// SPDX-License-Identifier: GPL-2.0-only
/*
* Rockchip Serial Flash Controller Driver
*
* Copyright (c) 2017-2021, Rockchip Inc.
* Author: Shawn Lin <shawn.lin@rock-chips.com>
* Chris Morgan <macroalpha82@gmail.com>
* Jon Lin <Jon.lin@rock-chips.com>
*/
#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/dma-mapping.h>
#include <linux/iopoll.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/spi/spi-mem.h>
/* System control */
#define SFC_CTRL 0x0
#define SFC_CTRL_PHASE_SEL_NEGETIVE BIT(1)
#define SFC_CTRL_CMD_BITS_SHIFT 8
#define SFC_CTRL_ADDR_BITS_SHIFT 10
#define SFC_CTRL_DATA_BITS_SHIFT 12
/* Interrupt mask */
#define SFC_IMR 0x4
#define SFC_IMR_RX_FULL BIT(0)
#define SFC_IMR_RX_UFLOW BIT(1)
#define SFC_IMR_TX_OFLOW BIT(2)
#define SFC_IMR_TX_EMPTY BIT(3)
#define SFC_IMR_TRAN_FINISH BIT(4)
#define SFC_IMR_BUS_ERR BIT(5)
#define SFC_IMR_NSPI_ERR BIT(6)
#define SFC_IMR_DMA BIT(7)
/* Interrupt clear */
#define SFC_ICLR 0x8
#define SFC_ICLR_RX_FULL BIT(0)
#define SFC_ICLR_RX_UFLOW BIT(1)
#define SFC_ICLR_TX_OFLOW BIT(2)
#define SFC_ICLR_TX_EMPTY BIT(3)
#define SFC_ICLR_TRAN_FINISH BIT(4)
#define SFC_ICLR_BUS_ERR BIT(5)
#define SFC_ICLR_NSPI_ERR BIT(6)
#define SFC_ICLR_DMA BIT(7)
/* FIFO threshold level */
#define SFC_FTLR 0xc
#define SFC_FTLR_TX_SHIFT 0
#define SFC_FTLR_TX_MASK 0x1f
#define SFC_FTLR_RX_SHIFT 8
#define SFC_FTLR_RX_MASK 0x1f
/* Reset FSM and FIFO */
#define SFC_RCVR 0x10
#define SFC_RCVR_RESET BIT(0)
/* Enhanced mode */
#define SFC_AX 0x14
/* Address Bit number */
#define SFC_ABIT 0x18
/* Interrupt status */
#define SFC_ISR 0x1c
#define SFC_ISR_RX_FULL_SHIFT BIT(0)
#define SFC_ISR_RX_UFLOW_SHIFT BIT(1)
#define SFC_ISR_TX_OFLOW_SHIFT BIT(2)
#define SFC_ISR_TX_EMPTY_SHIFT BIT(3)
#define SFC_ISR_TX_FINISH_SHIFT BIT(4)
#define SFC_ISR_BUS_ERR_SHIFT BIT(5)
#define SFC_ISR_NSPI_ERR_SHIFT BIT(6)
#define SFC_ISR_DMA_SHIFT BIT(7)
/* FIFO status */
#define SFC_FSR 0x20
#define SFC_FSR_TX_IS_FULL BIT(0)
#define SFC_FSR_TX_IS_EMPTY BIT(1)
#define SFC_FSR_RX_IS_EMPTY BIT(2)
#define SFC_FSR_RX_IS_FULL BIT(3)
#define SFC_FSR_TXLV_MASK GENMASK(12, 8)
#define SFC_FSR_TXLV_SHIFT 8
#define SFC_FSR_RXLV_MASK GENMASK(20, 16)
#define SFC_FSR_RXLV_SHIFT 16
/* FSM status */
#define SFC_SR 0x24
#define SFC_SR_IS_IDLE 0x0
#define SFC_SR_IS_BUSY 0x1
/* Raw interrupt status */
#define SFC_RISR 0x28
#define SFC_RISR_RX_FULL BIT(0)
#define SFC_RISR_RX_UNDERFLOW BIT(1)
#define SFC_RISR_TX_OVERFLOW BIT(2)
#define SFC_RISR_TX_EMPTY BIT(3)
#define SFC_RISR_TRAN_FINISH BIT(4)
#define SFC_RISR_BUS_ERR BIT(5)
#define SFC_RISR_NSPI_ERR BIT(6)
#define SFC_RISR_DMA BIT(7)
/* Version */
#define SFC_VER 0x2C
#define SFC_VER_3 0x3
#define SFC_VER_4 0x4
#define SFC_VER_5 0x5
/* Delay line controller resiter */
