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Message-ID: <1351580645-17260-1-git-send-email-ldewangan@nvidia.com>
Date: Tue, 30 Oct 2012 12:34:05 +0530
From: Laxman Dewangan <ldewangan@...dia.com>
To: <broonie@...nsource.wolfsonmicro.com>, <grant.likely@...retlab.ca>,
<rob.herring@...xeda.com>
CC: <spi-devel-general@...ts.sourceforge.net>,
<linux-kernel@...r.kernel.org>, <linux-tegra@...r.kernel.org>,
Laxman Dewangan <ldewangan@...dia.com>
Subject: [PATCH V3] spi: tegra: add spi driver for SLINK controller
Tegra20/Tegra30 supports the spi interface through its SLINK
controller. Add spi driver for SLINK controller.
Signed-off-by: Laxman Dewangan <ldewangan@...dia.com>
---
Changes from V1:
- Add dt file documentation.
- Renames some of props to match with other driver.
- Move clock control to run time pm.
- Rearrange code for isr handler as suggested by Stephen.
- fix typo in parse_dt.
- Move the spi max freq default setting for all i.e. for non-dt case also.
- Match device always with compatible.
- Convert pm_runtime_put_sync() to pm_runtime_put() as suggested by Mark.
- Check return error on differnt places as suggested by Mark.
- Use request_threaded_irq() in place of devm_request_threaded_irq().
- nit cleanups as suggested by Stephen.
Changes from V2:
- Simplify clear status
- get rid of tegra_slink_clk* api and move implementation to caller.
- Fix typo issue.
.../bindings/spi/nvidia,tegra20-slink.txt | 26 +
drivers/spi/Kconfig | 6 +
drivers/spi/Makefile | 2 +-
drivers/spi/spi-tegra20-slink.c | 1359 ++++++++++++++++++++
include/linux/spi/spi-tegra.h | 40 +
5 files changed, 1432 insertions(+), 1 deletions(-)
create mode 100644 Documentation/devicetree/bindings/spi/nvidia,tegra20-slink.txt
create mode 100644 drivers/spi/spi-tegra20-slink.c
create mode 100644 include/linux/spi/spi-tegra.h
diff --git a/Documentation/devicetree/bindings/spi/nvidia,tegra20-slink.txt b/Documentation/devicetree/bindings/spi/nvidia,tegra20-slink.txt
new file mode 100644
index 0000000..f5b1ad1
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/nvidia,tegra20-slink.txt
@@ -0,0 +1,26 @@
+NVIDIA Tegra20/Tegra30 SLINK controller.
+
+Required properties:
+- compatible : should be "nvidia,tegra20-slink", "nvidia,tegra30-slink".
+- reg: Should contain SLINK registers location and length.
+- interrupts: Should contain SLINK interrupts.
+- nvidia,dma-request-selector : The Tegra DMA controller's phandle and
+ request selector for this SLINK controller.
+
+Recommended properties:
+- spi-max-frequency: Definition as per
+ Documentation/devicetree/bindings/spi/spi-bus.txt
+
+Example:
+
+slink@...0d600 {
+ compatible = "nvidia,tegra20-slink";
+ reg = <0x7000d600 0x200>;
+ interrupts = <0 82 0x04>;
+ nvidia,dma-request-selector = <&apbdma 16>;
+ spi-max-frequency = <25000000>;
+ #address-cells = <1>;
+ #size-cells = <0>;
+ status = "disabled";
+};
+
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 1acae35..25290d9 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -385,6 +385,12 @@ config SPI_MXS
help
SPI driver for Freescale MXS devices.
+config SPI_TEGRA20_SLINK
+ tristate "Nvidia Tegra20/Tegra30 SLINK Controller"
+ depends on ARCH_TEGRA && TEGRA20_APB_DMA
+ help
+ SPI driver for Nvidia Tegra20/Tegra30 SLINK Controller interface.
+
config SPI_TI_SSP
tristate "TI Sequencer Serial Port - SPI Support"
depends on MFD_TI_SSP
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index c48df47..f87c0f1 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -60,10 +60,10 @@ obj-$(CONFIG_SPI_SH_MSIOF) += spi-sh-msiof.o
obj-$(CONFIG_SPI_SH_SCI) += spi-sh-sci.o
obj-$(CONFIG_SPI_SIRF) += spi-sirf.o
obj-$(CONFIG_SPI_STMP3XXX) += spi-stmp.o
+obj-$(CONFIG_SPI_TEGRA20_SLINK) += spi-tegra20-slink.o
obj-$(CONFIG_SPI_TI_SSP) += spi-ti-ssp.o
obj-$(CONFIG_SPI_TLE62X0) += spi-tle62x0.o
obj-$(CONFIG_SPI_TOPCLIFF_PCH) += spi-topcliff-pch.o
obj-$(CONFIG_SPI_TXX9) += spi-txx9.o
obj-$(CONFIG_SPI_XCOMM) += spi-xcomm.o
obj-$(CONFIG_SPI_XILINX) += spi-xilinx.o
-
diff --git a/drivers/spi/spi-tegra20-slink.c b/drivers/spi/spi-tegra20-slink.c
new file mode 100644
index 0000000..b8985be
--- /dev/null
+++ b/drivers/spi/spi-tegra20-slink.c
@@ -0,0 +1,1359 @@
+/*
+ * SPI driver for Nvidia's Tegra20/Tegra30 SLINK Controller.
