arm: sunxi: Move spl spi sunxi code to mach-sunxi

This SUNXI variant SPL SPI code doesn't use either SPI or
SPL_FLASG subsystems due to size constraints and also placing
this code in drivers/mtd/spi will unnecessary build SPI_FLASH
code(if defined) which never required, hence moved to arch area.

And also renamed the file according to kconfig which resembles
proper name.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>

3 files changed, 321 insertions, 0 deletions

diff --git a/arch/arm/mach-sunxi/Kconfig b/arch/arm/mach-sunxi/Kconfig
index 1fededd..dc48eef 100644
--- a/arch/arm/mach-sunxi/Kconfig
+++ b/arch/arm/mach-sunxi/Kconfig
@@ -847,4 +847,12 @@ config SPL_STACK_R_ADDR
 	default 0x2fe00000 if MACH_SUN9I
 	default 0x4fe00000 if MACH_SUN50I
 
+config SPL_SPI_SUNXI
+	bool "Support for SPI Flash on Allwinner SoCs in SPL"
+	depends on MACH_SUN4I || MACH_SUN5I || MACH_SUN7I || MACH_SUNXI_H3_H5 || MACH_SUN50I
+	help
+	  Enable support for SPI Flash. This option allows SPL to read from
+	  sunxi SPI Flash. It uses the same method as the boot ROM, so does
+	  not need any extra configuration.
+
 endif
diff --git a/arch/arm/mach-sunxi/Makefile b/arch/arm/mach-sunxi/Makefile
index 2a3c379..6ddf682 100644
--- a/arch/arm/mach-sunxi/Makefile
+++ b/arch/arm/mach-sunxi/Makefile
@@ -48,6 +48,7 @@ obj-$(CONFIG_MACH_SUN7I)	+= dram_sun4i.o
 obj-$(CONFIG_MACH_SUN8I_A23)	+= dram_sun8i_a23.o
 obj-$(CONFIG_MACH_SUN8I_A33)	+= dram_sun8i_a33.o
 obj-$(CONFIG_MACH_SUN8I_A83T)	+= dram_sun8i_a83t.o
+obj-$(CONFIG_SPL_SPI_SUNXI)	+= spl_spi_sunxi.o
 obj-$(CONFIG_SUNXI_DRAM_DW)	+= dram_sunxi_dw.o
 obj-$(CONFIG_SUNXI_DRAM_DW)	+= dram_timings/
 obj-$(CONFIG_MACH_SUN9I)	+= dram_sun9i.o
diff --git a/arch/arm/mach-sunxi/spl_spi_sunxi.c b/arch/arm/mach-sunxi/spl_spi_sunxi.c
new file mode 100644
index 0000000..fa22981
--- /dev/null
+++ b/arch/arm/mach-sunxi/spl_spi_sunxi.c
@@ -0,0 +1,312 @@
+/*
+ * Copyright (C) 2016 Siarhei Siamashka <siarhei.siamashka@gmail.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <spl.h>
+#include <asm/gpio.h>
+#include <asm/io.h>
+#include <linux/libfdt.h>
+
+#ifdef CONFIG_SPL_OS_BOOT
+#error CONFIG_SPL_OS_BOOT is not supported yet
+#endif
+
+/*
+ * This is a very simple U-Boot image loading implementation, trying to
+ * replicate what the boot ROM is doing when loading the SPL. Because we
+ * know the exact pins where the SPI Flash is connected and also know
+ * that the Read Data Bytes (03h) command is supported, the hardware
+ * configuration is very simple and we don't need the extra flexibility
+ * of the SPI framework. Moreover, we rely on the default settings of
+ * the SPI controler hardware registers and only adjust what needs to
+ * be changed. This is good for the code size and this implementation
+ * adds less than 400 bytes to the SPL.
+ *
+ * There are two variants of the SPI controller in Allwinner SoCs:
+ * A10/A13/A20 (sun4i variant) and everything else (sun6i variant).
+ * Both of them are supported.
