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linux-next/drivers/spi/spi-imx.c

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/*
* Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved.
* Copyright (C) 2008 Juergen Beisert
*
* 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
* 51 Franklin Street, Fifth Floor
* Boston, MA 02110-1301, USA.
*/
#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/err.h>
#include <linux/gpio.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 16:04:11 +08:00
#include <linux/slab.h>
#include <linux/spi/spi.h>
#include <linux/spi/spi_bitbang.h>
#include <linux/types.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_gpio.h>
#include <linux/platform_data/dma-imx.h>
#include <linux/platform_data/spi-imx.h>
#define DRIVER_NAME "spi_imx"
#define MXC_CSPIRXDATA 0x00
#define MXC_CSPITXDATA 0x04
#define MXC_CSPICTRL 0x08
#define MXC_CSPIINT 0x0c
#define MXC_RESET 0x1c
/* generic defines to abstract from the different register layouts */
#define MXC_INT_RR (1 << 0) /* Receive data ready interrupt */
#define MXC_INT_TE (1 << 1) /* Transmit FIFO empty interrupt */
/* The maximum bytes that a sdma BD can transfer.*/
#define MAX_SDMA_BD_BYTES (1 << 15)
#define IMX_DMA_TIMEOUT (msecs_to_jiffies(3000))
struct spi_imx_config {
unsigned int speed_hz;
unsigned int bpw;
unsigned int mode;
u8 cs;
};
enum spi_imx_devtype {
IMX1_CSPI,
IMX21_CSPI,
IMX27_CSPI,
IMX31_CSPI,
IMX35_CSPI, /* CSPI on all i.mx except above */
IMX51_ECSPI, /* ECSPI on i.mx51 and later */
};
struct spi_imx_data;
struct spi_imx_devtype_data {
void (*intctrl)(struct spi_imx_data *, int);
int (*config)(struct spi_imx_data *, struct spi_imx_config *);
void (*trigger)(struct spi_imx_data *);
int (*rx_available)(struct spi_imx_data *);
void (*reset)(struct spi_imx_data *);
enum spi_imx_devtype devtype;
};
struct spi_imx_data {
struct spi_bitbang bitbang;
struct completion xfer_done;
void __iomem *base;
int irq;
struct clk *clk_per;
struct clk *clk_ipg;
unsigned long spi_clk;
unsigned int count;
void (*tx)(struct spi_imx_data *);
void (*rx)(struct spi_imx_data *);
void *rx_buf;
const void *tx_buf;
unsigned int txfifo; /* number of words pushed in tx FIFO */
/* DMA */
unsigned int dma_is_inited;
unsigned int dma_finished;
bool usedma;
u32 rx_wml;
u32 tx_wml;
u32 rxt_wml;
struct completion dma_rx_completion;
struct completion dma_tx_completion;
const struct spi_imx_devtype_data *devtype_data;
int chipselect[0];
};
static inline int is_imx27_cspi(struct spi_imx_data *d)
{
return d->devtype_data->devtype == IMX27_CSPI;
}
static inline int is_imx35_cspi(struct spi_imx_data *d)
{
return d->devtype_data->devtype == IMX35_CSPI;
}
static inline unsigned spi_imx_get_fifosize(struct spi_imx_data *d)
{
return (d->devtype_data->devtype == IMX51_ECSPI) ? 64 : 8;
}
#define MXC_SPI_BUF_RX(type) \
static void spi_imx_buf_rx_##type(struct spi_imx_data *spi_imx) \
{ \
unsigned int val = readl(spi_imx->base + MXC_CSPIRXDATA); \
\
if (spi_imx->rx_buf) { \
*(type *)spi_imx->rx_buf = val; \
spi_imx->rx_buf += sizeof(type); \
} \
}
#define MXC_SPI_BUF_TX(type) \
static void spi_imx_buf_tx_##type(struct spi_imx_data *spi_imx) \
{ \
type val = 0; \
\
if (spi_imx->tx_buf) { \
val = *(type *)spi_imx->tx_buf; \
spi_imx->tx_buf += sizeof(type); \
} \
\
spi_imx->count -= sizeof(type); \
\
writel(val, spi_imx->base + MXC_CSPITXDATA); \
}
MXC_SPI_BUF_RX(u8)
MXC_SPI_BUF_TX(u8)
MXC_SPI_BUF_RX(u16)
MXC_SPI_BUF_TX(u16)
MXC_SPI_BUF_RX(u32)
MXC_SPI_BUF_TX(u32)
/* First entry is reserved, second entry is valid only if SDHC_SPIEN is set
* (which is currently not the case in this driver)
*/
static int mxc_clkdivs[] = {0, 3, 4, 6, 8, 12, 16, 24, 32, 48, 64, 96, 128, 192,
256, 384, 512, 768, 1024};
/* MX21, MX27 */
static unsigned int spi_imx_clkdiv_1(unsigned int fin,
unsigned int fspi, unsigned int max)
{
int i;
for (i = 2; i < max; i++)
if (fspi * mxc_clkdivs[i] >= fin)
return i;
return max;
}
/* MX1, MX31, MX35, MX51 CSPI */
static unsigned int spi_imx_clkdiv_2(unsigned int fin,
unsigned int fspi)
{
int i, div = 4;
for (i = 0; i < 7; i++) {
if (fspi * div >= fin)
return i;
div <<= 1;
}
return 7;
}
static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi,
struct spi_transfer *transfer)
{
struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
if (spi_imx->dma_is_inited && (transfer->len > spi_imx->rx_wml)
&& (transfer->len > spi_imx->tx_wml))
return true;
return false;
}
#define MX51_ECSPI_CTRL 0x08
#define MX51_ECSPI_CTRL_ENABLE (1 << 0)
#define MX51_ECSPI_CTRL_XCH (1 << 2)
#define MX51_ECSPI_CTRL_SMC (1 << 3)
#define MX51_ECSPI_CTRL_MODE_MASK (0xf << 4)
#define MX51_ECSPI_CTRL_POSTDIV_OFFSET 8
#define MX51_ECSPI_CTRL_PREDIV_OFFSET 12
#define MX51_ECSPI_CTRL_CS(cs) ((cs) << 18)
#define MX51_ECSPI_CTRL_BL_OFFSET 20
#define MX51_ECSPI_CONFIG 0x0c
#define MX51_ECSPI_CONFIG_SCLKPHA(cs) (1 << ((cs) + 0))
#define MX51_ECSPI_CONFIG_SCLKPOL(cs) (1 << ((cs) + 4))
#define MX51_ECSPI_CONFIG_SBBCTRL(cs) (1 << ((cs) + 8))
#define MX51_ECSPI_CONFIG_SSBPOL(cs) (1 << ((cs) + 12))
#define MX51_ECSPI_CONFIG_SCLKCTL(cs) (1 << ((cs) + 20))
#define MX51_ECSPI_INT 0x10
#define MX51_ECSPI_INT_TEEN (1 << 0)
#define MX51_ECSPI_INT_RREN (1 << 3)
#define MX51_ECSPI_DMA 0x14
#define MX51_ECSPI_DMA_TX_WML_OFFSET 0
#define MX51_ECSPI_DMA_TX_WML_MASK 0x3F
#define MX51_ECSPI_DMA_RX_WML_OFFSET 16
#define MX51_ECSPI_DMA_RX_WML_MASK (0x3F << 16)
#define MX51_ECSPI_DMA_RXT_WML_OFFSET 24
#define MX51_ECSPI_DMA_RXT_WML_MASK (0x3F << 24)
#define MX51_ECSPI_DMA_TEDEN_OFFSET 7
#define MX51_ECSPI_DMA_RXDEN_OFFSET 23
#define MX51_ECSPI_DMA_RXTDEN_OFFSET 31
#define MX51_ECSPI_STAT 0x18
#define MX51_ECSPI_STAT_RR (1 << 3)
/* MX51 eCSPI */
spi: spi-imx: Fix out-of-order CS/SCLK operation at low speeds Problem: -------- The problem this patch addresses has the following assumptions about the SPI bus setup: - The hardware used to find this is Freescale i.MX537 @ 1200MHz - The SPI SCLK operate at very low speed, less than 200 kHz - There are two SPI devices attached to the bus - Each device uses different GPIO for chipselect - Each device requires different SCLK signal polarity The observation of the SCLK and GPIO chipselect lines with a logic analyzer shows, that the SCLK polarity change does sometimes happen after the GPIO chipselect is asserted. The SPI slave device reacts on that by counting the SCLK polarity change as a clock pulse, which disrupts the communication with the SPI slave device. Explanation: ------------ We found an interesting correlation, that the maximum delay between the write into the ECSPIx_CONFIGREG register and the change of SCLK polarity at each SCLK frequency of 10 kHz, 20 kHz, 50 kHz and 100 kHz is 100 uS, 50 uS, 20 uS and 10 uS respectively. This lead us to a theory, that at SCLK frequency of 1 Hz, the delay would be 1 S. Therefore, the time it takes for the write to ECSPIx_CONFIGREG to take effect in the hardware is up to the duration of 1 tick of the SCLK clock. During this delay period, if the SCLK frequency is too low, the execution of the spi-imx.c driver can advance so much, that the GPIO chipselect will be asserted. The GPIO chipselect is asserted almost immediatelly. Solution: --------- The solution this patch presents is simple. We calculate the resulting SCLK clock first by dividing the ECSPI block clock by both dividers that are to be programmed into the configuration register. Based on the resulting SCLK clock, we derive the delay it will take for the changes to get really applied. We are extra careful here so we delay twice as long as we should. Note that the patch does not create additional overhead at high speeds as the delay will likely be close to zero there. Signed-off-by: Marek Vasut <marex@denx.de> To: linux-spi@vger.kernel.org Cc: Fabio Estevam <fabio.estevam@freescale.com> Cc: Huang Shijie <b32955@freescale.com> Cc: Mark Brown <broonie@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Mark Brown <broonie@linaro.org>
