--- /dev/null
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+/*
+ * Core driver for the Ocelot chip family.
+ *
+ * The VSC7511, 7512, 7513, and 7514 can be controlled internally via an
+ * on-chip MIPS processor, or externally via SPI, I2C, PCIe. This core driver is
+ * intended to be the bus-agnostic glue between, for example, the SPI bus and
+ * the child devices.
+ *
+ * Copyright 2021-2022 Innovative Advantage Inc.
+ *
+ * Author: Colin Foster <colin.foster@in-advantage.com>
+ */
+
+#include <linux/bits.h>
+#include <linux/device.h>
+#include <linux/export.h>
+#include <linux/iopoll.h>
+#include <linux/ioport.h>
+#include <linux/kernel.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/ocelot.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/types.h>
+
+#include <soc/mscc/ocelot.h>
+
+#include "ocelot.h"
+
+#define REG_GCB_SOFT_RST 0x0008
+
+#define BIT_SOFT_CHIP_RST BIT(0)
+
+#define VSC7512_MIIM0_RES_START 0x7107009c
+#define VSC7512_MIIM1_RES_START 0x710700c0
+#define VSC7512_MIIM_RES_SIZE 0x024
+
+#define VSC7512_PHY_RES_START 0x710700f0
+#define VSC7512_PHY_RES_SIZE 0x004
+
+#define VSC7512_GPIO_RES_START 0x71070034
+#define VSC7512_GPIO_RES_SIZE 0x06c
+
+#define VSC7512_SIO_CTRL_RES_START 0x710700f8
+#define VSC7512_SIO_CTRL_RES_SIZE 0x100
+
+#define VSC7512_GCB_RST_SLEEP_US 100
+#define VSC7512_GCB_RST_TIMEOUT_US 100000
+
+static int ocelot_gcb_chip_rst_status(struct ocelot_ddata *ddata)
+{
+ int val, err;
+
+ err = regmap_read(ddata->gcb_regmap, REG_GCB_SOFT_RST, &val);
+ if (err)
+ return err;
+
+ return val;
+}
+
+int ocelot_chip_reset(struct device *dev)
+{
+ struct ocelot_ddata *ddata = dev_get_drvdata(dev);
+ int ret, val;
+
+ /*
+ * Reset the entire chip here to put it into a completely known state.
+ * Other drivers may want to reset their own subsystems. The register
+ * self-clears, so one write is all that is needed and wait for it to
+ * clear.
+ */
+ ret = regmap_write(ddata->gcb_regmap, REG_GCB_SOFT_RST, BIT_SOFT_CHIP_RST);
+ if (ret)
+ return ret;
+
+ return readx_poll_timeout(ocelot_gcb_chip_rst_status, ddata, val, !val,
+ VSC7512_GCB_RST_SLEEP_US, VSC7512_GCB_RST_TIMEOUT_US);
+}
+EXPORT_SYMBOL_NS(ocelot_chip_reset, MFD_OCELOT);
+
+static const struct resource vsc7512_miim0_resources[] = {
+ DEFINE_RES_REG_NAMED(VSC7512_MIIM0_RES_START, VSC7512_MIIM_RES_SIZE, "gcb_miim0"),
+ DEFINE_RES_REG_NAMED(VSC7512_PHY_RES_START, VSC7512_PHY_RES_SIZE, "gcb_phy"),
+};
+
+static const struct resource vsc7512_miim1_resources[] = {
+ DEFINE_RES_REG_NAMED(VSC7512_MIIM1_RES_START, VSC7512_MIIM_RES_SIZE, "gcb_miim1"),
+};
+
+static const struct resource vsc7512_pinctrl_resources[] = {
+ DEFINE_RES_REG_NAMED(VSC7512_GPIO_RES_START, VSC7512_GPIO_RES_SIZE, "gcb_gpio"),
+};
+
+static const struct resource vsc7512_sgpio_resources[] = {
+ DEFINE_RES_REG_NAMED(VSC7512_SIO_CTRL_RES_START, VSC7512_SIO_CTRL_RES_SIZE, "gcb_sio"),
+};
+
+static const struct mfd_cell vsc7512_devs[] = {
+ {
+ .name = "ocelot-pinctrl",
+ .of_compatible = "mscc,ocelot-pinctrl",
+ .num_resources = ARRAY_SIZE(vsc7512_pinctrl_resources),
+ .resources = vsc7512_pinctrl_resources,
+ }, {
+ .name = "ocelot-sgpio",
+ .of_compatible = "mscc,ocelot-sgpio",
+ .num_resources = ARRAY_SIZE(vsc7512_sgpio_resources),
+ .resources = vsc7512_sgpio_resources,
