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/*
* Driver for Nvidia TEGRA spi controller.
*
* Copyright (C) 2010 Google, Inc.
*
* Author:
* Erik Gilling <konkers@android.com>
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* 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.
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/dma-mapping.h>
#include <linux/dmapool.h>
#include <linux/clk.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/spi/spi.h>
#include <mach/dma.h>
#define SLINK_COMMAND 0x000
#define SLINK_BIT_LENGTH(x) (((x) & 0x1f) << 0)
#define SLINK_WORD_SIZE(x) (((x) & 0x1f) << 5)
#define SLINK_BOTH_EN (1 << 10)
#define SLINK_CS_SW (1 << 11)
#define SLINK_CS_VALUE (1 << 12)
#define SLINK_CS_POLARITY (1 << 13)
#define SLINK_IDLE_SDA_DRIVE_LOW (0 << 16)
#define SLINK_IDLE_SDA_DRIVE_HIGH (1 << 16)
#define SLINK_IDLE_SDA_PULL_LOW (2 << 16)
#define SLINK_IDLE_SDA_PULL_HIGH (3 << 16)
#define SLINK_IDLE_SDA_MASK (3 << 16)
#define SLINK_CS_POLARITY1 (1 << 20)
#define SLINK_CK_SDA (1 << 21)
#define SLINK_CS_POLARITY2 (1 << 22)
#define SLINK_CS_POLARITY3 (1 << 23)
#define SLINK_IDLE_SCLK_DRIVE_LOW (0 << 24)
#define SLINK_IDLE_SCLK_DRIVE_HIGH (1 << 24)
#define SLINK_IDLE_SCLK_PULL_LOW (2 << 24)
#define SLINK_IDLE_SCLK_PULL_HIGH (3 << 24)
#define SLINK_IDLE_SCLK_MASK (3 << 24)
#define SLINK_M_S (1 << 28)
#define SLINK_WAIT (1 << 29)
#define SLINK_GO (1 << 30)
#define SLINK_ENB (1 << 31)
#define SLINK_COMMAND2 0x004
#define SLINK_LSBFE (1 << 0)
#define SLINK_SSOE (1 << 1)
#define SLINK_SPIE (1 << 4)
#define SLINK_BIDIROE (1 << 6)
#define SLINK_MODFEN (1 << 7)
#define SLINK_INT_SIZE(x) (((x) & 0x1f) << 8)
#define SLINK_CS_ACTIVE_BETWEEN (1 << 17)
#define SLINK_SS_EN_CS(x) (((x) & 0x3) << 18)
#define SLINK_SS_SETUP(x) (((x) & 0x3) << 20)
#define SLINK_FIFO_REFILLS_0 (0 << 22)
#define SLINK_FIFO_REFILLS_1 (1 << 22)
#define SLINK_FIFO_REFILLS_2 (2 << 22)
#define SLINK_FIFO_REFILLS_3 (3 << 22)
#define SLINK_FIFO_REFILLS_MASK (3 << 22)
#define SLINK_WAIT_PACK_INT(x) (((x) & 0x7) << 26)
#define SLINK_SPC0 (1 << 29)
#define SLINK_TXEN (1 << 30)
#define SLINK_RXEN (1 << 31)
#define SLINK_STATUS 0x008
#define SLINK_COUNT(val) (((val) >> 0) & 0x1f)
#define SLINK_WORD(val) (((val) >> 5) & 0x1f)
#define SLINK_BLK_CNT(val) (((val) >> 0) & 0xffff)
#define SLINK_MODF (1 << 16)
#define SLINK_RX_UNF (1 << 18)
#define SLINK_TX_OVF (1 << 19)
#define SLINK_TX_FULL (1 << 20)
#define SLINK_TX_EMPTY (1 << 21)
#define SLINK_RX_FULL (1 << 22)
#define SLINK_RX_EMPTY (1 << 23)
#define SLINK_TX_UNF (1 << 24)
#define SLINK_RX_OVF (1 << 25)
#define SLINK_TX_FLUSH (1 << 26)
#define SLINK_RX_FLUSH (1 << 27)
#define SLINK_SCLK (1 << 28)
#define SLINK_ERR (1 << 29)
#define SLINK_RDY (1 << 30)
#define SLINK_BSY (1 << 31)
#define SLINK_MAS_DATA 0x010
#define SLINK_SLAVE_DATA 0x014
#define SLINK_DMA_CTL 0x018
#define SLINK_DMA_BLOCK_SIZE(x) (((x) & 0xffff) << 0)
#define SLINK_TX_TRIG_1 (0 << 16)
#define SLINK_TX_TRIG_4 (1 << 16)
#define SLINK_TX_TRIG_8 (2 << 16)
#define SLINK_TX_TRIG_16 (3 << 16)
#define SLINK_TX_TRIG_MASK (3 << 16)
#define SLINK_RX_TRIG_1 (0 << 18)
#define SLINK_RX_TRIG_4 (1 << 18)
#define SLINK_RX_TRIG_8 (2 << 18)
#define SLINK_RX_TRIG_16 (3 << 18)
#define SLINK_RX_TRIG_MASK (3 << 18)
#define SLINK_PACKED (1 << 20)
#define SLINK_PACK_SIZE_4 (0 << 21)
#define SLINK_PACK_SIZE_8 (1 << 21)
#define SLINK_PACK_SIZE_16 (2 << 21)
#define SLINK_PACK_SIZE_32 (3 << 21)
#define SLINK_PACK_SIZE_MASK (3 << 21)
#define SLINK_IE_TXC (1 << 26)
#define SLINK_IE_RXC (1 << 27)
#define SLINK_DMA_EN (1 << 31)
#define SLINK_STATUS2 0x01c
#define SLINK_TX_FIFO_EMPTY_COUNT(val) (((val) & 0x3f) >> 0)
#define SLINK_RX_FIFO_FULL_COUNT(val) (((val) & 0x3f) >> 16)
#define SLINK_TX_FIFO 0x100
#define SLINK_RX_FIFO 0x180
static const unsigned long spi_tegra_req_sels[] = {
TEGRA_DMA_REQ_SEL_SL2B1,
TEGRA_DMA_REQ_SEL_SL2B2,
TEGRA_DMA_REQ_SEL_SL2B3,
TEGRA_DMA_REQ_SEL_SL2B4,
};
#define BB_LEN 32
struct spi_tegra_data {
struct spi_master *master;
struct platform_device *pdev;
spinlock_t lock;
struct clk *clk;
void __iomem *base;
unsigned long phys;
u32 cur_speed;
struct list_head queue;
struct spi_transfer *cur;
unsigned cur_pos;
unsigned cur_len;
unsigned cur_bytes_per_word;
/* The tegra spi controller has a bug which causes the first word
* in PIO transactions to be garbage. Since packed DMA transactions
* require transfers to be 4 byte aligned we need a bounce buffer
* for the generic case.
