// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause // // AMD SPI controller driver // // Copyright (c) 2020, Advanced Micro Devices, Inc. // // Author: Sanjay R Mehta <sanju.mehta@amd.com> #include <linux/acpi.h> #include <linux/init.h> #include <linux/module.h> #include <linux/platform_device.h> #include <linux/delay.h> #include <linux/spi/spi.h> #include <linux/iopoll.h> #define AMD_SPI_CTRL0_REG 0x00 #define AMD_SPI_EXEC_CMD BIT(16) #define AMD_SPI_FIFO_CLEAR BIT(20) #define AMD_SPI_BUSY BIT(31) #define AMD_SPI_OPCODE_REG 0x45 #define AMD_SPI_CMD_TRIGGER_REG 0x47 #define AMD_SPI_TRIGGER_CMD BIT(7) #define AMD_SPI_OPCODE_MASK 0xFF #define AMD_SPI_ALT_CS_REG 0x1D #define AMD_SPI_ALT_CS_MASK 0x3 #define AMD_SPI_FIFO_BASE 0x80 #define AMD_SPI_TX_COUNT_REG 0x48 #define AMD_SPI_RX_COUNT_REG 0x4B #define AMD_SPI_STATUS_REG 0x4C #define AMD_SPI_FIFO_SIZE 70 #define AMD_SPI_MEM_SIZE 200 #define AMD_SPI_ENA_REG 0x20 #define AMD_SPI_ALT_SPD_SHIFT 20 #define AMD_SPI_ALT_SPD_MASK GENMASK(23, AMD_SPI_ALT_SPD_SHIFT) #define AMD_SPI_SPI100_SHIFT 0 #define AMD_SPI_SPI100_MASK GENMASK(AMD_SPI_SPI100_SHIFT, AMD_SPI_SPI100_SHIFT) #define AMD_SPI_SPEED_REG 0x6C #define AMD_SPI_SPD7_SHIFT 8 #define AMD_SPI_SPD7_MASK GENMASK(13, AMD_SPI_SPD7_SHIFT) #define AMD_SPI_MAX_HZ 100000000 #define AMD_SPI_MIN_HZ 800000 /** * enum amd_spi_versions - SPI controller versions * @AMD_SPI_V1: AMDI0061 hardware version * @AMD_SPI_V2: AMDI0062 hardware version */ enum amd_spi_versions { AMD_SPI_V1 = 1, AMD_SPI_V2, }; enum amd_spi_speed { F_66_66MHz, F_33_33MHz, F_22_22MHz, F_16_66MHz, F_100MHz, F_800KHz, SPI_SPD7 = 0x7, F_50MHz = 0x4, F_4MHz = 0x32, F_3_17MHz = 0x3F }; /** * struct amd_spi_freq - Matches device speed with values to write in regs * @speed_hz: Device frequency * @enable_val: Value to be written to "enable register" * @spd7_val: Some frequencies requires to have a value written at SPISPEED register */ struct amd_spi_freq { u32 speed_hz; u32 enable_val; u32 spd7_val; }; /** * struct amd_spi - SPI driver instance * @io_remap_addr: Start address of the SPI controller registers * @version: SPI controller hardware version * @speed_hz: Device frequency */ struct amd_spi { void __iomem *io_remap_addr; enum amd_spi_versions version; unsigned int speed_hz; }; static inline u8 amd_spi_readreg8(struct amd_spi *amd_spi, int idx) { return ioread8((u8 __iomem *)amd_spi->io_remap_addr + idx); } static inline void amd_spi_writereg8(struct amd_spi *amd_spi, int idx, u8 val) { iowrite8(val, ((u8 __iomem *)amd_spi->io_remap_addr + idx)); } static void amd_spi_setclear_reg8(struct amd_spi *amd_spi, int idx, u8 set, u8 clear) { u8 tmp = amd_spi_readreg8(amd_spi, idx); tmp = (tmp & ~clear) | set; amd_spi_writereg8(amd_spi, idx, tmp); } static inline u32 amd_spi_readreg32(struct amd_spi *amd_spi, int idx) { return ioread32((u8 __iomem *)amd_spi->io_remap_addr + idx); } static inline void amd_spi_writereg32(struct amd_spi *amd_spi, int idx, u32 val) { iowrite32(val, ((u8 __iomem *)amd_spi->io_remap_addr + idx)); } static inline void amd_spi_setclear_reg32(struct amd_spi *amd_spi, int idx, u32 set, u32 clear) { u32 tmp = amd_spi_readreg32(amd_spi, idx); tmp = (tmp & ~clear) | set; amd_spi_writereg32(amd_spi, idx, tmp); } static void amd_spi_select_chip(struct amd_spi *amd_spi, u8 cs) { amd_spi_setclear_reg8(amd_spi, AMD_SPI_ALT_CS_REG, cs, AMD_SPI_ALT_CS_MASK); } static inline void amd_spi_clear_chip(struct amd_spi *amd_spi, u8 chip_select) { amd_spi_writereg8(amd_spi, AMD_SPI_ALT_CS_REG, chip_select & ~AMD_SPI_ALT_CS_MASK); } static void amd_spi_clear_fifo_ptr(struct amd_spi *amd_spi) { amd_spi_setclear_reg32(amd_spi, AMD_SPI_CTRL0_REG, AMD_SPI_FIFO_CLEAR, AMD_SPI_FIFO_CLEAR); } static int amd_spi_set_opcode(struct amd_spi *amd_spi, u8 cmd_opcode) { switch (amd_spi->version) { case AMD_SPI_V1: amd_spi_setclear_reg32(amd_spi, AMD_SPI_CTRL0_REG, cmd_opcode, AMD_SPI_OPCODE_MASK); return 0; case AMD_SPI_V2: amd_spi_writereg8(amd_spi, AMD_SPI_OPCODE_REG, cmd_opcode); return 0; default: return -ENODEV; } } static inline void amd_spi_set_rx_count(struct amd_spi *amd_spi, u8 rx_count) { amd_spi_setclear_reg8(amd_spi, AMD_SPI_RX_COUNT_REG, rx_count, 0xff); } static inline void amd_spi_set_tx_count(struct amd_spi *amd_spi, u8 tx_count) { amd_spi_setclear_reg8(amd_spi, AMD_SPI_TX_COUNT_REG, tx_count, 0xff); } static int amd_spi_busy_wait(struct amd_spi *amd_spi) { u32 val; int reg; switch (amd_spi->version) { case AMD_SPI_V1: reg = AMD_SPI_CTRL0_REG; break; case AMD_SPI_V2: reg = AMD_SPI_STATUS_REG; break; default: return -ENODEV; } return readl_poll_timeout(amd_spi->io_remap_addr + reg, val, !(val & AMD_SPI_BUSY), 20, 2000000); } static int amd_spi_execute_opcode(struct amd_spi *amd_spi) { int ret; ret = amd_spi_busy_wait(amd_spi); if (ret) return ret; switch (amd_spi->version) { case AMD_SPI_V1: /* Set ExecuteOpCode bit in the CTRL0 register */ amd_spi_setclear_reg32(amd_spi, AMD_SPI_CTRL0_REG, AMD_SPI_EXEC_CMD, AMD_SPI_EXEC_CMD); return 0; case AMD_SPI_V2: /* Trigger the command execution */ amd_spi_setclear_reg8(amd_spi, AMD_SPI_CMD_TRIGGER_REG, AMD_SPI_TRIGGER_CMD, AMD_SPI_TRIGGER_CMD); return 0; default: return -ENODEV; } } static int amd_spi_master_setup(struct spi_device *spi) { struct amd_spi *amd_spi = spi_master_get_devdata(spi->master); amd_spi_clear_fifo_ptr(amd_spi); return 0; } static const struct amd_spi_freq amd_spi_freq[] = { { AMD_SPI_MAX_HZ, F_100MHz, 0}, { 66660000, F_66_66MHz, 0}, { 50000000, SPI_SPD7, F_50MHz}, { 33330000, F_33_33MHz, 0}, { 22220000, F_22_22MHz, 0}, { 16660000, F_16_66MHz, 0}, { 4000000, SPI_SPD7, F_4MHz}, { 3170000, SPI_SPD7, F_3_17MHz}, { AMD_SPI_MIN_HZ, F_800KHz, 0}, }; static int amd_set_spi_freq(struct amd_spi *amd_spi, u32 speed_hz) { unsigned int i, spd7_val, alt_spd; if (speed_hz < AMD_SPI_MIN_HZ) return -EINVAL; for (i = 0; i < ARRAY_SIZE(amd_spi_freq); i++) if (speed_hz >= amd_spi_freq[i].speed_hz) break; if (amd_spi->speed_hz == amd_spi_freq[i].speed_hz) return 0; amd_spi->speed_hz = amd_spi_freq[i].speed_hz; alt_spd = (amd_spi_freq[i].enable_val << AMD_SPI_ALT_SPD_SHIFT) & AMD_SPI_ALT_SPD_MASK; amd_spi_setclear_reg32(amd_spi, AMD_SPI_ENA_REG, alt_spd, AMD_SPI_ALT_SPD_MASK); if (amd_spi->speed_hz == AMD_SPI_MAX_HZ) amd_spi_setclear_reg32(amd_spi, AMD_SPI_ENA_REG, 1, AMD_SPI_SPI100_MASK); if (amd_spi_freq[i].spd7_val) { spd7_val = (amd_spi_freq[i].spd7_val << AMD_SPI_SPD7_SHIFT) & AMD_SPI_SPD7_MASK; amd_spi_setclear_reg32(amd_spi, AMD_SPI_SPEED_REG, spd7_val, AMD_SPI_SPD7_MASK); } return 0; } static inline int amd_spi_fifo_xfer(struct amd_spi *amd_spi, struct spi_master *master, struct spi_message *message) { struct spi_transfer *xfer = NULL; struct spi_device *spi = message->spi; u8 cmd_opcode = 0, fifo_pos = AMD_SPI_FIFO_BASE; u8 *buf = NULL; u32 i = 0; u32 tx_len = 0, rx_len = 0; list_for_each_entry(xfer, &message->transfers, transfer_list) { if (xfer->speed_hz) amd_set_spi_freq(amd_spi, xfer->speed_hz); else amd_set_spi_freq(amd_spi, spi->max_speed_hz); if (xfer->tx_buf) { buf = (u8 *)xfer->tx_buf; if (!tx_len) { cmd_opcode = *(u8 *)xfer->tx_buf; buf++; xfer->len--; } tx_len += xfer->len; /* Write data into the FIFO. */ for (i = 0; i < xfer->len; i++) amd_spi_writereg8(amd_spi, fifo_pos + i, buf[i]); fifo_pos += xfer->len; } /* Store no. of bytes to be received from FIFO */ if (xfer->rx_buf) rx_len += xfer->len; } if (!buf) { message->status = -EINVAL; goto fin_msg; } amd_spi_set_opcode(amd_spi, cmd_opcode); amd_spi_set_tx_count(amd_spi, tx_len); amd_spi_set_rx_count(amd_spi, rx_len); /* Execute command */ message->status = amd_spi_execute_opcode(amd_spi); if (message->status) goto fin_msg; if (rx_len) { message->status = amd_spi_busy_wait(amd_spi); if (message->status) goto fin_msg; list_for_each_entry(xfer, &message->transfers, transfer_list) if (xfer->rx_buf) { buf = (u8 *)xfer->rx_buf; /* Read data from FIFO to receive buffer */ for (i = 0; i < xfer->len; i++) buf[i] = amd_spi_readreg8(amd_spi, fifo_pos + i); fifo_pos += xfer->len; } } /* Update statistics */ message->actual_length = tx_len + rx_len + 1; fin_msg: switch (amd_spi->version) { case AMD_SPI_V1: break; case AMD_SPI_V2: amd_spi_clear_chip(amd_spi, message->spi->chip_select); break; default: return -ENODEV; } spi_finalize_current_message(master); return message->status; } static int amd_spi_master_transfer(struct spi_master *master, struct spi_message *msg) { struct amd_spi *amd_spi = spi_master_get_devdata(master); struct spi_device *spi = msg->spi; amd_spi_select_chip(amd_spi, spi->chip_select); /* * Extract spi_transfers from the spi message and * program the controller. */ return amd_spi_fifo_xfer(amd_spi, master, msg); } static size_t amd_spi_max_transfer_size(struct spi_device *spi) { return AMD_SPI_FIFO_SIZE; } static int amd_spi_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct spi_master *master; struct amd_spi *amd_spi; int err; /* Allocate storage for spi_master and driver private data */ master = devm_spi_alloc_master(dev, sizeof(struct amd_spi)); if (!master) return dev_err_probe(dev, -ENOMEM, "Error allocating SPI master\n"); amd_spi = spi_master_get_devdata(master); amd_spi->io_remap_addr = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(amd_spi->io_remap_addr)) return dev_err_probe(dev, PTR_ERR(amd_spi->io_remap_addr), "ioremap of SPI registers failed\n"); dev_dbg(dev, "io_remap_address: %p\n", amd_spi->io_remap_addr); amd_spi->version = (enum amd_spi_versions) device_get_match_data(dev); /* Initialize the spi_master fields */ master->bus_num = 0; master->num_chipselect = 4; master->mode_bits = 0; master->flags = SPI_MASTER_HALF_DUPLEX; master->max_speed_hz = AMD_SPI_MAX_HZ; master->min_speed_hz = AMD_SPI_MIN_HZ; master->setup = amd_spi_master_setup; master->transfer_one_message = amd_spi_master_transfer; master->max_transfer_size = amd_spi_max_transfer_size; master->max_message_size = amd_spi_max_transfer_size; /* Register the controller with SPI framework */ err = devm_spi_register_master(dev, master); if (err) return dev_err_probe(dev, err, "error registering SPI controller\n"); return 0; } #ifdef CONFIG_ACPI static const struct acpi_device_id spi_acpi_match[] = { { "AMDI0061", AMD_SPI_V1 }, { "AMDI0062", AMD_SPI_V2 }, {}, }; MODULE_DEVICE_TABLE(acpi, spi_acpi_match); #endif static struct platform_driver amd_spi_driver = { .driver = { .name = "amd_spi", .acpi_match_table = ACPI_PTR(spi_acpi_match), }, .probe = amd_spi_probe, }; module_platform_driver(amd_spi_driver); MODULE_LICENSE("Dual BSD/GPL"); MODULE_AUTHOR("Sanjay Mehta <sanju.mehta@amd.com>"); MODULE_DESCRIPTION("AMD SPI Master Controller Driver");