drivers: mux: mmio-based syscon mux controller
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>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
diff --git a/drivers/mux/Kconfig b/drivers/mux/Kconfig
index 35c1c56..f15ee4f 100644
--- a/drivers/mux/Kconfig
+++ b/drivers/mux/Kconfig
@@ -8,4 +8,18 @@
controllers. It provides the same API as Linux and mux drivers should
be portable with a minimum effort.
+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 351e436..78ebf04 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 0000000..b986850
--- /dev/null
+++ b/drivers/mux/mmio.c
@@ -0,0 +1,142 @@
+// 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/device_compat.h>
+#include <dm/read.h>
+#include <dm/devres.h>
+#include <dt-bindings/mux/mux.h>
+#include <linux/bitops.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)
+ return log_msg_ret("mux-reg-masks missing", -EINVAL);
+
+ 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)
+ return log_msg_ret("mux_alloc_controllers", 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)
+ return log_msg_ret("mux-reg-masks read", 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) {
+ log_err("idle-states");
+ 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))
+ return log_msg_ret("invalid mask", -EINVAL);
+
+ fields[i] = devm_regmap_field_alloc(dev, regmap, field);
+ if (IS_ERR(fields[i])) {
+ ret = PTR_ERR(fields[i]);
+ return log_msg_ret("regmap_field_alloc", 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)
+ return log_msg_ret("idle-states range", -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,
+};