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path: root/drivers/spi/spi-clps711x.c
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Diffstat (limited to 'drivers/spi/spi-clps711x.c')
-rw-r--r--drivers/spi/spi-clps711x.c173
1 files changed, 173 insertions, 0 deletions
diff --git a/drivers/spi/spi-clps711x.c b/drivers/spi/spi-clps711x.c
new file mode 100644
index 000000000..c005ed26a
--- /dev/null
+++ b/drivers/spi/spi-clps711x.c
@@ -0,0 +1,173 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * CLPS711X SPI bus driver
+ *
+ * Copyright (C) 2012-2016 Alexander Shiyan <shc_work@mail.ru>
+ */
+
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/mfd/syscon.h>
+#include <linux/mfd/syscon/clps711x.h>
+#include <linux/spi/spi.h>
+
+#define DRIVER_NAME "clps711x-spi"
+
+#define SYNCIO_FRMLEN(x) ((x) << 8)
+#define SYNCIO_TXFRMEN (1 << 14)
+
+struct spi_clps711x_data {
+ void __iomem *syncio;
+ struct regmap *syscon;
+ struct clk *spi_clk;
+
+ u8 *tx_buf;
+ u8 *rx_buf;
+ unsigned int bpw;
+ int len;
+};
+
+static int spi_clps711x_prepare_message(struct spi_master *master,
+ struct spi_message *msg)
+{
+ struct spi_clps711x_data *hw = spi_master_get_devdata(master);
+ struct spi_device *spi = msg->spi;
+
+ /* Setup mode for transfer */
+ return regmap_update_bits(hw->syscon, SYSCON_OFFSET, SYSCON3_ADCCKNSEN,
+ (spi->mode & SPI_CPHA) ?
+ SYSCON3_ADCCKNSEN : 0);
+}
+
+static int spi_clps711x_transfer_one(struct spi_master *master,
+ struct spi_device *spi,
+ struct spi_transfer *xfer)
+{
+ struct spi_clps711x_data *hw = spi_master_get_devdata(master);
+ u8 data;
+
+ clk_set_rate(hw->spi_clk, xfer->speed_hz ? : spi->max_speed_hz);
+
+ hw->len = xfer->len;
+ hw->bpw = xfer->bits_per_word;
+ hw->tx_buf = (u8 *)xfer->tx_buf;
+ hw->rx_buf = (u8 *)xfer->rx_buf;
+
+ /* Initiate transfer */
+ data = hw->tx_buf ? *hw->tx_buf++ : 0;
+ writel(data | SYNCIO_FRMLEN(hw->bpw) | SYNCIO_TXFRMEN, hw->syncio);
+
+ return 1;
+}
+
+static irqreturn_t spi_clps711x_isr(int irq, void *dev_id)
+{
+ struct spi_master *master = dev_id;
+ struct spi_clps711x_data *hw = spi_master_get_devdata(master);
+ u8 data;
+
+ /* Handle RX */
+ data = readb(hw->syncio);
+ if (hw->rx_buf)
+ *hw->rx_buf++ = data;
+
+ /* Handle TX */
+ if (--hw->len > 0) {
+ data = hw->tx_buf ? *hw->tx_buf++ : 0;
+ writel(data | SYNCIO_FRMLEN(hw->bpw) | SYNCIO_TXFRMEN,
+ hw->syncio);
+ } else
+ spi_finalize_current_transfer(master);
+
+ return IRQ_HANDLED;
+}
+
+static int spi_clps711x_probe(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ struct spi_clps711x_data *hw;
+ struct spi_master *master;
+ int irq, ret;
+
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0)
+ return irq;
+
+ master = spi_alloc_master(&pdev->dev, sizeof(*hw));
+ if (!master)
+ return -ENOMEM;
+
+ master->use_gpio_descriptors = true;
+ master->bus_num = -1;
+ master->mode_bits = SPI_CPHA | SPI_CS_HIGH;
+ master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 8);
+ master->dev.of_node = pdev->dev.of_node;
+ master->prepare_message = spi_clps711x_prepare_message;
+ master->transfer_one = spi_clps711x_transfer_one;
+
+ hw = spi_master_get_devdata(master);
+
+ hw->spi_clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(hw->spi_clk)) {
+ ret = PTR_ERR(hw->spi_clk);
+ goto err_out;
+ }
+
+ hw->syscon = syscon_regmap_lookup_by_phandle(np, "syscon");
+ if (IS_ERR(hw->syscon)) {
+ ret = PTR_ERR(hw->syscon);
+ goto err_out;
+ }
+
+ hw->syncio = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(hw->syncio)) {
+ ret = PTR_ERR(hw->syncio);
+ goto err_out;
+ }
+
+ /* Disable extended mode due hardware problems */
+ regmap_update_bits(hw->syscon, SYSCON_OFFSET, SYSCON3_ADCCON, 0);
+
+ /* Clear possible pending interrupt */
+ readl(hw->syncio);
+
+ ret = devm_request_irq(&pdev->dev, irq, spi_clps711x_isr, 0,
+ dev_name(&pdev->dev), master);
+ if (ret)
+ goto err_out;
+
+ ret = devm_spi_register_master(&pdev->dev, master);
+ if (!ret)
+ return 0;
+
+err_out:
+ spi_master_put(master);
+
+ return ret;
+}
+
+static const struct of_device_id clps711x_spi_dt_ids[] = {
+ { .compatible = "cirrus,ep7209-spi", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, clps711x_spi_dt_ids);
+
+static struct platform_driver clps711x_spi_driver = {
+ .driver = {
+ .name = DRIVER_NAME,
+ .of_match_table = clps711x_spi_dt_ids,
+ },
+ .probe = spi_clps711x_probe,
+};
+module_platform_driver(clps711x_spi_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
+MODULE_DESCRIPTION("CLPS711X SPI bus driver");
+MODULE_ALIAS("platform:" DRIVER_NAME);