u-boot/drivers/spi/rk_spi.c

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/*
* spi driver for rockchip
*
* (C) Copyright 2015 Google, Inc
*
* (C) Copyright 2008-2013 Rockchip Electronics
* Peter, Software Engineering, <superpeter.cai@gmail.com>.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <clk.h>
#include <dm.h>
#include <errno.h>
#include <spi.h>
#include <linux/errno.h>
#include <asm/io.h>
#include <asm/arch/clock.h>
#include <asm/arch/periph.h>
#include <dm/pinctrl.h>
#include "rk_spi.h"
DECLARE_GLOBAL_DATA_PTR;
/* Change to 1 to output registers at the start of each transaction */
#define DEBUG_RK_SPI 0
struct rockchip_spi_platdata {
s32 frequency; /* Default clock frequency, -1 for none */
fdt_addr_t base;
uint deactivate_delay_us; /* Delay to wait after deactivate */
uint activate_delay_us; /* Delay to wait after activate */
};
struct rockchip_spi_priv {
struct rockchip_spi *regs;
struct clk clk;
unsigned int max_freq;
unsigned int mode;
ulong last_transaction_us; /* Time of last transaction end */
u8 bits_per_word; /* max 16 bits per word */
u8 n_bytes;
unsigned int speed_hz;
unsigned int last_speed_hz;
unsigned int tmode;
uint input_rate;
};
#define SPI_FIFO_DEPTH 32
static void rkspi_dump_regs(struct rockchip_spi *regs)
{
debug("ctrl0: \t\t0x%08x\n", readl(&regs->ctrlr0));
debug("ctrl1: \t\t0x%08x\n", readl(&regs->ctrlr1));
debug("ssienr: \t\t0x%08x\n", readl(&regs->enr));
debug("ser: \t\t0x%08x\n", readl(&regs->ser));
debug("baudr: \t\t0x%08x\n", readl(&regs->baudr));
debug("txftlr: \t\t0x%08x\n", readl(&regs->txftlr));
debug("rxftlr: \t\t0x%08x\n", readl(&regs->rxftlr));
debug("txflr: \t\t0x%08x\n", readl(&regs->txflr));
debug("rxflr: \t\t0x%08x\n", readl(&regs->rxflr));
debug("sr: \t\t0x%08x\n", readl(&regs->sr));
debug("imr: \t\t0x%08x\n", readl(&regs->imr));
debug("isr: \t\t0x%08x\n", readl(&regs->isr));
debug("dmacr: \t\t0x%08x\n", readl(&regs->dmacr));
debug("dmatdlr: \t0x%08x\n", readl(&regs->dmatdlr));
debug("dmardlr: \t0x%08x\n", readl(&regs->dmardlr));
}
static void rkspi_enable_chip(struct rockchip_spi *regs, bool enable)
{
writel(enable ? 1 : 0, &regs->enr);
}
static void rkspi_set_clk(struct rockchip_spi_priv *priv, uint speed)
{
uint clk_div;
clk_div = clk_get_divisor(priv->input_rate, speed);
debug("spi speed %u, div %u\n", speed, clk_div);
writel(clk_div, &priv->regs->baudr);
priv->last_speed_hz = speed;
}
static int rkspi_wait_till_not_busy(struct rockchip_spi *regs)
{
unsigned long start;
start = get_timer(0);
while (readl(&regs->sr) & SR_BUSY) {
if (get_timer(start) > ROCKCHIP_SPI_TIMEOUT_MS) {
debug("RK SPI: Status keeps busy for 1000us after a read/write!\n");
return -ETIMEDOUT;
}
}
return 0;
}
static void spi_cs_activate(struct udevice *dev, uint cs)
{
struct udevice *bus = dev->parent;
struct rockchip_spi_platdata *plat = bus->platdata;
struct rockchip_spi_priv *priv = dev_get_priv(bus);
struct rockchip_spi *regs = priv->regs;
debug("activate cs%u\n", cs);
writel(1 << cs, &regs->ser);
if (plat->activate_delay_us)
udelay(plat->activate_delay_us);
