This adds a driver for mmio-based syscon multiplexers controlled by bitfields in a syscon register range. This is heavily based on the linux mmio-mux driver.
Signed-off-by: Jean-Jacques Hiblot jjhiblot@ti.com ---
Changes in v2: None
drivers/mux/Kconfig | 15 +++++ drivers/mux/Makefile | 1 + drivers/mux/mmio.c | 155 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 171 insertions(+) create mode 100644 drivers/mux/mmio.c
diff --git a/drivers/mux/Kconfig b/drivers/mux/Kconfig index ad0199c058..bda6a2d9f5 100644 --- a/drivers/mux/Kconfig +++ b/drivers/mux/Kconfig @@ -4,4 +4,19 @@ config MULTIPLEXER bool "Multiplexer Support" depends on DM
+ +if MULTIPLEXER + +config MUX_MMIO + bool "MMIO register bitfield-controlled Multiplexer" + depends on MULTIPLEXER && SYSCON + help + MMIO register bitfield-controlled Multiplexer controller. + + The driver builds multiplexer controllers for bitfields in a syscon + register. For N bit wide bitfields, there will be 2^N possible + multiplexer states. + +endif + endmenu diff --git a/drivers/mux/Makefile b/drivers/mux/Makefile index 351e4363d3..78ebf04c7a 100644 --- a/drivers/mux/Makefile +++ b/drivers/mux/Makefile @@ -4,3 +4,4 @@ # Jean-Jacques Hiblot jjhiblot@ti.com
obj-$(CONFIG_$(SPL_)MULTIPLEXER) += mux-uclass.o +obj-$(CONFIG_$(SPL_)MUX_MMIO) += mmio.o diff --git a/drivers/mux/mmio.c b/drivers/mux/mmio.c new file mode 100644 index 0000000000..a9faaeb9fd --- /dev/null +++ b/drivers/mux/mmio.c @@ -0,0 +1,155 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * MMIO register bitfield-controlled multiplexer driver + * Based on the linux mmio multiplexer driver + * + * Copyright (C) 2017 Pengutronix, Philipp Zabel kernel@pengutronix.de + * Copyright (C) 2019 Texas Instrument, Jean-jacques Hiblot jjhiblot@ti.com + */ +#include <common.h> +#include <dm.h> +#include <mux-internal.h> +#include <regmap.h> +#include <syscon.h> +#include <dm/device.h> +#include <dm/read.h> +#include <dt-bindings/mux/mux.h> + +static int mux_mmio_set(struct mux_control *mux, int state) +{ + struct regmap_field **fields = dev_get_priv(mux->dev); + + return regmap_field_write(fields[mux_control_get_index(mux)], state); +} + +static const struct mux_control_ops mux_mmio_ops = { + .set = mux_mmio_set, +}; + +static const struct udevice_id mmio_mux_of_match[] = { + { .compatible = "mmio-mux" }, + { /* sentinel */ }, +}; + +static int mmio_mux_probe(struct udevice *dev) +{ + struct regmap_field **fields; + struct mux_chip *mux_chip = dev_get_uclass_priv(dev); + struct regmap *regmap; + u32 *mux_reg_masks; + u32 *idle_states; + int num_fields; + int ret; + int i; + + regmap = syscon_node_to_regmap(dev_ofnode(dev->parent)); + if (IS_ERR(regmap)) { + ret = PTR_ERR(regmap); + dev_err(dev, "failed to get regmap: %d\n", ret); + return ret; + } + + num_fields = dev_read_size(dev, "mux-reg-masks"); + if (num_fields < 0) { + dev_err(dev, "mux-reg-masks property missing or invalid: %d\n", + num_fields); + return num_fields; + } + num_fields /= sizeof(u32); + if (num_fields == 0 || num_fields % 2) + ret = -EINVAL; + num_fields = num_fields / 2; + + ret = mux_alloc_controllers(dev, num_fields); + if (ret < 0) { + dev_err(dev, "failed to allocate mux controllers: %d\n", + ret); + return ret; + } + + fields = devm_kmalloc(dev, num_fields * sizeof(*fields), __GFP_ZERO); + if (!fields) + return -ENOMEM; + dev->priv = fields; + + mux_reg_masks = devm_kmalloc(dev, num_fields * 2 * sizeof(u32), + __GFP_ZERO); + if (!mux_reg_masks) + return -ENOMEM; + + ret = dev_read_u32_array(dev, "mux-reg-masks", mux_reg_masks, + num_fields * 2); + if (ret < 0) { + dev_err(dev, "failed to read mux-reg-masks property: %d\n", + ret); + return ret; + } + + idle_states = devm_kmalloc(dev, num_fields * sizeof(u32), __GFP_ZERO); + if (!idle_states) + return -ENOMEM; + + ret = dev_read_u32_array(dev, "idle-states", idle_states, num_fields); + if (ret < 0) { + dev_err(dev, "failed to read idle-states property: %d\n", + ret); + devm_kfree(dev, idle_states); + idle_states = NULL; + } + + for (i = 0; i < num_fields; i++) { + struct mux_control *mux = &mux_chip->mux[i]; + struct reg_field field; + u32 reg, mask; + int bits; + + reg = mux_reg_masks[2 * i]; + mask = mux_reg_masks[2 * i + 1]; + + field.reg = reg; + field.msb = fls(mask) - 1; + field.lsb = ffs(mask) - 1; + + if (mask != GENMASK(field.msb, field.lsb)) { + dev_err(dev, "bitfield %d: invalid mask 0x%x\n", + i, mask); + return -EINVAL; + } + + fields[i] = devm_regmap_field_alloc(dev, regmap, field); + if (IS_ERR(fields[i])) { + ret = PTR_ERR(fields[i]); + dev_err(dev, "bitfield %d: failed allocate: %d\n", + i, ret); + return ret; + } + + bits = 1 + field.msb - field.lsb; + mux->states = 1 << bits; + + if (!idle_states) + continue; + + if (idle_states[i] != MUX_IDLE_AS_IS && + idle_states[i] >= mux->states) { + dev_err(dev, "bitfield: %d: out of range idle state %d\n", + i, idle_states[i]); + return -EINVAL; + } + mux->idle_state = idle_states[i]; + } + + devm_kfree(dev, mux_reg_masks); + if (idle_states) + devm_kfree(dev, idle_states); + + return 0; +} + +U_BOOT_DRIVER(mmio_mux) = { + .name = "mmio-mux", + .id = UCLASS_MUX, + .of_match = mmio_mux_of_match, + .probe = mmio_mux_probe, + .ops = &mux_mmio_ops, +};