+ }, {
+ .name = "ocelot-miim0",
+ .of_compatible = "mscc,ocelot-miim",
+ .of_reg = VSC7512_MIIM0_RES_START,
+ .use_of_reg = true,
+ .num_resources = ARRAY_SIZE(vsc7512_miim0_resources),
+ .resources = vsc7512_miim0_resources,
+ }, {
+ .name = "ocelot-miim1",
+ .of_compatible = "mscc,ocelot-miim",
+ .of_reg = VSC7512_MIIM1_RES_START,
+ .use_of_reg = true,
+ .num_resources = ARRAY_SIZE(vsc7512_miim1_resources),
+ .resources = vsc7512_miim1_resources,
+ },
+};
+
+static void ocelot_core_try_add_regmap(struct device *dev,
+ const struct resource *res)
+{
+ if (dev_get_regmap(dev, res->name))
+ return;
+
+ ocelot_spi_init_regmap(dev, res);
+}
+
+static void ocelot_core_try_add_regmaps(struct device *dev,
+ const struct mfd_cell *cell)
+{
+ int i;
+
+ for (i = 0; i < cell->num_resources; i++)
+ ocelot_core_try_add_regmap(dev, &cell->resources[i]);
+}
+
+int ocelot_core_init(struct device *dev)
+{
+ int i, ndevs;
+
+ ndevs = ARRAY_SIZE(vsc7512_devs);
+
+ for (i = 0; i < ndevs; i++)
+ ocelot_core_try_add_regmaps(dev, &vsc7512_devs[i]);
+
+ return devm_mfd_add_devices(dev, PLATFORM_DEVID_AUTO, vsc7512_devs, ndevs, NULL, 0, NULL);
+}
+EXPORT_SYMBOL_NS(ocelot_core_init, MFD_OCELOT);
+
+MODULE_DESCRIPTION("Externally Controlled Ocelot Chip Driver");
+MODULE_AUTHOR("Colin Foster <colin.foster@in-advantage.com>");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(MFD_OCELOT_SPI);
--- /dev/null
+// SPDX-License-Identifier: (GPL-2.0 OR MIT)
+/*
+ * SPI core driver for the Ocelot chip family.
+ *
+ * This driver will handle everything necessary to allow for communication over
+ * SPI to the VSC7511, VSC7512, VSC7513 and VSC7514 chips. The main functions
+ * are to prepare the chip's SPI interface for a specific bus speed, and a host
+ * processor's endianness. This will create and distribute regmaps for any
+ * children.
+ *
+ * Copyright 2021-2022 Innovative Advantage Inc.
+ *
+ * Author: Colin Foster <colin.foster@in-advantage.com>
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/export.h>
+#include <linux/ioport.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/spi/spi.h>
+#include <linux/types.h>
+#include <linux/units.h>
+
+#include "ocelot.h"
+
+#define REG_DEV_CPUORG_IF_CTRL 0x0000
+#define REG_DEV_CPUORG_IF_CFGSTAT 0x0004
+
+#define CFGSTAT_IF_NUM_VCORE (0 << 24)
+#define CFGSTAT_IF_NUM_VRAP (1 << 24)
+#define CFGSTAT_IF_NUM_SI (2 << 24)
+#define CFGSTAT_IF_NUM_MIIM (3 << 24)
+
+#define VSC7512_DEVCPU_ORG_RES_START 0x71000000
+#define VSC7512_DEVCPU_ORG_RES_SIZE 0x38
+
+#define VSC7512_CHIP_REGS_RES_START 0x71070000
+#define VSC7512_CHIP_REGS_RES_SIZE 0x14
+
+static const struct resource vsc7512_dev_cpuorg_resource =
+ DEFINE_RES_REG_NAMED(VSC7512_DEVCPU_ORG_RES_START,
+ VSC7512_DEVCPU_ORG_RES_SIZE,
+ "devcpu_org");
+
+static const struct resource vsc7512_gcb_resource =
+ DEFINE_RES_REG_NAMED(VSC7512_CHIP_REGS_RES_START,
+ VSC7512_CHIP_REGS_RES_SIZE,
+ "devcpu_gcb_chip_regs");
+
+static int ocelot_spi_initialize(struct device *dev)
+{
+ struct ocelot_ddata *ddata = dev_get_drvdata(dev);
+ u32 val, check;
+ int err;
+
+ val = OCELOT_SPI_BYTE_ORDER;
+
+ /*
+ * The SPI address must be big-endian, but we want the payload to match
+ * our CPU. These are two bits (0 and 1) but they're repeated such that
