linux/drivers/spi/spi-efm32.c
Linus Walleij ebb3b9a92b
spi: efm32: Convert to use GPIO descriptors
This switches the EFM32 driver over to use the GPIO descriptor
handling in the core. The GPIO handling in this driver is
pretty simplistic so this should just work. Drop the GPIO headers
and insert the implicitly included <linux/of.h> header.

Signed-off-by: Linus Walleij <linus.walleij-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Cc: Uwe Kleine-König <u.kleine-koenig-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
Link: https://lore.kernel.org/r/20200317094914.331932-1-linus.walleij@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-03-27 15:52:23 +00:00

463 lines
11 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2012-2013 Uwe Kleine-Koenig for Pengutronix
*/
#include <linux/kernel.h>
#include <linux/io.h>
#include <linux/spi/spi.h>
#include <linux/spi/spi_bitbang.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/platform_data/efm32-spi.h>
#include <linux/of.h>
#define DRIVER_NAME "efm32-spi"
#define MASK_VAL(mask, val) ((val << __ffs(mask)) & mask)
#define REG_CTRL 0x00
#define REG_CTRL_SYNC 0x0001
#define REG_CTRL_CLKPOL 0x0100
#define REG_CTRL_CLKPHA 0x0200
#define REG_CTRL_MSBF 0x0400
#define REG_CTRL_TXBIL 0x1000
#define REG_FRAME 0x04
#define REG_FRAME_DATABITS__MASK 0x000f
#define REG_FRAME_DATABITS(n) ((n) - 3)
#define REG_CMD 0x0c
#define REG_CMD_RXEN 0x0001
#define REG_CMD_RXDIS 0x0002
#define REG_CMD_TXEN 0x0004
#define REG_CMD_TXDIS 0x0008
#define REG_CMD_MASTEREN 0x0010
#define REG_STATUS 0x10
#define REG_STATUS_TXENS 0x0002
#define REG_STATUS_TXC 0x0020
#define REG_STATUS_TXBL 0x0040
#define REG_STATUS_RXDATAV 0x0080
#define REG_CLKDIV 0x14
#define REG_RXDATAX 0x18
#define REG_RXDATAX_RXDATA__MASK 0x01ff
#define REG_RXDATAX_PERR 0x4000
#define REG_RXDATAX_FERR 0x8000
#define REG_TXDATA 0x34
#define REG_IF 0x40
#define REG_IF_TXBL 0x0002
#define REG_IF_RXDATAV 0x0004
#define REG_IFS 0x44
#define REG_IFC 0x48
#define REG_IEN 0x4c
#define REG_ROUTE 0x54
#define REG_ROUTE_RXPEN 0x0001
#define REG_ROUTE_TXPEN 0x0002
#define REG_ROUTE_CLKPEN 0x0008
#define REG_ROUTE_LOCATION__MASK 0x0700
#define REG_ROUTE_LOCATION(n) MASK_VAL(REG_ROUTE_LOCATION__MASK, (n))
struct efm32_spi_ddata {
struct spi_bitbang bitbang;
spinlock_t lock;
struct clk *clk;
void __iomem *base;
unsigned int rxirq, txirq;
struct efm32_spi_pdata pdata;
/* irq data */
struct completion done;
const u8 *tx_buf;
u8 *rx_buf;
unsigned tx_len, rx_len;
};
#define ddata_to_dev(ddata) (&(ddata->bitbang.master->dev))
#define efm32_spi_vdbg(ddata, format, arg...) \
dev_vdbg(ddata_to_dev(ddata), format, ##arg)
static void efm32_spi_write32(struct efm32_spi_ddata *ddata,
u32 value, unsigned offset)
{
writel_relaxed(value, ddata->base + offset);
}
static u32 efm32_spi_read32(struct efm32_spi_ddata *ddata, unsigned offset)
{
return readl_relaxed(ddata->base + offset);
}
static int efm32_spi_setup_transfer(struct spi_device *spi,
struct spi_transfer *t)
{
struct efm32_spi_ddata *ddata = spi_master_get_devdata(spi->master);
unsigned bpw = t->bits_per_word ?: spi->bits_per_word;
unsigned speed = t->speed_hz ?: spi->max_speed_hz;
unsigned long clkfreq = clk_get_rate(ddata->clk);
u32 clkdiv;
efm32_spi_write32(ddata, REG_CTRL_SYNC | REG_CTRL_MSBF |
(spi->mode & SPI_CPHA ? REG_CTRL_CLKPHA : 0) |
(spi->mode & SPI_CPOL ? REG_CTRL_CLKPOL : 0), REG_CTRL);
efm32_spi_write32(ddata,
REG_FRAME_DATABITS(bpw), REG_FRAME);
if (2 * speed >= clkfreq)
clkdiv = 0;
else
clkdiv = 64 * (DIV_ROUND_UP(2 * clkfreq, speed) - 4);
if (clkdiv > (1U << 21))
return -EINVAL;
efm32_spi_write32(ddata, clkdiv, REG_CLKDIV);