2013-12-19 01:31:47 +08:00
static unsigned int mx51_ecspi_clkdiv(unsigned int fin, unsigned int fspi,
unsigned int *fres)
{
/*
* there are two 4-bit dividers, the pre-divider divides by
* $pre, the post-divider by 2^$post
*/
unsigned int pre, post;
if (unlikely(fspi > fin))
return 0;
post = fls(fin) - fls(fspi);
if (fin > fspi << post)
post++;
/* now we have: (fin <= fspi << post) with post being minimal */
post = max(4U, post) - 4;
if (unlikely(post > 0xf)) {
pr_err("%s: cannot set clock freq: %u (base freq: %u)\n",
__func__, fspi, fin);
return 0xff;
}
pre = DIV_ROUND_UP(fin, fspi << post) - 1;
pr_debug("%s: fin: %u, fspi: %u, post: %u, pre: %u\n",
__func__, fin, fspi, post, pre);
spi: spi-imx: Fix out-of-order CS/SCLK operation at low speeds Problem: -------- The problem this patch addresses has the following assumptions about the SPI bus setup: - The hardware used to find this is Freescale i.MX537 @ 1200MHz - The SPI SCLK operate at very low speed, less than 200 kHz - There are two SPI devices attached to the bus - Each device uses different GPIO for chipselect - Each device requires different SCLK signal polarity The observation of the SCLK and GPIO chipselect lines with a logic analyzer shows, that the SCLK polarity change does sometimes happen after the GPIO chipselect is asserted. The SPI slave device reacts on that by counting the SCLK polarity change as a clock pulse, which disrupts the communication with the SPI slave device. Explanation: ------------ We found an interesting correlation, that the maximum delay between the write into the ECSPIx_CONFIGREG register and the change of SCLK polarity at each SCLK frequency of 10 kHz, 20 kHz, 50 kHz and 100 kHz is 100 uS, 50 uS, 20 uS and 10 uS respectively. This lead us to a theory, that at SCLK frequency of 1 Hz, the delay would be 1 S. Therefore, the time it takes for the write to ECSPIx_CONFIGREG to take effect in the hardware is up to the duration of 1 tick of the SCLK clock. During this delay period, if the SCLK frequency is too low, the execution of the spi-imx.c driver can advance so much, that the GPIO chipselect will be asserted. The GPIO chipselect is asserted almost immediatelly. Solution: --------- The solution this patch presents is simple. We calculate the resulting SCLK clock first by dividing the ECSPI block clock by both dividers that are to be programmed into the configuration register. Based on the resulting SCLK clock, we derive the delay it will take for the changes to get really applied. We are extra careful here so we delay twice as long as we should. Note that the patch does not create additional overhead at high speeds as the delay will likely be close to zero there. Signed-off-by: Marek Vasut <marex@denx.de> To: linux-spi@vger.kernel.org Cc: Fabio Estevam <fabio.estevam@freescale.com> Cc: Huang Shijie <b32955@freescale.com> Cc: Mark Brown <broonie@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Mark Brown <broonie@linaro.org>
2013-12-19 01:31:47 +08:00
/* Resulting frequency for the SCLK line. */
*fres = (fin / (pre + 1)) >> post;
return (pre << MX51_ECSPI_CTRL_PREDIV_OFFSET) |
(post << MX51_ECSPI_CTRL_POSTDIV_OFFSET);
}
static void __maybe_unused mx51_ecspi_intctrl(struct spi_imx_data *spi_imx, int enable)
{
unsigned val = 0;
if (enable & MXC_INT_TE)
val |= MX51_ECSPI_INT_TEEN;
if (enable & MXC_INT_RR)
val |= MX51_ECSPI_INT_RREN;
writel(val, spi_imx->base + MX51_ECSPI_INT);
}
static void __maybe_unused mx51_ecspi_trigger(struct spi_imx_data *spi_imx)
{
u32 reg = readl(spi_imx->base + MX51_ECSPI_CTRL);
if (!spi_imx->usedma)
reg |= MX51_ECSPI_CTRL_XCH;
else if (!spi_imx->dma_finished)
reg |= MX51_ECSPI_CTRL_SMC;
else
reg &= ~MX51_ECSPI_CTRL_SMC;
writel(reg, spi_imx->base + MX51_ECSPI_CTRL);
}
static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx,
struct spi_imx_config *config)
{
u32 ctrl = MX51_ECSPI_CTRL_ENABLE, cfg = 0, dma = 0;
u32 tx_wml_cfg, rx_wml_cfg, rxt_wml_cfg;
spi: spi-imx: Fix out-of-order CS/SCLK operation at low speeds Problem: -------- The problem this patch addresses has the following assumptions about the SPI bus setup: - The hardware used to find this is Freescale i.MX537 @ 1200MHz - The SPI SCLK operate at very low speed, less than 200 kHz - There are two SPI devices attached to the bus - Each device uses different GPIO for chipselect - Each device requires different SCLK signal polarity The observation of the SCLK and GPIO chipselect lines with a logic analyzer shows, that the SCLK polarity change does sometimes happen after the GPIO chipselect is asserted. The SPI slave device reacts on that by counting the SCLK polarity change as a clock pulse, which disrupts the communication with the SPI slave device. Explanation: ------------ We found an interesting correlation, that the maximum delay between the write into the ECSPIx_CONFIGREG register and the change of SCLK polarity at each SCLK frequency of 10 kHz, 20 kHz, 50 kHz and 100 kHz is 100 uS, 50 uS, 20 uS and 10 uS respectively. This lead us to a theory, that at SCLK frequency of 1 Hz, the delay would be 1 S. Therefore, the time it takes for the write to ECSPIx_CONFIGREG to take effect in the hardware is up to the duration of 1 tick of the SCLK clock. During this delay period, if the SCLK frequency is too low, the execution of the spi-imx.c driver can advance so much, that the GPIO chipselect will be asserted. The GPIO chipselect is asserted almost immediatelly. Solution: --------- The solution this patch presents is simple. We calculate the resulting SCLK clock first by dividing the ECSPI block clock by both dividers that are to be programmed into the configuration register. Based on the resulting SCLK clock, we derive the delay it will take for the changes to get really applied. We are extra careful here so we delay twice as long as we should. Note that the patch does not create additional overhead at high speeds as the delay will likely be close to zero there. Signed-off-by: Marek Vasut <marex@denx.de> To: linux-spi@vger.kernel.org Cc: Fabio Estevam <fabio.estevam@freescale.com> Cc: Huang Shijie <b32955@freescale.com> Cc: Mark Brown <broonie@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Mark Brown <broonie@linaro.org>
2013-12-19 01:31:47 +08:00
u32 clk = config->speed_hz, delay;
/*
* The hardware seems to have a race condition when changing modes. The
* current assumption is that the selection of the channel arrives
* earlier in the hardware than the mode bits when they are written at
* the same time.
