linux/drivers/spi/spi-hisi-kunpeng.c
Devyn Liu 7430764f5a
spi: hisi-kunpeng: Delete the dump interface of data registers in debugfs
Due to the reading of FIFO during the dump of data registers in
debugfs, if SPI transmission is in progress, it will be affected
and may result in transmission failure. Therefore, the dump
interface of data registers in debugfs is removed.

Fixes: 2b2142f247 ("spi: hisi-kunpeng: Add debugfs support")
Signed-off-by: Devyn Liu <liudingyuan@huawei.com>
Reviewed-by: Jay Fang <f.fangjian@huawei.com>
Link: https://lore.kernel.org/r/20240416015839.3323398-1-liudingyuan@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2024-04-16 19:59:48 +09:00

552 lines
14 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
//
// HiSilicon SPI Controller Driver for Kunpeng SoCs
//
// Copyright (c) 2021 HiSilicon Technologies Co., Ltd.
// Author: Jay Fang <f.fangjian@huawei.com>
//
// This code is based on spi-dw-core.c.
#include <linux/acpi.h>
#include <linux/bitfield.h>
#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/property.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/spi/spi.h>
/* Register offsets */
#define HISI_SPI_CSCR 0x00 /* cs control register */
#define HISI_SPI_CR 0x04 /* spi common control register */
#define HISI_SPI_ENR 0x08 /* spi enable register */
#define HISI_SPI_FIFOC 0x0c /* fifo level control register */
#define HISI_SPI_IMR 0x10 /* interrupt mask register */
#define HISI_SPI_DIN 0x14 /* data in register */
#define HISI_SPI_DOUT 0x18 /* data out register */
#define HISI_SPI_SR 0x1c /* status register */
#define HISI_SPI_RISR 0x20 /* raw interrupt status register */
#define HISI_SPI_ISR 0x24 /* interrupt status register */
#define HISI_SPI_ICR 0x28 /* interrupt clear register */
#define HISI_SPI_VERSION 0xe0 /* version register */
/* Bit fields in HISI_SPI_CR */
#define CR_LOOP_MASK GENMASK(1, 1)
#define CR_CPOL_MASK GENMASK(2, 2)
#define CR_CPHA_MASK GENMASK(3, 3)
#define CR_DIV_PRE_MASK GENMASK(11, 4)
#define CR_DIV_POST_MASK GENMASK(19, 12)
#define CR_BPW_MASK GENMASK(24, 20)
#define CR_SPD_MODE_MASK GENMASK(25, 25)
/* Bit fields in HISI_SPI_FIFOC */
#define FIFOC_TX_MASK GENMASK(5, 3)
#define FIFOC_RX_MASK GENMASK(11, 9)
/* Bit fields in HISI_SPI_IMR, 4 bits */
#define IMR_RXOF BIT(0) /* Receive Overflow */
#define IMR_RXTO BIT(1) /* Receive Timeout */
#define IMR_RX BIT(2) /* Receive */
#define IMR_TX BIT(3) /* Transmit */
#define IMR_MASK (IMR_RXOF | IMR_RXTO | IMR_RX | IMR_TX)
/* Bit fields in HISI_SPI_SR, 5 bits */
#define SR_TXE BIT(0) /* Transmit FIFO empty */
#define SR_TXNF BIT(1) /* Transmit FIFO not full */
#define SR_RXNE BIT(2) /* Receive FIFO not empty */
#define SR_RXF BIT(3) /* Receive FIFO full */
#define SR_BUSY BIT(4) /* Busy Flag */