+ *
+ * The pin mixing part is SoC specific and only A10/A13/A20/H3/A64 are
+ * supported at the moment.
+ */
+
+/*****************************************************************************/
+/* SUN4I variant of the SPI controller                                       */
+/*****************************************************************************/
+
+#define SUN4I_SPI0_CCTL             (0x01C05000 + 0x1C)
+#define SUN4I_SPI0_CTL              (0x01C05000 + 0x08)
+#define SUN4I_SPI0_RX               (0x01C05000 + 0x00)
+#define SUN4I_SPI0_TX               (0x01C05000 + 0x04)
+#define SUN4I_SPI0_FIFO_STA         (0x01C05000 + 0x28)
+#define SUN4I_SPI0_BC               (0x01C05000 + 0x20)
+#define SUN4I_SPI0_TC               (0x01C05000 + 0x24)
+
+#define SUN4I_CTL_ENABLE            BIT(0)
+#define SUN4I_CTL_MASTER            BIT(1)
+#define SUN4I_CTL_TF_RST            BIT(8)
+#define SUN4I_CTL_RF_RST            BIT(9)
+#define SUN4I_CTL_XCH               BIT(10)
+
+/*****************************************************************************/
+/* SUN6I variant of the SPI controller                                       */
+/*****************************************************************************/
+
+#define SUN6I_SPI0_CCTL             (0x01C68000 + 0x24)
+#define SUN6I_SPI0_GCR              (0x01C68000 + 0x04)
+#define SUN6I_SPI0_TCR              (0x01C68000 + 0x08)
+#define SUN6I_SPI0_FIFO_STA         (0x01C68000 + 0x1C)
+#define SUN6I_SPI0_MBC              (0x01C68000 + 0x30)
+#define SUN6I_SPI0_MTC              (0x01C68000 + 0x34)
+#define SUN6I_SPI0_BCC              (0x01C68000 + 0x38)
+#define SUN6I_SPI0_TXD              (0x01C68000 + 0x200)
+#define SUN6I_SPI0_RXD              (0x01C68000 + 0x300)
+
+#define SUN6I_CTL_ENABLE            BIT(0)
+#define SUN6I_CTL_MASTER            BIT(1)
+#define SUN6I_CTL_SRST              BIT(31)
+#define SUN6I_TCR_XCH               BIT(31)
+
+/*****************************************************************************/
+
+#define CCM_AHB_GATING0             (0x01C20000 + 0x60)
+#define CCM_SPI0_CLK                (0x01C20000 + 0xA0)
+#define SUN6I_BUS_SOFT_RST_REG0     (0x01C20000 + 0x2C0)
+
+#define AHB_RESET_SPI0_SHIFT        20
+#define AHB_GATE_OFFSET_SPI0        20
+
+#define SPI0_CLK_DIV_BY_2           0x1000
+#define SPI0_CLK_DIV_BY_4           0x1001
+
+/*****************************************************************************/
+
+/*
+ * Allwinner A10/A20 SoCs were using pins PC0,PC1,PC2,PC23 for booting
+ * from SPI Flash, everything else is using pins PC0,PC1,PC2,PC3.
+ */
+static void spi0_pinmux_setup(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);
+}
+
+/*
+ * Setup 6 MHz from OSC24M (because the BROM is doing the same).
+ */
+static void spi0_enable_clock(void)
+{
+	/* Deassert SPI0 reset on SUN6I */
+	if (IS_ENABLED(CONFIG_SUNXI_GEN_SUN6I))
+		setbits_le32(SUN6I_BUS_SOFT_RST_REG0,
+			     (1 << AHB_RESET_SPI0_SHIFT));
+
+	/* Open the SPI0 gate */
+	setbits_le32(CCM_AHB_GATING0, (1 << AHB_GATE_OFFSET_SPI0));
+
+	/* Divide by 4 */
+	writel(SPI0_CLK_DIV_BY_4, IS_ENABLED(CONFIG_SUNXI_GEN_SUN6I) ?