* So set master mode for all channels as we do not support slave mode.
*/
ctrl |= MX51_ECSPI_CTRL_MODE_MASK;
/* set clock speed */
spi: spi-imx: Fix out-of-order CS/SCLK operation at low speeds Problem: -------- The problem this patch addresses has the following assumptions about the SPI bus setup: - The hardware used to find this is Freescale i.MX537 @ 1200MHz - The SPI SCLK operate at very low speed, less than 200 kHz - There are two SPI devices attached to the bus - Each device uses different GPIO for chipselect - Each device requires different SCLK signal polarity The observation of the SCLK and GPIO chipselect lines with a logic analyzer shows, that the SCLK polarity change does sometimes happen after the GPIO chipselect is asserted. The SPI slave device reacts on that by counting the SCLK polarity change as a clock pulse, which disrupts the communication with the SPI slave device. Explanation: ------------ We found an interesting correlation, that the maximum delay between the write into the ECSPIx_CONFIGREG register and the change of SCLK polarity at each SCLK frequency of 10 kHz, 20 kHz, 50 kHz and 100 kHz is 100 uS, 50 uS, 20 uS and 10 uS respectively. This lead us to a theory, that at SCLK frequency of 1 Hz, the delay would be 1 S. Therefore, the time it takes for the write to ECSPIx_CONFIGREG to take effect in the hardware is up to the duration of 1 tick of the SCLK clock. During this delay period, if the SCLK frequency is too low, the execution of the spi-imx.c driver can advance so much, that the GPIO chipselect will be asserted. The GPIO chipselect is asserted almost immediatelly. Solution: --------- The solution this patch presents is simple. We calculate the resulting SCLK clock first by dividing the ECSPI block clock by both dividers that are to be programmed into the configuration register. Based on the resulting SCLK clock, we derive the delay it will take for the changes to get really applied. We are extra careful here so we delay twice as long as we should. Note that the patch does not create additional overhead at high speeds as the delay will likely be close to zero there. Signed-off-by: Marek Vasut <marex@denx.de> To: linux-spi@vger.kernel.org Cc: Fabio Estevam <fabio.estevam@freescale.com> Cc: Huang Shijie <b32955@freescale.com> Cc: Mark Brown <broonie@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Mark Brown <broonie@linaro.org>
2013-12-19 01:31:47 +08:00
ctrl |= mx51_ecspi_clkdiv(spi_imx->spi_clk, config->speed_hz, &clk);
/* set chip select to use */
ctrl |= MX51_ECSPI_CTRL_CS(config->cs);
ctrl |= (config->bpw - 1) << MX51_ECSPI_CTRL_BL_OFFSET;
cfg |= MX51_ECSPI_CONFIG_SBBCTRL(config->cs);
if (config->mode & SPI_CPHA)
cfg |= MX51_ECSPI_CONFIG_SCLKPHA(config->cs);
if (config->mode & SPI_CPOL) {
cfg |= MX51_ECSPI_CONFIG_SCLKPOL(config->cs);
cfg |= MX51_ECSPI_CONFIG_SCLKCTL(config->cs);
}
if (config->mode & SPI_CS_HIGH)
cfg |= MX51_ECSPI_CONFIG_SSBPOL(config->cs);
writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL);
writel(cfg, spi_imx->base + MX51_ECSPI_CONFIG);
spi: spi-imx: Fix out-of-order CS/SCLK operation at low speeds Problem: -------- The problem this patch addresses has the following assumptions about the SPI bus setup: - The hardware used to find this is Freescale i.MX537 @ 1200MHz - The SPI SCLK operate at very low speed, less than 200 kHz - There are two SPI devices attached to the bus - Each device uses different GPIO for chipselect - Each device requires different SCLK signal polarity The observation of the SCLK and GPIO chipselect lines with a logic analyzer shows, that the SCLK polarity change does sometimes happen after the GPIO chipselect is asserted. The SPI slave device reacts on that by counting the SCLK polarity change as a clock pulse, which disrupts the communication with the SPI slave device. Explanation: ------------ We found an interesting correlation, that the maximum delay between the write into the ECSPIx_CONFIGREG register and the change of SCLK polarity at each SCLK frequency of 10 kHz, 20 kHz, 50 kHz and 100 kHz is 100 uS, 50 uS, 20 uS and 10 uS respectively. This lead us to a theory, that at SCLK frequency of 1 Hz, the delay would be 1 S. Therefore, the time it takes for the write to ECSPIx_CONFIGREG to take effect in the hardware is up to the duration of 1 tick of the SCLK clock. During this delay period, if the SCLK frequency is too low, the execution of the spi-imx.c driver can advance so much, that the GPIO chipselect will be asserted. The GPIO chipselect is asserted almost immediatelly. Solution: --------- The solution this patch presents is simple. We calculate the resulting SCLK clock first by dividing the ECSPI block clock by both dividers that are to be programmed into the configuration register. Based on the resulting SCLK clock, we derive the delay it will take for the changes to get really applied. We are extra careful here so we delay twice as long as we should. Note that the patch does not create additional overhead at high speeds as the delay will likely be close to zero there. Signed-off-by: Marek Vasut <marex@denx.de> To: linux-spi@vger.kernel.org Cc: Fabio Estevam <fabio.estevam@freescale.com> Cc: Huang Shijie <b32955@freescale.com> Cc: Mark Brown <broonie@kernel.org> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Mark Brown <broonie@linaro.org>
2013-12-19 01:31:47 +08:00
/*
* Wait until the changes in the configuration register CONFIGREG
* propagate into the hardware. It takes exactly one tick of the
* SCLK clock, but we will wait two SCLK clock just to be sure. The
* effect of the delay it takes for the hardware to apply changes
* is noticable if the SCLK clock run very slow. In such a case, if
* the polarity of SCLK should be inverted, the GPIO ChipSelect might
* be asserted before the SCLK polarity changes, which would disrupt
* the SPI communication as the device on the other end would consider
* the change of SCLK polarity as a clock tick already.
*/
delay = (2 * 1000000) / clk;
if (likely(delay < 10)) /* SCLK is faster than 100 kHz */
udelay(delay);
else /* SCLK is _very_ slow */
usleep_range(delay, delay + 10);
/*
* Configure the DMA register: setup the watermark
* and enable DMA request.