efm32_spi_write32(ddata, REG_CMD_MASTEREN, REG_CMD);
efm32_spi_write32(ddata, REG_CMD_RXEN | REG_CMD_TXEN, REG_CMD);
return 0;
}
static void efm32_spi_tx_u8(struct efm32_spi_ddata *ddata)
{
u8 val = 0;
if (ddata->tx_buf) {
val = *ddata->tx_buf;
ddata->tx_buf++;
}
ddata->tx_len--;
efm32_spi_write32(ddata, val, REG_TXDATA);
efm32_spi_vdbg(ddata, "%s: tx 0x%x\n", __func__, val);
}
static void efm32_spi_rx_u8(struct efm32_spi_ddata *ddata)
{
u32 rxdata = efm32_spi_read32(ddata, REG_RXDATAX);
efm32_spi_vdbg(ddata, "%s: rx 0x%x\n", __func__, rxdata);
if (ddata->rx_buf) {
*ddata->rx_buf = rxdata;
ddata->rx_buf++;
}
ddata->rx_len--;
}
static void efm32_spi_filltx(struct efm32_spi_ddata *ddata)
{
while (ddata->tx_len &&
ddata->tx_len + 2 > ddata->rx_len &&
efm32_spi_read32(ddata, REG_STATUS) & REG_STATUS_TXBL) {
efm32_spi_tx_u8(ddata);
}
}
static int efm32_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
{
struct efm32_spi_ddata *ddata = spi_master_get_devdata(spi->master);
int ret = -EBUSY;
spin_lock_irq(&ddata->lock);
if (ddata->tx_buf || ddata->rx_buf)
goto out_unlock;
ddata->tx_buf = t->tx_buf;
ddata->rx_buf = t->rx_buf;
ddata->tx_len = ddata->rx_len =
t->len * DIV_ROUND_UP(t->bits_per_word, 8);
efm32_spi_filltx(ddata);
reinit_completion(&ddata->done);
efm32_spi_write32(ddata, REG_IF_TXBL | REG_IF_RXDATAV, REG_IEN);
spin_unlock_irq(&ddata->lock);
wait_for_completion(&ddata->done);
spin_lock_irq(&ddata->lock);
ret = t->len - max(ddata->tx_len, ddata->rx_len);
efm32_spi_write32(ddata, 0, REG_IEN);
ddata->tx_buf = ddata->rx_buf = NULL;
out_unlock:
spin_unlock_irq(&ddata->lock);
return ret;
}
static irqreturn_t efm32_spi_rxirq(int irq, void *data)
{
struct efm32_spi_ddata *ddata = data;
irqreturn_t ret = IRQ_NONE;
spin_lock(&ddata->lock);
while (ddata->rx_len > 0 &&
efm32_spi_read32(ddata, REG_STATUS) &
REG_STATUS_RXDATAV) {
efm32_spi_rx_u8(ddata);
ret = IRQ_HANDLED;
}
if (!ddata->rx_len) {
u32 ien = efm32_spi_read32(ddata, REG_IEN);
ien &= ~REG_IF_RXDATAV;
efm32_spi_write32(ddata, ien, REG_IEN);
complete(&ddata->done);
}
spin_unlock(&ddata->lock);
return ret;
}
static irqreturn_t efm32_spi_txirq(int irq, void *data)
{
struct efm32_spi_ddata *ddata = data;
efm32_spi_vdbg(ddata,
"%s: txlen = %u, rxlen = %u, if=0x%08x, stat=0x%08x\n",
__func__, ddata->tx_len, ddata->rx_len,
efm32_spi_read32(ddata, REG_IF),
efm32_spi_read32(ddata, REG_STATUS));
spin_lock(&ddata->lock);
efm32_spi_filltx(ddata);
efm32_spi_vdbg(ddata, "%s: txlen = %u, rxlen = %u\n",
__func__, ddata->tx_len, ddata->rx_len);
if (!ddata->tx_len) {
u32 ien = efm32_spi_read32(ddata, REG_IEN);
ien &= ~REG_IF_TXBL;
efm32_spi_write32(ddata, ien, REG_IEN);
efm32_spi_vdbg(ddata, "disable TXBL\n");
}
spin_unlock(&ddata->lock);
return IRQ_HANDLED;
}
static u32 efm32_spi_get_configured_location(struct efm32_spi_ddata *ddata)
{
u32 reg = efm32_spi_read32(ddata, REG_ROUTE);
return (reg & REG_ROUTE_LOCATION__MASK) >> __ffs(REG_ROUTE_LOCATION__MASK);
}
static void efm32_spi_probe_dt(struct platform_device *pdev,
struct spi_master *master, struct efm32_spi_ddata *ddata)
{
struct device_node *np = pdev->dev.of_node;
u32 location;
int ret;
ret = of_property_read_u32(np, "energymicro,location", &location);
if (ret)
/* fall back to wrongly namespaced property */
ret = of_property_read_u32(np, "efm32,location", &location);
if (ret)
/* fall back to old and (wrongly) generic property "location" */
ret = of_property_read_u32(np, "location", &location);
if (!ret) {
dev_dbg(&pdev->dev, "using location %u\n", location);
} else {
/* default to location configured in hardware */
location = efm32_spi_get_configured_location(ddata);