+ *
+ * Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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/clk.h>
+#include <linux/completion.h>
+#include <linux/delay.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/dmapool.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/kthread.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/spi/spi.h>
+#include <linux/spi/spi-tegra.h>
+#include <mach/clk.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_MODES (SLINK_IDLE_SCLK_MASK | SLINK_CK_SDA)
+
+#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_FIFO_ERROR (SLINK_TX_OVF | SLINK_RX_UNF | \
+ SLINK_TX_UNF | SLINK_RX_OVF)
+
+#define SLINK_FIFO_EMPTY (SLINK_TX_EMPTY | SLINK_RX_EMPTY)
+
+#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) & 0x3f0000) >> 16)
+#define SLINK_SS_HOLD_TIME(val) (((val) & 0xF) << 6)
+
+#define SLINK_TX_FIFO 0x100
+#define SLINK_RX_FIFO 0x180
+
+#define DATA_DIR_TX (1 << 0)
+#define DATA_DIR_RX (1 << 1)
+
+#define SLINK_DMA_TIMEOUT (msecs_to_jiffies(1000))
+
+#define DEFAULT_SPI_DMA_BUF_LEN (16*1024)
+#define TX_FIFO_EMPTY_COUNT_MAX SLINK_TX_FIFO_EMPTY_COUNT(0x20)
+#define RX_FIFO_FULL_COUNT_ZERO SLINK_RX_FIFO_FULL_COUNT(0)
+
+#define SLINK_STATUS2_RESET \
+ (TX_FIFO_EMPTY_COUNT_MAX | RX_FIFO_FULL_COUNT_ZERO << 16)
+
+#define MAX_CHIP_SELECT 4
+#define SLINK_FIFO_DEPTH 32
+
+struct tegra_slink_chip_data {
+ bool cs_hold_time;
+};
+
+struct tegra_slink_data {
+ struct device *dev;
+ struct spi_master *master;
+ const struct tegra_slink_chip_data *chip_data;
+ spinlock_t lock;
+
+ struct clk *clk;
+ void __iomem *base;
+ phys_addr_t phys;
+ unsigned irq;
+ int dma_req_sel;
+ u32 spi_max_frequency;
+ u32 cur_speed;
+
+ struct spi_device *cur_spi;
+ unsigned cur_pos;
+ unsigned cur_len;
+ unsigned words_per_32bit;
+ unsigned bytes_per_word;
+ unsigned curr_dma_words;
+ unsigned cur_direction;
+
+ unsigned cur_rx_pos;
+ unsigned cur_tx_pos;
+
+ unsigned dma_buf_size;
+ unsigned max_buf_size;
+ bool is_curr_dma_xfer;
+ bool is_hw_based_cs;
+
+ struct completion rx_dma_complete;
+ struct completion tx_dma_complete;
+
+ u32 tx_status;
+ u32 rx_status;
+ u32 status_reg;
+ bool is_packed;
+ unsigned long packed_size;
+
+ u32 command_reg;
+ u32 command2_reg;
+ u32 dma_control_reg;
+ u32 def_command_reg;
+ u32 def_command2_reg;
+
+ struct completion xfer_completion;
+ struct spi_transfer *curr_xfer;
+ struct dma_chan *rx_dma_chan;
+ u32 *rx_dma_buf;
+ dma_addr_t rx_dma_phys;
+ struct dma_async_tx_descriptor *rx_dma_desc;
+
+ struct dma_chan *tx_dma_chan;
+ u32 *tx_dma_buf;
+ dma_addr_t tx_dma_phys;
+ struct dma_async_tx_descriptor *tx_dma_desc;
+};
+
+static int tegra_slink_runtime_suspend(struct device *dev);
+static int tegra_slink_runtime_resume(struct device *dev);
+
+static inline unsigned long tegra_slink_readl(struct tegra_slink_data *tspi,
+ unsigned long reg)
+{
+ return readl(tspi->base + reg);
+}
+
+static inline void tegra_slink_writel(struct tegra_slink_data *tspi,
+ unsigned long val, unsigned long reg)
+{
+ writel(val, tspi->base + reg);
+
+ /* Read back register to make sure that register writes completed */
+ if (reg != SLINK_TX_FIFO)
+ readl(tspi->base + SLINK_MAS_DATA);
+}
+
+static void tegra_slink_clear_status(struct tegra_slink_data *tspi)
+{
+ unsigned long val;
+ unsigned long val_write = 0;
+
+ val = tegra_slink_readl(tspi, SLINK_STATUS);
+
+ /* Write 1 to clear status register */
+ val_write = SLINK_RDY | SLINK_FIFO_ERROR;
+ tegra_slink_writel(tspi, val_write, SLINK_STATUS);
+}
+
+static unsigned long tegra_slink_get_packed_size(struct tegra_slink_data *tspi,
+ struct spi_transfer *t)
+{
+ unsigned long val;
+
+ switch (tspi->bytes_per_word) {
+ case 0:
+ val = SLINK_PACK_SIZE_4;
+ break;
+ case 1:
+ val = SLINK_PACK_SIZE_8;
+ break;
+ case 2:
+ val = SLINK_PACK_SIZE_16;
+ break;
+ case 4:
+ val = SLINK_PACK_SIZE_32;
+ break;
+ default:
+ val = 0;
+ }
+ return val;
+}
+
+static unsigned tegra_slink_calculate_curr_xfer_param(
+ struct spi_device *spi, struct tegra_slink_data *tspi,
+ struct spi_transfer *t)
+{
+ unsigned remain_len = t->len - tspi->cur_pos;
+ unsigned max_word;
+ unsigned bits_per_word ;
+ unsigned max_len;
+ unsigned total_fifo_words;
+
+ bits_per_word = t->bits_per_word ? t->bits_per_word :
+ spi->bits_per_word;
+ tspi->bytes_per_word = (bits_per_word - 1) / 8 + 1;
+
+ if (bits_per_word == 8 || bits_per_word == 16) {
+ tspi->is_packed = 1;
+ tspi->words_per_32bit = 32/bits_per_word;
+ } else {
+ tspi->is_packed = 0;
+ tspi->words_per_32bit = 1;
+ }
+ tspi->packed_size = tegra_slink_get_packed_size(tspi, t);
+
+ if (tspi->is_packed) {
+ max_len = min(remain_len, tspi->max_buf_size);
+ tspi->curr_dma_words = max_len/tspi->bytes_per_word;
+ total_fifo_words = max_len/4;
+ } else {
+ max_word = (remain_len - 1) / tspi->bytes_per_word + 1;
+ max_word = min(max_word, tspi->max_buf_size/4);
+ tspi->curr_dma_words = max_word;
+ total_fifo_words = max_word;
+ }
+ return total_fifo_words;
+}
+
+static unsigned tegra_slink_fill_tx_fifo_from_client_txbuf(
+ struct tegra_slink_data *tspi, struct spi_transfer *t)
