diff options
Diffstat (limited to 'drivers/spi/spi-efm32.c')
| -rw-r--r-- | drivers/spi/spi-efm32.c | 462 |
1 files changed, 0 insertions, 462 deletions
diff --git a/drivers/spi/spi-efm32.c b/drivers/spi/spi-efm32.c deleted file mode 100644 index ea6e4a7b3feb..000000000000 --- a/drivers/spi/spi-efm32.c +++ /dev/null @@ -1,462 +0,0 @@ -// 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); |