*/
if (spi_imx->dma_is_inited) {
dma = readl(spi_imx->base + MX51_ECSPI_DMA);
spi_imx->tx_wml = spi_imx_get_fifosize(spi_imx) / 2;
spi_imx->rx_wml = spi_imx_get_fifosize(spi_imx) / 2;
spi_imx->rxt_wml = spi_imx_get_fifosize(spi_imx) / 2;
rx_wml_cfg = spi_imx->rx_wml << MX51_ECSPI_DMA_RX_WML_OFFSET;
tx_wml_cfg = spi_imx->tx_wml << MX51_ECSPI_DMA_TX_WML_OFFSET;
rxt_wml_cfg = spi_imx->rxt_wml << MX51_ECSPI_DMA_RXT_WML_OFFSET;
dma = (dma & ~MX51_ECSPI_DMA_TX_WML_MASK
& ~MX51_ECSPI_DMA_RX_WML_MASK
& ~MX51_ECSPI_DMA_RXT_WML_MASK)
| rx_wml_cfg | tx_wml_cfg | rxt_wml_cfg
|(1 << MX51_ECSPI_DMA_TEDEN_OFFSET)
|(1 << MX51_ECSPI_DMA_RXDEN_OFFSET)
|(1 << MX51_ECSPI_DMA_RXTDEN_OFFSET);
writel(dma, spi_imx->base + MX51_ECSPI_DMA);
}
return 0;
}
static int __maybe_unused mx51_ecspi_rx_available(struct spi_imx_data *spi_imx)
{
return readl(spi_imx->base + MX51_ECSPI_STAT) & MX51_ECSPI_STAT_RR;
}
static void __maybe_unused mx51_ecspi_reset(struct spi_imx_data *spi_imx)
{
/* drain receive buffer */
while (mx51_ecspi_rx_available(spi_imx))
readl(spi_imx->base + MXC_CSPIRXDATA);
}
#define MX31_INTREG_TEEN (1 << 0)
#define MX31_INTREG_RREN (1 << 3)
#define MX31_CSPICTRL_ENABLE (1 << 0)
#define MX31_CSPICTRL_MASTER (1 << 1)
#define MX31_CSPICTRL_XCH (1 << 2)
#define MX31_CSPICTRL_POL (1 << 4)
#define MX31_CSPICTRL_PHA (1 << 5)
#define MX31_CSPICTRL_SSCTL (1 << 6)
#define MX31_CSPICTRL_SSPOL (1 << 7)
#define MX31_CSPICTRL_BC_SHIFT 8
#define MX35_CSPICTRL_BL_SHIFT 20
#define MX31_CSPICTRL_CS_SHIFT 24
#define MX35_CSPICTRL_CS_SHIFT 12
#define MX31_CSPICTRL_DR_SHIFT 16
#define MX31_CSPISTATUS 0x14
#define MX31_STATUS_RR (1 << 3)
/* These functions also work for the i.MX35, but be aware that
* the i.MX35 has a slightly different register layout for bits
* we do not use here.
*/
static void __maybe_unused mx31_intctrl(struct spi_imx_data *spi_imx, int enable)
{
unsigned int val = 0;
if (enable & MXC_INT_TE)
val |= MX31_INTREG_TEEN;
if (enable & MXC_INT_RR)
val |= MX31_INTREG_RREN;
writel(val, spi_imx->base + MXC_CSPIINT);
}
static void __maybe_unused mx31_trigger(struct spi_imx_data *spi_imx)
{
unsigned int reg;
reg = readl(spi_imx->base + MXC_CSPICTRL);
reg |= MX31_CSPICTRL_XCH;
writel(reg, spi_imx->base + MXC_CSPICTRL);
}
static int __maybe_unused mx31_config(struct spi_imx_data *spi_imx,
struct spi_imx_config *config)
{
unsigned int reg = MX31_CSPICTRL_ENABLE | MX31_CSPICTRL_MASTER;
int cs = spi_imx->chipselect[config->cs];
reg |= spi_imx_clkdiv_2(spi_imx->spi_clk, config->speed_hz) <<
MX31_CSPICTRL_DR_SHIFT;
if (is_imx35_cspi(spi_imx)) {
reg |= (config->bpw - 1) << MX35_CSPICTRL_BL_SHIFT;
reg |= MX31_CSPICTRL_SSCTL;
} else {
reg |= (config->bpw - 1) << MX31_CSPICTRL_BC_SHIFT;
}
if (config->mode & SPI_CPHA)
reg |= MX31_CSPICTRL_PHA;
if (config->mode & SPI_CPOL)
reg |= MX31_CSPICTRL_POL;
if (config->mode & SPI_CS_HIGH)
reg |= MX31_CSPICTRL_SSPOL;
if (cs < 0)
reg |= (cs + 32) <<
(is_imx35_cspi(spi_imx) ? MX35_CSPICTRL_CS_SHIFT :
MX31_CSPICTRL_CS_SHIFT);
writel(reg, spi_imx->base + MXC_CSPICTRL);
return 0;
}
static int __maybe_unused mx31_rx_available(struct spi_imx_data *spi_imx)
{
return readl(spi_imx->base + MX31_CSPISTATUS) & MX31_STATUS_RR;
}
static void __maybe_unused mx31_reset(struct spi_imx_data *spi_imx)
{
/* drain receive buffer */
while (readl(spi_imx->base + MX31_CSPISTATUS) & MX31_STATUS_RR)
readl(spi_imx->base + MXC_CSPIRXDATA);
}
#define MX21_INTREG_RR (1 << 4)
#define MX21_INTREG_TEEN (1 << 9)
#define MX21_INTREG_RREN (1 << 13)
#define MX21_CSPICTRL_POL (1 << 5)
#define MX21_CSPICTRL_PHA (1 << 6)
#define MX21_CSPICTRL_SSPOL (1 << 8)
#define MX21_CSPICTRL_XCH (1 << 9)
#define MX21_CSPICTRL_ENABLE (1 << 10)
#define MX21_CSPICTRL_MASTER (1 << 11)
#define MX21_CSPICTRL_DR_SHIFT 14
#define MX21_CSPICTRL_CS_SHIFT 19
static void __maybe_unused mx21_intctrl(struct spi_imx_data *spi_imx, int enable)
{
unsigned int val = 0;
if (enable & MXC_INT_TE)
val |= MX21_INTREG_TEEN;
if (enable & MXC_INT_RR)
val |= MX21_INTREG_RREN;
writel(val, spi_imx->base + MXC_CSPIINT);
}
static void __maybe_unused mx21_trigger(struct spi_imx_data *spi_imx)
{
unsigned int reg;
reg = readl(spi_imx->base + MXC_CSPICTRL);
reg |= MX21_CSPICTRL_XCH;
writel(reg, spi_imx->base + MXC_CSPICTRL);
}
static int __maybe_unused mx21_config(struct spi_imx_data *spi_imx,
struct spi_imx_config *config)
{
unsigned int reg = MX21_CSPICTRL_ENABLE | MX21_CSPICTRL_MASTER;
int cs = spi_imx->chipselect[config->cs];
unsigned int max = is_imx27_cspi(spi_imx) ? 16 : 18;
reg |= spi_imx_clkdiv_1(spi_imx->spi_clk, config->speed_hz, max) <<
MX21_CSPICTRL_DR_SHIFT;
reg |= config->bpw - 1;
if (config->mode & SPI_CPHA)
reg |= MX21_CSPICTRL_PHA;
if (config->mode & SPI_CPOL)
reg |= MX21_CSPICTRL_POL;
if (config->mode & SPI_CS_HIGH)
reg |= MX21_CSPICTRL_SSPOL;
if (cs < 0)
reg |= (cs + 32) << MX21_CSPICTRL_CS_SHIFT;
writel(reg, spi_imx->base + MXC_CSPICTRL);
return 0;
}
static int __maybe_unused mx21_rx_available(struct spi_imx_data *spi_imx)
{
return readl(spi_imx->base + MXC_CSPIINT) & MX21_INTREG_RR;
}
static void __maybe_unused mx21_reset(struct spi_imx_data *spi_imx)
{
writel(1, spi_imx->base + MXC_RESET);
}
#define MX1_INTREG_RR (1 << 3)
#define MX1_INTREG_TEEN (1 << 8)
#define MX1_INTREG_RREN (1 << 11)
#define MX1_CSPICTRL_POL (1 << 4)
#define MX1_CSPICTRL_PHA (1 << 5)
#define MX1_CSPICTRL_XCH (1 << 8)
#define MX1_CSPICTRL_ENABLE (1 << 9)
#define MX1_CSPICTRL_MASTER (1 << 10)
#define MX1_CSPICTRL_DR_SHIFT 13
static void __maybe_unused mx1_intctrl(struct spi_imx_data *spi_imx, int enable)
{
unsigned int val = 0;
if (enable & MXC_INT_TE)
val |= MX1_INTREG_TEEN;
if (enable & MXC_INT_RR)
val |= MX1_INTREG_RREN;
writel(val, spi_imx->base + MXC_CSPIINT);
}
static void __maybe_unused mx1_trigger(struct spi_imx_data *spi_imx)
{
unsigned int reg;
reg = readl(spi_imx->base + MXC_CSPICTRL);
reg |= MX1_CSPICTRL_XCH;
writel(reg, spi_imx->base + MXC_CSPICTRL);
}
static int __maybe_unused mx1_config(struct spi_imx_data *spi_imx,
struct spi_imx_config *config)
{
unsigned int reg = MX1_CSPICTRL_ENABLE | MX1_CSPICTRL_MASTER;
reg |= spi_imx_clkdiv_2(spi_imx->spi_clk, config->speed_hz) <<
MX1_CSPICTRL_DR_SHIFT;
reg |= config->bpw - 1;
if (config->mode & SPI_CPHA)
reg |= MX1_CSPICTRL_PHA;
if (config->mode & SPI_CPOL)
reg |= MX1_CSPICTRL_POL;
writel(reg, spi_imx->base + MXC_CSPICTRL);
return 0;
}
static int __maybe_unused mx1_rx_available(struct spi_imx_data *spi_imx)
{
return readl(spi_imx->base + MXC_CSPIINT) & MX1_INTREG_RR;
}
static void __maybe_unused mx1_reset(struct spi_imx_data *spi_imx)
{
