blob: b86b5a00adb9032672daaa02b640b2199002986d [file] [log] [blame]
/*
* (C) Copyright 2017 Whitebox Systems / Northend Systems B.V.
* S.J.R. van Schaik <stephan@whiteboxsystems.nl>
* M.B.W. Wajer <merlijn@whiteboxsystems.nl>
*
* (C) Copyright 2017 Olimex Ltd..
* Stefan Mavrodiev <stefan@olimex.com>
*
* Based on linux spi driver. Original copyright follows:
* linux/drivers/spi/spi-sun4i.c
*
* Copyright (C) 2012 - 2014 Allwinner Tech
* Pan Nan <pannan@allwinnertech.com>
*
* Copyright (C) 2014 Maxime Ripard
* Maxime Ripard <maxime.ripard@free-electrons.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <dm.h>
#include <spi.h>
#include <errno.h>
#include <fdt_support.h>
#include <wait_bit.h>
#include <asm/bitops.h>
#include <asm/gpio.h>
#include <asm/io.h>
#include <asm/arch/clock.h>
#define SUN4I_FIFO_DEPTH 64
#define SUN4I_RXDATA_REG 0x00
#define SUN4I_TXDATA_REG 0x04
#define SUN4I_CTL_REG 0x08
#define SUN4I_CTL_ENABLE BIT(0)
#define SUN4I_CTL_MASTER BIT(1)
#define SUN4I_CTL_CPHA BIT(2)
#define SUN4I_CTL_CPOL BIT(3)
#define SUN4I_CTL_CS_ACTIVE_LOW BIT(4)
#define SUN4I_CTL_LMTF BIT(6)
#define SUN4I_CTL_TF_RST BIT(8)
#define SUN4I_CTL_RF_RST BIT(9)
#define SUN4I_CTL_XCH_MASK 0x0400
#define SUN4I_CTL_XCH BIT(10)
#define SUN4I_CTL_CS_MASK 0x3000
#define SUN4I_CTL_CS(cs) (((cs) << 12) & SUN4I_CTL_CS_MASK)
#define SUN4I_CTL_DHB BIT(15)
#define SUN4I_CTL_CS_MANUAL BIT(16)
#define SUN4I_CTL_CS_LEVEL BIT(17)
#define SUN4I_CTL_TP BIT(18)
#define SUN4I_INT_CTL_REG 0x0c
#define SUN4I_INT_CTL_RF_F34 BIT(4)
#define SUN4I_INT_CTL_TF_E34 BIT(12)
#define SUN4I_INT_CTL_TC BIT(16)
#define SUN4I_INT_STA_REG 0x10
#define SUN4I_DMA_CTL_REG 0x14
#define SUN4I_WAIT_REG 0x18
#define SUN4I_CLK_CTL_REG 0x1c
#define SUN4I_CLK_CTL_CDR2_MASK 0xff
#define SUN4I_CLK_CTL_CDR2(div) ((div) & SUN4I_CLK_CTL_CDR2_MASK)
#define SUN4I_CLK_CTL_CDR1_MASK 0xf
#define SUN4I_CLK_CTL_CDR1(div) (((div) & SUN4I_CLK_CTL_CDR1_MASK) << 8)
#define SUN4I_CLK_CTL_DRS BIT(12)
#define SUN4I_MAX_XFER_SIZE 0xffffff
#define SUN4I_BURST_CNT_REG 0x20
#define SUN4I_BURST_CNT(cnt) ((cnt) & SUN4I_MAX_XFER_SIZE)
#define SUN4I_XMIT_CNT_REG 0x24
#define SUN4I_XMIT_CNT(cnt) ((cnt) & SUN4I_MAX_XFER_SIZE)
#define SUN4I_FIFO_STA_REG 0x28
#define SUN4I_FIFO_STA_RF_CNT_MASK 0x7f
#define SUN4I_FIFO_STA_RF_CNT_BITS 0
#define SUN4I_FIFO_STA_TF_CNT_MASK 0x7f
#define SUN4I_FIFO_STA_TF_CNT_BITS 16
#define SUN4I_SPI_MAX_RATE 24000000
#define SUN4I_SPI_MIN_RATE 3000
#define SUN4I_SPI_DEFAULT_RATE 1000000
#define SUN4I_SPI_TIMEOUT_US 1000000
/* sun4i spi register set */
struct sun4i_spi_regs {
u32 rxdata;
u32 txdata;
u32 ctl;
u32 intctl;
u32 st;
u32 dmactl;
u32 wait;
u32 cctl;
u32 bc;
u32 tc;
u32 fifo_sta;
};
struct sun4i_spi_platdata {
u32 base_addr;
u32 max_hz;
};
struct sun4i_spi_priv {
struct sun4i_spi_regs *regs;
u32 freq;
u32 mode;
const u8 *tx_buf;
u8 *rx_buf;
};
DECLARE_GLOBAL_DATA_PTR;
static inline void sun4i_spi_drain_fifo(struct sun4i_spi_priv *priv, int len)
{
u8 byte;
while (len--) {
byte = readb(&priv->regs->rxdata);
*priv->rx_buf++ = byte;
}
}
static inline void sun4i_spi_fill_fifo(struct sun4i_spi_priv *priv, int len)
{
u8 byte;
while (len--) {
byte = priv->tx_buf ? *priv->tx_buf++ : 0;
writeb(byte, &priv->regs->txdata);
}
}