#define SFC_DLL_CTRL0 0x3C
#define SFC_DLL_CTRL0_SCLK_SMP_DLL BIT(15)
#define SFC_DLL_CTRL0_DLL_MAX_VER4 0xFFU
#define SFC_DLL_CTRL0_DLL_MAX_VER5 0x1FFU
/* Master trigger */
#define SFC_DMA_TRIGGER 0x80
#define SFC_DMA_TRIGGER_START 1
/* Src or Dst addr for master */
#define SFC_DMA_ADDR 0x84
/* Length control register extension 32GB */
#define SFC_LEN_CTRL 0x88
#define SFC_LEN_CTRL_TRB_SEL 1
#define SFC_LEN_EXT 0x8C
/* Command */
#define SFC_CMD 0x100
#define SFC_CMD_IDX_SHIFT 0
#define SFC_CMD_DUMMY_SHIFT 8
#define SFC_CMD_DIR_SHIFT 12
#define SFC_CMD_DIR_RD 0
#define SFC_CMD_DIR_WR 1
#define SFC_CMD_ADDR_SHIFT 14
#define SFC_CMD_ADDR_0BITS 0
#define SFC_CMD_ADDR_24BITS 1
#define SFC_CMD_ADDR_32BITS 2
#define SFC_CMD_ADDR_XBITS 3
#define SFC_CMD_TRAN_BYTES_SHIFT 16
#define SFC_CMD_CS_SHIFT 30
/* Address */
#define SFC_ADDR 0x104
/* Data */
#define SFC_DATA 0x108
/* The controller and documentation reports that it supports up to 4 CS
* devices (0-3), however I have only been able to test a single CS (CS 0)
* due to the configuration of my device.
*/
#define SFC_MAX_CHIPSELECT_NUM 4
/* The SFC can transfer max 16KB - 1 at one time
* we set it to 15.5KB here for alignment.
*/
#define SFC_MAX_IOSIZE_VER3 (512 * 31)
/* DMA is only enabled for large data transmission */
#define SFC_DMA_TRANS_THRETHOLD (0x40)
/* Maximum clock values from datasheet suggest keeping clock value under
* 150MHz. No minimum or average value is suggested.
*/
#define SFC_MAX_SPEED (150 * 1000 * 1000)
struct rockchip_sfc {
struct device *dev;
void __iomem *regbase;
struct clk *hclk;
struct clk *clk;
u32 frequency;
/* virtual mapped addr for dma_buffer */
void *buffer;
dma_addr_t dma_buffer;
struct completion cp;
bool use_dma;
u32 max_iosize;
u16 version;
};
static int rockchip_sfc_reset(struct rockchip_sfc *sfc)
{
int err;
u32 status;
writel_relaxed(SFC_RCVR_RESET, sfc->regbase + SFC_RCVR);
err = readl_poll_timeout(sfc->regbase + SFC_RCVR, status,
!(status & SFC_RCVR_RESET), 20,
jiffies_to_usecs(HZ));
if (err)
dev_err(sfc->dev, "SFC reset never finished\n");
/* Still need to clear the masked interrupt from RISR */
writel_relaxed(0xFFFFFFFF, sfc->regbase + SFC_ICLR);
dev_dbg(sfc->dev, "reset\n");
return err;
}
static u16 rockchip_sfc_get_version(struct rockchip_sfc *sfc)
{
return (u16)(readl(sfc->regbase + SFC_VER) & 0xffff);
}
static u32 rockchip_sfc_get_max_iosize(struct rockchip_sfc *sfc)
{
return SFC_MAX_IOSIZE_VER3;
}
static void rockchip_sfc_irq_unmask(struct rockchip_sfc *sfc, u32 mask)
{
u32 reg;
/* Enable transfer complete interrupt */
reg = readl(sfc->regbase + SFC_IMR);
reg &= ~mask;
writel(reg, sfc->regbase + SFC_IMR);
}
static void rockchip_sfc_irq_mask(struct rockchip_sfc *sfc, u32 mask)
{
u32 reg;
