Adding upstream version 5.10.209.upstream/5.10.209upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 564 insertions, 0 deletions

diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
new file mode 100644
index 000000000..803d92f8d
--- /dev/null
+++ b/drivers/spi/spi-sun6i.c
@@ -0,0 +1,564 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2012 - 2014 Allwinner Tech
+ * Pan Nan <pannan@allwinnertech.com>
+ *
+ * Copyright (C) 2014 Maxime Ripard
+ * Maxime Ripard <maxime.ripard@free-electrons.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/reset.h>
+
+#include <linux/spi/spi.h>
+
+#define SUN6I_FIFO_DEPTH		128
+#define SUN8I_FIFO_DEPTH		64
+
+#define SUN6I_GBL_CTL_REG		0x04
+#define SUN6I_GBL_CTL_BUS_ENABLE		BIT(0)
+#define SUN6I_GBL_CTL_MASTER			BIT(1)
+#define SUN6I_GBL_CTL_TP			BIT(7)
+#define SUN6I_GBL_CTL_RST			BIT(31)
+
+#define SUN6I_TFR_CTL_REG		0x08
+#define SUN6I_TFR_CTL_CPHA			BIT(0)
+#define SUN6I_TFR_CTL_CPOL			BIT(1)
+#define SUN6I_TFR_CTL_SPOL			BIT(2)
+#define SUN6I_TFR_CTL_CS_MASK			0x30
+#define SUN6I_TFR_CTL_CS(cs)			(((cs) << 4) & SUN6I_TFR_CTL_CS_MASK)
+#define SUN6I_TFR_CTL_CS_MANUAL			BIT(6)
+#define SUN6I_TFR_CTL_CS_LEVEL			BIT(7)
+#define SUN6I_TFR_CTL_DHB			BIT(8)
+#define SUN6I_TFR_CTL_FBS			BIT(12)
+#define SUN6I_TFR_CTL_XCH			BIT(31)
+
+#define SUN6I_INT_CTL_REG		0x10
+#define SUN6I_INT_CTL_RF_RDY			BIT(0)
+#define SUN6I_INT_CTL_TF_ERQ			BIT(4)
+#define SUN6I_INT_CTL_RF_OVF			BIT(8)
+#define SUN6I_INT_CTL_TC			BIT(12)
+
+#define SUN6I_INT_STA_REG		0x14
+
+#define SUN6I_FIFO_CTL_REG		0x18
+#define SUN6I_FIFO_CTL_RF_RDY_TRIG_LEVEL_MASK	0xff
+#define SUN6I_FIFO_CTL_RF_RDY_TRIG_LEVEL_BITS	0
+#define SUN6I_FIFO_CTL_RF_RST			BIT(15)
+#define SUN6I_FIFO_CTL_TF_ERQ_TRIG_LEVEL_MASK	0xff
+#define SUN6I_FIFO_CTL_TF_ERQ_TRIG_LEVEL_BITS	16
+#define SUN6I_FIFO_CTL_TF_RST			BIT(31)
+
+#define SUN6I_FIFO_STA_REG		0x1c
+#define SUN6I_FIFO_STA_RF_CNT_MASK		GENMASK(7, 0)
+#define SUN6I_FIFO_STA_TF_CNT_MASK		GENMASK(23, 16)
+
+#define SUN6I_CLK_CTL_REG		0x24
+#define SUN6I_CLK_CTL_CDR2_MASK			0xff
+#define SUN6I_CLK_CTL_CDR2(div)			(((div) & SUN6I_CLK_CTL_CDR2_MASK) << 0)
+#define SUN6I_CLK_CTL_CDR1_MASK			0xf
+#define SUN6I_CLK_CTL_CDR1(div)			(((div) & SUN6I_CLK_CTL_CDR1_MASK) << 8)
+#define SUN6I_CLK_CTL_DRS			BIT(12)
+
+#define SUN6I_MAX_XFER_SIZE		0xffffff
+
+#define SUN6I_BURST_CNT_REG		0x30
+
+#define SUN6I_XMIT_CNT_REG		0x34
+
+#define SUN6I_BURST_CTL_CNT_REG		0x38
+
+#define SUN6I_TXDATA_REG		0x200
