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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2017 Álvaro Fernández Rojas <noltari@gmail.com>
*
* Derived from linux/drivers/spi/spi-bcm63xx.c:
* Copyright (C) 2009-2012 Florian Fainelli <florian@openwrt.org>
* Copyright (C) 2010 Tanguy Bouzeloc <tanguy.bouzeloc@efixo.com>
*/
#include <common.h>
#include <clk.h>
#include <dm.h>
#include <spi.h>
#include <reset.h>
#include <wait_bit.h>
#include <asm/io.h>
DECLARE_GLOBAL_DATA_PTR;
/* BCM6348 SPI core */
#define SPI_6348_CLK 0x06
#define SPI_6348_CMD 0x00
#define SPI_6348_CTL 0x40
#define SPI_6348_CTL_SHIFT 6
#define SPI_6348_FILL 0x07
#define SPI_6348_IR_MASK 0x04
#define SPI_6348_IR_STAT 0x02
#define SPI_6348_RX 0x80
#define SPI_6348_RX_SIZE 0x3f
#define SPI_6348_TX 0x41
#define SPI_6348_TX_SIZE 0x3f
/* BCM6358 SPI core */
#define SPI_6358_CLK 0x706
#define SPI_6358_CMD 0x700
#define SPI_6358_CTL 0x000
#define SPI_6358_CTL_SHIFT 14
#define SPI_6358_FILL 0x707
#define SPI_6358_IR_MASK 0x702
#define SPI_6358_IR_STAT 0x704
#define SPI_6358_RX 0x400
#define SPI_6358_RX_SIZE 0x220
#define SPI_6358_TX 0x002
#define SPI_6358_TX_SIZE 0x21e
/* SPI Clock register */
#define SPI_CLK_SHIFT 0
#define SPI_CLK_20MHZ (0 << SPI_CLK_SHIFT)
#define SPI_CLK_0_391MHZ (1 << SPI_CLK_SHIFT)
#define SPI_CLK_0_781MHZ (2 << SPI_CLK_SHIFT)
#define SPI_CLK_1_563MHZ (3 << SPI_CLK_SHIFT)
#define SPI_CLK_3_125MHZ (4 << SPI_CLK_SHIFT)
#define SPI_CLK_6_250MHZ (5 << SPI_CLK_SHIFT)
#define SPI_CLK_12_50MHZ (6 << SPI_CLK_SHIFT)
#define SPI_CLK_25MHZ (7 << SPI_CLK_SHIFT)
#define SPI_CLK_MASK (7 << SPI_CLK_SHIFT)
#define SPI_CLK_SSOFF_SHIFT 3
#define SPI_CLK_SSOFF_2 (2 << SPI_CLK_SSOFF_SHIFT)
#define SPI_CLK_SSOFF_MASK (7 << SPI_CLK_SSOFF_SHIFT)
#define SPI_CLK_BSWAP_SHIFT 7
#define SPI_CLK_BSWAP_MASK (1 << SPI_CLK_BSWAP_SHIFT)
/* SPI Command register */
#define SPI_CMD_OP_SHIFT 0
#define SPI_CMD_OP_START (0x3 << SPI_CMD_OP_SHIFT)
#define SPI_CMD_SLAVE_SHIFT 4
#define SPI_CMD_SLAVE_MASK (0xf << SPI_CMD_SLAVE_SHIFT)
#define SPI_CMD_PREPEND_SHIFT 8
#define SPI_CMD_PREPEND_BYTES 0xf
#define SPI_CMD_3WIRE_SHIFT 12
#define SPI_CMD_3WIRE_MASK (1 << SPI_CMD_3WIRE_SHIFT)
/* SPI Control register */
#define SPI_CTL_TYPE_FD_RW 0
#define SPI_CTL_TYPE_HD_W 1
#define SPI_CTL_TYPE_HD_R 2
/* SPI Interrupt registers */
#define SPI_IR_DONE_SHIFT 0
#define SPI_IR_DONE_MASK (1 << SPI_IR_DONE_SHIFT)
#define SPI_IR_RXOVER_SHIFT 1
#define SPI_IR_RXOVER_MASK (1 << SPI_IR_RXOVER_SHIFT)
#define SPI_IR_TXUNDER_SHIFT 2
#define SPI_IR_TXUNDER_MASK (1 << SPI_IR_TXUNDER_SHIFT)
#define SPI_IR_TXOVER_SHIFT 3
#define SPI_IR_TXOVER_MASK (1 << SPI_IR_TXOVER_SHIFT)