writel(1, spi_imx->base + MXC_RESET);
}
static struct spi_imx_devtype_data imx1_cspi_devtype_data = {
.intctrl = mx1_intctrl,
.config = mx1_config,
.trigger = mx1_trigger,
.rx_available = mx1_rx_available,
.reset = mx1_reset,
.devtype = IMX1_CSPI,
};
static struct spi_imx_devtype_data imx21_cspi_devtype_data = {
.intctrl = mx21_intctrl,
.config = mx21_config,
.trigger = mx21_trigger,
.rx_available = mx21_rx_available,
.reset = mx21_reset,
.devtype = IMX21_CSPI,
};
static struct spi_imx_devtype_data imx27_cspi_devtype_data = {
/* i.mx27 cspi shares the functions with i.mx21 one */
.intctrl = mx21_intctrl,
.config = mx21_config,
.trigger = mx21_trigger,
.rx_available = mx21_rx_available,
.reset = mx21_reset,
.devtype = IMX27_CSPI,
};
static struct spi_imx_devtype_data imx31_cspi_devtype_data = {
.intctrl = mx31_intctrl,
.config = mx31_config,
.trigger = mx31_trigger,
.rx_available = mx31_rx_available,
.reset = mx31_reset,
.devtype = IMX31_CSPI,
};
static struct spi_imx_devtype_data imx35_cspi_devtype_data = {
/* i.mx35 and later cspi shares the functions with i.mx31 one */
.intctrl = mx31_intctrl,
.config = mx31_config,
.trigger = mx31_trigger,
.rx_available = mx31_rx_available,
.reset = mx31_reset,
.devtype = IMX35_CSPI,
};
static struct spi_imx_devtype_data imx51_ecspi_devtype_data = {
.intctrl = mx51_ecspi_intctrl,
.config = mx51_ecspi_config,
.trigger = mx51_ecspi_trigger,
.rx_available = mx51_ecspi_rx_available,
.reset = mx51_ecspi_reset,
.devtype = IMX51_ECSPI,
};
static struct platform_device_id spi_imx_devtype[] = {
{
.name = "imx1-cspi",
.driver_data = (kernel_ulong_t) &imx1_cspi_devtype_data,
}, {
.name = "imx21-cspi",
.driver_data = (kernel_ulong_t) &imx21_cspi_devtype_data,
}, {
.name = "imx27-cspi",
.driver_data = (kernel_ulong_t) &imx27_cspi_devtype_data,
}, {
.name = "imx31-cspi",
.driver_data = (kernel_ulong_t) &imx31_cspi_devtype_data,
}, {
.name = "imx35-cspi",
.driver_data = (kernel_ulong_t) &imx35_cspi_devtype_data,
}, {
.name = "imx51-ecspi",
.driver_data = (kernel_ulong_t) &imx51_ecspi_devtype_data,
}, {
/* sentinel */
}
};
static const struct of_device_id spi_imx_dt_ids[] = {
{ .compatible = "fsl,imx1-cspi", .data = &imx1_cspi_devtype_data, },
{ .compatible = "fsl,imx21-cspi", .data = &imx21_cspi_devtype_data, },
{ .compatible = "fsl,imx27-cspi", .data = &imx27_cspi_devtype_data, },
{ .compatible = "fsl,imx31-cspi", .data = &imx31_cspi_devtype_data, },
{ .compatible = "fsl,imx35-cspi", .data = &imx35_cspi_devtype_data, },
{ .compatible = "fsl,imx51-ecspi", .data = &imx51_ecspi_devtype_data, },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, spi_imx_dt_ids);
static void spi_imx_chipselect(struct spi_device *spi, int is_active)
{
struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
int gpio = spi_imx->chipselect[spi->chip_select];
int active = is_active != BITBANG_CS_INACTIVE;
int dev_is_lowactive = !(spi->mode & SPI_CS_HIGH);
if (!gpio_is_valid(gpio))
return;
gpio_set_value(gpio, dev_is_lowactive ^ active);
}
static void spi_imx_push(struct spi_imx_data *spi_imx)
{
while (spi_imx->txfifo < spi_imx_get_fifosize(spi_imx)) {
if (!spi_imx->count)
break;
spi_imx->tx(spi_imx);
spi_imx->txfifo++;
}
spi_imx->devtype_data->trigger(spi_imx);
}
static irqreturn_t spi_imx_isr(int irq, void *dev_id)
{
struct spi_imx_data *spi_imx = dev_id;
while (spi_imx->devtype_data->rx_available(spi_imx)) {
spi_imx->rx(spi_imx);
spi_imx->txfifo--;
}
if (spi_imx->count) {
spi_imx_push(spi_imx);
return IRQ_HANDLED;
}
if (spi_imx->txfifo) {
/* No data left to push, but still waiting for rx data,
* enable receive data available interrupt.
*/
spi_imx->devtype_data->intctrl(
spi_imx, MXC_INT_RR);
return IRQ_HANDLED;
}
spi_imx->devtype_data->intctrl(spi_imx, 0);
complete(&spi_imx->xfer_done);
return IRQ_HANDLED;
}
static int spi_imx_setupxfer(struct spi_device *spi,
struct spi_transfer *t)
{
struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
struct spi_imx_config config;
config.bpw = t ? t->bits_per_word : spi->bits_per_word;
config.speed_hz = t ? t->speed_hz : spi->max_speed_hz;
config.mode = spi->mode;
config.cs = spi->chip_select;
if (!config.speed_hz)
config.speed_hz = spi->max_speed_hz;
if (!config.bpw)
config.bpw = spi->bits_per_word;
/* Initialize the functions for transfer */
if (config.bpw <= 8) {
spi_imx->rx = spi_imx_buf_rx_u8;
spi_imx->tx = spi_imx_buf_tx_u8;
} else if (config.bpw <= 16) {
spi_imx->rx = spi_imx_buf_rx_u16;
spi_imx->tx = spi_imx_buf_tx_u16;
} else {
spi_imx->rx = spi_imx_buf_rx_u32;
spi_imx->tx = spi_imx_buf_tx_u32;
}
spi_imx->devtype_data->config(spi_imx, &config);
return 0;
}
static void spi_imx_sdma_exit(struct spi_imx_data *spi_imx)
{
struct spi_master *master = spi_imx->bitbang.master;
if (master->dma_rx) {
dma_release_channel(master->dma_rx);
master->dma_rx = NULL;
}
if (master->dma_tx) {
dma_release_channel(master->dma_tx);
master->dma_tx = NULL;
}
spi_imx->dma_is_inited = 0;
}
static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx,
struct spi_master *master,
const struct resource *res)
{
struct dma_slave_config slave_config = {};
int ret;
/* use pio mode for i.mx6dl chip TKT238285 */
if (of_machine_is_compatible("fsl,imx6dl"))
return 0;
/* Prepare for TX DMA: */
master->dma_tx = dma_request_slave_channel(dev, "tx");
if (!master->dma_tx) {
dev_err(dev, "cannot get the TX DMA channel!\n");
ret = -EINVAL;
goto err;
}
slave_config.direction = DMA_MEM_TO_DEV;
slave_config.dst_addr = res->start + MXC_CSPITXDATA;
slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
slave_config.dst_maxburst = spi_imx_get_fifosize(spi_imx) / 2;
ret = dmaengine_slave_config(master->dma_tx, &slave_config);
if (ret) {
dev_err(dev, "error in TX dma configuration.\n");
goto err;
}
/* Prepare for RX : */
master->dma_rx = dma_request_slave_channel(dev, "rx");
if (!master->dma_rx) {
dev_dbg(dev, "cannot get the DMA channel.\n");
ret = -EINVAL;
goto err;
}
slave_config.direction = DMA_DEV_TO_MEM;
slave_config.src_addr = res->start + MXC_CSPIRXDATA;
slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
slave_config.src_maxburst = spi_imx_get_fifosize(spi_imx) / 2;
ret = dmaengine_slave_config(master->dma_rx, &slave_config);
if (ret) {
dev_err(dev, "error in RX dma configuration.\n");
goto err;
}
init_completion(&spi_imx->dma_rx_completion);
init_completion(&spi_imx->dma_tx_completion);
master->can_dma = spi_imx_can_dma;
master->max_dma_len = MAX_SDMA_BD_BYTES;
spi_imx->bitbang.master->flags = SPI_MASTER_MUST_RX |
SPI_MASTER_MUST_TX;
spi_imx->dma_is_inited = 1;
return 0;
err:
spi_imx_sdma_exit(spi_imx);
return ret;