+#define SUN6I_RXDATA_REG		0x300
+
+struct sun6i_spi {
+	struct spi_master	*master;
+	void __iomem		*base_addr;
+	struct clk		*hclk;
+	struct clk		*mclk;
+	struct reset_control	*rstc;
+
+	struct completion	done;
+
+	const u8		*tx_buf;
+	u8			*rx_buf;
+	int			len;
+	unsigned long		fifo_depth;
+};
+
+static inline u32 sun6i_spi_read(struct sun6i_spi *sspi, u32 reg)
+{
+	return readl(sspi->base_addr + reg);
+}
+
+static inline void sun6i_spi_write(struct sun6i_spi *sspi, u32 reg, u32 value)
+{
+	writel(value, sspi->base_addr + reg);
+}
+
+static inline u32 sun6i_spi_get_rx_fifo_count(struct sun6i_spi *sspi)
+{
+	u32 reg = sun6i_spi_read(sspi, SUN6I_FIFO_STA_REG);
+
+	return FIELD_GET(SUN6I_FIFO_STA_RF_CNT_MASK, reg);
+}
+
+static inline u32 sun6i_spi_get_tx_fifo_count(struct sun6i_spi *sspi)
+{
+	u32 reg = sun6i_spi_read(sspi, SUN6I_FIFO_STA_REG);
+
+	return FIELD_GET(SUN6I_FIFO_STA_TF_CNT_MASK, reg);
+}
+
+static inline void sun6i_spi_disable_interrupt(struct sun6i_spi *sspi, u32 mask)
+{
+	u32 reg = sun6i_spi_read(sspi, SUN6I_INT_CTL_REG);
+
+	reg &= ~mask;
+	sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, reg);
+}
+
+static inline void sun6i_spi_drain_fifo(struct sun6i_spi *sspi)
+{
+	u32 len;
+	u8 byte;
+
+	/* See how much data is available */
+	len = sun6i_spi_get_rx_fifo_count(sspi);
+
+	while (len--) {
+		byte = readb(sspi->base_addr + SUN6I_RXDATA_REG);
+		if (sspi->rx_buf)
+			*sspi->rx_buf++ = byte;
+	}
+}
+
+static inline void sun6i_spi_fill_fifo(struct sun6i_spi *sspi)
+{
+	u32 cnt;
+	int len;
+	u8 byte;
+
+	/* See how much data we can fit */
+	cnt = sspi->fifo_depth - sun6i_spi_get_tx_fifo_count(sspi);
+
+	len = min((int)cnt, sspi->len);
+
+	while (len--) {
+		byte = sspi->tx_buf ? *sspi->tx_buf++ : 0;
+		writeb(byte, sspi->base_addr + SUN6I_TXDATA_REG);
+		sspi->len--;
+	}
+}
+
+static void sun6i_spi_set_cs(struct spi_device *spi, bool enable)
+{
+	struct sun6i_spi *sspi = spi_master_get_devdata(spi->master);
+	u32 reg;
+
+	reg = sun6i_spi_read(sspi, SUN6I_TFR_CTL_REG);
+	reg &= ~SUN6I_TFR_CTL_CS_MASK;
+	reg |= SUN6I_TFR_CTL_CS(spi->chip_select);
+
+	if (enable)
+		reg |= SUN6I_TFR_CTL_CS_LEVEL;
+	else
+		reg &= ~SUN6I_TFR_CTL_CS_LEVEL;
+
+	sun6i_spi_write(sspi, SUN6I_TFR_CTL_REG, reg);
+}
+
+static size_t sun6i_spi_max_transfer_size(struct spi_device *spi)
+{
+	return SUN6I_MAX_XFER_SIZE - 1;
+}
+
+static int sun6i_spi_transfer_one(struct spi_master *master,
+				  struct spi_device *spi,