/* Bit fields in HISI_SPI_ISR, 4 bits */
#define ISR_RXOF BIT(0) /* Receive Overflow */
#define ISR_RXTO BIT(1) /* Receive Timeout */
#define ISR_RX BIT(2) /* Receive */
#define ISR_TX BIT(3) /* Transmit */
#define ISR_MASK (ISR_RXOF | ISR_RXTO | ISR_RX | ISR_TX)
/* Bit fields in HISI_SPI_ICR, 2 bits */
#define ICR_RXOF BIT(0) /* Receive Overflow */
#define ICR_RXTO BIT(1) /* Receive Timeout */
#define ICR_MASK (ICR_RXOF | ICR_RXTO)
#define DIV_POST_MAX 0xFF
#define DIV_POST_MIN 0x00
#define DIV_PRE_MAX 0xFE
#define DIV_PRE_MIN 0x02
#define CLK_DIV_MAX ((1 + DIV_POST_MAX) * DIV_PRE_MAX)
#define CLK_DIV_MIN ((1 + DIV_POST_MIN) * DIV_PRE_MIN)
#define DEFAULT_NUM_CS 1
#define HISI_SPI_WAIT_TIMEOUT_MS 10UL
enum hisi_spi_rx_level_trig {
HISI_SPI_RX_1,
HISI_SPI_RX_4,
HISI_SPI_RX_8,
HISI_SPI_RX_16,
HISI_SPI_RX_32,
HISI_SPI_RX_64,
HISI_SPI_RX_128
};
enum hisi_spi_tx_level_trig {
HISI_SPI_TX_1_OR_LESS,
HISI_SPI_TX_4_OR_LESS,
HISI_SPI_TX_8_OR_LESS,
HISI_SPI_TX_16_OR_LESS,
HISI_SPI_TX_32_OR_LESS,
HISI_SPI_TX_64_OR_LESS,
HISI_SPI_TX_128_OR_LESS
};
enum hisi_spi_frame_n_bytes {
HISI_SPI_N_BYTES_NULL,
HISI_SPI_N_BYTES_U8,
HISI_SPI_N_BYTES_U16,
HISI_SPI_N_BYTES_U32 = 4
};
/* Slave spi_dev related */
struct hisi_chip_data {
u32 cr;
u32 speed_hz; /* baud rate */
u16 clk_div; /* baud rate divider */
/* clk_div = (1 + div_post) * div_pre */
u8 div_post; /* value from 0 to 255 */
u8 div_pre; /* value from 2 to 254 (even only!) */
};
struct hisi_spi {
struct device *dev;
void __iomem *regs;
int irq;
u32 fifo_len; /* depth of the FIFO buffer */
/* Current message transfer state info */
const void *tx;
unsigned int tx_len;
void *rx;
unsigned int rx_len;
u8 n_bytes; /* current is a 1/2/4 bytes op */
struct dentry *debugfs;
struct debugfs_regset32 regset;
};
#define HISI_SPI_DBGFS_REG(_name, _off) \
{ \
.name = _name, \
.offset = _off, \
}
static const struct debugfs_reg32 hisi_spi_regs[] = {
HISI_SPI_DBGFS_REG("CSCR", HISI_SPI_CSCR),
HISI_SPI_DBGFS_REG("CR", HISI_SPI_CR),
HISI_SPI_DBGFS_REG("ENR", HISI_SPI_ENR),
HISI_SPI_DBGFS_REG("FIFOC", HISI_SPI_FIFOC),
HISI_SPI_DBGFS_REG("IMR", HISI_SPI_IMR),
HISI_SPI_DBGFS_REG("SR", HISI_SPI_SR),
HISI_SPI_DBGFS_REG("RISR", HISI_SPI_RISR),
HISI_SPI_DBGFS_REG("ISR", HISI_SPI_ISR),
HISI_SPI_DBGFS_REG("ICR", HISI_SPI_ICR),
HISI_SPI_DBGFS_REG("VERSION", HISI_SPI_VERSION),
};
static int hisi_spi_debugfs_init(struct hisi_spi *hs)
{
char name[32];
struct spi_controller *host;
host = container_of(hs->dev, struct spi_controller, dev);
snprintf(name, 32, "hisi_spi%d", host->bus_num);
hs->debugfs = debugfs_create_dir(name, NULL);
if (IS_ERR(hs->debugfs))
return -ENOMEM;
hs->regset.regs = hisi_spi_regs;
hs->regset.nregs = ARRAY_SIZE(hisi_spi_regs);
hs->regset.base = hs->regs;