dev_info(&pdev->dev, "fall back to location %u\n", location);
}
ddata->pdata.location = location;
}
static int efm32_spi_probe(struct platform_device *pdev)
{
struct efm32_spi_ddata *ddata;
struct resource *res;
int ret;
struct spi_master *master;
struct device_node *np = pdev->dev.of_node;
if (!np)
return -EINVAL;
master = spi_alloc_master(&pdev->dev, sizeof(*ddata));
if (!master) {
dev_dbg(&pdev->dev,
"failed to allocate spi master controller\n");
return -ENOMEM;
}
platform_set_drvdata(pdev, master);
master->dev.of_node = pdev->dev.of_node;
master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 16);
master->use_gpio_descriptors = true;
ddata = spi_master_get_devdata(master);
ddata->bitbang.master = master;
ddata->bitbang.setup_transfer = efm32_spi_setup_transfer;
ddata->bitbang.txrx_bufs = efm32_spi_txrx_bufs;
spin_lock_init(&ddata->lock);
init_completion(&ddata->done);
ddata->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(ddata->clk)) {
ret = PTR_ERR(ddata->clk);
dev_err(&pdev->dev, "failed to get clock: %d\n", ret);
goto err;
}
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
ret = -ENODEV;
dev_err(&pdev->dev, "failed to determine base address\n");
goto err;
}
if (resource_size(res) < 0x60) {
ret = -EINVAL;
dev_err(&pdev->dev, "memory resource too small\n");
goto err;
}
ddata->base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(ddata->base)) {
ret = PTR_ERR(ddata->base);
goto err;
}
ret = platform_get_irq(pdev, 0);
if (ret <= 0)
goto err;
ddata->rxirq = ret;
ret = platform_get_irq(pdev, 1);
if (ret <= 0)
ret = ddata->rxirq + 1;
ddata->txirq = ret;
ret = clk_prepare_enable(ddata->clk);
if (ret < 0) {
dev_err(&pdev->dev, "failed to enable clock (%d)\n", ret);
goto err;
}
efm32_spi_probe_dt(pdev, master, ddata);
efm32_spi_write32(ddata, 0, REG_IEN);
efm32_spi_write32(ddata, REG_ROUTE_TXPEN | REG_ROUTE_RXPEN |
REG_ROUTE_CLKPEN |
REG_ROUTE_LOCATION(ddata->pdata.location), REG_ROUTE);
ret = request_irq(ddata->rxirq, efm32_spi_rxirq,
0, DRIVER_NAME " rx", ddata);
if (ret) {
dev_err(&pdev->dev, "failed to register rxirq (%d)\n", ret);
goto err_disable_clk;
}
ret = request_irq(ddata->txirq, efm32_spi_txirq,
0, DRIVER_NAME " tx", ddata);
if (ret) {
dev_err(&pdev->dev, "failed to register txirq (%d)\n", ret);
goto err_free_rx_irq;
}
ret = spi_bitbang_start(&ddata->bitbang);
if (ret) {
dev_err(&pdev->dev, "spi_bitbang_start failed (%d)\n", ret);
free_irq(ddata->txirq, ddata);
err_free_rx_irq:
free_irq(ddata->rxirq, ddata);
err_disable_clk:
clk_disable_unprepare(ddata->clk);
err:
spi_master_put(master);
}
return ret;
}
static int efm32_spi_remove(struct platform_device *pdev)
{
struct spi_master *master = platform_get_drvdata(pdev);
struct efm32_spi_ddata *ddata = spi_master_get_devdata(master);
spi_bitbang_stop(&ddata->bitbang);
efm32_spi_write32(ddata, 0, REG_IEN);
free_irq(ddata->txirq, ddata);
free_irq(ddata->rxirq, ddata);
clk_disable_unprepare(ddata->clk);
spi_master_put(master);
return 0;
}
static const struct of_device_id efm32_spi_dt_ids[] = {
{
.compatible = "energymicro,efm32-spi",
}, {
/* doesn't follow the "vendor,device" scheme, don't use */
.compatible = "efm32,spi",
}, {
/* sentinel */
}
};
MODULE_DEVICE_TABLE(of, efm32_spi_dt_ids);
static struct platform_driver efm32_spi_driver = {
.probe = efm32_spi_probe,
.remove = efm32_spi_remove,
.driver = {
.name = DRIVER_NAME,
.of_match_table = efm32_spi_dt_ids,
},
};
module_platform_driver(efm32_spi_driver);
MODULE_AUTHOR("Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>");
MODULE_DESCRIPTION("EFM32 SPI driver");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:" DRIVER_NAME);