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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-27 10:05:51 +0000
commit5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch)
treea94efe259b9009378be6d90eb30d2b019d95c194 /drivers/spi/spi-altera.c
parentInitial commit. (diff)
downloadlinux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.tar.xz
linux-5d1646d90e1f2cceb9f0828f4b28318cd0ec7744.zip
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/spi/spi-altera.c')
-rw-r--r--drivers/spi/spi-altera.c378
1 files changed, 378 insertions, 0 deletions
diff --git a/drivers/spi/spi-altera.c b/drivers/spi/spi-altera.c
new file mode 100644
index 000000000..62ea0c9e3
--- /dev/null
+++ b/drivers/spi/spi-altera.c
@@ -0,0 +1,378 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Altera SPI driver
+ *
+ * Copyright (C) 2008 Thomas Chou <thomas@wytron.com.tw>
+ *
+ * Based on spi_s3c24xx.c, which is:
+ * Copyright (c) 2006 Ben Dooks
+ * Copyright (c) 2006 Simtec Electronics
+ * Ben Dooks <ben@simtec.co.uk>
+ */
+
+#include <linux/interrupt.h>
+#include <linux/errno.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/spi/altera.h>
+#include <linux/spi/spi.h>
+#include <linux/io.h>
+#include <linux/of.h>
+
+#define DRV_NAME "spi_altera"
+
+#define ALTERA_SPI_RXDATA 0
+#define ALTERA_SPI_TXDATA 4
+#define ALTERA_SPI_STATUS 8
+#define ALTERA_SPI_CONTROL 12
+#define ALTERA_SPI_SLAVE_SEL 20
+
+#define ALTERA_SPI_STATUS_ROE_MSK 0x8
+#define ALTERA_SPI_STATUS_TOE_MSK 0x10
+#define ALTERA_SPI_STATUS_TMT_MSK 0x20
+#define ALTERA_SPI_STATUS_TRDY_MSK 0x40
+#define ALTERA_SPI_STATUS_RRDY_MSK 0x80
+#define ALTERA_SPI_STATUS_E_MSK 0x100
+
+#define ALTERA_SPI_CONTROL_IROE_MSK 0x8
+#define ALTERA_SPI_CONTROL_ITOE_MSK 0x10
+#define ALTERA_SPI_CONTROL_ITRDY_MSK 0x40
+#define ALTERA_SPI_CONTROL_IRRDY_MSK 0x80
+#define ALTERA_SPI_CONTROL_IE_MSK 0x100
+#define ALTERA_SPI_CONTROL_SSO_MSK 0x400
+
+#define ALTERA_SPI_MAX_CS 32
+
+enum altera_spi_type {
+ ALTERA_SPI_TYPE_UNKNOWN,
+ ALTERA_SPI_TYPE_SUBDEV,
+};
+
+struct altera_spi {
+ int irq;
+ int len;
+ int count;
+ int bytes_per_word;
+ u32 imr;
+
+ /* data buffers */
+ const unsigned char *tx;
+ unsigned char *rx;
+
+ struct regmap *regmap;
+ u32 regoff;
+ struct device *dev;
+};
+
+static const struct regmap_config spi_altera_config = {
+ .reg_bits = 32,
+ .reg_stride = 4,
+ .val_bits = 32,
+ .fast_io = true,
+};
+
+static int altr_spi_writel(struct altera_spi *hw, unsigned int reg,
+ unsigned int val)
+{
+ int ret;
+
+ ret = regmap_write(hw->regmap, hw->regoff + reg, val);
+ if (ret)
+ dev_err(hw->dev, "fail to write reg 0x%x val 0x%x: %d\n",
+ reg, val, ret);
+
+ return ret;
+}
+
+static int altr_spi_readl(struct altera_spi *hw, unsigned int reg,
+ unsigned int *val)
+{
+ int ret;
+
+ ret = regmap_read(hw->regmap, hw->regoff + reg, val);
+ if (ret)
+ dev_err(hw->dev, "fail to read reg 0x%x: %d\n", reg, ret);
+
+ return ret;
+}
+
+static inline struct altera_spi *altera_spi_to_hw(struct spi_device *sdev)
+{
+ return spi_master_get_devdata(sdev->master);
+}
+
+static void altera_spi_set_cs(struct spi_device *spi, bool is_high)
+{
+ struct altera_spi *hw = altera_spi_to_hw(spi);
+
+ if (is_high) {
+ hw->imr &= ~ALTERA_SPI_CONTROL_SSO_MSK;
+ altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);
+ altr_spi_writel(hw, ALTERA_SPI_SLAVE_SEL, 0);
+ } else {
+ altr_spi_writel(hw, ALTERA_SPI_SLAVE_SEL,
+ BIT(spi->chip_select));
+ hw->imr |= ALTERA_SPI_CONTROL_SSO_MSK;
+ altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);
+ }
+}
+
+static void altera_spi_tx_word(struct altera_spi *hw)
+{
+ unsigned int txd = 0;
+
+ if (hw->tx) {
+ switch (hw->bytes_per_word) {
+ case 1:
+ txd = hw->tx[hw->count];
+ break;
+ case 2:
+ txd = (hw->tx[hw->count * 2]
+ | (hw->tx[hw->count * 2 + 1] << 8));
+ break;
+ case 4:
+ txd = (hw->tx[hw->count * 4]
+ | (hw->tx[hw->count * 4 + 1] << 8)
+ | (hw->tx[hw->count * 4 + 2] << 16)
+ | (hw->tx[hw->count * 4 + 3] << 24));
+ break;
+
+ }
+ }
+
+ altr_spi_writel(hw, ALTERA_SPI_TXDATA, txd);
+}
+
+static void altera_spi_rx_word(struct altera_spi *hw)
+{
+ unsigned int rxd;
+
+ altr_spi_readl(hw, ALTERA_SPI_RXDATA, &rxd);
+ if (hw->rx) {
+ switch (hw->bytes_per_word) {
+ case 1:
+ hw->rx[hw->count] = rxd;
+ break;
+ case 2:
+ hw->rx[hw->count * 2] = rxd;
+ hw->rx[hw->count * 2 + 1] = rxd >> 8;
+ break;
+ case 4:
+ hw->rx[hw->count * 4] = rxd;
+ hw->rx[hw->count * 4 + 1] = rxd >> 8;
+ hw->rx[hw->count * 4 + 2] = rxd >> 16;
+ hw->rx[hw->count * 4 + 3] = rxd >> 24;
+ break;
+
+ }
+ }
+
+ hw->count++;
+}
+
+static int altera_spi_txrx(struct spi_master *master,
+ struct spi_device *spi, struct spi_transfer *t)
+{
+ struct altera_spi *hw = spi_master_get_devdata(master);
+ u32 val;
+
+ hw->tx = t->tx_buf;
+ hw->rx = t->rx_buf;
+ hw->count = 0;
+ hw->bytes_per_word = DIV_ROUND_UP(t->bits_per_word, 8);
+ hw->len = t->len / hw->bytes_per_word;
+
+ if (hw->irq >= 0) {
+ /* enable receive interrupt */
+ hw->imr |= ALTERA_SPI_CONTROL_IRRDY_MSK;
+ altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);
+
+ /* send the first byte */
+ altera_spi_tx_word(hw);
+
+ return 1;
+ }
+
+ while (hw->count < hw->len) {
+ altera_spi_tx_word(hw);
+
+ for (;;) {
+ altr_spi_readl(hw, ALTERA_SPI_STATUS, &val);
+ if (val & ALTERA_SPI_STATUS_RRDY_MSK)
+ break;
+
+ cpu_relax();
+ }
+
+ altera_spi_rx_word(hw);
+ }
+ spi_finalize_current_transfer(master);
+
+ return 0;
+}
+
+static irqreturn_t altera_spi_irq(int irq, void *dev)
+{
+ struct spi_master *master = dev;
+ struct altera_spi *hw = spi_master_get_devdata(master);
+
+ altera_spi_rx_word(hw);
+
+ if (hw->count < hw->len) {
+ altera_spi_tx_word(hw);
+ } else {
+ /* disable receive interrupt */
+ hw->imr &= ~ALTERA_SPI_CONTROL_IRRDY_MSK;
+ altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);
+
+ spi_finalize_current_transfer(master);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static int altera_spi_probe(struct platform_device *pdev)
+{
+ const struct platform_device_id *platid = platform_get_device_id(pdev);
+ struct altera_spi_platform_data *pdata = dev_get_platdata(&pdev->dev);
+ enum altera_spi_type type = ALTERA_SPI_TYPE_UNKNOWN;
+ struct altera_spi *hw;
+ struct spi_master *master;
+ int err = -ENODEV;
+ u32 val;
+ u16 i;
+
+ master = spi_alloc_master(&pdev->dev, sizeof(struct altera_spi));
+ if (!master)
+ return err;
+
+ /* setup the master state. */
+ master->bus_num = pdev->id;
+
+ if (pdata) {
