx *ctx = context; > + unsigned int cmd; > + int ret; > + > + cmd = readl(ctx->base + INDIRECT_CMD_OFF); > + if (cmd) > + dev_warn(ctx->dev, "%s non-zero cmd 0x%x\n", __func__, cmd); > + > + writel(reg, ctx->base + INDIRECT_ADDR_OFF); > + writel(INDIRECT_CMD_RD, ctx->base + INDIRECT_CMD_OFF); > + ret = readl_poll_timeout((ctx->base + INDIRECT_CMD_OFF), cmd, > + (cmd & INDIRECT_CMD_ACK), INDIRECT_INT_US, > + INDIRECT_TIMEOUT_US); > + if (ret) { > + dev_err(ctx->dev, "%s timed out on reg 0x%x cmd 0x%x\n", __func__, reg, cmd); > + goto out; > + } > + > + *val = readl(ctx->base + INDIRECT_RD_OFF); > + > + if (indirect_bus_clr_cmd(ctx)) > + ret = -ETIMEDOUT; > + > +out: > + return ret; > +} > + > +static int indirect_bus_reg_write(void *context, unsigned int reg, > + unsigned int val) > +{ > + struct indirect_ctx *ctx = context; > + unsigned int cmd; > + int ret; > + > + cmd = readl(ctx->base + INDIRECT_CMD_OFF); > + if (cmd) > + dev_warn(ctx->dev, "%s non-zero cmd 0x%x\n", __func__, cmd); > + > + writel(val, ctx->base + INDIRECT_WR_OFF); > + writel(reg, ctx->base + INDIRECT_ADDR_OFF); > + writel(INDIRECT_CMD_WR, ctx->base + INDIRECT_CMD_OFF); > + ret = readl_poll_timeout((ctx->base + INDIRECT_CMD_OFF), cmd, > + (cmd & INDIRECT_CMD_ACK), INDIRECT_INT_US, > + INDIRECT_TIMEOUT_US); > + if (ret) { > + dev_err(ctx->dev, "%s timed out on reg 0x%x cmd 0x%x\n", __func__, reg, cmd); > + goto out; > + } > + > + if (indirect_bus_clr_cmd(ctx)) > + ret = -ETIMEDOUT; > + > +out: > + return ret; > +} > + > +static const struct regmap_bus indirect_bus = { > + .reg_write = indirect_bus_reg_write, > + .reg_read = indirect_bus_reg_read, > +}; > + > +/** > + * devm_regmap_init_indirect_register - create a regmap for indirect register access > + * @dev: device creating the regmap > + * @base: __iomem point to base of memory with mailbox > + * @cfg: regmap_config describing interface > + * > + * Return: 0 on success, negative error code otherwise. > + */ > +struct regmap *devm_regmap_init_indirect_register(struct device *dev, > + void __iomem *base, > + struct regmap_config *cfg) > +{ > + struct indirect_ctx *ctx; > + > + ctx = devm_kzalloc(dev, sizeof(*ctx), GFP_KERNEL); > + if (!ctx) > + return NULL; > + > + ctx->base = base; > + ctx->dev = dev; > + > + return devm_regmap_init(dev, &indirect_bus, ctx, cfg); > +} > +EXPORT_SYMBOL_GPL(devm_regmap_init_indirect_register); > + > +MODULE_DESCRIPTION("Indirect Register Access"); > +MODULE_AUTHOR("Intel Corporation"); > +MODULE_LICENSE("GPL"); > diff --git a/include/linux/regmap.h b/include/linux/regmap.h > index de81a94d7b30..72eb38883e88 100644 > --- a/include/linux/regmap.h > +++ b/include/linux/regmap.h > @@ -670,6 +670,18 @@ struct regmap *__devm_regmap_init_spi_avmm(struct spi_device *spi, > const struct regmap_config *config, > struct lock_class_key *lock_key, > const char *lock_name); > +/** > + * devm_regmap_init_indirect_register - create a regmap for indirect register access > + * @dev: device creating the regmap > + * @base: __iomem point to base of memory with mailbox > + * @cfg: regmap_config describing interface > + * > + * Return: 0 on success, negative error code otherwise. > + */ > +struct regmap *devm_regmap_init_indirect_register(struct device *dev, > + void __iomem *base, > + struct regmap_config *cfg); > + > /* > * Wrapper for regmap_init macros to include a unique lockdep key and name > * for each call. No-op if CONFIG_LOCKDEP is not set.
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