debugfs_create_regset32("registers", 0400, hs->debugfs, &hs->regset);
return 0;
}
static u32 hisi_spi_busy(struct hisi_spi *hs)
{
return readl(hs->regs + HISI_SPI_SR) & SR_BUSY;
}
static u32 hisi_spi_rx_not_empty(struct hisi_spi *hs)
{
return readl(hs->regs + HISI_SPI_SR) & SR_RXNE;
}
static u32 hisi_spi_tx_not_full(struct hisi_spi *hs)
{
return readl(hs->regs + HISI_SPI_SR) & SR_TXNF;
}
static void hisi_spi_flush_fifo(struct hisi_spi *hs)
{
unsigned long limit = loops_per_jiffy << 1;
do {
while (hisi_spi_rx_not_empty(hs))
readl(hs->regs + HISI_SPI_DOUT);
} while (hisi_spi_busy(hs) && limit--);
}
/* Disable the controller and all interrupts */
static void hisi_spi_disable(struct hisi_spi *hs)
{
writel(0, hs->regs + HISI_SPI_ENR);
writel(IMR_MASK, hs->regs + HISI_SPI_IMR);
writel(ICR_MASK, hs->regs + HISI_SPI_ICR);
}
static u8 hisi_spi_n_bytes(struct spi_transfer *transfer)
{
if (transfer->bits_per_word <= 8)
return HISI_SPI_N_BYTES_U8;
else if (transfer->bits_per_word <= 16)
return HISI_SPI_N_BYTES_U16;
else
return HISI_SPI_N_BYTES_U32;
}
static void hisi_spi_reader(struct hisi_spi *hs)
{
u32 max = min_t(u32, hs->rx_len, hs->fifo_len);
u32 rxw;
while (hisi_spi_rx_not_empty(hs) && max--) {
rxw = readl(hs->regs + HISI_SPI_DOUT);
/* Check the transfer's original "rx" is not null */
if (hs->rx) {
switch (hs->n_bytes) {
case HISI_SPI_N_BYTES_U8:
*(u8 *)(hs->rx) = rxw;
break;
case HISI_SPI_N_BYTES_U16:
*(u16 *)(hs->rx) = rxw;
break;
case HISI_SPI_N_BYTES_U32:
*(u32 *)(hs->rx) = rxw;
break;
}
hs->rx += hs->n_bytes;
}
--hs->rx_len;
}
}
static void hisi_spi_writer(struct hisi_spi *hs)
{
u32 max = min_t(u32, hs->tx_len, hs->fifo_len);
u32 txw = 0;
while (hisi_spi_tx_not_full(hs) && max--) {
/* Check the transfer's original "tx" is not null */
if (hs->tx) {
switch (hs->n_bytes) {
case HISI_SPI_N_BYTES_U8:
txw = *(u8 *)(hs->tx);
break;
case HISI_SPI_N_BYTES_U16:
txw = *(u16 *)(hs->tx);
break;
case HISI_SPI_N_BYTES_U32:
txw = *(u32 *)(hs->tx);
break;
}
hs->tx += hs->n_bytes;
}
writel(txw, hs->regs + HISI_SPI_DIN);
--hs->tx_len;
}
}
static void __hisi_calc_div_reg(struct hisi_chip_data *chip)
{
chip->div_pre = DIV_PRE_MAX;
while (chip->div_pre >= DIV_PRE_MIN) {
if (chip->clk_div % chip->div_pre == 0)
break;
chip->div_pre -= 2;
}
if (chip->div_pre > chip->clk_div)
chip->div_pre = chip->clk_div;
chip->div_post = (chip->clk_div / chip->div_pre) - 1;
}
static u32 hisi_calc_effective_speed(struct spi_controller *host,
struct hisi_chip_data *chip, u32 speed_hz)
{
u32 effective_speed;
/* Note clock divider doesn't support odd numbers */
chip->clk_div = DIV_ROUND_UP(host->max_speed_hz, speed_hz) + 1;
chip->clk_div &= 0xfffe;
if (chip->clk_div > CLK_DIV_MAX)
chip->clk_div = CLK_DIV_MAX;
effective_speed = host->max_speed_hz / chip->clk_div;
if (chip->speed_hz != effective_speed) {