}
static void spi_cs_deactivate(struct udevice *dev, uint cs)
{
struct udevice *bus = dev->parent;
struct rockchip_spi_platdata *plat = bus->platdata;
struct rockchip_spi_priv *priv = dev_get_priv(bus);
struct rockchip_spi *regs = priv->regs;
debug("deactivate cs%u\n", cs);
writel(0, &regs->ser);
/* Remember time of this transaction so we can honour the bus delay */
if (plat->deactivate_delay_us)
priv->last_transaction_us = timer_get_us();
}
static int rockchip_spi_ofdata_to_platdata(struct udevice *bus)
{
struct rockchip_spi_platdata *plat = bus->platdata;
struct rockchip_spi_priv *priv = dev_get_priv(bus);
const void *blob = gd->fdt_blob;
int node = bus->of_offset;
int ret;
plat->base = dev_get_addr(bus);
ret = clk_get_by_index(bus, 0, &priv->clk);
if (ret < 0) {
debug("%s: Could not get clock for %s: %d\n", __func__,
bus->name, ret);
return ret;
}
plat->frequency = fdtdec_get_int(blob, node, "spi-max-frequency",
50000000);
plat->deactivate_delay_us = fdtdec_get_int(blob, node,
"spi-deactivate-delay", 0);
plat->activate_delay_us = fdtdec_get_int(blob, node,
"spi-activate-delay", 0);
debug("%s: base=%x, max-frequency=%d, deactivate_delay=%d\n",
__func__, (uint)plat->base, plat->frequency,
plat->deactivate_delay_us);
return 0;
}
static int rockchip_spi_probe(struct udevice *bus)
{
struct rockchip_spi_platdata *plat = dev_get_platdata(bus);
struct rockchip_spi_priv *priv = dev_get_priv(bus);
int ret;
debug("%s: probe\n", __func__);
priv->regs = (struct rockchip_spi *)plat->base;
priv->last_transaction_us = timer_get_us();
priv->max_freq = plat->frequency;
/*
* Use 99 MHz as our clock since it divides nicely into 594 MHz which
* is the assumed speed for CLK_GENERAL.
*/
ret = clk_set_rate(&priv->clk, 99000000);
if (ret < 0) {
debug("%s: Failed to set clock: %d\n", __func__, ret);
return ret;
}
priv->input_rate = ret;
debug("%s: rate = %u\n", __func__, priv->input_rate);
priv->bits_per_word = 8;
priv->tmode = TMOD_TR; /* Tx & Rx */
return 0;
}
static int rockchip_spi_claim_bus(struct udevice *dev)
{
struct udevice *bus = dev->parent;
struct rockchip_spi_priv *priv = dev_get_priv(bus);
struct rockchip_spi *regs = priv->regs;
u8 spi_dfs, spi_tf;
uint ctrlr0;
/* Disable the SPI hardware */
rkspi_enable_chip(regs, 0);
switch (priv->bits_per_word) {
case 8:
priv->n_bytes = 1;
spi_dfs = DFS_8BIT;
spi_tf = HALF_WORD_OFF;
break;
case 16:
priv->n_bytes = 2;
spi_dfs = DFS_16BIT;
spi_tf = HALF_WORD_ON;
break;
default:
debug("%s: unsupported bits: %dbits\n", __func__,
priv->bits_per_word);
return -EPROTONOSUPPORT;
}
if (priv->speed_hz != priv->last_speed_hz)
rkspi_set_clk(priv, priv->speed_hz);
/* Operation Mode */
ctrlr0 = OMOD_MASTER << OMOD_SHIFT;
/* Data Frame Size */
ctrlr0 |= spi_dfs << DFS_SHIFT;
/* set SPI mode 0..3 */
if (priv->mode & SPI_CPOL)
ctrlr0 |= SCOL_HIGH << SCOL_SHIFT;
if (priv->mode & SPI_CPHA)
ctrlr0 |= SCPH_TOGSTA << SCPH_SHIFT;
/* Chip Select Mode */
ctrlr0 |= CSM_KEEP << CSM_SHIFT;
/* SSN to Sclk_out delay */
ctrlr0 |= SSN_DELAY_ONE << SSN_DELAY_SHIFT;
/* Serial Endian Mode */
