mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-24 03:22:23 +07:00
85ed0f63c0
Since ACPI_PTR() is used to NULLify the value when !CONFIG_ACPI,
struct 'spi_acpi_match' becomes defined but unused.
Fixes the following W=1 kernel build warning(s):
drivers/spi/spi-amd.c:297:36: warning: ‘spi_acpi_match’ defined but not used [-Wunused-const-variable=]
297 | static const struct acpi_device_id spi_acpi_match[] = {
| ^~~~~~~~~~~~~~
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Cc: Sanjay R Mehta <sanju.mehta@amd.com>
Link: https://lore.kernel.org/r/20200717135424.2442271-15-lee.jones@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
318 lines
7.7 KiB
C
318 lines
7.7 KiB
C
// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
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//
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// AMD SPI controller driver
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//
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// Copyright (c) 2020, Advanced Micro Devices, Inc.
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//
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// Author: Sanjay R Mehta <sanju.mehta@amd.com>
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#include <linux/acpi.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/delay.h>
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#include <linux/spi/spi.h>
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#define AMD_SPI_CTRL0_REG 0x00
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#define AMD_SPI_EXEC_CMD BIT(16)
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#define AMD_SPI_FIFO_CLEAR BIT(20)
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#define AMD_SPI_BUSY BIT(31)
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#define AMD_SPI_OPCODE_MASK 0xFF
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#define AMD_SPI_ALT_CS_REG 0x1D
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#define AMD_SPI_ALT_CS_MASK 0x3
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#define AMD_SPI_FIFO_BASE 0x80
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#define AMD_SPI_TX_COUNT_REG 0x48
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#define AMD_SPI_RX_COUNT_REG 0x4B
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#define AMD_SPI_STATUS_REG 0x4C
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#define AMD_SPI_MEM_SIZE 200
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/* M_CMD OP codes for SPI */
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#define AMD_SPI_XFER_TX 1
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#define AMD_SPI_XFER_RX 2
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struct amd_spi {
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void __iomem *io_remap_addr;
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unsigned long io_base_addr;
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u32 rom_addr;
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u8 chip_select;
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};
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static inline u8 amd_spi_readreg8(struct spi_master *master, int idx)
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{
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struct amd_spi *amd_spi = spi_master_get_devdata(master);
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return ioread8((u8 __iomem *)amd_spi->io_remap_addr + idx);
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}
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static inline void amd_spi_writereg8(struct spi_master *master, int idx,
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u8 val)
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{
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struct amd_spi *amd_spi = spi_master_get_devdata(master);
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iowrite8(val, ((u8 __iomem *)amd_spi->io_remap_addr + idx));
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}
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static inline void amd_spi_setclear_reg8(struct spi_master *master, int idx,
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u8 set, u8 clear)
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{
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u8 tmp = amd_spi_readreg8(master, idx);
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tmp = (tmp & ~clear) | set;
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amd_spi_writereg8(master, idx, tmp);
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}
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static inline u32 amd_spi_readreg32(struct spi_master *master, int idx)
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{
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struct amd_spi *amd_spi = spi_master_get_devdata(master);
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return ioread32((u8 __iomem *)amd_spi->io_remap_addr + idx);
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}
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static inline void amd_spi_writereg32(struct spi_master *master, int idx,
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u32 val)
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{
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struct amd_spi *amd_spi = spi_master_get_devdata(master);
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iowrite32(val, ((u8 __iomem *)amd_spi->io_remap_addr + idx));
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}
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static inline void amd_spi_setclear_reg32(struct spi_master *master, int idx,
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u32 set, u32 clear)
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{
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u32 tmp = amd_spi_readreg32(master, idx);
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tmp = (tmp & ~clear) | set;
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amd_spi_writereg32(master, idx, tmp);
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}
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static void amd_spi_select_chip(struct spi_master *master)
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{
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struct amd_spi *amd_spi = spi_master_get_devdata(master);
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u8 chip_select = amd_spi->chip_select;
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amd_spi_setclear_reg8(master, AMD_SPI_ALT_CS_REG, chip_select,
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AMD_SPI_ALT_CS_MASK);
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}
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static void amd_spi_clear_fifo_ptr(struct spi_master *master)
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{
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amd_spi_setclear_reg32(master, AMD_SPI_CTRL0_REG, AMD_SPI_FIFO_CLEAR,
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AMD_SPI_FIFO_CLEAR);
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}
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static void amd_spi_set_opcode(struct spi_master *master, u8 cmd_opcode)
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{
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amd_spi_setclear_reg32(master, AMD_SPI_CTRL0_REG, cmd_opcode,
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AMD_SPI_OPCODE_MASK);
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}
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static inline void amd_spi_set_rx_count(struct spi_master *master,
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u8 rx_count)
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{
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amd_spi_setclear_reg8(master, AMD_SPI_RX_COUNT_REG, rx_count, 0xff);
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}
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static inline void amd_spi_set_tx_count(struct spi_master *master,
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u8 tx_count)
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{
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amd_spi_setclear_reg8(master, AMD_SPI_TX_COUNT_REG, tx_count, 0xff);
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}
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static inline int amd_spi_busy_wait(struct amd_spi *amd_spi)
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{
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bool spi_busy;
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int timeout = 100000;
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/* poll for SPI bus to become idle */
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spi_busy = (ioread32((u8 __iomem *)amd_spi->io_remap_addr +
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AMD_SPI_CTRL0_REG) & AMD_SPI_BUSY) == AMD_SPI_BUSY;
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while (spi_busy) {
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usleep_range(10, 20);
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if (timeout-- < 0)
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return -ETIMEDOUT;
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spi_busy = (ioread32((u8 __iomem *)amd_spi->io_remap_addr +
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AMD_SPI_CTRL0_REG) & AMD_SPI_BUSY) == AMD_SPI_BUSY;
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}
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return 0;
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}
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static void amd_spi_execute_opcode(struct spi_master *master)
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{
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struct amd_spi *amd_spi = spi_master_get_devdata(master);
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/* Set ExecuteOpCode bit in the CTRL0 register */
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amd_spi_setclear_reg32(master, AMD_SPI_CTRL0_REG, AMD_SPI_EXEC_CMD,
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AMD_SPI_EXEC_CMD);
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amd_spi_busy_wait(amd_spi);
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}
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static int amd_spi_master_setup(struct spi_device *spi)