+				  struct spi_transfer *tfr)
+{
+	struct sun6i_spi *sspi = spi_master_get_devdata(master);
+	unsigned int mclk_rate, div, div_cdr1, div_cdr2, timeout;
+	unsigned int start, end, tx_time;
+	unsigned int trig_level;
+	unsigned int tx_len = 0, rx_len = 0;
+	int ret = 0;
+	u32 reg;
+
+	if (tfr->len > SUN6I_MAX_XFER_SIZE)
+		return -EINVAL;
+
+	reinit_completion(&sspi->done);
+	sspi->tx_buf = tfr->tx_buf;
+	sspi->rx_buf = tfr->rx_buf;
+	sspi->len = tfr->len;
+
+	/* Clear pending interrupts */
+	sun6i_spi_write(sspi, SUN6I_INT_STA_REG, ~0);
+
+	/* Reset FIFO */
+	sun6i_spi_write(sspi, SUN6I_FIFO_CTL_REG,
+			SUN6I_FIFO_CTL_RF_RST | SUN6I_FIFO_CTL_TF_RST);
+
+	/*
+	 * Setup FIFO interrupt trigger level
+	 * Here we choose 3/4 of the full fifo depth, as it's the hardcoded
+	 * value used in old generation of Allwinner SPI controller.
+	 * (See spi-sun4i.c)
+	 */
+	trig_level = sspi->fifo_depth / 4 * 3;
+	sun6i_spi_write(sspi, SUN6I_FIFO_CTL_REG,
+			(trig_level << SUN6I_FIFO_CTL_RF_RDY_TRIG_LEVEL_BITS) |
+			(trig_level << SUN6I_FIFO_CTL_TF_ERQ_TRIG_LEVEL_BITS));
+
+	/*
+	 * Setup the transfer control register: Chip Select,
+	 * polarities, etc.
+	 */
+	reg = sun6i_spi_read(sspi, SUN6I_TFR_CTL_REG);
+
+	if (spi->mode & SPI_CPOL)
+		reg |= SUN6I_TFR_CTL_CPOL;
+	else
+		reg &= ~SUN6I_TFR_CTL_CPOL;
+
+	if (spi->mode & SPI_CPHA)
+		reg |= SUN6I_TFR_CTL_CPHA;
+	else
+		reg &= ~SUN6I_TFR_CTL_CPHA;
+
+	if (spi->mode & SPI_LSB_FIRST)
+		reg |= SUN6I_TFR_CTL_FBS;
+	else
+		reg &= ~SUN6I_TFR_CTL_FBS;
+
+	/*
+	 * If it's a TX only transfer, we don't want to fill the RX
+	 * FIFO with bogus data
+	 */
+	if (sspi->rx_buf) {
+		reg &= ~SUN6I_TFR_CTL_DHB;
+		rx_len = tfr->len;
+	} else {
+		reg |= SUN6I_TFR_CTL_DHB;
+	}
+
+	/* We want to control the chip select manually */
+	reg |= SUN6I_TFR_CTL_CS_MANUAL;
+
+	sun6i_spi_write(sspi, SUN6I_TFR_CTL_REG, reg);
+
+	/* Ensure that we have a parent clock fast enough */
+	mclk_rate = clk_get_rate(sspi->mclk);
+	if (mclk_rate < (2 * tfr->speed_hz)) {
+		clk_set_rate(sspi->mclk, 2 * tfr->speed_hz);
+		mclk_rate = clk_get_rate(sspi->mclk);
+	}
+
+	/*
+	 * Setup clock divider.
+	 *
+	 * We have two choices there. Either we can use the clock
+	 * divide rate 1, which is calculated thanks to this formula:
+	 * SPI_CLK = MOD_CLK / (2 ^ cdr)
+	 * Or we can use CDR2, which is calculated with the formula:
+	 * SPI_CLK = MOD_CLK / (2 * (cdr + 1))
+	 * Wether we use the former or the latter is set through the
+	 * DRS bit.