__hisi_calc_div_reg(chip);
chip->speed_hz = effective_speed;
}
return effective_speed;
}
static u32 hisi_spi_prepare_cr(struct spi_device *spi)
{
u32 cr = FIELD_PREP(CR_SPD_MODE_MASK, 1);
cr |= FIELD_PREP(CR_CPHA_MASK, (spi->mode & SPI_CPHA) ? 1 : 0);
cr |= FIELD_PREP(CR_CPOL_MASK, (spi->mode & SPI_CPOL) ? 1 : 0);
cr |= FIELD_PREP(CR_LOOP_MASK, (spi->mode & SPI_LOOP) ? 1 : 0);
return cr;
}
static void hisi_spi_hw_init(struct hisi_spi *hs)
{
hisi_spi_disable(hs);
/* FIFO default config */
writel(FIELD_PREP(FIFOC_TX_MASK, HISI_SPI_TX_64_OR_LESS) |
FIELD_PREP(FIFOC_RX_MASK, HISI_SPI_RX_16),
hs->regs + HISI_SPI_FIFOC);
hs->fifo_len = 256;
}
static irqreturn_t hisi_spi_irq(int irq, void *dev_id)
{
struct spi_controller *host = dev_id;
struct hisi_spi *hs = spi_controller_get_devdata(host);
u32 irq_status = readl(hs->regs + HISI_SPI_ISR) & ISR_MASK;
if (!irq_status)
return IRQ_NONE;
if (!host->cur_msg)
return IRQ_HANDLED;
/* Error handling */
if (irq_status & ISR_RXOF) {
dev_err(hs->dev, "interrupt_transfer: fifo overflow\n");
host->cur_msg->status = -EIO;
goto finalize_transfer;
}
/*
* Read data from the Rx FIFO every time. If there is
* nothing left to receive, finalize the transfer.
*/
hisi_spi_reader(hs);
if (!hs->rx_len)
goto finalize_transfer;
/* Send data out when Tx FIFO IRQ triggered */
if (irq_status & ISR_TX)
hisi_spi_writer(hs);
return IRQ_HANDLED;
finalize_transfer:
hisi_spi_disable(hs);
spi_finalize_current_transfer(host);
return IRQ_HANDLED;
}
static int hisi_spi_transfer_one(struct spi_controller *host,
struct spi_device *spi, struct spi_transfer *transfer)
{
struct hisi_spi *hs = spi_controller_get_devdata(host);
struct hisi_chip_data *chip = spi_get_ctldata(spi);
u32 cr = chip->cr;
/* Update per transfer options for speed and bpw */
transfer->effective_speed_hz =
hisi_calc_effective_speed(host, chip, transfer->speed_hz);
cr |= FIELD_PREP(CR_DIV_PRE_MASK, chip->div_pre);
cr |= FIELD_PREP(CR_DIV_POST_MASK, chip->div_post);
cr |= FIELD_PREP(CR_BPW_MASK, transfer->bits_per_word - 1);
writel(cr, hs->regs + HISI_SPI_CR);
hisi_spi_flush_fifo(hs);
hs->n_bytes = hisi_spi_n_bytes(transfer);
hs->tx = transfer->tx_buf;
hs->tx_len = transfer->len / hs->n_bytes;
hs->rx = transfer->rx_buf;
hs->rx_len = hs->tx_len;
/*
* Ensure that the transfer data above has been updated
* before the interrupt to start.
*/
smp_mb();
/* Enable all interrupts and the controller */
writel(~(u32)IMR_MASK, hs->regs + HISI_SPI_IMR);
writel(1, hs->regs + HISI_SPI_ENR);
return 1;
}
static void hisi_spi_handle_err(struct spi_controller *host,
struct spi_message *msg)
{
struct hisi_spi *hs = spi_controller_get_devdata(host);
hisi_spi_disable(hs);
/*
* Wait for interrupt handler that is
* already in timeout to complete.