}
static void spi_imx_dma_rx_callback(void *cookie)
{
struct spi_imx_data *spi_imx = (struct spi_imx_data *)cookie;
complete(&spi_imx->dma_rx_completion);
}
static void spi_imx_dma_tx_callback(void *cookie)
{
struct spi_imx_data *spi_imx = (struct spi_imx_data *)cookie;
complete(&spi_imx->dma_tx_completion);
}
static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx,
struct spi_transfer *transfer)
{
struct dma_async_tx_descriptor *desc_tx = NULL, *desc_rx = NULL;
int ret;
u32 dma;
int left;
struct spi_master *master = spi_imx->bitbang.master;
struct sg_table *tx = &transfer->tx_sg, *rx = &transfer->rx_sg;
if (tx) {
desc_tx = dmaengine_prep_slave_sg(master->dma_tx,
tx->sgl, tx->nents, DMA_TO_DEVICE,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc_tx)
goto no_dma;
desc_tx->callback = spi_imx_dma_tx_callback;
desc_tx->callback_param = (void *)spi_imx;
dmaengine_submit(desc_tx);
}
if (rx) {
desc_rx = dmaengine_prep_slave_sg(master->dma_rx,
rx->sgl, rx->nents, DMA_FROM_DEVICE,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!desc_rx)
goto no_dma;
desc_rx->callback = spi_imx_dma_rx_callback;
desc_rx->callback_param = (void *)spi_imx;
dmaengine_submit(desc_rx);
}
reinit_completion(&spi_imx->dma_rx_completion);
reinit_completion(&spi_imx->dma_tx_completion);
/* Trigger the cspi module. */
spi_imx->dma_finished = 0;
dma = readl(spi_imx->base + MX51_ECSPI_DMA);
dma = dma & (~MX51_ECSPI_DMA_RXT_WML_MASK);
/* Change RX_DMA_LENGTH trigger dma fetch tail data */
left = transfer->len % spi_imx->rxt_wml;
if (left)
writel(dma | (left << MX51_ECSPI_DMA_RXT_WML_OFFSET),
spi_imx->base + MX51_ECSPI_DMA);
spi_imx->devtype_data->trigger(spi_imx);
dma_async_issue_pending(master->dma_tx);
dma_async_issue_pending(master->dma_rx);
/* Wait SDMA to finish the data transfer.*/
ret = wait_for_completion_timeout(&spi_imx->dma_tx_completion,
IMX_DMA_TIMEOUT);
if (!ret) {
pr_warn("%s %s: I/O Error in DMA TX\n",
dev_driver_string(&master->dev),
dev_name(&master->dev));
dmaengine_terminate_all(master->dma_tx);
} else {
ret = wait_for_completion_timeout(&spi_imx->dma_rx_completion,
IMX_DMA_TIMEOUT);
if (!ret) {
pr_warn("%s %s: I/O Error in DMA RX\n",
dev_driver_string(&master->dev),
dev_name(&master->dev));
spi_imx->devtype_data->reset(spi_imx);
dmaengine_terminate_all(master->dma_rx);
}
writel(dma |
spi_imx->rxt_wml << MX51_ECSPI_DMA_RXT_WML_OFFSET,
spi_imx->base + MX51_ECSPI_DMA);
}
spi_imx->dma_finished = 1;
spi_imx->devtype_data->trigger(spi_imx);
if (!ret)
ret = -ETIMEDOUT;
else if (ret > 0)
ret = transfer->len;
return ret;
no_dma:
pr_warn_once("%s %s: DMA not available, falling back to PIO\n",
dev_driver_string(&master->dev),
dev_name(&master->dev));
return -EAGAIN;
}
static int spi_imx_pio_transfer(struct spi_device *spi,
struct spi_transfer *transfer)
{
struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
spi_imx->tx_buf = transfer->tx_buf;
spi_imx->rx_buf = transfer->rx_buf;
spi_imx->count = transfer->len;
spi_imx->txfifo = 0;
reinit_completion(&spi_imx->xfer_done);
spi_imx_push(spi_imx);
spi_imx->devtype_data->intctrl(spi_imx, MXC_INT_TE);
wait_for_completion(&spi_imx->xfer_done);
return transfer->len;
}
static int spi_imx_transfer(struct spi_device *spi,
struct spi_transfer *transfer)
{
int ret;
struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
if (spi_imx->bitbang.master->can_dma &&
spi_imx_can_dma(spi_imx->bitbang.master, spi, transfer)) {
spi_imx->usedma = true;
ret = spi_imx_dma_transfer(spi_imx, transfer);
if (ret != -EAGAIN)
return ret;
}
spi_imx->usedma = false;
return spi_imx_pio_transfer(spi, transfer);
}
static int spi_imx_setup(struct spi_device *spi)
{
struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master);
int gpio = spi_imx->chipselect[spi->chip_select];
dev_dbg(&spi->dev, "%s: mode %d, %u bpw, %d hz\n", __func__,
spi->mode, spi->bits_per_word, spi->max_speed_hz);
if (gpio_is_valid(gpio))
gpio_direction_output(gpio, spi->mode & SPI_CS_HIGH ? 0 : 1);
spi_imx_chipselect(spi, BITBANG_CS_INACTIVE);
return 0;
}
static void spi_imx_cleanup(struct spi_device *spi)
{
}
static int
spi_imx_prepare_message(struct spi_master *master, struct spi_message *msg)
{
struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
int ret;
ret = clk_enable(spi_imx->clk_per);
if (ret)
return ret;
ret = clk_enable(spi_imx->clk_ipg);
if (ret) {
clk_disable(spi_imx->clk_per);
return ret;
}
return 0;
}
static int
spi_imx_unprepare_message(struct spi_master *master, struct spi_message *msg)
{
struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
clk_disable(spi_imx->clk_ipg);
clk_disable(spi_imx->clk_per);
return 0;
}
static int spi_imx_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
const struct of_device_id *of_id =
of_match_device(spi_imx_dt_ids, &pdev->dev);
struct spi_imx_master *mxc_platform_info =
dev_get_platdata(&pdev->dev);
struct spi_master *master;
struct spi_imx_data *spi_imx;
struct resource *res;
int i, ret, num_cs;
if (!np && !mxc_platform_info) {
dev_err(&pdev->dev, "can't get the platform data\n");
return -EINVAL;
}
ret = of_property_read_u32(np, "fsl,spi-num-chipselects", &num_cs);
if (ret < 0) {
if (mxc_platform_info)
num_cs = mxc_platform_info->num_chipselect;
else
return ret;
}
master = spi_alloc_master(&pdev->dev,
sizeof(struct spi_imx_data) + sizeof(int) * num_cs);
if (!master)
return -ENOMEM;
platform_set_drvdata(pdev, master);
master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32);
master->bus_num = pdev->id;
master->num_chipselect = num_cs;
spi_imx = spi_master_get_devdata(master);
spi_imx->bitbang.master = master;
for (i = 0; i < master->num_chipselect; i++) {
int cs_gpio = of_get_named_gpio(np, "cs-gpios", i);
if (!gpio_is_valid(cs_gpio) && mxc_platform_info)
cs_gpio = mxc_platform_info->chipselect[i];