/* Disable transfer finish interrupt */
reg = readl(sfc->regbase + SFC_IMR);
reg |= mask;
writel(reg, sfc->regbase + SFC_IMR);
}
static int rockchip_sfc_init(struct rockchip_sfc *sfc)
{
writel(0, sfc->regbase + SFC_CTRL);
writel(0xFFFFFFFF, sfc->regbase + SFC_ICLR);
rockchip_sfc_irq_mask(sfc, 0xFFFFFFFF);
if (rockchip_sfc_get_version(sfc) >= SFC_VER_4)
writel(SFC_LEN_CTRL_TRB_SEL, sfc->regbase + SFC_LEN_CTRL);
return 0;
}
static int rockchip_sfc_wait_txfifo_ready(struct rockchip_sfc *sfc, u32 timeout_us)
{
int ret = 0;
u32 status;
ret = readl_poll_timeout(sfc->regbase + SFC_FSR, status,
status & SFC_FSR_TXLV_MASK, 0,
timeout_us);
if (ret) {
dev_dbg(sfc->dev, "sfc wait tx fifo timeout\n");
return -ETIMEDOUT;
}
return (status & SFC_FSR_TXLV_MASK) >> SFC_FSR_TXLV_SHIFT;
}
static int rockchip_sfc_wait_rxfifo_ready(struct rockchip_sfc *sfc, u32 timeout_us)
{
int ret = 0;
u32 status;
ret = readl_poll_timeout(sfc->regbase + SFC_FSR, status,
status & SFC_FSR_RXLV_MASK, 0,
timeout_us);
if (ret) {
dev_dbg(sfc->dev, "sfc wait rx fifo timeout\n");
return -ETIMEDOUT;
}
return (status & SFC_FSR_RXLV_MASK) >> SFC_FSR_RXLV_SHIFT;
}
static void rockchip_sfc_adjust_op_work(struct spi_mem_op *op)
{
if (unlikely(op->dummy.nbytes && !op->addr.nbytes)) {
/*
* SFC not support output DUMMY cycles right after CMD cycles, so
* treat it as ADDR cycles.
*/
op->addr.nbytes = op->dummy.nbytes;
op->addr.buswidth = op->dummy.buswidth;
op->addr.val = 0xFFFFFFFFF;
op->dummy.nbytes = 0;
}
}
static int rockchip_sfc_xfer_setup(struct rockchip_sfc *sfc,
struct spi_mem *mem,
const struct spi_mem_op *op,
u32 len)
{
u32 ctrl = 0, cmd = 0;
/* set CMD */
cmd = op->cmd.opcode;
ctrl |= ((op->cmd.buswidth >> 1) << SFC_CTRL_CMD_BITS_SHIFT);
/* set ADDR */
if (op->addr.nbytes) {
if (op->addr.nbytes == 4) {
cmd |= SFC_CMD_ADDR_32BITS << SFC_CMD_ADDR_SHIFT;
} else if (op->addr.nbytes == 3) {
cmd |= SFC_CMD_ADDR_24BITS << SFC_CMD_ADDR_SHIFT;
} else {
cmd |= SFC_CMD_ADDR_XBITS << SFC_CMD_ADDR_SHIFT;
writel(op->addr.nbytes * 8 - 1, sfc->regbase + SFC_ABIT);
}
ctrl |= ((op->addr.buswidth >> 1) << SFC_CTRL_ADDR_BITS_SHIFT);
}
/* set DUMMY */
if (op->dummy.nbytes) {
if (op->dummy.buswidth == 4)
cmd |= op->dummy.nbytes * 2 << SFC_CMD_DUMMY_SHIFT;
else if (op->dummy.buswidth == 2)
cmd |= op->dummy.nbytes * 4 << SFC_CMD_DUMMY_SHIFT;
else
cmd |= op->dummy.nbytes * 8 << SFC_CMD_DUMMY_SHIFT;
}
/* set DATA */
if (sfc->version >= SFC_VER_4) /* Clear it if no data to transfer */
writel(len, sfc->regbase + SFC_LEN_EXT);
else
cmd |= len << SFC_CMD_TRAN_BYTES_SHIFT;
if (len) {
if (op->data.dir == SPI_MEM_DATA_OUT)
cmd |= SFC_CMD_DIR_WR << SFC_CMD_DIR_SHIFT;
ctrl |= ((op->data.buswidth >> 1) << SFC_CTRL_DATA_BITS_SHIFT);
}
if (!len && op->addr.nbytes)