+	 *
+	 * First try CDR2, and if we can't reach the expected
+	 * frequency, fall back to CDR1.
+	 */
+	div_cdr1 = DIV_ROUND_UP(mclk_rate, tfr->speed_hz);
+	div_cdr2 = DIV_ROUND_UP(div_cdr1, 2);
+	if (div_cdr2 <= (SUN6I_CLK_CTL_CDR2_MASK + 1)) {
+		reg = SUN6I_CLK_CTL_CDR2(div_cdr2 - 1) | SUN6I_CLK_CTL_DRS;
+		tfr->effective_speed_hz = mclk_rate / (2 * div_cdr2);
+	} else {
+		div = min(SUN6I_CLK_CTL_CDR1_MASK, order_base_2(div_cdr1));
+		reg = SUN6I_CLK_CTL_CDR1(div);
+		tfr->effective_speed_hz = mclk_rate / (1 << div);
+	}
+
+	sun6i_spi_write(sspi, SUN6I_CLK_CTL_REG, reg);
+	/* Finally enable the bus - doing so before might raise SCK to HIGH */
+	reg = sun6i_spi_read(sspi, SUN6I_GBL_CTL_REG);
+	reg |= SUN6I_GBL_CTL_BUS_ENABLE;
+	sun6i_spi_write(sspi, SUN6I_GBL_CTL_REG, reg);
+
+	/* Setup the transfer now... */
+	if (sspi->tx_buf)
+		tx_len = tfr->len;
+
+	/* Setup the counters */
+	sun6i_spi_write(sspi, SUN6I_BURST_CNT_REG, tfr->len);
+	sun6i_spi_write(sspi, SUN6I_XMIT_CNT_REG, tx_len);
+	sun6i_spi_write(sspi, SUN6I_BURST_CTL_CNT_REG, tx_len);
+
+	/* Fill the TX FIFO */
+	sun6i_spi_fill_fifo(sspi);
+
+	/* Enable the interrupts */
+	reg = SUN6I_INT_CTL_TC;
+
+	if (rx_len > sspi->fifo_depth)
+		reg |= SUN6I_INT_CTL_RF_RDY;
+	if (tx_len > sspi->fifo_depth)
+		reg |= SUN6I_INT_CTL_TF_ERQ;
+
+	sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, reg);
+
+	/* Start the transfer */
+	reg = sun6i_spi_read(sspi, SUN6I_TFR_CTL_REG);
+	sun6i_spi_write(sspi, SUN6I_TFR_CTL_REG, reg | SUN6I_TFR_CTL_XCH);
+
+	tx_time = max(tfr->len * 8 * 2 / (tfr->speed_hz / 1000), 100U);
+	start = jiffies;
+	timeout = wait_for_completion_timeout(&sspi->done,
+					      msecs_to_jiffies(tx_time));
+	end = jiffies;
+	if (!timeout) {
+		dev_warn(&master->dev,
+			 "%s: timeout transferring %u bytes@%iHz for %i(%i)ms",
+			 dev_name(&spi->dev), tfr->len, tfr->speed_hz,
+			 jiffies_to_msecs(end - start), tx_time);
+		ret = -ETIMEDOUT;
+	}
+
+	sun6i_spi_write(sspi, SUN6I_INT_CTL_REG, 0);
+
+	return ret;
+}
+
+static irqreturn_t sun6i_spi_handler(int irq, void *dev_id)
+{
+	struct sun6i_spi *sspi = dev_id;
+	u32 status = sun6i_spi_read(sspi, SUN6I_INT_STA_REG);
+
+	/* Transfer complete */
+	if (status & SUN6I_INT_CTL_TC) {
+		sun6i_spi_write(sspi, SUN6I_INT_STA_REG, SUN6I_INT_CTL_TC);
+		sun6i_spi_drain_fifo(sspi);
+		complete(&sspi->done);
+		return IRQ_HANDLED;
+	}
+
+	/* Receive FIFO 3/4 full */
+	if (status & SUN6I_INT_CTL_RF_RDY) {
+		sun6i_spi_drain_fifo(sspi);
+		/* Only clear the interrupt _after_ draining the FIFO */
+		sun6i_spi_write(sspi, SUN6I_INT_STA_REG, SUN6I_INT_CTL_RF_RDY);
+		return IRQ_HANDLED;