+{
+ unsigned nbytes;
+ unsigned tx_empty_count;
+ unsigned long fifo_status;
+ unsigned max_n_32bit;
+ unsigned i, count;
+ unsigned long x;
+ unsigned int written_words;
+ unsigned fifo_words_left;
+ u8 *tx_buf = (u8 *)t->tx_buf + tspi->cur_tx_pos;
+
+ fifo_status = tegra_slink_readl(tspi, SLINK_STATUS2);
+ tx_empty_count = SLINK_TX_FIFO_EMPTY_COUNT(fifo_status);
+
+ if (tspi->is_packed) {
+ fifo_words_left = tx_empty_count * tspi->words_per_32bit;
+ written_words = min(fifo_words_left, tspi->curr_dma_words);
+ nbytes = written_words * tspi->bytes_per_word;
+ max_n_32bit = DIV_ROUND_UP(nbytes, 4);
+ for (count = 0; count < max_n_32bit; count++) {
+ x = 0;
+ for (i = 0; (i < 4) && nbytes; i++, nbytes--)
+ x |= (*tx_buf++) << (i*8);
+ tegra_slink_writel(tspi, x, SLINK_TX_FIFO);
+ }
+ } else {
+ max_n_32bit = min(tspi->curr_dma_words, tx_empty_count);
+ written_words = max_n_32bit;
+ nbytes = written_words * tspi->bytes_per_word;
+ for (count = 0; count < max_n_32bit; count++) {
+ x = 0;
+ for (i = 0; nbytes && (i < tspi->bytes_per_word);
+ i++, nbytes--)
+ x |= ((*tx_buf++) << i*8);
+ tegra_slink_writel(tspi, x, SLINK_TX_FIFO);
+ }
+ }
+ tspi->cur_tx_pos += written_words * tspi->bytes_per_word;
+ return written_words;
+}
+
+static unsigned int tegra_slink_read_rx_fifo_to_client_rxbuf(
+ struct tegra_slink_data *tspi, struct spi_transfer *t)
+{
+ unsigned rx_full_count;
+ unsigned long fifo_status;
+ unsigned i, count;
+ unsigned long x;
+ unsigned int read_words = 0;
+ unsigned len;
+ u8 *rx_buf = (u8 *)t->rx_buf + tspi->cur_rx_pos;
+
+ fifo_status = tegra_slink_readl(tspi, SLINK_STATUS2);
+ rx_full_count = SLINK_RX_FIFO_FULL_COUNT(fifo_status);
+ if (tspi->is_packed) {
+ len = tspi->curr_dma_words * tspi->bytes_per_word;
+ for (count = 0; count < rx_full_count; count++) {
+ x = tegra_slink_readl(tspi, SLINK_RX_FIFO);
+ for (i = 0; len && (i < 4); i++, len--)
+ *rx_buf++ = (x >> i*8) & 0xFF;
+ }
+ tspi->cur_rx_pos += tspi->curr_dma_words * tspi->bytes_per_word;
+ read_words += tspi->curr_dma_words;
+ } else {
+ unsigned int bits_per_word;
+
+ bits_per_word = t->bits_per_word ? t->bits_per_word :
+ tspi->cur_spi->bits_per_word;
+ for (count = 0; count < rx_full_count; count++) {
+ x = tegra_slink_readl(tspi, SLINK_RX_FIFO);
+ for (i = 0; (i < tspi->bytes_per_word); i++)
+ *rx_buf++ = (x >> (i*8)) & 0xFF;
+ }
+ tspi->cur_rx_pos += rx_full_count * tspi->bytes_per_word;
+ read_words += rx_full_count;
+ }
+ return read_words;
+}
+
+static void tegra_slink_copy_client_txbuf_to_spi_txbuf(
+ struct tegra_slink_data *tspi, struct spi_transfer *t)
+{
+ unsigned len;
+
+ /* Make the dma buffer to read by cpu */
+ dma_sync_single_for_cpu(tspi->dev, tspi->tx_dma_phys,
+ tspi->dma_buf_size, DMA_TO_DEVICE);
+
+ if (tspi->is_packed) {
+ len = tspi->curr_dma_words * tspi->bytes_per_word;
+ memcpy(tspi->tx_dma_buf, t->tx_buf + tspi->cur_pos, len);
+ } else {
+ unsigned int i;
+ unsigned int count;
+ u8 *tx_buf = (u8 *)t->tx_buf + tspi->cur_tx_pos;
+ unsigned consume = tspi->curr_dma_words * tspi->bytes_per_word;
+ unsigned int x;
+
+ for (count = 0; count < tspi->curr_dma_words; count++) {
+ x = 0;
+ for (i = 0; consume && (i < tspi->bytes_per_word);
+ i++, consume--)
+ x |= ((*tx_buf++) << i * 8);
+ tspi->tx_dma_buf[count] = x;
+ }
+ }
+ tspi->cur_tx_pos += tspi->curr_dma_words * tspi->bytes_per_word;
+
+ /* Make the dma buffer to read by dma */
+ dma_sync_single_for_device(tspi->dev, tspi->tx_dma_phys,
+ tspi->dma_buf_size, DMA_TO_DEVICE);
+}
+
+static void tegra_slink_copy_spi_rxbuf_to_client_rxbuf(
+ struct tegra_slink_data *tspi, struct spi_transfer *t)
+{
+ unsigned len;
+
+ /* Make the dma buffer to read by cpu */
+ dma_sync_single_for_cpu(tspi->dev, tspi->rx_dma_phys,
+ tspi->dma_buf_size, DMA_FROM_DEVICE);
+
+ if (tspi->is_packed) {
+ len = tspi->curr_dma_words * tspi->bytes_per_word;
+ memcpy(t->rx_buf + tspi->cur_rx_pos, tspi->rx_dma_buf, len);
+ } else {
+ unsigned int i;
+ unsigned int count;
+ unsigned char *rx_buf = t->rx_buf + tspi->cur_rx_pos;
+ unsigned int x;
+ unsigned int rx_mask, bits_per_word;
+
+ bits_per_word = t->bits_per_word ? t->bits_per_word :
+ tspi->cur_spi->bits_per_word;
+ rx_mask = (1 << bits_per_word) - 1;
+ for (count = 0; count < tspi->curr_dma_words; count++) {
+ x = tspi->rx_dma_buf[count];
+ x &= rx_mask;
+ for (i = 0; (i < tspi->bytes_per_word); i++)
+ *rx_buf++ = (x >> (i*8)) & 0xFF;
+ }
+ }
+ tspi->cur_rx_pos += tspi->curr_dma_words * tspi->bytes_per_word;
+
+ /* Make the dma buffer to read by dma */
+ dma_sync_single_for_device(tspi->dev, tspi->rx_dma_phys,
+ tspi->dma_buf_size, DMA_FROM_DEVICE);
+}
+
+static void tegra_slink_dma_complete(void *args)
+{
+ struct completion *dma_complete = args;
+
+ complete(dma_complete);
+}
+
+static int tegra_slink_start_tx_dma(struct tegra_slink_data *tspi, int len)
+{
+ INIT_COMPLETION(tspi->tx_dma_complete);
+ tspi->tx_dma_desc = dmaengine_prep_slave_single(tspi->tx_dma_chan,
+ tspi->tx_dma_phys, len, DMA_MEM_TO_DEV,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ if (!tspi->tx_dma_desc) {