+				  SUN6I_SPI0_CCTL : SUN4I_SPI0_CCTL);
+	/* 24MHz from OSC24M */
+	writel((1 << 31), CCM_SPI0_CLK);
+
+	if (IS_ENABLED(CONFIG_SUNXI_GEN_SUN6I)) {
+		/* Enable SPI in the master mode and do a soft reset */
+		setbits_le32(SUN6I_SPI0_GCR, SUN6I_CTL_MASTER |
+					     SUN6I_CTL_ENABLE |
+					     SUN6I_CTL_SRST);
+		/* Wait for completion */
+		while (readl(SUN6I_SPI0_GCR) & SUN6I_CTL_SRST)
+			;
+	} else {
+		/* Enable SPI in the master mode and reset FIFO */
+		setbits_le32(SUN4I_SPI0_CTL, SUN4I_CTL_MASTER |
+					     SUN4I_CTL_ENABLE |
+					     SUN4I_CTL_TF_RST |
+					     SUN4I_CTL_RF_RST);
+	}
+}
+
+static void spi0_disable_clock(void)
+{
+	/* Disable the SPI0 controller */
+	if (IS_ENABLED(CONFIG_SUNXI_GEN_SUN6I))
+		clrbits_le32(SUN6I_SPI0_GCR, SUN6I_CTL_MASTER |
+					     SUN6I_CTL_ENABLE);
+	else
+		clrbits_le32(SUN4I_SPI0_CTL, SUN4I_CTL_MASTER |
+					     SUN4I_CTL_ENABLE);
+
+	/* Disable the SPI0 clock */
+	writel(0, CCM_SPI0_CLK);
+
+	/* Close the SPI0 gate */
+	clrbits_le32(CCM_AHB_GATING0, (1 << AHB_GATE_OFFSET_SPI0));
+
+	/* Assert SPI0 reset on SUN6I */
+	if (IS_ENABLED(CONFIG_SUNXI_GEN_SUN6I))
+		clrbits_le32(SUN6I_BUS_SOFT_RST_REG0,
+			     (1 << AHB_RESET_SPI0_SHIFT));
+}
+
+static void spi0_init(void)
+{
+	unsigned int pin_function = SUNXI_GPC_SPI0;
+
+	if (IS_ENABLED(CONFIG_MACH_SUN50I))
+		pin_function = SUN50I_GPC_SPI0;
+
+	spi0_pinmux_setup(pin_function);
+	spi0_enable_clock();
+}
+
+static void spi0_deinit(void)
+{
+	/* New SoCs can disable pins, older could only set them as input */
+	unsigned int pin_function = SUNXI_GPIO_INPUT;
+	if (IS_ENABLED(CONFIG_SUNXI_GEN_SUN6I))
+		pin_function = SUNXI_GPIO_DISABLE;
+
+	spi0_disable_clock();
+	spi0_pinmux_setup(pin_function);
+}
+
+/*****************************************************************************/
+
+#define SPI_READ_MAX_SIZE 60 /* FIFO size, minus 4 bytes of the header */
+
+static void sunxi_spi0_read_data(u8 *buf, u32 addr, u32 bufsize,
+				 ulong spi_ctl_reg,
+				 ulong spi_ctl_xch_bitmask,
+				 ulong spi_fifo_reg,
+				 ulong spi_tx_reg,
+				 ulong spi_rx_reg,
+				 ulong spi_bc_reg,
+				 ulong spi_tc_reg,
+				 ulong spi_bcc_reg)
+{
+	writel(4 + bufsize, spi_bc_reg); /* Burst counter (total bytes) */
+	writel(4, spi_tc_reg);           /* Transfer counter (bytes to send) */
+	if (spi_bcc_reg)
+		writel(4, spi_bcc_reg);  /* SUN6I also needs this */
+
+	/* Send the Read Data Bytes (03h) command header */
+	writeb(0x03, spi_tx_reg);
+	writeb((u8)(addr >> 16), spi_tx_reg);
+	writeb((u8)(addr >> 8), spi_tx_reg);
+	writeb((u8)(addr), spi_tx_reg);