#define SPI_IR_RXUNDER_SHIFT 4
#define SPI_IR_RXUNDER_MASK (1 << SPI_IR_RXUNDER_SHIFT)
#define SPI_IR_CLEAR_MASK (SPI_IR_DONE_MASK |\
SPI_IR_RXOVER_MASK |\
SPI_IR_TXUNDER_MASK |\
SPI_IR_TXOVER_MASK |\
SPI_IR_RXUNDER_MASK)
enum bcm63xx_regs_spi {
SPI_CLK,
SPI_CMD,
SPI_CTL,
SPI_CTL_SHIFT,
SPI_FILL,
SPI_IR_MASK,
SPI_IR_STAT,
SPI_RX,
SPI_RX_SIZE,
SPI_TX,
SPI_TX_SIZE,
};
struct bcm63xx_spi_priv {
const unsigned long *regs;
void __iomem *base;
size_t tx_bytes;
uint8_t num_cs;
};
#define SPI_CLK_CNT 8
static const unsigned bcm63xx_spi_freq_table[SPI_CLK_CNT][2] = {
{ 25000000, SPI_CLK_25MHZ },
{ 20000000, SPI_CLK_20MHZ },
{ 12500000, SPI_CLK_12_50MHZ },
{ 6250000, SPI_CLK_6_250MHZ },
{ 3125000, SPI_CLK_3_125MHZ },
{ 1563000, SPI_CLK_1_563MHZ },
{ 781000, SPI_CLK_0_781MHZ },
{ 391000, SPI_CLK_0_391MHZ }
};
static int bcm63xx_spi_cs_info(struct udevice *bus, uint cs,
struct spi_cs_info *info)
{
struct bcm63xx_spi_priv *priv = dev_get_priv(bus);
if (cs >= priv->num_cs) {
printf("no cs %u\n", cs);
return -ENODEV;
}
return 0;
}
static int bcm63xx_spi_set_mode(struct udevice *bus, uint mode)
{
struct bcm63xx_spi_priv *priv = dev_get_priv(bus);
const unsigned long *regs = priv->regs;
if (mode & SPI_LSB_FIRST)
setbits_8(priv->base + regs[SPI_CLK], SPI_CLK_BSWAP_MASK);
else
clrbits_8(priv->base + regs[SPI_CLK], SPI_CLK_BSWAP_MASK);
return 0;
}
static int bcm63xx_spi_set_speed(struct udevice *bus, uint speed)
{
struct bcm63xx_spi_priv *priv = dev_get_priv(bus);
const unsigned long *regs = priv->regs;
uint8_t clk_cfg;
int i;
/* default to lowest clock configuration */
clk_cfg = SPI_CLK_0_391MHZ;
/* find the closest clock configuration */
for (i = 0; i < SPI_CLK_CNT; i++) {
if (speed >= bcm63xx_spi_freq_table[i][0]) {
clk_cfg = bcm63xx_spi_freq_table[i][1];
break;
}
}
/* write clock configuration */
clrsetbits_8(priv->base + regs[SPI_CLK],
SPI_CLK_SSOFF_MASK | SPI_CLK_MASK,
clk_cfg | SPI_CLK_SSOFF_2);
return 0;
}
/*
* BCM63xx SPI driver doesn't allow keeping CS active between transfers since
* they are HW controlled.
* However, it provides a mechanism to prepend write transfers prior to read
* transfers (with a maximum prepend of 15 bytes), which is usually enough for
* SPI-connected flashes since reading requires prepending a write transfer of
* 5 bytes.
*
* This implementation takes advantage of the prepend mechanism and combines
* multiple transfers into a single one where possible (single/multiple write
* transfer(s) followed by a final read/write transfer).
* However, it's not possible to buffer reads, which means that read transfers
* should always be done as the final ones.