*/
struct tegra_dma_req rx_dma_req;
struct tegra_dma_channel *rx_dma;
u32 *rx_bb;
dma_addr_t rx_bb_phys;
};
static inline unsigned long spi_tegra_readl(struct spi_tegra_data *tspi,
unsigned long reg)
{
return readl(tspi->base + reg);
}
static inline void spi_tegra_writel(struct spi_tegra_data *tspi,
unsigned long val,
unsigned long reg)
{
writel(val, tspi->base + reg);
}
static void spi_tegra_go(struct spi_tegra_data *tspi)
{
unsigned long val;
wmb();
val = spi_tegra_readl(tspi, SLINK_DMA_CTL);
val &= ~SLINK_DMA_BLOCK_SIZE(~0) & ~SLINK_DMA_EN;
val |= SLINK_DMA_BLOCK_SIZE(tspi->rx_dma_req.size / 4 - 1);
spi_tegra_writel(tspi, val, SLINK_DMA_CTL);
tegra_dma_enqueue_req(tspi->rx_dma, &tspi->rx_dma_req);
val |= SLINK_DMA_EN;
spi_tegra_writel(tspi, val, SLINK_DMA_CTL);
}
static unsigned spi_tegra_fill_tx_fifo(struct spi_tegra_data *tspi,
struct spi_transfer *t)
{
unsigned len = min(t->len - tspi->cur_pos, BB_LEN *
tspi->cur_bytes_per_word);
u8 *tx_buf = (u8 *)t->tx_buf + tspi->cur_pos;
int i, j;
unsigned long val;
val = spi_tegra_readl(tspi, SLINK_COMMAND);
val &= ~SLINK_WORD_SIZE(~0);
val |= SLINK_WORD_SIZE(len / tspi->cur_bytes_per_word - 1);
spi_tegra_writel(tspi, val, SLINK_COMMAND);
for (i = 0; i < len; i += tspi->cur_bytes_per_word) {
val = 0;
for (j = 0; j < tspi->cur_bytes_per_word; j++)
val |= tx_buf[i + j] << j * 8;
spi_tegra_writel(tspi, val, SLINK_TX_FIFO);
}
tspi->rx_dma_req.size = len / tspi->cur_bytes_per_word * 4;
return len;
}
static unsigned spi_tegra_drain_rx_fifo(struct spi_tegra_data *tspi,
struct spi_transfer *t)
{
unsigned len = tspi->cur_len;
u8 *rx_buf = (u8 *)t->rx_buf + tspi->cur_pos;
int i, j;
unsigned long val;
for (i = 0; i < len; i += tspi->cur_bytes_per_word) {
val = tspi->rx_bb[i / tspi->cur_bytes_per_word];
for (j = 0; j < tspi->cur_bytes_per_word; j++)
rx_buf[i + j] = (val >> (j * 8)) & 0xff;
}
return len;
}
static void spi_tegra_start_transfer(struct spi_device *spi,
struct spi_transfer *t)
{
struct spi_tegra_data *tspi = spi_master_get_devdata(spi->master);
u32 speed;
u8 bits_per_word;
unsigned long val;
speed = t->speed_hz ? t->speed_hz : spi->max_speed_hz;
bits_per_word = t->bits_per_word ? t->bits_per_word :
spi->bits_per_word;
tspi->cur_bytes_per_word = (bits_per_word - 1) / 8 + 1;
if (speed != tspi->cur_speed)
clk_set_rate(tspi->clk, speed);
if (tspi->cur_speed == 0)
clk_enable(tspi->clk);
tspi->cur_speed = speed;
val = spi_tegra_readl(tspi, SLINK_COMMAND2);
val &= ~SLINK_SS_EN_CS(~0) | SLINK_RXEN | SLINK_TXEN;
if (t->rx_buf)
val |= SLINK_RXEN;
if (t->tx_buf)
val |=
|