static void sun4i_spi_set_cs(struct udevice *bus, u8 cs, bool enable)
{
struct sun4i_spi_priv *priv = dev_get_priv(bus);
u32 reg;
reg = readl(&priv->regs->ctl);
reg &= ~SUN4I_CTL_CS_MASK;
reg |= SUN4I_CTL_CS(cs);
if (enable)
reg &= ~SUN4I_CTL_CS_LEVEL;
else
reg |= SUN4I_CTL_CS_LEVEL;
writel(reg, &priv->regs->ctl);
}
static int sun4i_spi_parse_pins(struct udevice *dev)
{
const void *fdt = gd->fdt_blob;
const char *pin_name;
const fdt32_t *list;
u32 phandle;
int drive, pull = 0, pin, i;
int offset;
int size;
list = fdt_getprop(fdt, dev_of_offset(dev), "pinctrl-0", &size);
if (!list) {
printf("WARNING: sun4i_spi: cannot find pinctrl-0 node\n");
return -EINVAL;
}
while (size) {
phandle = fdt32_to_cpu(*list++);
size -= sizeof(*list);
offset = fdt_node_offset_by_phandle(fdt, phandle);
if (offset < 0)
return offset;
drive = fdt_getprop_u32_default_node(fdt, offset, 0,
"drive-strength", 0);
if (drive) {
if (drive <= 10)
drive = 0;
else if (drive <= 20)
drive = 1;
else if (drive <= 30)
drive = 2;
else
drive = 3;
} else {
drive = fdt_getprop_u32_default_node(fdt, offset, 0,
"allwinner,drive",
0);
drive = min(drive, 3);
}
if (fdt_get_property(fdt, offset, "bias-disable", NULL))
pull = 0;
else if (fdt_get_property(fdt, offset, "bias-pull-up", NULL))
pull = 1;
else if (fdt_get_property(fdt, offset, "bias-pull-down", NULL))
pull = 2;
else
pull = fdt_getprop_u32_default_node(fdt, offset, 0,
"allwinner,pull",
0);
pull = min(pull, 2);
for (i = 0; ; i++) {
pin_name = fdt_stringlist_get(fdt, offset,
"pins", i, NULL);
if (!pin_name) {
pin_name = fdt_stringlist_get(fdt, offset,
"allwinner,pins",
i, NULL);
if (!pin_name)
break;
}
pin = name_to_gpio(pin_name);
if (pin < 0)
break;
sunxi_gpio_set_cfgpin(pin, SUNXI_GPC_SPI0);
sunxi_gpio_set_drv(pin, drive);
sunxi_gpio_set_pull(pin, pull);
}
}
return 0;
}
static inline void sun4i_spi_enable_clock(void)
{
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 int sun4i_spi_ofdata_to_platdata(struct udevice *bus)
{
struct sun4i_spi_platdata *plat = dev_get_platdata(bus);
int node = dev_of_offset(bus);
plat->base_addr = devfdt_get_addr(bus);
plat->max_hz = fdtdec_get_int(gd->fdt_blob, node,
"spi-max-frequency",
SUN4I_SPI_DEFAULT_RATE);
if (plat->max_hz > SUN4I_SPI_MAX_RATE)
plat->max_hz = SUN4I_SPI_MAX_RATE;
return 0;
}
static int sun4i_spi_probe(struct udevice *bus)
{
struct sun4i_spi_platdata *plat = dev_get_platdata(bus);
struct sun4i_spi_priv *priv = dev_get_priv(bus);
sun4i_spi_enable_clock();
sun4i_spi_parse_pins(bus);
priv->regs = (struct sun4i_spi_regs *)(uintptr_t)plat->base_addr;
priv->freq = plat->max_hz;
return 0;
}
static int sun4i_spi_claim_bus(struct udevice *dev)
{
struct sun4i_spi_priv *priv = dev_get_priv(dev->parent);
writel(SUN4I_CTL_ENABLE | SUN4I_CTL_MASTER | SUN4I_CTL_TP |
SUN4I_CTL_CS_MANUAL | SUN4I_CTL_CS_ACTIVE_LOW,
&priv->regs->ctl);
return 0;
}
static int sun4i_spi_release_bus(struct udevice *dev)
{
struct sun4i_spi_priv *priv = dev_get_priv(dev->parent);
u32 reg;
reg = readl(&priv->regs->ctl);
reg &= ~SUN4I_CTL_ENABLE;
writel(reg, &priv->regs->ctl);
return 0;
}
static int sun4i_spi_xfer(struct udevice *dev, unsigned int bitlen,
const void *dout, void *din, unsigned long flags)
{
struct udevice *bus = dev->parent;
struct sun4i_spi_priv *priv = dev_get_priv(bus);
