The Sparx5 mux driver may be used to control selecting between two
alternate SPI bus segments connected to the SPI controller
(spi-dw-mmio).
Signed-off-by: Lars Povlsen <lars.povlsen@xxxxxxxxxxxxx>
---
drivers/mux/Makefile | 2 +
drivers/mux/sparx5-spi.c | 138 +++++++++++++++++++++++++++++++++++++++
2 files changed, 140 insertions(+)
create mode 100644 drivers/mux/sparx5-spi.c
diff --git a/drivers/mux/Makefile b/drivers/mux/Makefile
index 6e9fa47daf566..18c3ae3582ece 100644
--- a/drivers/mux/Makefile
+++ b/drivers/mux/Makefile
@@ -8,9 +8,11 @@ mux-adg792a-objs := adg792a.o
mux-adgs1408-objs := adgs1408.o
mux-gpio-objs := gpio.o
mux-mmio-objs := mmio.o
+mux-sparx5-objs := sparx5-spi.o
obj-$(CONFIG_MULTIPLEXER) += mux-core.o
obj-$(CONFIG_MUX_ADG792A) += mux-adg792a.o
obj-$(CONFIG_MUX_ADGS1408) += mux-adgs1408.o
obj-$(CONFIG_MUX_GPIO) += mux-gpio.o
obj-$(CONFIG_MUX_MMIO) += mux-mmio.o
+obj-$(CONFIG_SPI_DW_MMIO) += mux-sparx5.o
diff --git a/drivers/mux/sparx5-spi.c b/drivers/mux/sparx5-spi.c
new file mode 100644
index 0000000000000..5fe9025b96a5e
--- /dev/null
+++ b/drivers/mux/sparx5-spi.c
@@ -0,0 +1,138 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Sparx5 SPI MUX driver
+ *
+ * Copyright (c) 2019 Microsemi Corporation
+ *
+ * Author: Lars Povlsen <lars.povlsen@xxxxxxxxxxxxx>
+ */
+
+#include <linux/err.h>
+#include <linux/module.h>
+#include <linux/mux/driver.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/mux/driver.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/bitfield.h>
+
+#define MSCC_IF_SI_OWNER_SISL 0
+#define MSCC_IF_SI_OWNER_SIBM 1
+#define MSCC_IF_SI_OWNER_SIMC 2
+
+#define SPARX5_CPU_SYSTEM_CTRL_GENERAL_CTRL 0x88
+#define SPARX5_IF_SI_OWNER GENMASK(7, 6)
+#define SPARX5_IF_SI2_OWNER GENMASK(5, 4)
+
+#define SPARX5_MAX_CS 16
+
+struct mux_sparx5 {
+ struct regmap *syscon;
+ u8 bus[SPARX5_MAX_CS];
+ int cur_bus;
+};
+
+/*
+ * Set the owner of the SPI interfaces
+ */
+static void mux_sparx5_set_owner(struct regmap *syscon,
+ u8 owner, u8 owner2)
+{
+ u32 val, msk;
+
+ val = FIELD_PREP(SPARX5_IF_SI_OWNER, owner) |
+ FIELD_PREP(SPARX5_IF_SI2_OWNER, owner2);
+ msk = SPARX5_IF_SI_OWNER | SPARX5_IF_SI2_OWNER;
+ regmap_update_bits(syscon,
+ SPARX5_CPU_SYSTEM_CTRL_GENERAL_CTRL,
+ msk, val);
+}
+
+static void mux_sparx5_set_cs_owner(struct mux_sparx5 *mux_sparx5,
+ u8 cs, u8 owner)
+{
+ u8 other = (owner == MSCC_IF_SI_OWNER_SIBM ?
+ MSCC_IF_SI_OWNER_SIMC : MSCC_IF_SI_OWNER_SIBM);
+ if (mux_sparx5->bus[cs])
+ /* SPI2 */
+ mux_sparx5_set_owner(mux_sparx5->syscon, other, owner);
+ else
+ /* SPI1 */
+ mux_sparx5_set_owner(mux_sparx5->syscon, owner, other);
+}
+
+static int mux_sparx5_set(struct mux_control *mux, int state)
+{
+ struct mux_sparx5 *mux_sparx5 = mux_chip_priv(mux->chip);
+
+ mux_sparx5_set_cs_owner(mux_sparx5, state, MSCC_IF_SI_OWNER_SIMC);
+
+ return 0;
+}
+
+static const struct mux_control_ops mux_sparx5_ops = {
+ .set = mux_sparx5_set,
+};
+
+static const struct of_device_id mux_sparx5_dt_ids[] = {
+ { .compatible = "microchip,sparx5-spi-mux", },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, mux_sparx5_dt_ids);
+
+static int mux_sparx5_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct mux_chip *mux_chip;
+ struct mux_sparx5 *mux_sparx5;
+ struct device_node *nc;
+ const char *syscon_name = "microchip,sparx5-cpu-syscon";
+ int ret;
+
+ mux_chip = devm_mux_chip_alloc(dev, 1, sizeof(*mux_sparx5));
+ if (IS_ERR(mux_chip))
+ return PTR_ERR(mux_chip);
+
+ mux_sparx5 = mux_chip_priv(mux_chip);
+ mux_chip->ops = &mux_sparx5_ops;
+
+ mux_sparx5->syscon =
+ syscon_regmap_lookup_by_compatible(syscon_name);
+ if (IS_ERR(mux_sparx5->syscon)) {
+ dev_err(dev, "No syscon map %s\n", syscon_name);
+ return PTR_ERR(mux_sparx5->syscon);
+ }
+
+ /* Get bus interface mapping */
+ for_each_available_child_of_node(dev->of_node, nc) {
+ u32 cs, bus;
+
+ if (of_property_read_u32(nc, "reg", &cs) == 0 &&
+ cs < SPARX5_MAX_CS &&
+ of_property_read_u32(nc, "microchip,bus-interface",
+ &bus) == 0)
+ mux_sparx5->bus[cs] = bus;
+ }
+
+ mux_chip->mux->states = SPARX5_MAX_CS;
+
+ ret = devm_mux_chip_register(dev, mux_chip);
+ if (ret < 0)
+ return ret;
+
+ dev_info(dev, "%u-way mux-controller registered\n",
+ mux_chip->mux->states);
+
+ return 0;
+}
+
+static struct platform_driver mux_sparx5_driver = {
+ .driver = {
+ .name = "sparx5-mux",
+ .of_match_table = of_match_ptr(mux_sparx5_dt_ids),
+ },
+ .probe = mux_sparx5_probe,
+};
+module_platform_driver(mux_sparx5_driver);
--
2.27.0