+ if (pdata->num_chipselect > ALTERA_SPI_MAX_CS) {
+ dev_err(&pdev->dev,
+ "Invalid number of chipselect: %hu\n",
+ pdata->num_chipselect);
+ err = -EINVAL;
+ goto exit;
+ }
+
+ master->num_chipselect = pdata->num_chipselect;
+ master->mode_bits = pdata->mode_bits;
+ master->bits_per_word_mask = pdata->bits_per_word_mask;
+ } else {
+ master->num_chipselect = 16;
+ master->mode_bits = SPI_CS_HIGH;
+ master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 16);
+ }
+
+ master->dev.of_node = pdev->dev.of_node;
+ master->transfer_one = altera_spi_txrx;
+ master->set_cs = altera_spi_set_cs;
+
+ hw = spi_master_get_devdata(master);
+ hw->dev = &pdev->dev;
+
+ if (platid)
+ type = platid->driver_data;
+
+ /* find and map our resources */
+ if (type == ALTERA_SPI_TYPE_SUBDEV) {
+ struct resource *regoff;
+
+ hw->regmap = dev_get_regmap(pdev->dev.parent, NULL);
+ if (!hw->regmap) {
+ dev_err(&pdev->dev, "get regmap failed\n");
+ goto exit;
+ }
+
+ regoff = platform_get_resource(pdev, IORESOURCE_REG, 0);
+ if (regoff)
+ hw->regoff = regoff->start;
+ } else {
+ void __iomem *res;
+
+ res = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(res)) {
+ err = PTR_ERR(res);
+ goto exit;
+ }
+
+ hw->regmap = devm_regmap_init_mmio(&pdev->dev, res,
+ &spi_altera_config);
+ if (IS_ERR(hw->regmap)) {
+ dev_err(&pdev->dev, "regmap mmio init failed\n");
+ err = PTR_ERR(hw->regmap);
+ goto exit;
+ }
+ }
+
+ /* program defaults into the registers */
+ hw->imr = 0; /* disable spi interrupts */
+ altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);
+ altr_spi_writel(hw, ALTERA_SPI_STATUS, 0); /* clear status reg */
+ altr_spi_readl(hw, ALTERA_SPI_STATUS, &val);
+ if (val & ALTERA_SPI_STATUS_RRDY_MSK)
+ altr_spi_readl(hw, ALTERA_SPI_RXDATA, &val); /* flush rxdata */
+ /* irq is optional */
+ hw->irq = platform_get_irq(pdev, 0);
+ if (hw->irq >= 0) {
+ err = devm_request_irq(&pdev->dev, hw->irq, altera_spi_irq, 0,
+ pdev->name, master);
+ if (err)
+ goto exit;
+ }
+
+ err = devm_spi_register_master(&pdev->dev, master);
+ if (err)
+ goto exit;
+
+ if (pdata) {
+ for (i = 0; i < pdata->num_devices; i++) {
+ if (!spi_new_device(master, pdata->devices + i))
+ dev_warn(&pdev->dev,
+ "unable to create SPI device: %s\n",
+ pdata->devices[i].modalias);
+ }
+ }
+
+ dev_info(&pdev->dev, "regoff %u, irq %d\n", hw->regoff, hw->irq);
+
+ return 0;
+exit:
+ spi_master_put(master);
+ return err;
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id altera_spi_match[] = {
+ { .compatible = "ALTR,spi-1.0", },
+ { .compatible = "altr,spi-1.0", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, altera_spi_match);
+#endif /* CONFIG_OF */
+
+static const struct platform_device_id altera_spi_ids[] = {
+ { DRV_NAME, ALTERA_SPI_TYPE_UNKNOWN },
+ { "subdev_spi_altera", ALTERA_SPI_TYPE_SUBDEV },
+ { }
+};
+MODULE_DEVICE_TABLE(platform, altera_spi_ids);
+
+static struct platform_driver altera_spi_driver = {
+ .probe = altera_spi_probe,
+ .driver = {
+ .name = DRV_NAME,
+ .pm = NULL,
+ .of_match_table = of_match_ptr(altera_spi_match),
+ },
+ .id_table = altera_spi_ids,
+};
+module_platform_driver(altera_spi_driver);
+
+MODULE_DESCRIPTION("Altera SPI driver");
+MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" DRV_NAME);