cmd |= SFC_CMD_DIR_WR << SFC_CMD_DIR_SHIFT;
/* set the Controller */
ctrl |= SFC_CTRL_PHASE_SEL_NEGETIVE;
cmd |= mem->spi->chip_select << SFC_CMD_CS_SHIFT;
dev_dbg(sfc->dev, "sfc addr.nbytes=%x(x%d) dummy.nbytes=%x(x%d)\n",
op->addr.nbytes, op->addr.buswidth,
op->dummy.nbytes, op->dummy.buswidth);
dev_dbg(sfc->dev, "sfc ctrl=%x cmd=%x addr=%llx len=%x\n",
ctrl, cmd, op->addr.val, len);
writel(ctrl, sfc->regbase + SFC_CTRL);
writel(cmd, sfc->regbase + SFC_CMD);
if (op->addr.nbytes)
writel(op->addr.val, sfc->regbase + SFC_ADDR);
return 0;
}
static int rockchip_sfc_write_fifo(struct rockchip_sfc *sfc, const u8 *buf, int len)
{
u8 bytes = len & 0x3;
u32 dwords;
int tx_level;
u32 write_words;
u32 tmp = 0;
dwords = len >> 2;
while (dwords) {
tx_level = rockchip_sfc_wait_txfifo_ready(sfc, 1000);
if (tx_level < 0)
return tx_level;
write_words = min_t(u32, tx_level, dwords);
iowrite32_rep(sfc->regbase + SFC_DATA, buf, write_words);
buf += write_words << 2;
dwords -= write_words;
}
/* write the rest non word aligned bytes */
if (bytes) {
tx_level = rockchip_sfc_wait_txfifo_ready(sfc, 1000);
if (tx_level < 0)
return tx_level;
memcpy(&tmp, buf, bytes);
writel(tmp, sfc->regbase + SFC_DATA);
}
return len;
}
static int rockchip_sfc_read_fifo(struct rockchip_sfc *sfc, u8 *buf, int len)
{
u8 bytes = len & 0x3;
u32 dwords;
u8 read_words;
int rx_level;
int tmp;
/* word aligned access only */
dwords = len >> 2;
while (dwords) {
rx_level = rockchip_sfc_wait_rxfifo_ready(sfc, 1000);
if (rx_level < 0)
return rx_level;
read_words = min_t(u32, rx_level, dwords);
ioread32_rep(sfc->regbase + SFC_DATA, buf, read_words);
buf += read_words << 2;
dwords -= read_words;
}
/* read the rest non word aligned bytes */
if (bytes) {
rx_level = rockchip_sfc_wait_rxfifo_ready(sfc, 1000);
if (rx_level < 0)
return rx_level;
tmp = readl(sfc->regbase + SFC_DATA);
memcpy(buf, &tmp, bytes);
}
return len;
}
static int rockchip_sfc_fifo_transfer_dma(struct rockchip_sfc *sfc, dma_addr_t dma_buf, size_t len)
{
writel(0xFFFFFFFF, sfc->regbase + SFC_ICLR);
writel((u32)dma_buf, sfc->regbase + SFC_DMA_ADDR);
writel(SFC_DMA_TRIGGER_START, sfc->regbase + SFC_DMA_TRIGGER);
return len;
}
static int rockchip_sfc_xfer_data_poll(struct rockchip_sfc *sfc,
const struct spi_mem_op *op, u32 len)
{
dev_dbg(sfc->dev, "sfc xfer_poll len=%x\n", len);
if (op->data.dir == SPI_MEM_DATA_OUT)
return rockchip_sfc_write_fifo(sfc, op->data.buf.out, len);
else
return rockchip_sfc_read_fifo(sfc, op->data.buf.in, len);
}
static int rockchip_sfc_xfer_data_dma(struct rockchip_sfc *sfc,
const struct spi_mem_op *op, u32 len)
{
int ret;
dev_dbg(sfc->dev, "sfc xfer_dma len=%x\n", len);
if (op->data.dir == SPI_MEM_DATA_OUT)
memcpy(sfc->buffer, op->data.buf.out, len);