+ dev_err(tspi->dev, "Not able to get desc for Tx\n");
+ return -EIO;
+ }
+
+ tspi->tx_dma_desc->callback = tegra_slink_dma_complete;
+ tspi->tx_dma_desc->callback_param = &tspi->tx_dma_complete;
+
+ dmaengine_submit(tspi->tx_dma_desc);
+ dma_async_issue_pending(tspi->tx_dma_chan);
+ return 0;
+}
+
+static int tegra_slink_start_rx_dma(struct tegra_slink_data *tspi, int len)
+{
+ INIT_COMPLETION(tspi->rx_dma_complete);
+ tspi->rx_dma_desc = dmaengine_prep_slave_single(tspi->rx_dma_chan,
+ tspi->rx_dma_phys, len, DMA_DEV_TO_MEM,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ if (!tspi->rx_dma_desc) {
+ dev_err(tspi->dev, "Not able to get desc for Rx\n");
+ return -EIO;
+ }
+
+ tspi->rx_dma_desc->callback = tegra_slink_dma_complete;
+ tspi->rx_dma_desc->callback_param = &tspi->rx_dma_complete;
+
+ dmaengine_submit(tspi->rx_dma_desc);
+ dma_async_issue_pending(tspi->rx_dma_chan);
+ return 0;
+}
+
+static int tegra_slink_start_dma_based_transfer(
+ struct tegra_slink_data *tspi, struct spi_transfer *t)
+{
+ unsigned long val;
+ unsigned long test_val;
+ unsigned int len;
+ int ret = 0;
+ unsigned long status;
+
+ /* Make sure that Rx and Tx fifo are empty */
+ status = tegra_slink_readl(tspi, SLINK_STATUS);
+ if ((status & SLINK_FIFO_EMPTY) != SLINK_FIFO_EMPTY) {
+ dev_err(tspi->dev,
+ "Rx/Tx fifo are not empty status 0x%08lx\n", status);
+ return -EIO;
+ }
+
+ val = SLINK_DMA_BLOCK_SIZE(tspi->curr_dma_words - 1);
+ val |= tspi->packed_size;
+ if (tspi->is_packed)
+ len = DIV_ROUND_UP(tspi->curr_dma_words * tspi->bytes_per_word,
+ 4) * 4;
+ else
+ len = tspi->curr_dma_words * 4;
+
+ /* Set attention level based on length of transfer */
+ if (len & 0xF)
+ val |= SLINK_TX_TRIG_1 | SLINK_RX_TRIG_1;
+ else if (((len) >> 4) & 0x1)
+ val |= SLINK_TX_TRIG_4 | SLINK_RX_TRIG_4;
+ else
+ val |= SLINK_TX_TRIG_8 | SLINK_RX_TRIG_8;
+
+ if (tspi->cur_direction & DATA_DIR_TX)
+ val |= SLINK_IE_TXC;
+
+ if (tspi->cur_direction & DATA_DIR_RX)
+ val |= SLINK_IE_RXC;
+
+ tegra_slink_writel(tspi, val, SLINK_DMA_CTL);
+ tspi->dma_control_reg = val;
+
+ if (tspi->cur_direction & DATA_DIR_TX) {
+ tegra_slink_copy_client_txbuf_to_spi_txbuf(tspi, t);
+ wmb();
+ ret = tegra_slink_start_tx_dma(tspi, len);
+ if (ret < 0) {
+ dev_err(tspi->dev,
+ "Starting tx dma failed, err %d\n", ret);
+ return ret;
+ }
+
+ /* Wait for tx fifo to be fill before starting slink */
+ test_val = tegra_slink_readl(tspi, SLINK_STATUS);
+ while (!(test_val & SLINK_TX_FULL))
+ test_val = tegra_slink_readl(tspi, SLINK_STATUS);
+ }
+
+ if (tspi->cur_direction & DATA_DIR_RX) {
+ /* Make the dma buffer to read by dma */
+ dma_sync_single_for_device(tspi->dev, tspi->rx_dma_phys,
+ tspi->dma_buf_size, DMA_FROM_DEVICE);
+
+ ret = tegra_slink_start_rx_dma(tspi, len);
+ if (ret < 0) {
+ dev_err(tspi->dev,
+ "Starting rx dma failed, err %d\n", ret);
+ if (tspi->cur_direction & DATA_DIR_TX)
+ dmaengine_terminate_all(tspi->tx_dma_chan);
+ return ret;
+ }
+ }
+ tspi->is_curr_dma_xfer = true;
+ if (tspi->is_packed) {
+ val |= SLINK_PACKED;
+ tegra_slink_writel(tspi, val, SLINK_DMA_CTL);
+ /* HW need small delay after settign Packed mode */
+ udelay(1);
+ }
+ tspi->dma_control_reg = val;
+
+ val |= SLINK_DMA_EN;
+ tegra_slink_writel(tspi, val, SLINK_DMA_CTL);
+ return ret;
+}
+
+static int tegra_slink_start_cpu_based_transfer(
+ struct tegra_slink_data *tspi, struct spi_transfer *t)
+{
+ unsigned long val;
+ unsigned cur_words;
+
+ val = tspi->packed_size;
+ if (tspi->cur_direction & DATA_DIR_TX)
+ val |= SLINK_IE_TXC;
+
+ if (tspi->cur_direction & DATA_DIR_RX)
+ val |= SLINK_IE_RXC;
+
+ tegra_slink_writel(tspi, val, SLINK_DMA_CTL);
+ tspi->dma_control_reg = val;
+
+ if (tspi->cur_direction & DATA_DIR_TX)
+ cur_words = tegra_slink_fill_tx_fifo_from_client_txbuf(tspi, t);
+ else
+ cur_words = tspi->curr_dma_words;
+ val |= SLINK_DMA_BLOCK_SIZE(cur_words - 1);
+ tegra_slink_writel(tspi, val, SLINK_DMA_CTL);
+ tspi->dma_control_reg = val;
+
+ tspi->is_curr_dma_xfer = false;
+ if (tspi->is_packed) {
+ val |= SLINK_PACKED;
+ tegra_slink_writel(tspi, val, SLINK_DMA_CTL);
+ udelay(1);
+ wmb();
+ }
+ tspi->dma_control_reg = val;
+ val |= SLINK_DMA_EN;
+ tegra_slink_writel(tspi, val, SLINK_DMA_CTL);
+ return 0;
+}
+
+static int tegra_slink_init_dma_param(struct tegra_slink_data *tspi,
+ bool dma_to_memory)
+{
+ struct dma_chan *dma_chan;
+ u32 *dma_buf;
+ dma_addr_t dma_phys;
+ int ret;
+ struct dma_slave_config dma_sconfig;
+ dma_cap_mask_t mask;
+
+ dma_cap_zero(mask);
+ dma_cap_set(DMA_SLAVE, mask);
+ dma_chan = dma_request_channel(mask, NULL, NULL);
+ if (!dma_chan) {
+ dev_err(tspi->dev,
+ "Dma channel is not available, will try later\n");
+ return -EPROBE_DEFER;
+ }
+
+ dma_buf = dma_alloc_coherent(tspi->dev, tspi->dma_buf_size,
+ &dma_phys, GFP_KERNEL);
+ if (!dma_buf) {
+ dev_err(tspi->dev, " Not able to allocate the dma buffer\n");
+ dma_release_channel(dma_chan);
+ return -ENOMEM;
+ }
+
+ dma_sconfig.slave_id = tspi->dma_req_sel;
+ if (dma_to_memory) {
+ dma_sconfig.src_addr = tspi->phys + SLINK_RX_FIFO;
+ dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+ dma_sconfig.src_maxburst = 0;
+ } else {
+ dma_sconfig.dst_addr = tspi->phys + SLINK_TX_FIFO;
+ dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+ dma_sconfig.dst_maxburst = 0;
+ }
+
+ ret = dmaengine_slave_config(dma_chan, &dma_sconfig);
+ if (ret)
+ goto scrub;
+ if (dma_to_memory) {
+ tspi->rx_dma_chan = dma_chan;
+ tspi->rx_dma_buf = dma_buf;
+ tspi->rx_dma_phys = dma_phys;
+ } else {
+ tspi->tx_dma_chan = dma_chan;
+ tspi->tx_dma_buf = dma_buf;
+ tspi->tx_dma_phys = dma_phys;
+ }
+ return 0;
+
+scrub:
+ dma_free_coherent(tspi->dev, tspi->dma_buf_size, dma_buf, dma_phys);
+ dma_release_channel(dma_chan);
+ return ret;
+}
+
+static void tegra_slink_deinit_dma_param(struct tegra_slink_data *tspi,
+ bool dma_to_memory)
+{
+ u32 *dma_buf;
+ dma_addr_t dma_phys;
+ struct dma_chan *dma_chan;
+
+ if (dma_to_memory) {
+ dma_buf = tspi->rx_dma_buf;
+ dma_chan = tspi->rx_dma_chan;
+ dma_phys = tspi->rx_dma_phys;
+ tspi->rx_dma_chan = NULL;
+ tspi->rx_dma_buf = NULL;
+ } else {
+ dma_buf = tspi->tx_dma_buf;
+ dma_chan = tspi->tx_dma_chan;
+ dma_phys = tspi->tx_dma_phys;
+ tspi->tx_dma_buf = NULL;
+ tspi->tx_dma_chan = NULL;
+ }
+ if (!dma_chan)
+ return;
+
+ dma_free_coherent(tspi->dev, tspi->dma_buf_size, dma_buf, dma_phys);
+ dma_release_channel(dma_chan);
+}
+
+static int tegra_slink_start_transfer_one(struct spi_device *spi,
+ struct spi_transfer *t, bool is_first_of_msg,
+ bool is_single_xfer)
+{
+ struct tegra_slink_data *tspi = spi_master_get_devdata(spi->master);
+ u32 speed;
+ u8 bits_per_word;
+ unsigned total_fifo_words;
+ int ret;
+ struct tegra_spi_device_controller_data *cdata = spi->controller_data;
+ unsigned long command;
+ unsigned long command2;
+
+ bits_per_word = t->bits_per_word ? t->bits_per_word :
+ spi->bits_per_word;
+ speed = t->speed_hz ? t->speed_hz : spi->max_speed_hz;
+ if (!speed)
+ speed = tspi->spi_max_frequency;
+ if (speed != tspi->cur_speed) {
+ clk_set_rate(tspi->clk, speed * 4);
+ tspi->cur_speed = speed;
+ }
+
+ tspi->cur_spi = spi;
+ tspi->cur_pos = 0;
+ tspi->cur_rx_pos = 0;
+ tspi->cur_tx_pos = 0;
+ tspi->curr_xfer = t;
+ total_fifo_words = tegra_slink_calculate_curr_xfer_param(spi, tspi, t);
+
+ if (is_first_of_msg) {
+ tegra_slink_clear_status(tspi);
+
+ command = tspi->def_command_reg;
+ command |= SLINK_BIT_LENGTH(bits_per_word - 1);
+
+ command2 = tspi->def_command2_reg;
+ command2 |= SLINK_SS_EN_CS(spi->chip_select);
+
+ /* possibly use the hw based chip select */
+ tspi->is_hw_based_cs = false;
+ if (cdata && cdata->is_hw_based_cs && is_single_xfer &&
+ ((tspi->curr_dma_words * tspi->bytes_per_word) ==
+ (t->len - tspi->cur_pos))) {
+ int setup_count;
+ int sts2;
+
+ setup_count = cdata->cs_setup_clk_count >> 1;
+ setup_count = max(setup_count, 3);
+ command2 |= SLINK_SS_SETUP(setup_count);
+ if (tspi->chip_data->cs_hold_time) {
+ int hold_count;
+
+ hold_count = cdata->cs_hold_clk_count;
+ hold_count = max(hold_count, 0xF);
+ sts2 = tegra_slink_readl(tspi, SLINK_STATUS2);
+ sts2 &= ~SLINK_SS_HOLD_TIME(0xF);
+ sts2 |= SLINK_SS_HOLD_TIME(hold_count);
+ tegra_slink_writel(tspi, sts2, SLINK_STATUS2);
+ }
+ tspi->is_hw_based_cs = true;
+ }
+
+ if (tspi->is_hw_based_cs)
+ command &= ~SLINK_CS_SW;
+ else
+ command |= SLINK_CS_SW | SLINK_CS_VALUE;
+
+ command &= ~SLINK_MODES;
+ if (spi->mode & SPI_CPHA)
+ command |= SLINK_CK_SDA;
+
+ if (spi->mode & SPI_CPOL)
+ command |= SLINK_IDLE_SCLK_DRIVE_HIGH;
+ else
+ command |= SLINK_IDLE_SCLK_DRIVE_LOW;
+ } else {
+ command = tspi->command_reg;
+ command &= ~SLINK_BIT_LENGTH(~0);
+ command |= SLINK_BIT_LENGTH(bits_per_word - 1);
+
+ command2 = tspi->command2_reg;
+ command2 &= ~(SLINK_RXEN | SLINK_TXEN);
+ }
+
+ tegra_slink_writel(tspi, command, SLINK_COMMAND);
+ tspi->command_reg = command;
+
+ tspi->cur_direction = 0;
+ if (t->rx_buf) {
+ command2 |= SLINK_RXEN;
+ tspi->cur_direction |= DATA_DIR_RX;
+ }
+ if (t->tx_buf) {
+ command2 |= SLINK_TXEN;
+ tspi->cur_direction |= DATA_DIR_TX;
+ }
+ tegra_slink_writel(tspi, command2, SLINK_COMMAND2);
+ tspi->command2_reg = command2;
+
+ if (total_fifo_words > SLINK_FIFO_DEPTH)
+ ret = tegra_slink_start_dma_based_transfer(tspi, t);
+ else
+ ret = tegra_slink_start_cpu_based_transfer(tspi, t);
+ return ret;
+}
+
+static int tegra_slink_setup(struct spi_device *spi)
+{
+ struct tegra_slink_data *tspi = spi_master_get_devdata(spi->master);
+ unsigned long val;
+ unsigned long flags;
+ int ret;
+ unsigned int cs_pol_bit[MAX_CHIP_SELECT] = {
+ SLINK_CS_POLARITY,
+ SLINK_CS_POLARITY1,
+ SLINK_CS_POLARITY2,
+ SLINK_CS_POLARITY3,
+ };
+
+ dev_dbg(&spi->dev, "setup %d bpw, %scpol, %scpha, %dHz\n",
+ spi->bits_per_word,
+ spi->mode & SPI_CPOL ? "" : "~",
+ spi->mode & SPI_CPHA ? "" : "~",
+ spi->max_speed_hz);
+
+ BUG_ON(spi->chip_select >= MAX_CHIP_SELECT);
+
+ ret = pm_runtime_get_sync(tspi->dev);
+ if (ret < 0) {
+ dev_err(tspi->dev, "pm runtime failed, e = %d\n", ret);
+ return ret;
+ }
+
+ spin_lock_irqsave(&tspi->lock, flags);
+ val = tspi->def_command_reg;