spi/imx: Fix spi-imx when the hardware SPI chipselects are used commit 22a85e4cd51 (spi/imx: add device tree probe support) broke spi-imx usage when the SPI chipselect is the one internal to the controller. On a mx31pdk board the following error is seen: Registering mxc_nand as whole device ------------[ cut here ]------------ WARNING: at drivers/gpio/gpiolib.c:101 gpio_ensure_requested+0x4c/0xf4() autorequest GPIO-0 Modules linked in: [<c0014410>] (unwind_backtrace+0x0/0xf4) from [<c0025754>] (warn_slowpath_common+0x4c/0x64) [<c0025754>] (warn_slowpath_common+0x4c/0x64) from [<c0025800>] (warn_slowpath_fmt+0x30/0x40) [<c0025800>] (warn_slowpath_fmt+0x30/0x40) from [<c0198688>] (gpio_ensure_requested+0x4c/0xf4) [<c0198688>] (gpio_ensure_requested+0x4c/0xf4) from [<c01988c8>] (gpio_direction_output+0xa0/0x138) [<c01988c8>] (gpio_direction_output+0xa0/0x138) from [<c01ed198>] (spi_imx_setup+0x38/0x4c) [<c01ed198>] (spi_imx_setup+0x38/0x4c) from [<c01eb5d0>] (spi_setup+0x38/0x50) [<c01eb5d0>] (spi_setup+0x38/0x50) from [<c01eb85c>] (spi_add_device+0x94/0x124) [<c01eb85c>] (spi_add_device+0x94/0x124) from [<c01eb960>] (spi_new_device+0x74/0xac) [<c01eb960>] (spi_new_device+0x74/0xac) from [<c01eb9b8>] (spi_match_master_to_boardinfo+0x20/0x40) [<c01eb9b8>] (spi_match_master_to_boardinfo+0x20/0x40) from [<c01eba88>] (spi_register_master+0xb0/0x104) [<c01eba88>] (spi_register_master+0xb0/0x104) from [<c01ec0b4>] (spi_bitbang_start+0x104/0x17c) [<c01ec0b4>] (spi_bitbang_start+0x104/0x17c) from [<c02c2c4c>] (spi_imx_probe+0x2fc/0x404) [<c02c2c4c>] (spi_imx_probe+0x2fc/0x404) from [<c01c2498>] (platform_drv_probe+0x18/0x1c) [<c01c2498>] (platform_drv_probe+0x18/0x1c) from [<c01c1058>] (driver_probe_device+0x78/0x174) [<c01c1058>] (driver_probe_device+0x78/0x174) from [<c01c11e0>] (__driver_attach+0x8c/0x90) [<c01c11e0>] (__driver_attach+0x8c/0x90) from [<c01c0860>] (bus_for_each_dev+0x60/0x8c) [<c01c0860>] (bus_for_each_dev+0x60/0x8c) from [<c01c0088>] (bus_add_driver+0xa0/0x288) [<c01c0088>] (bus_add_driver+0xa0/0x288) from [<c01c179c>] (driver_register+0x78/0x18c) [<c01c179c>] (driver_register+0x78/0x18c) from [<c0008490>] (do_one_initcall+0x34/0x178) [<c0008490>] (do_one_initcall+0x34/0x178) from [<c03a5204>] (kernel_init+0x74/0x118) [<c03a5204>] (kernel_init+0x74/0x118) from [<c000f65c>] (kernel_thread_exit+0x0/0x8) ---[ end trace 759f924b30fd5a44 ]--- Fix this issue by using the original chip select logic and make spi-imx to work again. Tested on a mx31pdk that uses the hardware SPI chipselect pins and also on a mx27pdk that uses GPIO as SPI chipselect. Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-09-16 04:21:15 +08:00
spi_imx->chipselect[i] = cs_gpio;
if (!gpio_is_valid(cs_gpio))
continue;
spi/imx: Fix spi-imx when the hardware SPI chipselects are used commit 22a85e4cd51 (spi/imx: add device tree probe support) broke spi-imx usage when the SPI chipselect is the one internal to the controller. On a mx31pdk board the following error is seen: Registering mxc_nand as whole device ------------[ cut here ]------------ WARNING: at drivers/gpio/gpiolib.c:101 gpio_ensure_requested+0x4c/0xf4() autorequest GPIO-0 Modules linked in: [<c0014410>] (unwind_backtrace+0x0/0xf4) from [<c0025754>] (warn_slowpath_common+0x4c/0x64) [<c0025754>] (warn_slowpath_common+0x4c/0x64) from [<c0025800>] (warn_slowpath_fmt+0x30/0x40) [<c0025800>] (warn_slowpath_fmt+0x30/0x40) from [<c0198688>] (gpio_ensure_requested+0x4c/0xf4) [<c0198688>] (gpio_ensure_requested+0x4c/0xf4) from [<c01988c8>] (gpio_direction_output+0xa0/0x138) [<c01988c8>] (gpio_direction_output+0xa0/0x138) from [<c01ed198>] (spi_imx_setup+0x38/0x4c) [<c01ed198>] (spi_imx_setup+0x38/0x4c) from [<c01eb5d0>] (spi_setup+0x38/0x50) [<c01eb5d0>] (spi_setup+0x38/0x50) from [<c01eb85c>] (spi_add_device+0x94/0x124) [<c01eb85c>] (spi_add_device+0x94/0x124) from [<c01eb960>] (spi_new_device+0x74/0xac) [<c01eb960>] (spi_new_device+0x74/0xac) from [<c01eb9b8>] (spi_match_master_to_boardinfo+0x20/0x40) [<c01eb9b8>] (spi_match_master_to_boardinfo+0x20/0x40) from [<c01eba88>] (spi_register_master+0xb0/0x104) [<c01eba88>] (spi_register_master+0xb0/0x104) from [<c01ec0b4>] (spi_bitbang_start+0x104/0x17c) [<c01ec0b4>] (spi_bitbang_start+0x104/0x17c) from [<c02c2c4c>] (spi_imx_probe+0x2fc/0x404) [<c02c2c4c>] (spi_imx_probe+0x2fc/0x404) from [<c01c2498>] (platform_drv_probe+0x18/0x1c) [<c01c2498>] (platform_drv_probe+0x18/0x1c) from [<c01c1058>] (driver_probe_device+0x78/0x174) [<c01c1058>] (driver_probe_device+0x78/0x174) from [<c01c11e0>] (__driver_attach+0x8c/0x90) [<c01c11e0>] (__driver_attach+0x8c/0x90) from [<c01c0860>] (bus_for_each_dev+0x60/0x8c) [<c01c0860>] (bus_for_each_dev+0x60/0x8c) from [<c01c0088>] (bus_add_driver+0xa0/0x288) [<c01c0088>] (bus_add_driver+0xa0/0x288) from [<c01c179c>] (driver_register+0x78/0x18c) [<c01c179c>] (driver_register+0x78/0x18c) from [<c0008490>] (do_one_initcall+0x34/0x178) [<c0008490>] (do_one_initcall+0x34/0x178) from [<c03a5204>] (kernel_init+0x74/0x118) [<c03a5204>] (kernel_init+0x74/0x118) from [<c000f65c>] (kernel_thread_exit+0x0/0x8) ---[ end trace 759f924b30fd5a44 ]--- Fix this issue by using the original chip select logic and make spi-imx to work again. Tested on a mx31pdk that uses the hardware SPI chipselect pins and also on a mx27pdk that uses GPIO as SPI chipselect. Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com> Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2011-09-16 04:21:15 +08:00
ret = devm_gpio_request(&pdev->dev, spi_imx->chipselect[i],
DRIVER_NAME);
if (ret) {
dev_err(&pdev->dev, "can't get cs gpios\n");
goto out_master_put;
}
}
spi_imx->bitbang.chipselect = spi_imx_chipselect;
spi_imx->bitbang.setup_transfer = spi_imx_setupxfer;
spi_imx->bitbang.txrx_bufs = spi_imx_transfer;
spi_imx->bitbang.master->setup = spi_imx_setup;
spi_imx->bitbang.master->cleanup = spi_imx_cleanup;
spi_imx->bitbang.master->prepare_message = spi_imx_prepare_message;
spi_imx->bitbang.master->unprepare_message = spi_imx_unprepare_message;
spi_imx->bitbang.master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH;
init_completion(&spi_imx->xfer_done);
spi_imx->devtype_data = of_id ? of_id->data :
(struct spi_imx_devtype_data *) pdev->id_entry->driver_data;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
spi_imx->base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(spi_imx->base)) {
ret = PTR_ERR(spi_imx->base);
goto out_master_put;
}
spi_imx->irq = platform_get_irq(pdev, 0);
if (spi_imx->irq < 0) {
ret = spi_imx->irq;
goto out_master_put;
}
ret = devm_request_irq(&pdev->dev, spi_imx->irq, spi_imx_isr, 0,
dev_name(&pdev->dev), spi_imx);
if (ret) {
dev_err(&pdev->dev, "can't get irq%d: %d\n", spi_imx->irq, ret);
goto out_master_put;
}
spi_imx->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
if (IS_ERR(spi_imx->clk_ipg)) {
ret = PTR_ERR(spi_imx->clk_ipg);
goto out_master_put;
}
spi_imx->clk_per = devm_clk_get(&pdev->dev, "per");
if (IS_ERR(spi_imx->clk_per)) {
ret = PTR_ERR(spi_imx->clk_per);
goto out_master_put;
}
ret = clk_prepare_enable(spi_imx->clk_per);
if (ret)
goto out_master_put;
ret = clk_prepare_enable(spi_imx->clk_ipg);
if (ret)
goto out_put_per;
spi_imx->spi_clk = clk_get_rate(spi_imx->clk_per);
/*
* Only validated on i.mx6 now, can remove the constrain if validated on
* other chips.