+ * the write from any configuration will be valid. The four
+ * configurations are:
+ *
+ * 0b00: little-endian, MSB first
+ * | 111111 | 22221111 | 33222222 |
+ * | 76543210 | 54321098 | 32109876 | 10987654 |
+ *
+ * 0b01: big-endian, MSB first
+ * | 33222222 | 22221111 | 111111 | |
+ * | 10987654 | 32109876 | 54321098 | 76543210 |
+ *
+ * 0b10: little-endian, LSB first
+ * | 111111 | 11112222 | 22222233 |
+ * | 01234567 | 89012345 | 67890123 | 45678901 |
+ *
+ * 0b11: big-endian, LSB first
+ * | 22222233 | 11112222 | 111111 | |
+ * | 45678901 | 67890123 | 89012345 | 01234567 |
+ */
+ err = regmap_write(ddata->cpuorg_regmap, REG_DEV_CPUORG_IF_CTRL, val);
+ if (err)
+ return err;
+
+ /*
+ * Apply the number of padding bytes between a read request and the data
+ * payload. Some registers have access times of up to 1us, so if the
+ * first payload bit is shifted out too quickly, the read will fail.
+ */
+ val = ddata->spi_padding_bytes;
+ err = regmap_write(ddata->cpuorg_regmap, REG_DEV_CPUORG_IF_CFGSTAT, val);
+ if (err)
+ return err;
+
+ /*
+ * After we write the interface configuration, read it back here. This
+ * will verify several different things. The first is that the number of
+ * padding bytes actually got written correctly. These are found in bits
+ * 0:3.
+ *
+ * The second is that bit 16 is cleared. Bit 16 is IF_CFGSTAT:IF_STAT,
+ * and will be set if the register access is too fast. This would be in
+ * the condition that the number of padding bytes is insufficient for
+ * the SPI bus frequency.
+ *
+ * The last check is for bits 31:24, which define the interface by which
+ * the registers are being accessed. Since we're accessing them via the
+ * serial interface, it must return IF_NUM_SI.
+ */
+ check = val | CFGSTAT_IF_NUM_SI;
+
+ err = regmap_read(ddata->cpuorg_regmap, REG_DEV_CPUORG_IF_CFGSTAT, &val);
+ if (err)
+ return err;
+
+ if (check != val)
+ return -ENODEV;
+
+ return 0;
+}
+
+static const struct regmap_config ocelot_spi_regmap_config = {
+ .reg_bits = 24,
+ .reg_stride = 4,
+ .reg_downshift = 2,
+ .val_bits = 32,
+
+ .write_flag_mask = 0x80,
+
+ .use_single_write = true,
+ .can_multi_write = false,
+
+ .reg_format_endian = REGMAP_ENDIAN_BIG,
+ .val_format_endian = REGMAP_ENDIAN_NATIVE,
+};
+
+static int ocelot_spi_regmap_bus_read(void *context, const void *reg, size_t reg_size,
+ void *val, size_t val_size)
+{
+ struct spi_transfer xfers[3] = {0};
+ struct device *dev = context;
+ struct ocelot_ddata *ddata;
+ struct spi_device *spi;
+ struct spi_message msg;
+ unsigned int index = 0;
+
+ ddata = dev_get_drvdata(dev);
+ spi = to_spi_device(dev);
+
+ xfers[index].tx_buf = reg;
+ xfers[index].len = reg_size;
+ index++;
+
+ if (ddata->spi_padding_bytes) {
+ xfers[index].len = ddata->spi_padding_bytes;
+ xfers[index].tx_buf = ddata->dummy_buf;
+ xfers[index].dummy_data = 1;
+ index++;
+ }
+
+ xfers[index].rx_buf = val;
+ xfers[index].len = val_size;
+ index++;
+
+ spi_message_init_with_transfers(&msg, xfers, index);
+
+ return spi_sync(spi, &msg);
+}
+
+static int ocelot_spi_regmap_bus_write(void *context, const void *data, size_t count)
+{
+ struct device *dev = context;
+ struct spi_device *spi = to_spi_device(dev);
+
+ return spi_write(spi, data, count);
+}
+
+static const struct regmap_bus ocelot_spi_regmap_bus = {