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{
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struct spi_master *master = spi->master;
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amd_spi_clear_fifo_ptr(master);
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return 0;
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}
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static inline int amd_spi_fifo_xfer(struct amd_spi *amd_spi,
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struct spi_master *master,
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struct spi_message *message)
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{
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struct spi_transfer *xfer = NULL;
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u8 cmd_opcode;
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u8 *buf = NULL;
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u32 m_cmd = 0;
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u32 i = 0;
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u32 tx_len = 0, rx_len = 0;
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list_for_each_entry(xfer, &message->transfers,
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transfer_list) {
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if (xfer->rx_buf)
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m_cmd = AMD_SPI_XFER_RX;
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if (xfer->tx_buf)
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m_cmd = AMD_SPI_XFER_TX;
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if (m_cmd & AMD_SPI_XFER_TX) {
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buf = (u8 *)xfer->tx_buf;
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tx_len = xfer->len - 1;
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cmd_opcode = *(u8 *)xfer->tx_buf;
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buf++;
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amd_spi_set_opcode(master, cmd_opcode);
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/* Write data into the FIFO. */
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for (i = 0; i < tx_len; i++) {
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iowrite8(buf[i],
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((u8 __iomem *)amd_spi->io_remap_addr +
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AMD_SPI_FIFO_BASE + i));
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}
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amd_spi_set_tx_count(master, tx_len);
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amd_spi_clear_fifo_ptr(master);
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/* Execute command */
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amd_spi_execute_opcode(master);
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}
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if (m_cmd & AMD_SPI_XFER_RX) {
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/*
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* Store no. of bytes to be received from
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* FIFO
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*/
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rx_len = xfer->len;
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buf = (u8 *)xfer->rx_buf;
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amd_spi_set_rx_count(master, rx_len);
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amd_spi_clear_fifo_ptr(master);
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/* Execute command */
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amd_spi_execute_opcode(master);
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/* Read data from FIFO to receive buffer */
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for (i = 0; i < rx_len; i++)
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buf[i] = amd_spi_readreg8(master,
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AMD_SPI_FIFO_BASE +
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tx_len + i);
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}
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}
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/* Update statistics */
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message->actual_length = tx_len + rx_len + 1;
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/* complete the transaction */
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message->status = 0;
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spi_finalize_current_message(master);
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return 0;
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}
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static int amd_spi_master_transfer(struct spi_master *master,
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struct spi_message *msg)
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{
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struct amd_spi *amd_spi = spi_master_get_devdata(master);
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struct spi_device *spi = msg->spi;
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amd_spi->chip_select = spi->chip_select;
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amd_spi_select_chip(master);
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/*
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* Extract spi_transfers from the spi message and
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* program the controller.
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*/
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amd_spi_fifo_xfer(amd_spi, master, msg);
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return 0;
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}
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static int amd_spi_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct spi_master *master;
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struct amd_spi *amd_spi;
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struct resource *res;
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int err = 0;
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/* Allocate storage for spi_master and driver private data */
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master = spi_alloc_master(dev, sizeof(struct amd_spi));
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if (!master) {
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dev_err(dev, "Error allocating SPI master\n");
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return -ENOMEM;
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}
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amd_spi = spi_master_get_devdata(master);
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res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
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amd_spi->io_remap_addr = devm_ioremap_resource(&pdev->dev, res);
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if (IS_ERR(amd_spi->io_remap_addr)) {
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err = PTR_ERR(amd_spi->io_remap_addr);
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dev_err(dev, "error %d ioremap of SPI registers failed\n", err);
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goto err_free_master;
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}
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dev_dbg(dev, "io_remap_address: %p\n", amd_spi->io_remap_addr);
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/* Initialize the spi_master fields */
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master->bus_num = 0;
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master->num_chipselect = 4;
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master->mode_bits = 0;
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master->flags = SPI_MASTER_HALF_DUPLEX;
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master->setup = amd_spi_master_setup;
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master->transfer_one_message = amd_spi_master_transfer;
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/* Register the controller with SPI framework */
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err = devm_spi_register_master(dev, master);
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if (err) {
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dev_err(dev, "error %d registering SPI controller\n", err);
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goto err_free_master;
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}
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return 0;
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err_free_master:
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spi_master_put(master);
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return err;
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}
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#ifdef CONFIG_ACPI
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static const struct acpi_device_id spi_acpi_match[] = {
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{ "AMDI0061", 0 },
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{},
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};
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MODULE_DEVICE_TABLE(acpi, spi_acpi_match);
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#endif
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static struct platform_driver amd_spi_driver = {
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.driver = {
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.name = "amd_spi",
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.acpi_match_table = ACPI_PTR(spi_acpi_match),
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},
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.probe = amd_spi_probe,
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};
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module_platform_driver(amd_spi_driver);
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MODULE_LICENSE("Dual BSD/GPL");
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MODULE_AUTHOR("Sanjay Mehta <sanju.mehta@amd.com>");
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MODULE_DESCRIPTION("AMD SPI Master Controller Driver");
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