+ if (spi->mode & SPI_CS_HIGH)
+ val |= cs_pol_bit[spi->chip_select];
+ else
+ val &= ~cs_pol_bit[spi->chip_select];
+ tspi->def_command_reg = val;
+ tegra_slink_writel(tspi, tspi->def_command_reg, SLINK_COMMAND);
+ spin_unlock_irqrestore(&tspi->lock, flags);
+
+ pm_runtime_put(tspi->dev);
+ return 0;
+}
+
+static int tegra_slink_prepare_transfer(struct spi_master *master)
+{
+ struct tegra_slink_data *tspi = spi_master_get_devdata(master);
+
+ return pm_runtime_get_sync(tspi->dev);
+}
+
+static int tegra_slink_unprepare_transfer(struct spi_master *master)
+{
+ struct tegra_slink_data *tspi = spi_master_get_devdata(master);
+
+ pm_runtime_put(tspi->dev);
+ return 0;
+}
+
+static int tegra_slink_transfer_one_message(struct spi_master *master,
+ struct spi_message *msg)
+{
+ bool is_first_msg = true;
+ int single_xfer;
+ struct tegra_slink_data *tspi = spi_master_get_devdata(master);
+ struct spi_transfer *xfer;
+ struct spi_device *spi = msg->spi;
+ int ret;
+
+ msg->status = 0;
+ msg->actual_length = 0;
+ single_xfer = list_is_singular(&msg->transfers);
+ list_for_each_entry(xfer, &msg->transfers, transfer_list) {
+ INIT_COMPLETION(tspi->xfer_completion);
+ ret = tegra_slink_start_transfer_one(spi, xfer,
+ is_first_msg, single_xfer);
+ if (ret < 0) {
+ dev_err(tspi->dev,
+ "spi can not start transfer, err %d\n", ret);
+ goto exit;
+ }
+ is_first_msg = false;
+ ret = wait_for_completion_timeout(&tspi->xfer_completion,
+ SLINK_DMA_TIMEOUT);
+ if (WARN_ON(ret == 0)) {
+ dev_err(tspi->dev,
+ "spi trasfer timeout, err %d\n", ret);
+ ret = -EIO;
+ goto exit;
+ }
+
+ if (tspi->tx_status || tspi->rx_status) {
+ dev_err(tspi->dev, "Error in Transfer\n");
+ ret = -EIO;
+ goto exit;
+ }
+ msg->actual_length += xfer->len;
+ if (xfer->cs_change && xfer->delay_usecs) {
+ tegra_slink_writel(tspi, tspi->def_command_reg,
+ SLINK_COMMAND);
+ udelay(xfer->delay_usecs);
+ }
+ }
+ ret = 0;
+exit:
+ tegra_slink_writel(tspi, tspi->def_command_reg, SLINK_COMMAND);
+ tegra_slink_writel(tspi, tspi->def_command2_reg, SLINK_COMMAND2);
+ msg->status = ret;
+ spi_finalize_current_message(master);
+ return ret;
+}
+
+static irqreturn_t handle_cpu_based_xfer(struct tegra_slink_data *tspi)
+{
+ struct spi_transfer *t = tspi->curr_xfer;
+ unsigned long flags;
+
+ spin_lock_irqsave(&tspi->lock, flags);
+ if (tspi->tx_status || tspi->rx_status ||
+ (tspi->status_reg & SLINK_BSY)) {
+ dev_err(tspi->dev,
+ "CpuXfer ERROR bit set 0x%x\n", tspi->status_reg);
+ dev_err(tspi->dev,
+ "CpuXfer 0x%08x:0x%08x:0x%08x\n", tspi->command_reg,
+ tspi->command2_reg, tspi->dma_control_reg);
+ tegra_periph_reset_assert(tspi->clk);
+ udelay(2);
+ tegra_periph_reset_deassert(tspi->clk);
+ complete(&tspi->xfer_completion);
+ goto exit;
+ }
+
+ if (tspi->cur_direction & DATA_DIR_RX)
+ tegra_slink_read_rx_fifo_to_client_rxbuf(tspi, t);
+
+ if (tspi->cur_direction & DATA_DIR_TX)
+ tspi->cur_pos = tspi->cur_tx_pos;
+ else
+ tspi->cur_pos = tspi->cur_rx_pos;
+
+ if (tspi->cur_pos == t->len) {
+ complete(&tspi->xfer_completion);
+ goto exit;
+ }
+
+ tegra_slink_calculate_curr_xfer_param(tspi->cur_spi, tspi, t);
+ tegra_slink_start_cpu_based_transfer(tspi, t);
+exit:
+ spin_unlock_irqrestore(&tspi->lock, flags);
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t handle_dma_based_xfer(struct tegra_slink_data *tspi)
+{
+ struct spi_transfer *t = tspi->curr_xfer;
+ long wait_status;
+ int err = 0;
+ unsigned total_fifo_words;
+ unsigned long flags;
+
+ /* Abort dmas if any error */
+ if (tspi->cur_direction & DATA_DIR_TX) {
+ if (tspi->tx_status) {
+ dmaengine_terminate_all(tspi->tx_dma_chan);
+ err += 1;
+ } else {
+ wait_status = wait_for_completion_interruptible_timeout(
+ &tspi->tx_dma_complete, SLINK_DMA_TIMEOUT);
+ if (wait_status <= 0) {
+ dmaengine_terminate_all(tspi->tx_dma_chan);
+ dev_err(tspi->dev, "TxDma Xfer failed\n");
+ err += 1;
+ }
+ }
+ }
+
+ if (tspi->cur_direction & DATA_DIR_RX) {
+ if (tspi->rx_status) {
+ dmaengine_terminate_all(tspi->rx_dma_chan);
+ err += 2;
+ } else {
+ wait_status = wait_for_completion_interruptible_timeout(
+ &tspi->rx_dma_complete, SLINK_DMA_TIMEOUT);
+ if (wait_status <= 0) {
+ dmaengine_terminate_all(tspi->rx_dma_chan);
+ dev_err(tspi->dev, "RxDma Xfer failed\n");
+ err += 2;
+ }
+ }
+ }
+
+ spin_lock_irqsave(&tspi->lock, flags);
+ if (err) {
+ dev_err(tspi->dev,
+ "DmaXfer: ERROR bit set 0x%x\n", tspi->status_reg);
+ dev_err(tspi->dev,
+ "DmaXfer 0x%08x:0x%08x:0x%08x\n", tspi->command_reg,
+ tspi->command2_reg, tspi->dma_control_reg);
+ tegra_periph_reset_assert(tspi->clk);
+ udelay(2);
+ tegra_periph_reset_deassert(tspi->clk);
+ complete(&tspi->xfer_completion);
+ spin_unlock_irqrestore(&tspi->lock, flags);
+ return IRQ_HANDLED;
+ }
+
+ if (tspi->cur_direction & DATA_DIR_RX)
+ tegra_slink_copy_spi_rxbuf_to_client_rxbuf(tspi, t);
+
+ if (tspi->cur_direction & DATA_DIR_TX)
+ tspi->cur_pos = tspi->cur_tx_pos;
+ else
+ tspi->cur_pos = tspi->cur_rx_pos;
+
+ if (tspi->cur_pos == t->len) {
+ complete(&tspi->xfer_completion);
+ goto exit;
+ }
+
+ /* Continue transfer in current message */