+
+	/* Start the data transfer */
+	setbits_le32(spi_ctl_reg, spi_ctl_xch_bitmask);
+
+	/* Wait until everything is received in the RX FIFO */
+	while ((readl(spi_fifo_reg) & 0x7F) < 4 + bufsize)
+		;
+
+	/* Skip 4 bytes */
+	readl(spi_rx_reg);
+
+	/* Read the data */
+	while (bufsize-- > 0)
+		*buf++ = readb(spi_rx_reg);
+
+	/* tSHSL time is up to 100 ns in various SPI flash datasheets */
+	udelay(1);
+}
+
+static void spi0_read_data(void *buf, u32 addr, u32 len)
+{
+	u8 *buf8 = buf;
+	u32 chunk_len;
+
+	while (len > 0) {
+		chunk_len = len;
+		if (chunk_len > SPI_READ_MAX_SIZE)
+			chunk_len = SPI_READ_MAX_SIZE;
+
+		if (IS_ENABLED(CONFIG_SUNXI_GEN_SUN6I)) {
+			sunxi_spi0_read_data(buf8, addr, chunk_len,
+					     SUN6I_SPI0_TCR,
+					     SUN6I_TCR_XCH,
+					     SUN6I_SPI0_FIFO_STA,
+					     SUN6I_SPI0_TXD,
+					     SUN6I_SPI0_RXD,
+					     SUN6I_SPI0_MBC,
+					     SUN6I_SPI0_MTC,
+					     SUN6I_SPI0_BCC);
+		} else {
+			sunxi_spi0_read_data(buf8, addr, chunk_len,
+					     SUN4I_SPI0_CTL,
+					     SUN4I_CTL_XCH,
+					     SUN4I_SPI0_FIFO_STA,
+					     SUN4I_SPI0_TX,
+					     SUN4I_SPI0_RX,
+					     SUN4I_SPI0_BC,
+					     SUN4I_SPI0_TC,
+					     0);
+		}
+
+		len  -= chunk_len;
+		buf8 += chunk_len;
+		addr += chunk_len;
+	}
+}
+
+static ulong spi_load_read(struct spl_load_info *load, ulong sector,
+			   ulong count, void *buf)
+{
+	spi0_read_data(buf, sector, count);
+
+	return count;
+}
+
+/*****************************************************************************/
+
+static int spl_spi_load_image(struct spl_image_info *spl_image,
+			      struct spl_boot_device *bootdev)
+{
+	int ret = 0;
+	struct image_header *header;
+	header = (struct image_header *)(CONFIG_SYS_TEXT_BASE);
+
+	spi0_init();
+
+	spi0_read_data((void *)header, CONFIG_SYS_SPI_U_BOOT_OFFS, 0x40);
+
+        if (IS_ENABLED(CONFIG_SPL_LOAD_FIT) &&
+		image_get_magic(header) == FDT_MAGIC) {
+		struct spl_load_info load;
+
+		debug("Found FIT image\n");
+		load.dev = NULL;
+		load.priv = NULL;
+		load.filename = NULL;
+		load.bl_len = 1;
+		load.read = spi_load_read;
+		ret = spl_load_simple_fit(spl_image, &load,
+					  CONFIG_SYS_SPI_U_BOOT_OFFS, header);
+	} else {
+		ret = spl_parse_image_header(spl_image, header);
+		if (ret)
+			return ret;
+
+		spi0_read_data((void *)spl_image->load_addr,
+			       CONFIG_SYS_SPI_U_BOOT_OFFS, spl_image->size);
+	}
+
+	spi0_deinit();
+
+	return ret;
+}
+/* Use priorty 0 to override the default if it happens to be linked in */
+SPL_LOAD_IMAGE_METHOD("sunxi SPI", 0, BOOT_DEVICE_SPI, spl_spi_load_image);