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/*
* linux/drivers/video/mmp/hw/mmp_spi.c
* using the spi in LCD controler for commands send
*
* Copyright (C) 2012 Marvell Technology Group Ltd.
* Authors: Guoqing Li <ligq@marvell.com>
* Lisa Du <cldu@marvell.com>
* Zhou Zhu <zzhu3@marvell.com>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2 of the License, or (at your
* option) any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program. If not, see <http://www.gnu.org/licenses/>.
*
*/
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/spi/spi.h>
#include "mmp_ctrl.h"
/**
* spi_write - write command to the SPI port
* @data: can be 8/16/32-bit, MSB justified data to write.
* @len: data length.
*
* Wait bus transfer complete IRQ.
* The caller is expected to perform the necessary locking.
*
* Returns:
* %-ETIMEDOUT timeout occurred
* 0 success
*/
static inline int lcd_spi_write(struct spi_device *spi, u32 data)
{
int timeout = 100000, isr, ret = 0;
u32 tmp;
void *reg_base =
*(void **)spi_master_get_devdata(spi->master);
/* clear ISR */
writel_relaxed(~SPI_IRQ_MASK, reg_base + SPU_IRQ_ISR);
switch (spi->bits_per_word) {
case 8:
writel_relaxed((u8)data, reg_base + LCD_SPU_SPI_TXDATA);
break;
case 16:
writel_relaxed((u16)data, reg_base + LCD_SPU_SPI_TXDATA);
break;
case 32:
writel_relaxed((u32)data, reg_base + LCD_SPU_SPI_TXDATA);
break;
default:
dev_err(&spi->dev, "Wrong spi bit length\n");
}
/* SPI start to send command */
tmp = readl_relaxed(reg_base + LCD_SPU_SPI_CTRL);
tmp &= ~CFG_SPI_START_MASK;
tmp |= CFG_SPI_START(1);
writel(tmp, reg_base + LCD_SPU_SPI_CTRL);
isr = readl_relaxed(reg_base + SPU_IRQ_ISR);
while (!(isr & SPI_IRQ_ENA_MASK)) {
udelay(100);
isr = readl_relaxed(reg_base + SPU_IRQ_ISR);
if (!--timeout) {
ret = -ETIMEDOUT;
dev_err(&spi->dev, "spi cmd send time out\n");
break;
}
}
tmp = readl_relaxed(reg_base + LCD_SPU_SPI_CTRL);
tmp &= ~CFG_SPI_START_MASK;
tmp |= CFG_SPI_START(0);
writel_relaxed(tmp, reg_base + LCD_SPU_SPI_CTRL);
writel_relaxed(~SPI_IRQ_MASK, reg_base + SPU_IRQ_ISR);
return ret;
}
static int lcd_spi_setup(struct spi_device *spi)
{
void *reg_base =
*(void **)spi_master_get_devdata(spi->master);
u32 tmp;
tmp = CFG_SCLKCNT(16) |
CFG_TXBITS(spi->bits_per_word) |
CFG_SPI_SEL(1) | CFG_SPI_ENA(1) |
CFG_SPI_3W4WB(1);
writel(tmp, reg_base + LCD_SPU_SPI_CTRL);
/*
* After set mode it need a time to pull up the spi singals,
* or it would cause the wrong waveform when send spi command,
* especially on pxa910h
*/
tmp = readl_relaxed(reg_base + SPU_IOPAD_CONTROL);
if ((tmp & CFG_IOPADMODE_MASK) != IOPAD_DUMB18SPI)
writel_relaxed(IOPAD_DUMB18SPI |
(tmp & ~CFG_IOPADMODE_MASK),
reg_base + SPU_IOPAD_CONTROL);
udelay(20);
return 0;
}
static int lcd_spi_one_transfer(struct spi_device *spi, struct spi_message *m)
{
struct spi_transfer *t;
int i;
list_for_each_entry(t, &m->transfers, transfer_list) {
switch (spi->bits_per_word) {
case 8:
for (i = 0; i < t->len; i++)
lcd_spi_write(spi, ((u8 *)t->tx_buf)[i]);
break;
case 16:
for (i = 0; i < t->len/2; i++)
lcd_spi_write(spi, ((u16 *)t->tx_buf)[i]);
break;
case 32:
for (i = 0; i < t->len/4; i++)
lcd_spi_write(spi, ((u32 *)t->tx_buf)[i]);
break;
default:
dev_err(&spi->dev, "Wrong spi bit length\n");
}
}
m->status = 0;
if (m->complete)
m->complete(m->context);
return 0;
}
int lcd_spi_register(struct mmphw_ctrl *ctrl)
{
struct spi_master *master;
void **p_regbase;
int err;
master = spi_alloc_master(ctrl->dev, sizeof(void *));
if (!master) {
dev_err(ctrl->dev, "unable to allocate SPI master\n");
return -ENOMEM;
}
p_regbase = spi_master_get_devdata(master);
*p_regbase = ctrl->reg_base;
/* set bus num to 5 to avoid conflict with other spi hosts */
master->bus_num = 5;
master->num_chipselect = 1;
master->setup = lcd_spi_setup;
master->transfer = lcd_spi_one_transfer;
err = spi_register_master(master);
if (err < 0) {
dev_err(ctrl->dev, "unable to register SPI master\n");
spi_master_put(master);
return err;
}
dev_info(&master->dev, "registered\n");
return 0;
}
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