diff options
Diffstat (limited to 'drivers/mtd/spi/sunxi_spi_spl.c')
-rw-r--r-- | drivers/mtd/spi/sunxi_spi_spl.c | 283 |
1 files changed, 283 insertions, 0 deletions
diff --git a/drivers/mtd/spi/sunxi_spi_spl.c b/drivers/mtd/spi/sunxi_spi_spl.c new file mode 100644 index 00000000000..e3ded5b4e81 --- /dev/null +++ b/drivers/mtd/spi/sunxi_spi_spl.c @@ -0,0 +1,283 @@ +/* + * 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> + +#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 int 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, + u32 spi_ctl_reg, + u32 spi_ctl_xch_bitmask, + u32 spi_fifo_reg, + u32 spi_tx_reg, + u32 spi_rx_reg, + u32 spi_bc_reg, + u32 spi_tc_reg, + u32 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; + } +} + +/*****************************************************************************/ + +int spl_spi_load_image(void) +{ + int err; + 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); + err = spl_parse_image_header(header); + if (err) + return err; + + spi0_read_data((void *)spl_image.load_addr, CONFIG_SYS_SPI_U_BOOT_OFFS, + spl_image.size); + + spi0_deinit(); + return 0; +} |