+ total_fifo_words = tegra_slink_calculate_curr_xfer_param(tspi->cur_spi,
+ tspi, t);
+ if (total_fifo_words > SLINK_FIFO_DEPTH)
+ err = tegra_slink_start_dma_based_transfer(tspi, t);
+ else
+ err = tegra_slink_start_cpu_based_transfer(tspi, t);
+
+exit:
+ spin_unlock_irqrestore(&tspi->lock, flags);
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t tegra_slink_isr_thread(int irq, void *context_data)
+{
+ struct tegra_slink_data *tspi = context_data;
+
+ if (!tspi->is_curr_dma_xfer)
+ return handle_cpu_based_xfer(tspi);
+ return handle_dma_based_xfer(tspi);
+}
+
+static irqreturn_t tegra_slink_isr(int irq, void *context_data)
+{
+ struct tegra_slink_data *tspi = context_data;
+
+ tspi->status_reg = tegra_slink_readl(tspi, SLINK_STATUS);
+ if (tspi->cur_direction & DATA_DIR_TX)
+ tspi->tx_status = tspi->status_reg &
+ (SLINK_TX_OVF | SLINK_TX_UNF);
+
+ if (tspi->cur_direction & DATA_DIR_RX)
+ tspi->rx_status = tspi->status_reg &
+ (SLINK_RX_OVF | SLINK_RX_UNF);
+ tegra_slink_clear_status(tspi);
+
+ return IRQ_WAKE_THREAD;
+}
+
+static struct tegra_spi_platform_data *tegra_slink_parse_dt(
+ struct platform_device *pdev)
+{
+ struct tegra_spi_platform_data *pdata;
+ const unsigned int *prop;
+ struct device_node *np = pdev->dev.of_node;
+ u32 of_dma[2];
+
+ pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+ if (!pdata) {
+ dev_err(&pdev->dev, "Memory alloc for pdata failed\n");
+ return NULL;
+ }
+
+ if (of_property_read_u32_array(np, "nvidia,dma-request-selector",
+ of_dma, 2) >= 0)
+ pdata->dma_req_sel = of_dma[1];
+
+ prop = of_get_property(np, "spi-max-frequency", NULL);
+ if (prop)
+ pdata->spi_max_frequency = be32_to_cpup(prop);
+
+ return pdata;
+}
+
+const struct tegra_slink_chip_data tegra30_spi_cdata = {
+ .cs_hold_time = true,
+};
+
+const struct tegra_slink_chip_data tegra20_spi_cdata = {
+ .cs_hold_time = false,
+};
+
+static struct of_device_id tegra_slink_of_match[] __devinitconst = {
+ { .compatible = "nvidia,tegra20-slink", .data = &tegra20_spi_cdata, },
+ { .compatible = "nvidia,tegra30-slink", .data = &tegra30_spi_cdata, },
+ {}
+};
+MODULE_DEVICE_TABLE(of, tegra_slink_of_match);
+
+static int __devinit tegra_slink_probe(struct platform_device *pdev)
+{
+ struct spi_master *master;
+ struct tegra_slink_data *tspi;
+ struct resource *r;
+ struct tegra_spi_platform_data *pdata = pdev->dev.platform_data;
+ int ret, spi_irq;
+ const struct tegra_slink_chip_data *cdata = NULL;
+ const struct of_device_id *match;
+
+ match = of_match_device(of_match_ptr(tegra_slink_of_match), &pdev->dev);
+ if (!match) {
+ dev_err(&pdev->dev, "Error: No device match found\n");
+ return -ENODEV;
+ }
+ cdata = match->data;
+ if (!pdata && pdev->dev.of_node)
+ pdata = tegra_slink_parse_dt(pdev);
+
+ if (!pdata) {
+ dev_err(&pdev->dev, "No platform data, exiting\n");
+ return -ENODEV;
+ }
+
+ if (!pdata->spi_max_frequency)
+ pdata->spi_max_frequency = 25000000; /* 25MHz */
+
+ master = spi_alloc_master(&pdev->dev, sizeof(*tspi));
+ if (!master) {
+ dev_err(&pdev->dev, "master allocation failed\n");
+ return -ENOMEM;
+ }
+
+ /* the spi->mode bits understood by this driver: */
+ master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
+ master->setup = tegra_slink_setup;
+ master->prepare_transfer_hardware = tegra_slink_prepare_transfer;
+ master->transfer_one_message = tegra_slink_transfer_one_message;
+ master->unprepare_transfer_hardware = tegra_slink_unprepare_transfer;
+ master->num_chipselect = MAX_CHIP_SELECT;
+ master->bus_num = -1;
+
+ dev_set_drvdata(&pdev->dev, master);
+ tspi = spi_master_get_devdata(master);
+ tspi->master = master;
+ tspi->dma_req_sel = pdata->dma_req_sel;
+ tspi->dev = &pdev->dev;
+ tspi->chip_data = cdata;
+ spin_lock_init(&tspi->lock);
+
+ r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!r) {
+ dev_err(&pdev->dev, "No IO memory resource\n");
+ ret = -ENODEV;
+ goto exit_free_master;
+ }
+ tspi->phys = r->start;
+ tspi->base = devm_request_and_ioremap(&pdev->dev, r);
+ if (!tspi->base) {
+ dev_err(&pdev->dev,
+ "Cannot request memregion/iomap dma address\n");
+ ret = -EADDRNOTAVAIL;
+ goto exit_free_master;
+ }
+
+ spi_irq = platform_get_irq(pdev, 0);
+ tspi->irq = spi_irq;
+ ret = request_threaded_irq(tspi->irq, tegra_slink_isr,
+ tegra_slink_isr_thread, IRQF_ONESHOT,
+ dev_name(&pdev->dev), tspi);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "Failed to register ISR for IRQ %d\n",
+ tspi->irq);
+ goto exit_free_master;
+ }
+
+ tspi->clk = devm_clk_get(&pdev->dev, "slink");
+ if (IS_ERR(tspi->clk)) {
+ dev_err(&pdev->dev, "can not get clock\n");
+ ret = PTR_ERR(tspi->clk);
+ goto exit_free_irq;
+ }
+
+ tspi->max_buf_size = SLINK_FIFO_DEPTH << 2;
+ tspi->dma_buf_size = DEFAULT_SPI_DMA_BUF_LEN;
+ tspi->spi_max_frequency = pdata->spi_max_frequency;
+
+ if (pdata->dma_req_sel) {
+ ret = tegra_slink_init_dma_param(tspi, true);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "RxDma Init failed, err %d\n", ret);
+ goto exit_free_irq;
+ }
+
