[U-Boot] [RFC PATCH 4/4] arm: sunxi: added SPI driver for Allwinner devices

S.J.R. van Schaik stephan at whiteboxsystems.nl
Fri Feb 10 15:25:35 UTC 2017


Implements a driver model SPI driver for Allwinner devices (sunxi).

Signed-off-by: S.J.R. van Schaik <stephan at whiteboxsystems.nl>
---
 drivers/spi/Kconfig     |   5 +
 drivers/spi/Makefile    |   1 +
 drivers/spi/sunxi_spi.c | 329 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 335 insertions(+)
 create mode 100644 drivers/spi/sunxi_spi.c

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index f3f7dbe089..d243e69a3c 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -132,6 +132,11 @@ config STM32_QSPI
 	  used to access the SPI NOR flash chips on platforms embedding
 	  this ST IP core.
 
+config SUNXI_SPI
+	bool "Allwinner SPI driver"
+	help
+	  Enable the Allwinner SPI driver.
+
 config TEGRA114_SPI
 	bool "nVidia Tegra114 SPI driver"
 	help
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index fa9a1d2496..b2011f4da3 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -43,6 +43,7 @@ obj-$(CONFIG_SANDBOX_SPI) += sandbox_spi.o
 obj-$(CONFIG_SH_SPI) += sh_spi.o
 obj-$(CONFIG_SH_QSPI) += sh_qspi.o
 obj-$(CONFIG_STM32_QSPI) += stm32_qspi.o
+obj-$(CONFIG_SUNXI_SPI) += sunxi_spi.o
 obj-$(CONFIG_TEGRA114_SPI) += tegra114_spi.o
 obj-$(CONFIG_TEGRA20_SFLASH) += tegra20_sflash.o
 obj-$(CONFIG_TEGRA20_SLINK) += tegra20_slink.o
diff --git a/drivers/spi/sunxi_spi.c b/drivers/spi/sunxi_spi.c
new file mode 100644
index 0000000000..721d5167cd
--- /dev/null
+++ b/drivers/spi/sunxi_spi.c
@@ -0,0 +1,329 @@
+/*
+ * (C) Copyright 2017 Whitebox Systems / Northend Systems B.V.
+ * Stephan van Schaik <stephan at whiteboxsystems.nl>
+ * Merlijn Wajer <merlijn at whiteboxsystems.nl>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <errno.h>
+#include <spi.h>
+
+#include <asm/bitops.h>
+#include <asm/gpio.h>
+#include <asm/io.h>
+
+#include <asm/arch/clock.h>
+#include <asm/arch/spi.h>
+
+#define SUNXI_SPI_MAX_RATE (24 * 1000 * 1000)
+#define SUNXI_SPI_MIN_RATE (3 * 1000)
+
+struct sunxi_spi_platdata {
+	struct sunxi_spi_regs *regs;
+	unsigned int activate_delay_us;
+	unsigned int deactivate_delay_us;
+	uint32_t freq;
+};
+
+struct sunxi_spi_priv {
+	struct sunxi_spi_regs *regs;
+	unsigned int max_freq;
+	unsigned int last_transaction_us;
+};
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static void sunxi_spi_setup_pinmux(unsigned int pin_function)
+{
+	unsigned int pin;
+
+	for (pin = SUNXI_GPC(0); pin <= SUNXI_GPC(2); pin++)
+		sunxi_gpio_set_cfgpin(pin, pin_function);
+
+	if (IS_ENABLED(CONFIG_MACH_SUN4I) || IS_ENABLED(CONFIG_MACH_SUN7I)) {
+		sunxi_gpio_set_cfgpin(SUNXI_GPC(23), pin_function);
+	} else {
+		sunxi_gpio_set_cfgpin(SUNXI_GPC(3), pin_function);
+	}
+}
+
+static void sunxi_spi_enable_clock(struct udevice *bus)
+{
+	struct sunxi_ccm_reg * const ccm =
+		(struct sunxi_ccm_reg * const)SUNXI_CCM_BASE;
+	
+	setbits_le32(&ccm->ahb_gate0, (1 << AHB_GATE_OFFSET_SPI0));
+	writel((1 << 31), &ccm->spi0_clk_cfg);
+}
+
+static void sunxi_spi_disable_clock(void)
+{
+	struct sunxi_ccm_reg * const ccm =
+		(struct sunxi_ccm_reg * const)SUNXI_CCM_BASE;
+
+	writel(0, &ccm->spi0_clk_cfg);
+	clrbits_le32(&ccm->ahb_gate0, (1 << AHB_GATE_OFFSET_SPI0));
+}
+
+static void sunxi_spi_cs_activate(struct udevice *dev, unsigned int cs)
+{
+	struct udevice *bus = dev->parent;
