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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (c) 2001 Navin Boppuri / Prashant Patel
* <nboppuri@trinetcommunication.com>,
* <pmpatel@trinetcommunication.com>
* Copyright (c) 2001 Gerd Mennchen <Gerd.Mennchen@icn.siemens.de>
* Copyright (c) 2001 Wolfgang Denk, DENX Software Engineering, <wd@denx.de>.
*/
/*
* MPC8xx CPM SPI interface.
*
* Parts of this code are probably not portable and/or specific to
* the board which I used for the tests. Please send fixes/complaints
* to wd@denx.de
*
*/
#include <dm.h>
#include <malloc.h>
#include <mpc8xx.h>
#include <spi.h>
#include <linux/delay.h>
#include <asm/cpm_8xx.h>
#include <asm/io.h>
#include <asm/gpio.h>
#define CPM_SPI_BASE_RX CPM_SPI_BASE
#define CPM_SPI_BASE_TX (CPM_SPI_BASE + sizeof(cbd_t))
#define MAX_BUFFER 0x8000 /* Max possible is 0xffff. We want power of 2 */
#define MIN_HWORD_XFER 64 /* Minimum size for 16 bits transfer */
struct mpc8xx_priv {
spi_t __iomem *spi;
struct gpio_desc gpios[16];
int max_cs;
};
static char dummy_buffer[MAX_BUFFER];
static int mpc8xx_spi_set_mode(struct udevice *dev, uint mod)
{
return 0;
}
static int mpc8xx_spi_set_speed(struct udevice *dev, uint speed)
{
immap_t __iomem *immr = (immap_t __iomem *)CONFIG_SYS_IMMR;
cpm8xx_t __iomem *cp = &immr->im_cpm;
u8 pm = (gd->arch.brg_clk - 1) / (speed * 16);
if (pm > 16) {
setbits_be16(&cp->cp_spmode, SPMODE_DIV16);
pm /= 16;
if (pm > 16)
pm = 16;
} else {
clrbits_be16(&cp->cp_spmode, SPMODE_DIV16);
}
clrsetbits_be16(&cp->cp_spmode, SPMODE_PM(0xf), SPMODE_PM(pm));
return 0;
}
static int mpc8xx_spi_probe(struct udevice *dev)
{
immap_t __iomem *immr = (immap_t __iomem *)CONFIG_SYS_IMMR;
cpm8xx_t __iomem *cp = &immr->im_cpm;
spi_t __iomem *spi = (spi_t __iomem *)&cp->cp_dpmem[PROFF_SPI];
u16 spi_rpbase;
cbd_t __iomem *tbdf, *rbdf;
spi_rpbase = in_be16(&spi->spi_rpbase);
if (spi_rpbase)
spi = (spi_t __iomem *)&cp->cp_dpmem[spi_rpbase];
/* 1 */
/* Initialize the parameter ram.
* We need to make sure many things are initialized to zero
*/
out_be32(&spi->spi_rstate, 0);
out_be32(&spi->spi_rdp, 0);
out_be16(&spi->spi_rbptr, 0);
out_be16(&spi->spi_rbc, 0);
out_be32(&spi->spi_rxtmp, 0);
out_be32(&spi->spi_tstate, 0);
out_be32(&spi->spi_tdp, 0);
out_be16(&spi->spi_tbptr, 0);
out_be16(&spi->spi_tbc, 0);
out_be32(&spi->spi_txtmp, 0);
/* 3 */
/* Set up the SPI parameters in the parameter ram */
out_be16(&spi->spi_rbase, CPM_SPI_BASE_RX);
out_be16(&spi->spi_tbase, CPM_SPI_BASE_TX);
/***********IMPORTANT******************/
/*
* Setting transmit and receive buffer descriptor pointers
* initially to rbase and tbase. Only the microcode patches
* documentation talks about initializing this pointer. This
* is missing from the sample I2C driver. If you dont
* initialize these pointers, the kernel hangs.
*/
out_be16(&spi->spi_rbptr, CPM_SPI_BASE_RX);
out_be16(&spi->spi_tbptr, CPM_SPI_BASE_TX);
/* 4 */
/* Init SPI Tx + Rx Parameters */
while (in_be16(&cp->cp_cpcr) & CPM_CR_FLG)
;
out_be16(&cp->cp_cpcr, mk_cr_cmd(CPM_CR_CH_SPI, CPM_CR_INIT_TRX) |
CPM_CR_FLG);
while (in_be16(&cp->cp_cpcr) & CPM_CR_FLG)
;
/* 6 */
/* Set to big endian. */
out_8(&spi->spi_tfcr, SMC_EB);
out_8(&spi->spi_rfcr, SMC_EB);
/* 7 */
/* Set maximum receive size. */
out_be16(&spi->spi_mrblr, MAX_BUFFER);
/* 8 + 9 */
/* tx and rx buffer descriptors */
tbdf = (cbd_t __iomem *)&cp->cp_dpmem[CPM_SPI_BASE_TX];
rbdf = (cbd_t __iomem *)&cp->cp_dpmem[CPM_SPI_BASE_RX];
clrbits_be16(&tbdf->cbd_sc, BD_SC_READY);
clrbits_be16(&rbdf->cbd_sc, BD_SC_EMPTY);
/* 10 + 11 */
out_8(&cp->cp_spim, 0); /* Mask all SPI events */
out_8(&cp->cp_spie, SPI_EMASK); /* Clear all SPI events */
return 0;
}
static void mpc8xx_spi_cs_activate(struct udevice *dev)
{
struct mpc8xx_priv *priv = dev_get_priv(dev->parent);
struct dm_spi_slave_plat *platdata = dev_get_parent_plat(dev);