+ ret = tegra_slink_init_dma_param(tspi, false);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "TxDma Init failed, err %d\n", ret);
+ goto exit_rx_dma_free;
+ }
+ tspi->max_buf_size = tspi->dma_buf_size;
+ init_completion(&tspi->tx_dma_complete);
+ init_completion(&tspi->rx_dma_complete);
+ }
+
+ init_completion(&tspi->xfer_completion);
+
+ pm_runtime_enable(&pdev->dev);
+ if (!pm_runtime_enabled(&pdev->dev)) {
+ ret = tegra_slink_runtime_resume(&pdev->dev);
+ if (ret)
+ goto exit_pm_disable;
+ }
+
+ ret = pm_runtime_get_sync(&pdev->dev);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "pm runtime get failed, e = %d\n", ret);
+ goto exit_pm_disable;
+ }
+ tspi->def_command_reg = SLINK_M_S;
+ tspi->def_command2_reg = SLINK_CS_ACTIVE_BETWEEN;
+ tegra_slink_writel(tspi, tspi->def_command_reg, SLINK_COMMAND);
+ tegra_slink_writel(tspi, tspi->def_command2_reg, SLINK_COMMAND2);
+ pm_runtime_put(&pdev->dev);
+
+ master->dev.of_node = pdev->dev.of_node;
+ ret = spi_register_master(master);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "can not register to master err %d\n", ret);
+ goto exit_pm_disable;
+ }
+ return ret;
+
+exit_pm_disable:
+ pm_runtime_disable(&pdev->dev);
+ if (!pm_runtime_status_suspended(&pdev->dev))
+ tegra_slink_runtime_suspend(&pdev->dev);
+ tegra_slink_deinit_dma_param(tspi, false);
+exit_rx_dma_free:
+ tegra_slink_deinit_dma_param(tspi, true);
+exit_free_irq:
+ free_irq(spi_irq, tspi);
+exit_free_master:
+ spi_master_put(master);
+ return ret;
+}
+
+static int __devexit tegra_slink_remove(struct platform_device *pdev)
+{
+ struct spi_master *master = dev_get_drvdata(&pdev->dev);
+ struct tegra_slink_data *tspi = spi_master_get_devdata(master);
+
+ free_irq(tspi->irq, tspi);
+ spi_unregister_master(master);
+
+ if (tspi->tx_dma_chan)
+ tegra_slink_deinit_dma_param(tspi, false);
+
+ if (tspi->rx_dma_chan)
+ tegra_slink_deinit_dma_param(tspi, true);
+
+ pm_runtime_disable(&pdev->dev);
+ if (!pm_runtime_status_suspended(&pdev->dev))
+ tegra_slink_runtime_suspend(&pdev->dev);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int tegra_slink_suspend(struct device *dev)
+{
+ struct spi_master *master = dev_get_drvdata(dev);
+
+ return spi_master_suspend(master);
+}
+
+static int tegra_slink_resume(struct device *dev)
+{
+ struct spi_master *master = dev_get_drvdata(dev);
+ struct tegra_slink_data *tspi = spi_master_get_devdata(master);
+ int ret;
+
+ ret = pm_runtime_get_sync(dev);
+ if (ret < 0) {
+ dev_err(dev, "pm runtime failed, e = %d\n", ret);
+ return ret;
+ }
+ tegra_slink_writel(tspi, tspi->command_reg, SLINK_COMMAND);
+ tegra_slink_writel(tspi, tspi->command2_reg, SLINK_COMMAND2);
+ pm_runtime_put(dev);
+
+ return spi_master_resume(master);
+}
+#endif
+
+static int tegra_slink_runtime_suspend(struct device *dev)
+{
+ struct spi_master *master = dev_get_drvdata(dev);
+ struct tegra_slink_data *tspi = spi_master_get_devdata(master);
+
+ /* Flush all write which are in PPSB queue by reading back */
+ tegra_slink_readl(tspi, SLINK_MAS_DATA);
+
+ clk_disable_unprepare(tspi->clk);
+ return 0;
+}
+
+static int tegra_slink_runtime_resume(struct device *dev)
+{
+ struct spi_master *master = dev_get_drvdata(dev);
+ struct tegra_slink_data *tspi = spi_master_get_devdata(master);
+ int ret;
+
+ ret = clk_prepare_enable(tspi->clk);
+ if (ret < 0) {
+ dev_err(tspi->dev, "clk_prepare failed: %d\n", ret);
+ return ret;
+ }
+ return 0;
+}
+
+static const struct dev_pm_ops slink_pm_ops = {
+ SET_RUNTIME_PM_OPS(tegra_slink_runtime_suspend,
+ tegra_slink_runtime_resume, NULL)
+ SET_SYSTEM_SLEEP_PM_OPS(tegra_slink_suspend, tegra_slink_resume)
+};
+static struct platform_driver tegra_slink_driver = {
+ .driver = {
+ .name = "spi-tegra-slink",
+ .owner = THIS_MODULE,
+ .pm = &slink_pm_ops,
+ .of_match_table = of_match_ptr(tegra_slink_of_match),
+ },
+ .probe = tegra_slink_probe,
+ .remove = __devexit_p(tegra_slink_remove),
+};
+module_platform_driver(tegra_slink_driver);
+
+MODULE_ALIAS("platform:spi-tegra-slink");
+MODULE_DESCRIPTION("NVIDIA Tegra20/Tegra30 SLINK Controller Driver");
+MODULE_AUTHOR("Laxman Dewangan <ldewangan@...dia.com>");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/spi/spi-tegra.h b/include/linux/spi/spi-tegra.h
new file mode 100644
index 0000000..786932c
--- /dev/null
+++ b/include/linux/spi/spi-tegra.h
@@ -0,0 +1,40 @@
+/*
+ * spi-tegra.h: SPI interface for Nvidia Tegra20 SLINK controller.
+ *
+ * Copyright (C) 2011 NVIDIA Corporation
+ *
+ * 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, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+#ifndef _LINUX_SPI_TEGRA_H
+#define _LINUX_SPI_TEGRA_H
+
+struct tegra_spi_platform_data {
+ int dma_req_sel;
+ unsigned int spi_max_frequency;
+};
+
+/*
+ * Controller data from device to pass some info like
+ * hw based chip select can be used or not and if yes
+ * then CS hold and setup time.
+ */
+struct tegra_spi_device_controller_data {
+ bool is_hw_based_cs;
+ int cs_setup_clk_count;
+ int cs_hold_clk_count;
+};
+
+#endif /* _LINUX_SPI_TEGRA_H */
--
1.7.1.1
--
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