* On the other hand, take into account that combining write transfers into
* a single one is just buffering and doesn't require prepend mechanism.
*/
static int bcm63xx_spi_xfer(struct udevice *dev, unsigned int bitlen,
const void *dout, void *din, unsigned long flags)
{
struct bcm63xx_spi_priv *priv = dev_get_priv(dev->parent);
const unsigned long *regs = priv->regs;
size_t data_bytes = bitlen / 8;
if (flags & SPI_XFER_BEGIN) {
/* clear prepends */
priv->tx_bytes = 0;
/* initialize hardware */
writeb_be(0, priv->base + regs[SPI_IR_MASK]);
}
if (din) {
/* buffering reads not possible since cs is hw controlled */
if (!(flags & SPI_XFER_END)) {
printf("unable to buffer reads\n");
return -EINVAL;
}
/* check rx size */
if (data_bytes > regs[SPI_RX_SIZE]) {
printf("max rx bytes exceeded\n");
return -EMSGSIZE;
}
}
if (dout) {
/* check tx size */
if (priv->tx_bytes + data_bytes > regs[SPI_TX_SIZE]) {
printf("max tx bytes exceeded\n");
return -EMSGSIZE;
}
/* copy tx data */
memcpy_toio(priv->base + regs[SPI_TX] + priv->tx_bytes,
dout, data_bytes);
priv->tx_bytes += data_bytes;
}
if (flags & SPI_XFER_END) {
struct dm_spi_slave_platdata *plat =
dev_get_parent_platdata(dev);
uint16_t val, cmd;
int ret;
/* determine control config */
if (dout && !din) {
/* buffered write transfers */
val = priv->tx_bytes;
val |= (SPI_CTL_TYPE_HD_W << regs[SPI_CTL_SHIFT]);
priv->tx_bytes = 0;
} else {
if (dout && din && (flags & SPI_XFER_ONCE)) {
/* full duplex read/write */
val = data_bytes;
val |= (SPI_CTL_TYPE_FD_RW <<
regs[SPI_CTL_SHIFT]);
priv->tx_bytes = 0;
} else {
/* prepended write transfer */
val = data_bytes;
val |= (SPI_CTL_TYPE_HD_R <<
regs[SPI_CTL_SHIFT]);
if (priv->tx_bytes > SPI_CMD_PREPEND_BYTES) {
printf("max prepend bytes exceeded\n");
return -EMSGSIZE;
}
}
}
if (regs[SPI_CTL_SHIFT] >= 8)
writew_be(val, priv->base + regs[SPI_CTL]);
else
writeb_be(val, priv->base + regs[SPI_CTL]);
/* clear interrupts */
writeb_be(SPI_IR_CLEAR_MASK, priv->base + regs[SPI_IR_STAT]);
/* issue the transfer */
cmd = SPI_CMD_OP_START;
cmd |= (plat->cs << SPI_CMD_SLAVE_SHIFT) & SPI_CMD_SLAVE_MASK;
cmd |= (priv->tx_bytes << SPI_CMD_PREPEND_SHIFT);
if (plat->mode & SPI_3WIRE)
cmd |= SPI_CMD_3WIRE_MASK;
writew_be(cmd, priv->base + regs[SPI_CMD]);
/* enable interrupts */
writeb_be(SPI_IR_DONE_MASK, priv->base + regs[SPI_IR_MASK]);
ret = wait_for_bit_8(priv->base + regs[SPI_IR_STAT],
SPI_IR_DONE_MASK, true, 1000, false);
if (ret) {
printf("interrupt timeout\n");
return ret;
}
/* copy rx data */
if (din)
memcpy_fromio(din, priv->base + regs[SPI_RX],
data_bytes);
}
return 0;
}
static const struct dm_spi_ops bcm63xx_spi_ops = {
.cs_info = bcm63xx_spi_cs_info,
.set_mode = bcm63xx_spi_set_mode,
.set_speed = bcm63xx_spi_set_speed,
.xfer = bcm63xx_spi_xfer,
};
