On Sun, May 08, 2022 at 11:53:05AM -0700, Colin Foster wrote: > The VSC7512 is a networking chip that contains several peripherals. Many of > these peripherals are currently supported by the VSC7513 and VSC7514 chips, > but those run on an internal CPU. The VSC7512 lacks this CPU, and must be > controlled externally. > > Utilize the existing drivers by referencing the chip as an MFD. Add support > for the two MDIO buses, the internal phys, pinctrl, and serial GPIO. > > Signed-off-by: Colin Foster <colin.foster@xxxxxxxxxxxxxxxx> > --- > drivers/mfd/Kconfig | 18 +++ > drivers/mfd/Makefile | 2 + > drivers/mfd/ocelot-core.c | 135 +++++++++++++++++ > drivers/mfd/ocelot-spi.c | 311 ++++++++++++++++++++++++++++++++++++++ > drivers/mfd/ocelot.h | 34 +++++ > include/soc/mscc/ocelot.h | 5 + > 6 files changed, 505 insertions(+) > create mode 100644 drivers/mfd/ocelot-core.c > create mode 100644 drivers/mfd/ocelot-spi.c > create mode 100644 drivers/mfd/ocelot.h > > diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig > index 3b59456f5545..ff177173ca11 100644 > --- a/drivers/mfd/Kconfig > +++ b/drivers/mfd/Kconfig > @@ -962,6 +962,24 @@ config MFD_MENF21BMC > This driver can also be built as a module. If so the module > will be called menf21bmc. > > +config MFD_OCELOT > + tristate "Microsemi Ocelot External Control Support" > + depends on SPI_MASTER > + select MFD_CORE > + select REGMAP_SPI > + help > + Ocelot is a family of networking chips that support multiple ethernet > + and fibre interfaces. In addition to networking, they contain several > + other functions, including pictrl, MDIO, and communication with > + external chips. While some chips have an internal processor capable of > + running an OS, others don't. All chips can be controlled externally > + through different interfaces, including SPI, I2C, and PCIe. > + > + Say yes here to add support for Ocelot chips (VSC7511, VSC7512, > + VSC7513, VSC7514) controlled externally. > + > + If unsure, say N > + > config EZX_PCAP > bool "Motorola EZXPCAP Support" > depends on SPI_MASTER > diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile > index 858cacf659d6..bc517632ba5f 100644 > --- a/drivers/mfd/Makefile > +++ b/drivers/mfd/Makefile > @@ -120,6 +120,8 @@ obj-$(CONFIG_MFD_MC13XXX_I2C) += mc13xxx-i2c.o > > obj-$(CONFIG_MFD_CORE) += mfd-core.o > > +obj-$(CONFIG_MFD_OCELOT) += ocelot-core.o ocelot-spi.o > + > obj-$(CONFIG_EZX_PCAP) += ezx-pcap.o > obj-$(CONFIG_MFD_CPCAP) += motorola-cpcap.o > > diff --git a/drivers/mfd/ocelot-core.c b/drivers/mfd/ocelot-core.c > new file mode 100644 > index 000000000000..117028f7d845 > --- /dev/null > +++ b/drivers/mfd/ocelot-core.c > @@ -0,0 +1,135 @@ > +// 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@xxxxxxxxxxxxxxxx> > + */ > + > +#include <linux/mfd/core.h> > +#include <linux/module.h> > +#include <linux/regmap.h> > +#include <soc/mscc/ocelot.h> > + > +#include <asm/byteorder.h> > + > +#include "ocelot.h" > + > +#define GCB_SOFT_RST 0x0008 > + > +#define SOFT_CHIP_RST 0x1 > + > +#define VSC7512_MIIM0_RES_START 0x7107009c > +#define VSC7512_MIIM0_RES_SIZE 0x24 > + > +#define VSC7512_MIIM1_RES_START 0x710700c0 > +#define VSC7512_MIIM1_RES_SIZE 0x24 > + > +#define VSC7512_PHY_RES_START 0x710700f0 > +#define VSC7512_PHY_RES_SIZE 