+ .write = ocelot_spi_regmap_bus_write,
+ .read = ocelot_spi_regmap_bus_read,
+};
+
+struct regmap *ocelot_spi_init_regmap(struct device *dev, const struct resource *res)
+{
+ struct regmap_config regmap_config;
+
+ memcpy(®map_config, &ocelot_spi_regmap_config, sizeof(regmap_config));
+
+ regmap_config.name = res->name;
+ regmap_config.max_register = resource_size(res) - 1;
+ regmap_config.reg_base = res->start;
+
+ return devm_regmap_init(dev, &ocelot_spi_regmap_bus, dev, ®map_config);
+}
+EXPORT_SYMBOL_NS(ocelot_spi_init_regmap, MFD_OCELOT_SPI);
+
+static int ocelot_spi_probe(struct spi_device *spi)
+{
+ struct device *dev = &spi->dev;
+ struct ocelot_ddata *ddata;
+ struct regmap *r;
+ int err;
+
+ ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL);
+ if (!ddata)
+ return -ENOMEM;
+
+ spi_set_drvdata(spi, ddata);
+
+ if (spi->max_speed_hz <= 500000) {
+ ddata->spi_padding_bytes = 0;
+ } else {
+ /*
+ * Calculation taken from the manual for IF_CFGSTAT:IF_CFG.
+ * Register access time is 1us, so we need to configure and send
+ * out enough padding bytes between the read request and data
+ * transmission that lasts at least 1 microsecond.
+ */
+ ddata->spi_padding_bytes = 1 + (spi->max_speed_hz / HZ_PER_MHZ + 2) / 8;
+
+ ddata->dummy_buf = devm_kzalloc(dev, ddata->spi_padding_bytes, GFP_KERNEL);
+ if (!ddata->dummy_buf)
+ return -ENOMEM;
+ }
+
+ spi->bits_per_word = 8;
+
+ err = spi_setup(spi);
+ if (err)
+ return dev_err_probe(&spi->dev, err, "Error performing SPI setup\n");
+
+ r = ocelot_spi_init_regmap(dev, &vsc7512_dev_cpuorg_resource);
+ if (IS_ERR(r))
+ return PTR_ERR(r);
+
+ ddata->cpuorg_regmap = r;
+
+ r = ocelot_spi_init_regmap(dev, &vsc7512_gcb_resource);
+ if (IS_ERR(r))
+ return PTR_ERR(r);
+
+ ddata->gcb_regmap = r;
+
+ /*
+ * The chip must be set up for SPI before it gets initialized and reset.
+ * This must be done before calling init, and after a chip reset is
+ * performed.
+ */
+ err = ocelot_spi_initialize(dev);
+ if (err)
+ return dev_err_probe(dev, err, "Error initializing SPI bus\n");
+
+ err = ocelot_chip_reset(dev);
+ if (err)
+ return dev_err_probe(dev, err, "Error resetting device\n");
+
+ /*
+ * A chip reset will clear the SPI configuration, so it needs to be done
+ * again before we can access any registers.
+ */
+ err = ocelot_spi_initialize(dev);
+ if (err)
+ return dev_err_probe(dev, err, "Error initializing SPI bus after reset\n");
+
+ err = ocelot_core_init(dev);
+ if (err)
+ return dev_err_probe(dev, err, "Error initializing Ocelot core\n");
+
+ return 0;
+}
+
+static const struct spi_device_id ocelot_spi_ids[] = {
+ { "vsc7512", 0 },
+ { }
+};
+
+static const struct of_device_id ocelot_spi_of_match[] = {
+ { .compatible = "mscc,vsc7512" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, ocelot_spi_of_match);
+
+static struct spi_driver ocelot_spi_driver = {
+ .driver = {
+ .name = "ocelot-soc",
+ .of_match_table = ocelot_spi_of_match,
+ },
+ .id_table = ocelot_spi_ids,
+ .probe = ocelot_spi_probe,
+};
+module_spi_driver(ocelot_spi_driver);
+
+MODULE_DESCRIPTION("SPI Controlled Ocelot Chip Driver");
+MODULE_AUTHOR("Colin Foster <colin.foster@in-advantage.com>");
+MODULE_LICENSE("Dual MIT/GPL");
+MODULE_IMPORT_NS(MFD_OCELOT);
projects / users / jedix / linux-maple.git / commitdiff