+	struct sunxi_spi_platdata *plat = dev_get_platdata(bus);
+	struct sunxi_spi_priv *priv = dev_get_priv(bus);
+	uint32_t reg;
+
+	/* If it is too soon to perform another transaction, wait. */
+	if (plat->deactivate_delay_us && priv->last_transaction_us) {
+		unsigned int delay_us;
+
+		delay_us = timer_get_us() - priv->last_transaction_us;
+
+		if (delay_us < plat->deactivate_delay_us)
+			udelay(plat->deactivate_delay_us - delay_us);
+	}
+
+	debug("%s: activate cs: %u, bus: '%s'\n", __func__, cs, bus->name);
+
+	reg = readl(&priv->regs->xfer_ctl);
+	reg &= ~(SUNXI_SPI_CTL_CS_MASK | SUNXI_SPI_CTL_CS_LEVEL);
+	reg |= SUNXI_SPI_CTL_CS(cs);
+	writel(reg, &priv->regs->xfer_ctl);
+
+	if (plat->activate_delay_us)
+		udelay(plat->activate_delay_us);
+}
+
+static void sunxi_spi_cs_deactivate(struct udevice *dev, unsigned int cs)
+{
+	struct udevice *bus = dev->parent;
+	struct sunxi_spi_platdata *plat = dev_get_platdata(bus);
+	struct sunxi_spi_priv *priv = dev_get_priv(bus);
+	uint32_t reg;
+
+	debug("%s: deactivate cs: %u, bus: '%s'\n", __func__, cs, bus->name);
+	
+	reg = readl(&priv->regs->xfer_ctl);
+	reg &= ~SUNXI_SPI_CTL_CS_MASK;
+	reg |= SUNXI_SPI_CTL_CS_LEVEL;
+	writel(reg, &priv->regs->xfer_ctl);
+
+	/* 
+	 * Remember the time of this transaction so that we can honour the bus
+	 * delay.
+	 */
+	if (plat->deactivate_delay_us)
+		priv->last_transaction_us = timer_get_us();
+}
+
+static int sunxi_spi_ofdata_to_platdata(struct udevice *bus)
+{
+	struct sunxi_spi_platdata *plat = dev_get_platdata(bus);
+	const void *blob = gd->fdt_blob;
+	int node = bus->of_offset;
+
+	plat->regs = (struct sunxi_spi_regs *)dev_get_addr(bus);
+	plat->activate_delay_us = fdtdec_get_int(
+		blob, node, "spi-activate_delay", 0);
+	plat->deactivate_delay_us = fdtdec_get_int(
+		blob, node, "spi-deactivate-delay", 0);
+
+	debug("%s: regs=%p, activate-delay=%u, deactivate-delay=%u\n",
+		__func__, plat->regs, plat->activate_delay_us,
+		plat->deactivate_delay_us);
+
+	return 0;
+}
+
+static int sunxi_spi_probe(struct udevice *bus)
+{
+	struct sunxi_spi_platdata *plat = dev_get_platdata(bus);
+	struct sunxi_spi_priv *priv = dev_get_priv(bus);
+
+	debug("%s: probe\n", __func__);
+
+	priv->regs = plat->regs;
+	priv->last_transaction_us = timer_get_us();
+
+	return 0;
+}
+
+static int sunxi_spi_claim_bus(struct udevice *dev)
+{
+	struct udevice *bus = dev->parent;
+	struct sunxi_spi_priv *priv = dev_get_priv(bus);
+
+	debug("%s: claiming bus\n", __func__);
+
+	sunxi_spi_setup_pinmux(SUNXI_GPC_SPI0);
+	sunxi_spi_enable_clock(bus);
+	setbits_le32(&priv->regs->glb_ctl, SUNXI_SPI_CTL_MASTER |
+		SUNXI_SPI_CTL_ENABLE | SUNXI_SPI_CTL_TP | SUNXI_SPI_CTL_SRST);
+	setbits_le32(&priv->regs->xfer_ctl, SUNXI_SPI_CTL_CS_MANUAL |
+		SUNXI_SPI_CTL_CS_LEVEL);
+	setbits_le32(&priv->regs->fifo_ctl, SUNXI_SPI_CTL_RF_RST |
+		SUNXI_SPI_CTL_TF_RST);
+
+	if (IS_ENABLED(CONFIG_GEN_SUN6I))
+		while (readl(&priv->regs->glb_ctl) & SUNXI_SPI_CTL_SRST)
+			;
+
+	return 0;
+}
+
+static int sunxi_spi_release_bus(struct udevice *dev)
+{
+	struct udevice *bus = dev->parent;
+	struct sunxi_spi_priv *priv = dev_get_priv(bus);
+
+	debug("%s: releasing bus\n", __func__);
+
+	clrbits_le32(&priv->regs->glb_ctl, SUNXI_SPI_CTL_ENABLE);
+	sunxi_spi_disable_clock();
+
+	return 0;
+}
+
+static int sunxi_spi_xfer(struct udevice *dev, unsigned int bitlen,
+	const void *dout, void *din, unsigned long flags)