dm_gpio_set_value(&priv->gpios[platdata->cs], 1);
}
static void mpc8xx_spi_cs_deactivate(struct udevice *dev)
{
struct mpc8xx_priv *priv = dev_get_priv(dev->parent);
struct dm_spi_slave_plat *platdata = dev_get_parent_plat(dev);
dm_gpio_set_value(&priv->gpios[platdata->cs], 0);
}
static int mpc8xx_spi_xfer_one(struct udevice *dev, size_t count,
const void *dout, void *din)
{
immap_t __iomem *immr = (immap_t __iomem *)CONFIG_SYS_IMMR;
cpm8xx_t __iomem *cp = &immr->im_cpm;
cbd_t __iomem *tbdf, *rbdf;
void *bufout, *bufin;
u16 spmode_len;
int tm;
tbdf = (cbd_t __iomem *)&cp->cp_dpmem[CPM_SPI_BASE_TX];
rbdf = (cbd_t __iomem *)&cp->cp_dpmem[CPM_SPI_BASE_RX];
if (!(count & 1) && count >= MIN_HWORD_XFER) {
spmode_len = SPMODE_LEN(16);
if (dout) {
int i;
bufout = malloc(count);
for (i = 0; i < count; i += 2)
*(u16 *)(bufout + i) = swab16(*(u16 *)(dout + i));
} else {
bufout = NULL;
}
if (din)
bufin = malloc(count);
else
bufin = NULL;
} else {
spmode_len = SPMODE_LEN(8);
bufout = (void *)dout;
bufin = din;
}
/* Setting tx bd status and data length */
out_be32(&tbdf->cbd_bufaddr, bufout ? (ulong)bufout : (ulong)dummy_buffer);
out_be16(&tbdf->cbd_sc, BD_SC_READY | BD_SC_LAST | BD_SC_WRAP);
out_be16(&tbdf->cbd_datlen, count);
/* Setting rx bd status and data length */
out_be32(&rbdf->cbd_bufaddr, bufin ? (ulong)bufin : (ulong)dummy_buffer);
out_be16(&rbdf->cbd_sc, BD_SC_EMPTY | BD_SC_WRAP);
out_be16(&rbdf->cbd_datlen, 0); /* rx length has no significance */
clrsetbits_be16(&cp->cp_spmode, ~(SPMODE_LOOP | SPMODE_PM(0xf) | SPMODE_DIV16),
SPMODE_REV | SPMODE_MSTR | SPMODE_EN | spmode_len);
out_8(&cp->cp_spim, 0); /* Mask all SPI events */
out_8(&cp->cp_spie, SPI_EMASK); /* Clear all SPI events */
/* start spi transfer */
setbits_8(&cp->cp_spcom, SPI_STR); /* Start transmit */
/* --------------------------------
* Wait for SPI transmit to get out
* or time out (1 second = 1000 ms)
* -------------------------------- */
for (tm = 0; tm < 1000; ++tm) {
if (in_8(&cp->cp_spie) & SPI_TXB) /* Tx Buffer Empty */
break;
if ((in_be16(&tbdf->cbd_sc) & BD_SC_READY) == 0)
break;
udelay(1000);
}
if (tm >= 1000)
return -ETIMEDOUT;
if (!(count & 1) && count > MIN_HWORD_XFER) {
if (dout)
free(bufout);
if (din) {
int i;
bufout = malloc(count);
for (i = 0; i < count; i += 2)
*(u16 *)(din + i) = swab16(*(u16 *)(bufin + i));
free(bufin);
}
}
return 0;
}
static int mpc8xx_spi_xfer(struct udevice *dev, unsigned int bitlen,
const void *dout, void *din, unsigned long flags)
{
size_t count = (bitlen + 7) / 8;
size_t offset = 0;
int ret = 0;
if (!din && !dout)
return -EINVAL;
/* Set CS for device */
if (flags & SPI_XFER_BEGIN)
mpc8xx_spi_cs_activate(dev);
while (count > 0 && !ret) {
size_t chunk = min(count, (size_t)MAX_BUFFER);
const void *out = dout ? dout + offset : NULL;
void *in = din ? din + offset : NULL;
ret = mpc8xx_spi_xfer_one(dev, chunk, out, in);
offset += chunk;
count -= chunk;
}
/* Clear CS for device */
if (flags & SPI_XFER_END)
mpc8xx_spi_cs_deactivate(dev);
if (ret)
printf("*** spi_xfer: Time out while xferring to/from SPI!\n");
return ret;
}
static int mpc8xx_spi_ofdata_to_platdata(struct udevice *dev)
{
struct mpc8xx_priv *priv = dev_get_priv(dev);
int ret;
ret = gpio_request_list_by_name(dev, "gpios", priv->gpios,
ARRAY_SIZE(priv->gpios), GPIOD_IS_OUT);
if (ret < 0)
return ret;
priv->max_cs = ret;
return 0;
}
static const struct dm_spi_ops mpc8xx_spi_ops = {
.xfer = mpc8xx_spi_xfer,
.set_speed = mpc8xx_spi_set_speed,
.set_mode = mpc8xx_spi_set_mode,
};
static const struct udevice_id mpc8xx_spi_ids[] = {
{ .compatible = "fsl,mpc8xx-spi" },
{ }
};
U_BOOT_DRIVER(mpc8xx_spi) = {
.name = "mpc8xx_spi",
.id = UCLASS_SPI,
.of_match = mpc8xx_spi_ids,
.of_to_plat = mpc8xx_spi_ofdata_to_platdata,
.ops = &mpc8xx_spi_ops,
.probe = mpc8xx_spi_probe,
.priv_auto = sizeof(struct mpc8xx_priv),
};