ret = rockchip_sfc_fifo_transfer_dma(sfc, sfc->dma_buffer, len);
if (!wait_for_completion_timeout(&sfc->cp, msecs_to_jiffies(2000))) {
dev_err(sfc->dev, "DMA wait for transfer finish timeout\n");
ret = -ETIMEDOUT;
}
rockchip_sfc_irq_mask(sfc, SFC_IMR_DMA);
if (op->data.dir == SPI_MEM_DATA_IN)
memcpy(op->data.buf.in, sfc->buffer, len);
return ret;
}
static int rockchip_sfc_xfer_done(struct rockchip_sfc *sfc, u32 timeout_us)
{
int ret = 0;
u32 status;
ret = readl_poll_timeout(sfc->regbase + SFC_SR, status,
!(status & SFC_SR_IS_BUSY),
20, timeout_us);
if (ret) {
dev_err(sfc->dev, "wait sfc idle timeout\n");
rockchip_sfc_reset(sfc);
ret = -EIO;
}
return ret;
}
static int rockchip_sfc_exec_mem_op(struct spi_mem *mem, const struct spi_mem_op *op)
{
struct rockchip_sfc *sfc = spi_master_get_devdata(mem->spi->master);
u32 len = op->data.nbytes;
int ret;
if (unlikely(mem->spi->max_speed_hz != sfc->frequency)) {
ret = clk_set_rate(sfc->clk, mem->spi->max_speed_hz);
if (ret)
return ret;
sfc->frequency = mem->spi->max_speed_hz;
dev_dbg(sfc->dev, "set_freq=%dHz real_freq=%ldHz\n",
sfc->frequency, clk_get_rate(sfc->clk));
}
rockchip_sfc_adjust_op_work((struct spi_mem_op *)op);
rockchip_sfc_xfer_setup(sfc, mem, op, len);
if (len) {
if (likely(sfc->use_dma) && len >= SFC_DMA_TRANS_THRETHOLD) {
init_completion(&sfc->cp);
rockchip_sfc_irq_unmask(sfc, SFC_IMR_DMA);
ret = rockchip_sfc_xfer_data_dma(sfc, op, len);
} else {
ret = rockchip_sfc_xfer_data_poll(sfc, op, len);
}
if (ret != len) {
dev_err(sfc->dev, "xfer data failed ret %d dir %d\n", ret, op->data.dir);
return -EIO;
}
}
return rockchip_sfc_xfer_done(sfc, 100000);
}
static int rockchip_sfc_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op)
{
struct rockchip_sfc *sfc = spi_master_get_devdata(mem->spi->master);
op->data.nbytes = min(op->data.nbytes, sfc->max_iosize);
return 0;
}
static const struct spi_controller_mem_ops rockchip_sfc_mem_ops = {
.exec_op = rockchip_sfc_exec_mem_op,
.adjust_op_size = rockchip_sfc_adjust_op_size,
};
static irqreturn_t rockchip_sfc_irq_handler(int irq, void *dev_id)
{
struct rockchip_sfc *sfc = dev_id;
u32 reg;
reg = readl(sfc->regbase + SFC_RISR);
/* Clear interrupt */
writel_relaxed(reg, sfc->regbase + SFC_ICLR);
if (reg & SFC_RISR_DMA) {
complete(&sfc->cp);
return IRQ_HANDLED;
}
return IRQ_NONE;
}
static int rockchip_sfc_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct spi_master *master;
struct resource *res;
struct rockchip_sfc *sfc;
int ret;
master = devm_spi_alloc_master(&pdev->dev, sizeof(*sfc));
if (!master)
return -ENOMEM;
master->flags = SPI_MASTER_HALF_DUPLEX;
master->mem_ops = &rockchip_sfc_mem_ops;
master->dev.of_node = pdev->dev.of_node;
master->mode_bits = SPI_TX_QUAD | SPI_TX_DUAL | SPI_RX_QUAD | SPI_RX_DUAL;