0x4 > + > +#define VSC7512_GPIO_RES_START 0x71070034 > +#define VSC7512_GPIO_RES_SIZE 0x6c > + > +#define VSC7512_SIO_RES_START 0x710700f8 > +#define VSC7512_SIO_RES_SIZE 0x100 > + > +int ocelot_chip_reset(struct device *dev) > +{ > + struct ocelot_ddata *ddata = dev_get_drvdata(dev); > + int ret; > + > + /* > + * 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 > + */ > + ret = regmap_write(ddata->gcb_regmap, GCB_SOFT_RST, SOFT_CHIP_RST); > + if (ret) > + return ret; > + > + msleep(100); Isn't this a bit too long? > + > + return ret; return 0 > +} > +EXPORT_SYMBOL(ocelot_chip_reset); > + > +struct regmap *ocelot_init_regmap_from_resource(struct device *child, > + const struct resource *res) > +{ > + struct device *dev = child->parent; > + > + return ocelot_spi_devm_init_regmap(dev, child, res); So much for being bus-agnostic :-/ Maybe get the struct ocelot_ddata and call ocelot_spi_devm_init_regmap() via a function pointer which is populated by ocelot-spi.c? If you do that don't forget to clean up drivers/mfd/ocelot.h of SPI specific stuff. > +} > +EXPORT_SYMBOL(ocelot_init_regmap_from_resource); > + > +static const struct resource vsc7512_miim0_resources[] = { > + DEFINE_RES_REG_NAMED(VSC7512_MIIM0_RES_START, VSC7512_MIIM0_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_MIIM1_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_RES_START, VSC7512_SIO_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", > + .num_resources = ARRAY_SIZE(vsc7512_miim0_resources), > + .resources = vsc7512_miim0_resources, > + }, { > + .name = "ocelot-miim1", > + .of_compatible = "mscc,ocelot-miim", > + .num_resources = ARRAY_SIZE(vsc7512_miim1_resources), > + .resources = vsc7512_miim1_resources, > + }, > +}; > + > +int ocelot_core_init(struct device *dev) > +{ > + int ret; > + > + ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_AUTO, vsc7512_devs, > + ARRAY_SIZE(vsc7512_devs), NULL, 0, NULL); > + if (ret) { > + dev_err(dev, "Failed to add sub-devices: %d\n", ret); > + return ret; > + } > + > + return 0; > +} > +EXPORT_SYMBOL(ocelot_core_init); > + > +MODULE_DESCRIPTION("Externally Controlled Ocelot Chip Driver"); > +MODULE_AUTHOR("Colin Foster <colin.foster@xxxxxxxxxxxxxxxx>"); > +MODULE_LICENSE("GPL"); > diff --git a/drivers/mfd/ocelot-spi.c b/drivers/mfd/ocelot-spi.c > new file mode 100644 > index 000000000000..95754deb0b57 > --- /dev/null > +++ b/drivers/mfd/ocelot-spi.c > @@ -0,0 +1,311 @@ > +// 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 Innovative Advantage Inc. > + * > + * Author: Colin Foster <colin.foster@xxxxxxxxxxxxxxxx> > + */ > + > +#include <linux/iopoll.h> > +#include <linux/kconfig.h> > +#include <linux/module.h> > +#include <linux/of.h> > +#include <linux/regmap.h> > +#include <linux/spi/spi.h> > + > +#include <asm/byteorder.h> > + > +#include "ocelot.h" > + > +#define DEV_CPUORG_IF_CTRL 0x0000 > +#define 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_CPUORG_RES_START 0x71000000 > +#define VSC7512_CPUORG_RES_SIZE 0x2ff > + > +#define VSC7512_GCB_RES_START 0x71070000 > +#define VSC7512_GCB_RES_SIZE 0x14 > + > +static const struct resource vsc7512_dev_cpuorg_resource = > + DEFINE_RES_REG_NAMED(VSC7512_CPUORG_RES_START, VSC7512_CPUORG_RES_SIZE, > + "devcpu_org"); > + > +static const struct