ctrlr0 |= SEM_LITTLE << SEM_SHIFT;
/* First Bit Mode */
ctrlr0 |= FBM_MSB << FBM_SHIFT;
/* Byte and Halfword Transform */
ctrlr0 |= spi_tf << HALF_WORD_TX_SHIFT;
/* Rxd Sample Delay */
ctrlr0 |= 0 << RXDSD_SHIFT;
/* Frame Format */
ctrlr0 |= FRF_SPI << FRF_SHIFT;
/* Tx and Rx mode */
ctrlr0 |= (priv->tmode & TMOD_MASK) << TMOD_SHIFT;
writel(ctrlr0, &regs->ctrlr0);
return 0;
}
static int rockchip_spi_release_bus(struct udevice *dev)
{
struct udevice *bus = dev->parent;
struct rockchip_spi_priv *priv = dev_get_priv(bus);
rkspi_enable_chip(priv->regs, false);
return 0;
}
static int rockchip_spi_xfer(struct udevice *dev, unsigned int bitlen,
const void *dout, void *din, unsigned long flags)
{
struct udevice *bus = dev->parent;
struct rockchip_spi_priv *priv = dev_get_priv(bus);
struct rockchip_spi *regs = priv->regs;
struct dm_spi_slave_platdata *slave_plat = dev_get_parent_platdata(dev);
int len = bitlen >> 3;
const u8 *out = dout;
u8 *in = din;
int toread, towrite;
int ret;
debug("%s: dout=%p, din=%p, len=%x, flags=%lx\n", __func__, dout, din,
len, flags);
if (DEBUG_RK_SPI)
rkspi_dump_regs(regs);
/* Assert CS before transfer */
if (flags & SPI_XFER_BEGIN)
spi_cs_activate(dev, slave_plat->cs);
while (len > 0) {
int todo = min(len, 0xffff);
rkspi_enable_chip(regs, false);
writel(todo - 1, &regs->ctrlr1);
rkspi_enable_chip(regs, true);
toread = todo;
towrite = todo;
while (toread || towrite) {
u32 status = readl(&regs->sr);
if (towrite && !(status & SR_TF_FULL)) {
writel(out ? *out++ : 0, regs->txdr);
towrite--;
}
if (toread && !(status & SR_RF_EMPT)) {
u32 byte = readl(regs->rxdr);
if (in)
*in++ = byte;
toread--;
}
}
ret = rkspi_wait_till_not_busy(regs);
if (ret)
break;
len -= todo;
}
/* Deassert CS after transfer */
if (flags & SPI_XFER_END)
spi_cs_deactivate(dev, slave_plat->cs);
rkspi_enable_chip(regs, false);
return ret;
}
static int rockchip_spi_set_speed(struct udevice *bus, uint speed)
{
struct rockchip_spi_priv *priv = dev_get_priv(bus);
if (speed > ROCKCHIP_SPI_MAX_RATE)
return -EINVAL;
if (speed > priv->max_freq)
speed = priv->max_freq;
priv->speed_hz = speed;
return 0;
}
static int rockchip_spi_set_mode(struct udevice *bus, uint mode)
{
struct rockchip_spi_priv *priv = dev_get_priv(bus);
priv->mode = mode;
return 0;
}
static const struct dm_spi_ops rockchip_spi_ops = {
.claim_bus = rockchip_spi_claim_bus,
.release_bus = rockchip_spi_release_bus,
.xfer = rockchip_spi_xfer,
.set_speed = rockchip_spi_set_speed,
.set_mode = rockchip_spi_set_mode,
/*
* cs_info is not needed, since we require all chip selects to be
* in the device tree explicitly
*/
};
static const struct udevice_id rockchip_spi_ids[] = {
{ .compatible = "rockchip,rk3288-spi" },
{ }
};
U_BOOT_DRIVER(rockchip_spi) = {
.name = "rockchip_spi",
.id = UCLASS_SPI,
.of_match = rockchip_spi_ids,
.ops = &rockchip_spi_ops,
.ofdata_to_platdata = rockchip_spi_ofdata_to_platdata,
.platdata_auto_alloc_size = sizeof(struct rockchip_spi_platdata),
.priv_auto_alloc_size = sizeof(struct rockchip_spi_priv),
.probe = rockchip_spi_probe,
};