master->max_speed_hz = SFC_MAX_SPEED;
master->num_chipselect = SFC_MAX_CHIPSELECT_NUM;
sfc = spi_master_get_devdata(master);
sfc->dev = dev;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
sfc->regbase = devm_ioremap_resource(dev, res);
if (IS_ERR(sfc->regbase))
return PTR_ERR(sfc->regbase);
sfc->clk = devm_clk_get(&pdev->dev, "clk_sfc");
if (IS_ERR(sfc->clk)) {
dev_err(&pdev->dev, "Failed to get sfc interface clk\n");
return PTR_ERR(sfc->clk);
}
sfc->hclk = devm_clk_get(&pdev->dev, "hclk_sfc");
if (IS_ERR(sfc->hclk)) {
dev_err(&pdev->dev, "Failed to get sfc ahb clk\n");
return PTR_ERR(sfc->hclk);
}
sfc->use_dma = !of_property_read_bool(sfc->dev->of_node,
"rockchip,sfc-no-dma");
if (sfc->use_dma) {
ret = dma_set_mask_and_coherent(dev, DMA_BIT_MASK(32));
if (ret) {
dev_warn(dev, "Unable to set dma mask\n");
return ret;
}
sfc->buffer = dmam_alloc_coherent(dev, SFC_MAX_IOSIZE_VER3,
&sfc->dma_buffer,
GFP_KERNEL);
if (!sfc->buffer)
return -ENOMEM;
}
ret = clk_prepare_enable(sfc->hclk);
if (ret) {
dev_err(&pdev->dev, "Failed to enable ahb clk\n");
goto err_hclk;
}
ret = clk_prepare_enable(sfc->clk);
if (ret) {
dev_err(&pdev->dev, "Failed to enable interface clk\n");
goto err_clk;
}
/* Find the irq */
ret = platform_get_irq(pdev, 0);
if (ret < 0) {
dev_err(dev, "Failed to get the irq\n");
goto err_irq;
}
ret = devm_request_irq(dev, ret, rockchip_sfc_irq_handler,
0, pdev->name, sfc);
if (ret) {
dev_err(dev, "Failed to request irq\n");
return ret;
}
ret = rockchip_sfc_init(sfc);
if (ret)
goto err_irq;
sfc->max_iosize = rockchip_sfc_get_max_iosize(sfc);
sfc->version = rockchip_sfc_get_version(sfc);
ret = spi_register_master(master);
if (ret)
goto err_irq;
return 0;
err_irq:
clk_disable_unprepare(sfc->clk);
err_clk:
clk_disable_unprepare(sfc->hclk);
err_hclk:
return ret;
}
static int rockchip_sfc_remove(struct platform_device *pdev)
{
struct spi_master *master = platform_get_drvdata(pdev);
struct rockchip_sfc *sfc = platform_get_drvdata(pdev);
spi_unregister_master(master);
clk_disable_unprepare(sfc->clk);
clk_disable_unprepare(sfc->hclk);
return 0;
}
static const struct of_device_id rockchip_sfc_dt_ids[] = {
{ .compatible = "rockchip,sfc"},
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, rockchip_sfc_dt_ids);
static struct platform_driver rockchip_sfc_driver = {
.driver = {
.name = "rockchip-sfc",
.of_match_table = rockchip_sfc_dt_ids,
},
.probe = rockchip_sfc_probe,
.remove = rockchip_sfc_remove,
};
module_platform_driver(rockchip_sfc_driver);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Rockchip Serial Flash Controller Driver");
MODULE_AUTHOR("Shawn Lin <shawn.lin@rock-chips.com>");
MODULE_AUTHOR("Chris Morgan <macromorgan@hotmail.com>");
MODULE_AUTHOR("Jon Lin <Jon.lin@rock-chips.com>");