*/
msleep(HISI_SPI_WAIT_TIMEOUT_MS);
}
static int hisi_spi_setup(struct spi_device *spi)
{
struct hisi_chip_data *chip;
/* Only alloc on first setup */
chip = spi_get_ctldata(spi);
if (!chip) {
chip = kzalloc(sizeof(*chip), GFP_KERNEL);
if (!chip)
return -ENOMEM;
spi_set_ctldata(spi, chip);
}
chip->cr = hisi_spi_prepare_cr(spi);
return 0;
}
static void hisi_spi_cleanup(struct spi_device *spi)
{
struct hisi_chip_data *chip = spi_get_ctldata(spi);
kfree(chip);
spi_set_ctldata(spi, NULL);
}
static int hisi_spi_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct spi_controller *host;
struct hisi_spi *hs;
int ret, irq;
irq = platform_get_irq(pdev, 0);
if (irq < 0)
return irq;
host = devm_spi_alloc_host(dev, sizeof(*hs));
if (!host)
return -ENOMEM;
platform_set_drvdata(pdev, host);
hs = spi_controller_get_devdata(host);
hs->dev = dev;
hs->irq = irq;
hs->regs = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(hs->regs))
return PTR_ERR(hs->regs);
/* Specify maximum SPI clocking speed (host only) by firmware */
ret = device_property_read_u32(dev, "spi-max-frequency",
&host->max_speed_hz);
if (ret) {
dev_err(dev, "failed to get max SPI clocking speed, ret=%d\n",
ret);
return -EINVAL;
}
ret = device_property_read_u16(dev, "num-cs",
&host->num_chipselect);
if (ret)
host->num_chipselect = DEFAULT_NUM_CS;
host->use_gpio_descriptors = true;
host->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LOOP;
host->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 32);
host->bus_num = pdev->id;
host->setup = hisi_spi_setup;
host->cleanup = hisi_spi_cleanup;
host->transfer_one = hisi_spi_transfer_one;
host->handle_err = hisi_spi_handle_err;
host->dev.fwnode = dev->fwnode;
hisi_spi_hw_init(hs);
ret = devm_request_irq(dev, hs->irq, hisi_spi_irq, 0, dev_name(dev),
host);
if (ret < 0) {
dev_err(dev, "failed to get IRQ=%d, ret=%d\n", hs->irq, ret);
return ret;
}
ret = spi_register_controller(host);
if (ret) {
dev_err(dev, "failed to register spi host, ret=%d\n", ret);
return ret;
}
if (hisi_spi_debugfs_init(hs))
dev_info(dev, "failed to create debugfs dir\n");
dev_info(dev, "hw version:0x%x max-freq:%u kHz\n",
readl(hs->regs + HISI_SPI_VERSION),
host->max_speed_hz / 1000);
return 0;
}
static void hisi_spi_remove(struct platform_device *pdev)
{
struct spi_controller *host = platform_get_drvdata(pdev);
struct hisi_spi *hs = spi_controller_get_devdata(host);
debugfs_remove_recursive(hs->debugfs);
spi_unregister_controller(host);
}
static const struct acpi_device_id hisi_spi_acpi_match[] = {
{"HISI03E1", 0},
{}
};
MODULE_DEVICE_TABLE(acpi, hisi_spi_acpi_match);
static struct platform_driver hisi_spi_driver = {
.probe = hisi_spi_probe,
.remove_new = hisi_spi_remove,
.driver = {
.name = "hisi-kunpeng-spi",
.acpi_match_table = hisi_spi_acpi_match,
},
};
module_platform_driver(hisi_spi_driver);
MODULE_AUTHOR("Jay Fang <f.fangjian@huawei.com>");
MODULE_DESCRIPTION("HiSilicon SPI Controller Driver for Kunpeng SoCs");
MODULE_LICENSE("GPL v2");