+{
+	struct udevice *bus = dev->parent;
+	struct sunxi_spi_priv *priv = dev_get_priv(bus);
+	struct dm_spi_slave_platdata *slave_plat = dev_get_parent_platdata(dev);
+	const char *tx_buf = dout;
+	char *rx_buf = din;
+	size_t len = bitlen / 8;
+	size_t i, nbytes;
+	char byte;
+
+	if (bitlen % 8) {
+		debug("%s: non byte-aligned SPI transfer.\n", __func__);
+		return -1;
+	}
+
+	if (flags & SPI_XFER_BEGIN)
+		sunxi_spi_cs_activate(dev, slave_plat->cs);
+
+	while (len) {
+		nbytes = min(len, (size_t)64 - 1);
+
+		writel(SUNXI_SPI_BURST_CNT(nbytes), &priv->regs->burst_cnt);
+
+		if (IS_ENABLED(CONFIG_SUNXI_GEN_SUN6I))
+			writel(SUNXI_SPI_BURST_CNT(nbytes),
+				&priv->regs->burst_ctl);
+
+		if (!tx_buf) {
+			writel(0, &priv->regs->xmit_cnt);
+		} else {
+			writel(SUNXI_SPI_XMIT_CNT(nbytes),
+				&priv->regs->xmit_cnt);
+
+			for (i = 0; i < nbytes; ++i) {
+				byte = tx_buf ? *tx_buf++ : 0;
+				writeb(byte, &priv->regs->tx_data);
+			}
+		}
+		
+		setbits_le32(&priv->regs->xfer_ctl, SUNXI_SPI_CTL_XCH);
+
+		while (((readl(&priv->regs->fifo_sta) &
+			SUNXI_SPI_FIFO_RF_CNT_MASK) >>
+			SUNXI_SPI_FIFO_RF_CNT_BITS) < nbytes)
+			;
+
+		for (i = 0; i < nbytes; ++i) {
+			byte = readb(&priv->regs->rx_data);
+
+			if (rx_buf)
+				*rx_buf++ = byte;
+		}
+
+		len -= nbytes;
+	}
+
+	if (flags & SPI_XFER_END)
+		sunxi_spi_cs_deactivate(dev, slave_plat->cs);
+
+	return 0;
+}
+
+static int sunxi_spi_set_speed(struct udevice *bus, uint speed)
+{
+	struct sunxi_spi_priv *priv = dev_get_priv(bus);
+	unsigned int div;
+	uint32_t reg;
+
+	speed = min(speed, (unsigned int)SUNXI_SPI_MAX_RATE);
+	speed = max((unsigned int)SUNXI_SPI_MIN_RATE, speed);
+
+	div = SUNXI_SPI_MAX_RATE / (2 * speed);
+
+	if (div <= (SUNXI_SPI_CLK_CTL_CDR2_MASK + 1)) {
+		if (div > 0)
+			div--;
+
+		reg = SUNXI_SPI_CLK_CTL_CDR2(div) | SUNXI_SPI_CLK_CTL_DRS;
+	} else {
+		div = __ilog2(SUNXI_SPI_MAX_RATE) - __ilog2(speed);
+		reg = SUNXI_SPI_CLK_CTL_CDR1(div);
+	}
+
+	writel(reg, &priv->regs->clk_ctl);
+
+	debug("%s: speed=%u\n", __func__, speed);
+
+	return 0;
+}
+
+static int sunxi_spi_set_mode(struct udevice *bus, uint mode)
+{
+	struct sunxi_spi_priv *priv = dev_get_priv(bus);
+	uint32_t reg;
+
+	reg = readl(&priv->regs->xfer_ctl);
+	reg &= ~(SUNXI_SPI_CTL_CPOL | SUNXI_SPI_CTL_CPHA |
+		SUNXI_SPI_CTL_CS_ACTIVE_LOW);
+
+	if (mode & SPI_CPOL)
+		reg |= SUNXI_SPI_CTL_CPOL;
+
+	if (mode & SPI_CPHA)
+		reg |= SUNXI_SPI_CTL_CPHA;
+
+	if (!(mode & SPI_CS_HIGH))
+		reg |= SUNXI_SPI_CTL_CS_ACTIVE_LOW;
+
+	writel(reg, &priv->regs->xfer_ctl);
+
+	debug("%s: mode=%d\n", __func__, mode);
+
+	return 0;
+}
+
+static const struct dm_spi_ops sunxi_spi_ops = {
+	.claim_bus	= sunxi_spi_claim_bus,
+	.release_bus	= sunxi_spi_release_bus,
+	.xfer		= sunxi_spi_xfer,
+	.set_speed	= sunxi_spi_set_speed,
+	.set_mode	= sunxi_spi_set_mode,
+};
+
+static const struct udevice_id sunxi_spi_ids[] = {
+	{ .compatible = "allwinner,sun4i-a10-spi" },
+	{ .compatible = "allwinner,sun6i-a31-spi" },
+	{ }
+};
+
+U_BOOT_DRIVER(sunxi_spi) = {
+	.name	= "sunxi_spi",
+	.id	= UCLASS_SPI,
+	.of_match = sunxi_spi_ids,
+	.ops	= &sunxi_spi_ops,
+	.ofdata_to_platdata = sunxi_spi_ofdata_to_platdata,
+	.platdata_auto_alloc_size = sizeof(struct sunxi_spi_platdata),
+	.priv_auto_alloc_size = sizeof(struct sunxi_spi_priv),
+	.probe	= sunxi_spi_probe,
+};
-- 
2.11.0



More information about the U-Boot mailing list