struct dm_spi_slave_platdata *slave_plat = dev_get_parent_platdata(dev);
u32 len = bitlen / 8;
u32 reg;
u8 nbytes;
int ret;
priv->tx_buf = dout;
priv->rx_buf = din;
if (bitlen % 8) {
debug("%s: non byte-aligned SPI transfer.\n", __func__);
return -ENAVAIL;
}
if (flags & SPI_XFER_BEGIN)
sun4i_spi_set_cs(bus, slave_plat->cs, true);
reg = readl(&priv->regs->ctl);
/* Reset FIFOs */
writel(reg | SUN4I_CTL_RF_RST | SUN4I_CTL_TF_RST, &priv->regs->ctl);
while (len) {
/* Setup the transfer now... */
nbytes = min(len, (u32)(SUN4I_FIFO_DEPTH - 1));
/* Setup the counters */
writel(SUN4I_BURST_CNT(nbytes), &priv->regs->bc);
writel(SUN4I_XMIT_CNT(nbytes), &priv->regs->tc);
/* Fill the TX FIFO */
sun4i_spi_fill_fifo(priv, nbytes);
/* Start the transfer */
reg = readl(&priv->regs->ctl);
writel(reg | SUN4I_CTL_XCH, &priv->regs->ctl);
/* Wait transfer to complete */
ret = wait_for_bit_le32(&priv->regs->ctl, SUN4I_CTL_XCH_MASK,
false, SUN4I_SPI_TIMEOUT_US, false);
if (ret) {
printf("ERROR: sun4i_spi: Timeout transferring data\n");
sun4i_spi_set_cs(bus, slave_plat->cs, false);
return ret;
}
/* Drain the RX FIFO */
sun4i_spi_drain_fifo(priv, nbytes);
len -= nbytes;
}
if (flags & SPI_XFER_END)
sun4i_spi_set_cs(bus, slave_plat->cs, false);
return 0;
}
static int sun4i_spi_set_speed(struct udevice *dev, uint speed)
{
struct sun4i_spi_platdata *plat = dev_get_platdata(dev);
struct sun4i_spi_priv *priv = dev_get_priv(dev);
unsigned int div;
u32 reg;
if (speed > plat->max_hz)
speed = plat->max_hz;
if (speed < SUN4I_SPI_MIN_RATE)
speed = SUN4I_SPI_MIN_RATE;
/*
* 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 + 1))
* Or we can use CDR2, which is calculated with the formula:
* SPI_CLK = MOD_CLK / (2 * (cdr + 1))
* Whether 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 = SUN4I_SPI_MAX_RATE / (2 * speed);
reg = readl(&priv->regs->cctl);
if (div <= (SUN4I_CLK_CTL_CDR2_MASK + 1)) {
if (div > 0)
div--;
reg &= ~(SUN4I_CLK_CTL_CDR2_MASK | SUN4I_CLK_CTL_DRS);
reg |= SUN4I_CLK_CTL_CDR2(div) | SUN4I_CLK_CTL_DRS;
} else {
div = __ilog2(SUN4I_SPI_MAX_RATE) - __ilog2(speed);
reg &= ~((SUN4I_CLK_CTL_CDR1_MASK << 8) | SUN4I_CLK_CTL_DRS);
reg |= SUN4I_CLK_CTL_CDR1(div);
}
priv->freq = speed;
writel(reg, &priv->regs->cctl);
return 0;
}
static int sun4i_spi_set_mode(struct udevice *dev, uint mode)
{
struct sun4i_spi_priv *priv = dev_get_priv(dev);
u32 reg;
reg = readl(&priv->regs->ctl);
reg &= ~(SUN4I_CTL_CPOL | SUN4I_CTL_CPHA);
if (mode & SPI_CPOL)
reg |= SUN4I_CTL_CPOL;
if (mode & SPI_CPHA)
reg |= SUN4I_CTL_CPHA;
priv->mode = mode;
writel(reg, &priv->regs->ctl);
return 0;
}
static const struct dm_spi_ops sun4i_spi_ops = {
.claim_bus = sun4i_spi_claim_bus,
.release_bus = sun4i_spi_release_bus,
.xfer = sun4i_spi_xfer,
.set_speed = sun4i_spi_set_speed,
.set_mode = sun4i_spi_set_mode,
};
static const struct udevice_id sun4i_spi_ids[] = {
{ .compatible = "allwinner,sun4i-a10-spi" },
{ }
};
U_BOOT_DRIVER(sun4i_spi) = {
.name = "sun4i_spi",
.id = UCLASS_SPI,
.of_match = sun4i_spi_ids,
.ops = &sun4i_spi_ops,
.ofdata_to_platdata = sun4i_spi_ofdata_to_platdata,
.platdata_auto_alloc_size = sizeof(struct sun4i_spi_platdata),
.priv_auto_alloc_size = sizeof(struct sun4i_spi_priv),
.probe = sun4i_spi_probe,
};