+	}
+
+	/* Transmit FIFO 3/4 empty */
+	if (status & SUN6I_INT_CTL_TF_ERQ) {
+		sun6i_spi_fill_fifo(sspi);
+
+		if (!sspi->len)
+			/* nothing left to transmit */
+			sun6i_spi_disable_interrupt(sspi, SUN6I_INT_CTL_TF_ERQ);
+
+		/* Only clear the interrupt _after_ re-seeding the FIFO */
+		sun6i_spi_write(sspi, SUN6I_INT_STA_REG, SUN6I_INT_CTL_TF_ERQ);
+
+		return IRQ_HANDLED;
+	}
+
+	return IRQ_NONE;
+}
+
+static int sun6i_spi_runtime_resume(struct device *dev)
+{
+	struct spi_master *master = dev_get_drvdata(dev);
+	struct sun6i_spi *sspi = spi_master_get_devdata(master);
+	int ret;
+
+	ret = clk_prepare_enable(sspi->hclk);
+	if (ret) {
+		dev_err(dev, "Couldn't enable AHB clock\n");
+		goto out;
+	}
+
+	ret = clk_prepare_enable(sspi->mclk);
+	if (ret) {
+		dev_err(dev, "Couldn't enable module clock\n");
+		goto err;
+	}
+
+	ret = reset_control_deassert(sspi->rstc);
+	if (ret) {
+		dev_err(dev, "Couldn't deassert the device from reset\n");
+		goto err2;
+	}
+
+	sun6i_spi_write(sspi, SUN6I_GBL_CTL_REG,
+			SUN6I_GBL_CTL_MASTER | SUN6I_GBL_CTL_TP);
+
+	return 0;
+
+err2:
+	clk_disable_unprepare(sspi->mclk);
+err:
+	clk_disable_unprepare(sspi->hclk);
+out:
+	return ret;
+}
+
+static int sun6i_spi_runtime_suspend(struct device *dev)
+{
+	struct spi_master *master = dev_get_drvdata(dev);
+	struct sun6i_spi *sspi = spi_master_get_devdata(master);
+
+	reset_control_assert(sspi->rstc);
+	clk_disable_unprepare(sspi->mclk);
+	clk_disable_unprepare(sspi->hclk);
+
+	return 0;
+}
+
+static int sun6i_spi_probe(struct platform_device *pdev)
+{
+	struct spi_master *master;
+	struct sun6i_spi *sspi;
+	int ret = 0, irq;
+
+	master = spi_alloc_master(&pdev->dev, sizeof(struct sun6i_spi));
+	if (!master) {
+		dev_err(&pdev->dev, "Unable to allocate SPI Master\n");
+		return -ENOMEM;
+	}
+
+	platform_set_drvdata(pdev, master);
+	sspi = spi_master_get_devdata(master);
+
+	sspi->base_addr = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(sspi->base_addr)) {
+		ret = PTR_ERR(sspi->base_addr);
+		goto err_free_master;
+	}
+
+	irq = platform_get_irq(pdev, 0);
+	if (irq < 0) {
+		ret = -ENXIO;
+		goto err_free_master;
+	}
+
+	ret = devm_request_irq(&pdev->dev, irq, sun6i_spi_handler,
+			       0, "sun6i-spi", sspi);
+	if (ret) {
+		dev_err(&pdev->dev, "Cannot request IRQ\n");
+		goto err_free_master;
+	}
+
+	sspi->master = master;
+	sspi->fifo_depth = (unsigned long)of_device_get_match_data(&pdev->dev);
+
+	master->max_speed_hz = 100 * 1000 * 1000;
+	master->min_speed_hz = 3 * 1000;
+	master->use_gpio_descriptors = true;
+	master->set_cs = sun6i_spi_set_cs;
+	master->transfer_one = sun6i_spi_transfer_one;
