+++ /dev/null
-// 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);
projects / linux-2.6-microblaze.git / commitdiff