static const unsigned long bcm6348_spi_regs[] = {
[SPI_CLK] = SPI_6348_CLK,
[SPI_CMD] = SPI_6348_CMD,
[SPI_CTL] = SPI_6348_CTL,
[SPI_CTL_SHIFT] = SPI_6348_CTL_SHIFT,
[SPI_FILL] = SPI_6348_FILL,
[SPI_IR_MASK] = SPI_6348_IR_MASK,
[SPI_IR_STAT] = SPI_6348_IR_STAT,
[SPI_RX] = SPI_6348_RX,
[SPI_RX_SIZE] = SPI_6348_RX_SIZE,
[SPI_TX] = SPI_6348_TX,
[SPI_TX_SIZE] = SPI_6348_TX_SIZE,
};
static const unsigned long bcm6358_spi_regs[] = {
[SPI_CLK] = SPI_6358_CLK,
[SPI_CMD] = SPI_6358_CMD,
[SPI_CTL] = SPI_6358_CTL,
[SPI_CTL_SHIFT] = SPI_6358_CTL_SHIFT,
[SPI_FILL] = SPI_6358_FILL,
[SPI_IR_MASK] = SPI_6358_IR_MASK,
[SPI_IR_STAT] = SPI_6358_IR_STAT,
[SPI_RX] = SPI_6358_RX,
[SPI_RX_SIZE] = SPI_6358_RX_SIZE,
[SPI_TX] = SPI_6358_TX,
[SPI_TX_SIZE] = SPI_6358_TX_SIZE,
};
static const struct udevice_id bcm63xx_spi_ids[] = {
{
.compatible = "brcm,bcm6348-spi",
.data = (ulong)&bcm6348_spi_regs,
}, {
.compatible = "brcm,bcm6358-spi",
.data = (ulong)&bcm6358_spi_regs,
}, { /* sentinel */ }
};
static int bcm63xx_spi_child_pre_probe(struct udevice *dev)
{
struct bcm63xx_spi_priv *priv = dev_get_priv(dev->parent);
const unsigned long *regs = priv->regs;
struct spi_slave *slave = dev_get_parent_priv(dev);
struct dm_spi_slave_platdata *plat = dev_get_parent_platdata(dev);
/* check cs */
if (plat->cs >= priv->num_cs) {
printf("no cs %u\n", plat->cs);
return -ENODEV;
}
/* max read/write sizes */
slave->max_read_size = regs[SPI_RX_SIZE];
slave->max_write_size = regs[SPI_TX_SIZE];
return 0;
}
static int bcm63xx_spi_probe(struct udevice *dev)
{
struct bcm63xx_spi_priv *priv = dev_get_priv(dev);
const unsigned long *regs =
(const unsigned long *)dev_get_driver_data(dev);
struct reset_ctl rst_ctl;
struct clk clk;
fdt_addr_t addr;
fdt_size_t size;
int ret;
addr = devfdt_get_addr_size_index(dev, 0, &size);
if (addr == FDT_ADDR_T_NONE)
return -EINVAL;
priv->regs = regs;
priv->base = ioremap(addr, size);
priv->num_cs = fdtdec_get_uint(gd->fdt_blob, dev_of_offset(dev),
"num-cs", 8);
/* enable clock */
ret = clk_get_by_index(dev, 0, &clk);
if (ret < 0)
return ret;
ret = clk_enable(&clk);
if (ret < 0)
return ret;
ret = clk_free(&clk);
if (ret < 0)
return ret;
/* perform reset */
ret = reset_get_by_index(dev, 0, &rst_ctl);
if (ret < 0)
return ret;
ret = reset_deassert(&rst_ctl);
if (ret < 0)
return ret;
ret = reset_free(&rst_ctl);
if (ret < 0)
return ret;
/* initialize hardware */
writeb_be(0, priv->base + regs[SPI_IR_MASK]);
/* set fill register */
writeb_be(0xff, priv->base + regs[SPI_FILL]);
return 0;
}
U_BOOT_DRIVER(bcm63xx_spi) = {
.name = "bcm63xx_spi",
.id = UCLASS_SPI,
.of_match = bcm63xx_spi_ids,
.ops = &bcm63xx_spi_ops,
.priv_auto_alloc_size = sizeof(struct bcm63xx_spi_priv),
.child_pre_probe = bcm63xx_spi_child_pre_probe,
.probe = bcm63xx_spi_probe,
};