+	master->num_chipselect = 4;
+	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST;
+	master->bits_per_word_mask = SPI_BPW_MASK(8);
+	master->dev.of_node = pdev->dev.of_node;
+	master->auto_runtime_pm = true;
+	master->max_transfer_size = sun6i_spi_max_transfer_size;
+
+	sspi->hclk = devm_clk_get(&pdev->dev, "ahb");
+	if (IS_ERR(sspi->hclk)) {
+		dev_err(&pdev->dev, "Unable to acquire AHB clock\n");
+		ret = PTR_ERR(sspi->hclk);
+		goto err_free_master;
+	}
+
+	sspi->mclk = devm_clk_get(&pdev->dev, "mod");
+	if (IS_ERR(sspi->mclk)) {
+		dev_err(&pdev->dev, "Unable to acquire module clock\n");
+		ret = PTR_ERR(sspi->mclk);
+		goto err_free_master;
+	}
+
+	init_completion(&sspi->done);
+
+	sspi->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
+	if (IS_ERR(sspi->rstc)) {
+		dev_err(&pdev->dev, "Couldn't get reset controller\n");
+		ret = PTR_ERR(sspi->rstc);
+		goto err_free_master;
+	}
+
+	/*
+	 * This wake-up/shutdown pattern is to be able to have the
+	 * device woken up, even if runtime_pm is disabled
+	 */
+	ret = sun6i_spi_runtime_resume(&pdev->dev);
+	if (ret) {
+		dev_err(&pdev->dev, "Couldn't resume the device\n");
+		goto err_free_master;
+	}
+
+	pm_runtime_set_active(&pdev->dev);
+	pm_runtime_enable(&pdev->dev);
+	pm_runtime_idle(&pdev->dev);
+
+	ret = devm_spi_register_master(&pdev->dev, master);
+	if (ret) {
+		dev_err(&pdev->dev, "cannot register SPI master\n");
+		goto err_pm_disable;
+	}
+
+	return 0;
+
+err_pm_disable:
+	pm_runtime_disable(&pdev->dev);
+	sun6i_spi_runtime_suspend(&pdev->dev);
+err_free_master:
+	spi_master_put(master);
+	return ret;
+}
+
+static int sun6i_spi_remove(struct platform_device *pdev)
+{
+	pm_runtime_force_suspend(&pdev->dev);
+
+	return 0;
+}
+
+static const struct of_device_id sun6i_spi_match[] = {
+	{ .compatible = "allwinner,sun6i-a31-spi", .data = (void *)SUN6I_FIFO_DEPTH },
+	{ .compatible = "allwinner,sun8i-h3-spi",  .data = (void *)SUN8I_FIFO_DEPTH },
+	{}
+};
+MODULE_DEVICE_TABLE(of, sun6i_spi_match);
+
+static const struct dev_pm_ops sun6i_spi_pm_ops = {
+	.runtime_resume		= sun6i_spi_runtime_resume,
+	.runtime_suspend	= sun6i_spi_runtime_suspend,
+};
+
+static struct platform_driver sun6i_spi_driver = {
+	.probe	= sun6i_spi_probe,
+	.remove	= sun6i_spi_remove,
+	.driver	= {
+		.name		= "sun6i-spi",
+		.of_match_table	= sun6i_spi_match,
+		.pm		= &sun6i_spi_pm_ops,
+	},
+};
+module_platform_driver(sun6i_spi_driver);
+
+MODULE_AUTHOR("Pan Nan <pannan@allwinnertech.com>");
+MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
+MODULE_DESCRIPTION("Allwinner A31 SPI controller driver");
+MODULE_LICENSE("GPL");