*/
if (spi_imx->devtype_data == &imx51_ecspi_devtype_data
&& spi_imx_sdma_init(&pdev->dev, spi_imx, master, res))
dev_err(&pdev->dev, "dma setup error,use pio instead\n");
spi_imx->devtype_data->reset(spi_imx);
spi_imx->devtype_data->intctrl(spi_imx, 0);
master->dev.of_node = pdev->dev.of_node;
ret = spi_bitbang_start(&spi_imx->bitbang);
if (ret) {
dev_err(&pdev->dev, "bitbang start failed with %d\n", ret);
goto out_clk_put;
}
dev_info(&pdev->dev, "probed\n");
clk_disable(spi_imx->clk_ipg);
clk_disable(spi_imx->clk_per);
return ret;
out_clk_put:
clk_disable_unprepare(spi_imx->clk_ipg);
out_put_per:
clk_disable_unprepare(spi_imx->clk_per);
out_master_put:
spi_master_put(master);
return ret;
}
static int spi_imx_remove(struct platform_device *pdev)
{
struct spi_master *master = platform_get_drvdata(pdev);
struct spi_imx_data *spi_imx = spi_master_get_devdata(master);
spi_bitbang_stop(&spi_imx->bitbang);
writel(0, spi_imx->base + MXC_CSPICTRL);
spi: spi-imx: spi_imx_remove: do not disable disabled clocks Currently, at module removal, one gets the following warnings: ------------[ cut here ]------------ WARNING: at drivers/clk/clk.c:780 clk_disable+0x18/0x24() Modules linked in: spi_imx(-) [last unloaded: ev76c560] CPU: 1 PID: 16337 Comm: rmmod Tainted: G W 3.10.17-80548-g90191eb-dirty #33 [<80013b4c>] (unwind_backtrace+0x0/0xf8) from [<800115dc>] (show_stack+0x10/0x14) [<800115dc>] (show_stack+0x10/0x14) from [<800257b8>] (warn_slowpath_common+0x4c/0x68) [<800257b8>] (warn_slowpath_common+0x4c/0x68) from [<800257f0>] (warn_slowpath_null+0x1c/0x24) [<800257f0>] (warn_slowpath_null+0x1c/0x24) from [<803f60ec>] (clk_disable+0x18/0x24) [<803f60ec>] (clk_disable+0x18/0x24) from [<7f02c9cc>] (spi_imx_remove+0x54/0x9c [spi_imx]) [<7f02c9cc>] (spi_imx_remove+0x54/0x9c [spi_imx]) from [<8025868c>] (platform_drv_remove+0x18/0x1c) [<8025868c>] (platform_drv_remove+0x18/0x1c) from [<80256f60>] (__device_release_driver+0x70/0xcc) [<80256f60>] (__device_release_driver+0x70/0xcc) from [<80257770>] (driver_detach+0xcc/0xd0) [<80257770>] (driver_detach+0xcc/0xd0) from [<80256d90>] (bus_remove_driver+0x7c/0xc0) [<80256d90>] (bus_remove_driver+0x7c/0xc0) from [<80068668>] (SyS_delete_module+0x144/0x1f8) [<80068668>] (SyS_delete_module+0x144/0x1f8) from [<8000e080>] (ret_fast_syscall+0x0/0x30) ---[ end trace 1f5df9ad54996300 ]--- ------------[ cut here ]------------ WARNING: at drivers/clk/clk.c:780 clk_disable+0x18/0x24() Modules linked in: spi_imx(-) [last unloaded: ev76c560] CPU: 1 PID: 16337 Comm: rmmod Tainted: G W 3.10.17-80548-g90191eb-dirty #33 [<80013b4c>] (unwind_backtrace+0x0/0xf8) from [<800115dc>] (show_stack+0x10/0x14) [<800115dc>] (show_stack+0x10/0x14) from [<800257b8>] (warn_slowpath_common+0x4c/0x68) [<800257b8>] (warn_slowpath_common+0x4c/0x68) from [<800257f0>] (warn_slowpath_null+0x1c/0x24) [<800257f0>] (warn_slowpath_null+0x1c/0x24) from [<803f60ec>] (clk_disable+0x18/0x24) [<803f60ec>] (clk_disable+0x18/0x24) from [<7f02c9e8>] (spi_imx_remove+0x70/0x9c [spi_imx]) [<7f02c9e8>] (spi_imx_remove+0x70/0x9c [spi_imx]) from [<8025868c>] (platform_drv_remove+0x18/0x1c) [<8025868c>] (platform_drv_remove+0x18/0x1c) from [<80256f60>] (__device_release_driver+0x70/0xcc) [<80256f60>] (__device_release_driver+0x70/0xcc) from [<80257770>] (driver_detach+0xcc/0xd0) [<80257770>] (driver_detach+0xcc/0xd0) from [<80256d90>] (bus_remove_driver+0x7c/0xc0) [<80256d90>] (bus_remove_driver+0x7c/0xc0) from [<80068668>] (SyS_delete_module+0x144/0x1f8) [<80068668>] (SyS_delete_module+0x144/0x1f8) from [<8000e080>] (ret_fast_syscall+0x0/0x30) ---[ end trace 1f5df9ad54996301 ]--- Since commit 9e556dcc55774c9a1032f32baa0e5cfafede8b70, "spi: spi-imx: only enable the clocks when we start to transfer a message", clocks are always disabled except when transmitting messages. There is thus no need to disable them at module removal. Fixes: 9e556dcc55774 (spi: spi-imx: only enable the clocks when we start to transfer a message) Signed-off-by: Philippe De Muyter <phdm@macqel.be> Acked-by: Huang Shijie <b32955@freescale.com> Signed-off-by: Mark Brown <broonie@linaro.org> Cc: stable@vger.kernel.org
2014-02-27 17:16:15 +08:00
clk_unprepare(spi_imx->clk_ipg);
clk_unprepare(spi_imx->clk_per);
spi_imx_sdma_exit(spi_imx);
spi_master_put(master);
return 0;
}
static struct platform_driver spi_imx_driver = {
.driver = {
.name = DRIVER_NAME,
.of_match_table = spi_imx_dt_ids,
},
.id_table = spi_imx_devtype,
.probe = spi_imx_probe,
.remove = spi_imx_remove,
};
module_platform_driver(spi_imx_driver);
MODULE_DESCRIPTION("SPI Master Controller driver");
MODULE_AUTHOR("Sascha Hauer, Pengutronix");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DRIVER_NAME);