resource vsc7512_gcb_resource = > + DEFINE_RES_REG_NAMED(VSC7512_GCB_RES_START, VSC7512_GCB_RES_SIZE, > + "devcpu_gcb_chip_regs"); > + > +int ocelot_spi_initialize(struct device *dev) Should be static and unexported. > +{ > + 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, 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, 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, DEV_CPUORG_IF_CFGSTAT, &val); > + if (err) > + return err; > + > + if (check != val) > + return -ENODEV; > + > + return 0; > +} > +EXPORT_SYMBOL(ocelot_spi_initialize); > + > +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, > + > + .max_register = 0xffffffff, > + .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) > +{ > + static const u8 dummy_buf[16] = {0}; > + struct spi_transfer tx, padding, rx; > + struct ocelot_ddata *ddata = context; > + struct spi_device *spi = ddata->spi; > + struct spi_message msg; > + > + spi = ddata->spi; > + > + spi_message_init(&msg); > + > + memset(&tx, 0, sizeof(tx)); > + > + tx.tx_buf = reg; > + tx.len = reg_size; > + > + spi_message_add_tail(&tx, &msg); > + > + if (ddata->spi_padding_bytes > 0) { > + memset(&padding, 0, sizeof(padding)); > + > + padding.len = ddata->spi_padding_bytes; > + padding.tx_buf = dummy_buf; > + padding.dummy_data = 1; > + > + spi_message_add_tail(&padding, &msg); > + } > + > + memset(&rx, 0, sizeof(rx)); > + rx.rx_buf = val; > + rx.len = val_size; > + > + spi_message_add_tail(&rx, &msg); > + > + return spi_sync(spi, &msg); > +} > + > +static int ocelot_spi_regmap_bus_write(void *context, const void *data, > + size_t count) > +{ > + struct ocelot_ddata *ddata = context; > + struct spi_device *spi = ddata->spi; > + > + 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_devm_init_regmap(struct device *dev, struct device *child, > + const struct resource *res) > +{ > + struct ocelot_ddata *ddata = dev_get_drvdata(dev); > + struct regmap_config regmap_config; > + > + memcpy(®map_config, &ocelot_spi_regmap_config, > + sizeof(ocelot_spi_regmap_config)); > + > + regmap_config.name = res->name; > + regmap_config.max_register = res->end - res->start; > + regmap_config.reg_base = res->start; > + > + return devm_regmap_init(child, &ocelot_spi_regmap_bus, ddata, > + ®map_config); > +} > + > +static int ocelot_spi_probe(struct spi_device *spi) > +{ > + struct device *dev = &spi->dev; > + struct ocelot_ddata *ddata; > + int err; > + > + ddata = devm_kzalloc(dev, sizeof(*ddata), GFP_KERNEL); > + if (!ddata) > + return -ENOMEM; > + > + ddata->dev = dev; > + dev_set_drvdata(dev, 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 / 1000000 + 2) / 8; > + } > + > + ddata->spi = spi; > + > + spi->bits_per_word = 8; > + > + err = spi_setup(spi); > + if (err < 0) { > + dev_err(&spi->dev, "Error %d initializing SPI\n", err); > + return err; > + } > + Personally I'd prefer: struct regmap *r; r = ocelot_spi_devm_init_regmap(dev, dev, &vsc7512_dev_cpuorg_resource); if (IS_ERR(r)) return ERR_PTR(r); ddata->cpuorg_regmap = r; and so on. > + ddata->cpuorg_regmap = > + ocelot_spi_devm_init_regmap(dev, dev, > + &vsc7512_dev_cpuorg_resource); > + if (IS_ERR(ddata->cpuorg_regmap)) > + return -ENOMEM; > + > + ddata->gcb_regmap = ocelot_spi_devm_init_regmap(dev, dev, > + &vsc7512_gcb_resource); > + if (IS_ERR(ddata->gcb_regmap)) > + return -ENOMEM; > + > + /* > + * 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) { > + dev_err(dev, "Error %d initializing Ocelot SPI bus\n", err); Maybe showing the symbolic value behind the error number would be helpful? dev_err(dev, "Initializing SPI bus returned %pe\n", ERR_PTR(err)); Similar for other places where you print the error using %d, I won't repeat this comment. > + return err; > + } > + > + err = ocelot_chip_reset(dev); > + if (err) { > + dev_err(dev, "Failed to reset device: %d\n", err); > + return err; > + } > + > + /* > + * 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) { > + dev_err(dev, > + "Failed to initialize Ocelot SPI bus after reset: %d\n", > + err); > + return err; > + } > + > + err = ocelot_core_init(dev); > + if (err < 0) { > + dev_err(dev, "Error %d initializing Ocelot core\n", err); > + return err; > + } > + > + return 0; > +} > + > +const struct of_device_id ocelot_spi_of_match[] = { static > + { .compatible = "mscc,vsc7512_mfd_spi" }, > + { }, > +}; > +MODULE_DEVICE_TABLE(of, ocelot_spi_of_match); > + > +static struct spi_driver ocelot_spi_driver = { > + .driver = { > + .name = "ocelot_mfd_spi", > + .of_match_table = of_match_ptr(ocelot_spi_of_match), > + }, > + .probe = ocelot_spi_probe, > +}; > +module_spi_driver(ocelot_spi_driver); > + > +MODULE_DESCRIPTION("SPI Controlled Ocelot Chip Driver"); > +MODULE_AUTHOR("Colin Foster <colin.foster@xxxxxxxxxxxxxxxx>"); > +MODULE_LICENSE("Dual MIT/GPL"); > diff --git a/drivers/mfd/ocelot.h b/drivers/mfd/ocelot.h > new file mode 100644 > index 000000000000..b68e6343caca > --- /dev/null > +++ b/drivers/mfd/ocelot.h > @@ -0,0 +1,34 @@ > +/* SPDX-License-Identifier: GPL-2.0 OR MIT */ > +/* > + * Copyright 2021 Innovative Advantage Inc. > + */ > + > +#include <linux/regmap.h> > + > +#include <asm/byteorder.h> > + > +struct ocelot_ddata { > + struct device *dev; > + struct regmap *gcb_regmap; > + struct regmap *cpuorg_regmap; > + int spi_padding_bytes; > + struct spi_device *spi; > +}; > + > +int ocelot_chip_reset(struct device *dev); > +int ocelot_core_init(struct device *dev); > + > +/* SPI-specific routines that won't be necessary for other interfaces */ > +struct regmap *ocelot_spi_devm_init_regmap(struct device *dev, > + struct device *child, > + const struct resource *res); > +int ocelot_spi_initialize(struct device *dev); > + > +#define OCELOT_SPI_BYTE_ORDER_LE 0x00000000 > +#define OCELOT_SPI_BYTE_ORDER_BE 0x81818181 > + > +#ifdef __LITTLE_ENDIAN > +#define OCELOT_SPI_BYTE_ORDER OCELOT_SPI_BYTE_ORDER_LE > +#else > +#define OCELOT_SPI_BYTE_ORDER OCELOT_SPI_BYTE_ORDER_BE > +#endif > diff --git a/include/soc/mscc/ocelot.h b/include/soc/mscc/ocelot.h > index 1897119ebb9a..f9124a66e386 100644 > --- a/include/soc/mscc/ocelot.h > +++ b/include/soc/mscc/ocelot.h > @@ -1039,11 +1039,16 @@ ocelot_mrp_del_ring_role(struct ocelot *ocelot, int port, > } > #endif > > +#if IS_ENABLED(CONFIG_MFD_OCELOT) > +struct regmap *ocelot_init_regmap_from_resource(struct device *child, > + const struct resource *res); > +#else > static inline struct regmap * > ocelot_init_regmap_from_resource(struct device *child, > const struct resource *res) > { > return ERR_PTR(-EOPNOTSUPP); > } > +#endif > > #endif > -- > 2.25.1 >