[PATCH 2/2] mux: mmio: Extend mmio-mux driver to configure mux with mux-reg-masks-state
From: Chintan Vankar <hidden>
Date: 2025-06-05 06:34:42
Also in:
lkml
Subsystem:
multiplexer subsystem, the rest · Maintainers:
Peter Rosin, Linus Torvalds
MMIO mux driver is designed to parse "mux-reg-masks" and "idle-states" property independently to configure mux. The current design is complex for the devices with larger memory space, which requires synchronization between the two properties. Extend mmio-mux driver to support a single property, "mux-reg-masks-state" which configures mux registers without above constraint. Signed-off-by: Chintan Vankar <redacted> --- drivers/mux/mmio.c | 144 +++++++++++++++++++++++++++++++++++++-------- 1 file changed, 118 insertions(+), 26 deletions(-)
diff --git a/drivers/mux/mmio.c b/drivers/mux/mmio.c
index 9993ce38a818..5ce9c16fd431 100644
--- a/drivers/mux/mmio.c
+++ b/drivers/mux/mmio.c@@ -2,7 +2,7 @@ /* * MMIO register bitfield-controlled multiplexer driver * - * Copyright (C) 2017 Pengutronix, Philipp Zabel <kernel@pengutronix.de> + * Copyright (C) 2017-2025 Pengutronix, Philipp Zabel <kernel@pengutronix.de> */ #include <linux/bitops.h>
@@ -39,10 +39,83 @@ static const struct regmap_config mux_mmio_regmap_cfg = { .reg_stride = 4, }; +static int reg_mux_get_controllers(const struct device_node *np, char *prop_name) +{ + int ret; + + ret = of_property_count_u32_elems(np, prop_name); + if (ret == 0 || ret % 2) + ret = -EINVAL; + + return ret; +} + +static int reg_mux_get_controllers_extended(const struct device_node *np, char *prop_name) +{ + int ret; + + ret = of_property_count_u32_elems(np, prop_name); + if (ret == 0 || ret % 3) + ret = -EINVAL; + + return ret; +} + +static int reg_mux_parse_dt(const struct device_node *np, bool *mux_reg_masks_state, + int *num_fields) +{ + int ret; + + if (of_property_present(np, "mux-reg-masks-state")) { + *mux_reg_masks_state = true; + ret = reg_mux_get_controllers_extended(np, "mux-reg-masks-state"); + if (ret < 0) + return ret; + *num_fields = ret / 3; + } else { + ret = reg_mux_get_controllers(np, "mux-reg-masks"); + if (ret < 0) + return ret; + *num_fields = ret / 2; + } + return ret; +} + +static int mux_reg_set_parameters(const struct device_node *np, char *prop_name, u32 *reg, + u32 *mask, int index) +{ + int ret; + + ret = of_property_read_u32_index(np, prop_name, 2 * index, reg); + if (!ret) + ret = of_property_read_u32_index(np, prop_name, 2 * index + 1, mask); + + return ret; +} + +static int mux_reg_set_parameters_extended(const struct device_node *np, char *prop_name, u32 *reg, + u32 *mask, u32 *state, int index) +{ + int ret; + + ret = of_property_read_u32_index(np, prop_name, 3 * index, reg); + if (ret < 0) + return ret; + + ret = of_property_read_u32_index(np, prop_name, 3 * index + 1, mask); + if (ret < 0) + return ret; + + ret = of_property_read_u32_index(np, prop_name, 3 * index + 2, state); + + return ret; +} + static int mux_mmio_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct device_node *np = dev->of_node; + bool mux_reg_masks_state = false; struct regmap_field **fields; struct mux_chip *mux_chip; struct regmap *regmap;
@@ -70,15 +143,16 @@ static int mux_mmio_probe(struct platform_device *pdev) return dev_err_probe(dev, PTR_ERR(regmap), "failed to get regmap\n"); - ret = of_property_count_u32_elems(np, "mux-reg-masks"); - if (ret == 0 || ret % 2) - ret = -EINVAL; + ret = reg_mux_parse_dt(np, &mux_reg_masks_state, &num_fields); if (ret < 0) { - dev_err(dev, "mux-reg-masks property missing or invalid: %d\n", - ret); + if (mux_reg_masks_state) + dev_err(dev, "mux-reg-masks-state property missing or invalid: %d\n", + ret); + else + dev_err(dev, "mux-reg-masks property missing or invalid: %d\n", + ret); return ret; } - num_fields = ret / 2; mux_chip = devm_mux_chip_alloc(dev, num_fields, num_fields * sizeof(*fields));
@@ -90,19 +164,25 @@ static int mux_mmio_probe(struct platform_device *pdev) for (i = 0; i < num_fields; i++) { struct mux_control *mux = &mux_chip->mux[i]; struct reg_field field; - s32 idle_state = MUX_IDLE_AS_IS; + s32 state, idle_state = MUX_IDLE_AS_IS; u32 reg, mask; int bits; - ret = of_property_read_u32_index(np, "mux-reg-masks", - 2 * i, ®); - if (!ret) - ret = of_property_read_u32_index(np, "mux-reg-masks", - 2 * i + 1, &mask); - if (ret < 0) { - dev_err(dev, "bitfield %d: failed to read mux-reg-masks property: %d\n", - i, ret); - return ret; + if (!mux_reg_masks_state) { + ret = mux_reg_set_parameters(np, "mux-reg-masks", ®, &mask, i); + if (ret < 0) { + dev_err(dev, "bitfield %d: failed to read mux-reg-masks property: %d\n", + i, ret); + return ret; + } + } else { + ret = mux_reg_set_parameters_extended(np, "mux-reg-masks-state", ®, + &mask, &state, i); + if (ret < 0) { + dev_err(dev, "bitfield %d: failed to read custom-states property: %d\n", + i, ret); + return ret; + } } field.reg = reg;
@@ -126,16 +206,28 @@ static int mux_mmio_probe(struct platform_device *pdev) bits = 1 + field.msb - field.lsb; mux->states = 1 << bits; - of_property_read_u32_index(np, "idle-states", i, - (u32 *)&idle_state); - if (idle_state != MUX_IDLE_AS_IS) { - if (idle_state < 0 || idle_state >= mux->states) { - dev_err(dev, "bitfield: %d: out of range idle state %d\n", - i, idle_state); - return -EINVAL; + if (!mux_reg_masks_state) { + of_property_read_u32_index(np, "idle-states", i, + (u32 *)&idle_state); + if (idle_state != MUX_IDLE_AS_IS) { + if (idle_state < 0 || idle_state >= mux->states) { + dev_err(dev, "bitfield: %d: out of range idle state %d\n", + i, idle_state); + return -EINVAL; + } + + mux->idle_state = idle_state; + } + } else { + if (state != MUX_IDLE_AS_IS) { + if (state < 0 || state >= mux->states) { + dev_err(dev, "bitfield: %d: out of range idle state %d\n", + i, state); + return -EINVAL; + } + + mux->idle_state = state; } - - mux->idle_state = idle_state; } }
--
2.34.1