/*
* SPI port driver for ETRAX FS et al. using a synchronous serial
* port, but simplified by using the spi_bitbang framework.
*
* Copyright (c) 2007 Axis Communications AB
*
* Author: Hans-Peter Nilsson, though copying parts of
* spi_s3c24xx_gpio.c, hence also:
* Copyright (c) 2006 Ben Dooks
* Copyright (c) 2006 Simtec Electronics
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This driver restricts frequency, polarity, "word" length and endian
* much more than the hardware does. I'm happy to unrestrict it, but
* only with what I can test myself (at time of writing, just SD/MMC
* SPI) and what people actually test and report.
*/
#include <linux/types.h>
#include <linux/device.h>
#include <linux/spi/spi.h>
#include <linux/spi/spi_bitbang.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/interrupt.h>
#include <asm/io.h>
#include <asm/arch/board.h>
#include <asm/arch/hwregs/reg_map.h>
#include <asm/arch/hwregs/reg_rdwr.h>
#include <asm/arch/hwregs/sser_defs.h>
#include <asm/arch/dma.h>
#include <asm/arch/hwregs/dma.h>
/* A size "not much larger" than the max typical transfer size. */
#define DMA_CHUNKSIZ 512
/*
* For a transfer expected to take this long, we busy-wait instead of enabling
* interrupts.
*/
#define IRQ_USAGE_THRESHOLD_NS 14000
/* A few register access macros to avoid verbiage and reduce typos. */
#define REG_RD_DI(reg) REG_RD(dma, regi_dmain, reg)
#define REG_RD_DO(reg) REG_RD(dma, regi_dmaout, reg)
#define REG_RD_SSER(reg) REG_RD(sser, regi_sser, reg)
#define REG_WR_DI(reg, val) REG_WR(dma, regi_dmain, reg, val)
#define REG_WR_DO(reg, val) REG_WR(dma, regi_dmaout, reg, val)
#define REG_WR_SSER(reg, val) REG_WR(sser, regi_sser, reg, val)
#define REG_WRINT_DI(reg, val) REG_WR_INT(dma, regi_dmain, reg, val)
#define REG_WRINT_DO(reg, val) REG_WR_INT(dma, regi_dmaout, reg, val)
#define REG_WRINT_SSER(reg, val) REG_WR_INT(sser, regi_sser, reg, val)
#define REG_RDINT_DI(reg) REG_RD_INT(dma, regi_dmain, reg)
#define REG_RDINT_DO(reg) REG_RD_INT(dma, regi_dmaout, reg)
#define REG_RDINT_SSER(reg) REG_RD_INT(sser, regi_sser, reg)
#define DMA_WAIT_UNTIL_RESET(inst) \
do { \
reg_dma_rw_stat r; \
do { \
r = REG_RD(dma, (inst), rw_stat); \
} while (r.mode != regk_dma_rst); \
} while (0)
#define DMA_BUSY(inst) (REG_RD(dma, inst, rw_stream_cmd)).busy
/* Our main driver state. */
struct crisv32_spi_hw_info {
struct crisv32_regi_n_int sser;
struct crisv32_regi_n_int dmain;
struct crisv32_regi_n_int dmaout;
reg_sser_rw_cfg cfg;
reg_sser_rw_frm_cfg frm_cfg;
reg_sser_rw_tr_cfg tr_cfg;
reg_sser_rw_rec_cfg rec_cfg;
reg_sser_rw_extra extra;
/* We store the speed in kHz, so we can have expressions
* multiplying 100MHz by * 4 before dividing by it, and still
* keep it in an u32. */
u32 effective_speed_kHz;
/*
* The time in 10s of nanoseconds for half a cycles.
* For convenience and performance; derived from the above.
*/
u32 half_cycle_delay_ns;
/* This should be overridable by a module parameter. */
u32 max_speed_Hz;
/* Pre-computed timout for the max transfer chunk-size. */
u32 dma_timeout;
struct completion dma_done;
/*
* If we get a timeout from wait_for_completion_timeout on the
* above, first look at this before panicking.
*/
u32 dma_actually_done;
/*
* Resources don't seem available at the remove call, so we
* have to save information we get through them.
*/
struct crisv32_spi_sser_controller_data *gc;
};
/*
* The driver state hides behind the spi_bitbang state; we're
* responsible for allocating that, so we can get a little something
* for ourselves.
*/
struct crisv32_spi_sser_devdata {
struct spi_bitbang bitbang;
struct crisv32_spi_hw_info hw;
};
/* Our DMA descriptors that need alignment. */
struct crisv32_spi_dma_descrs {
dma_descr_context in_ctxt __attribute__ ((__aligned__(32)));
dma_descr_context out_ctxt __attribute__ ((__aligned__(32)));
/*
* The code takes advantage of the fact that in_descr and
* out_descr are on the same cache-line when working around
* the cache-bug in TR 106.
*/
dma_descr_data in_descr __attribute__ ((__aligned__(16)));
dma_descr_data out_descr __attribute__ ((__aligned__(16)));
};
/*
* Whatever needs DMA access is here, besides whatever DMA-able memory
* comes in transfers.
*/
struct crisv32_spi_dma_cs {
struct crisv32_spi_dma_descrs *descrp;
/* Scratch-buffers when the original was non-DMA. */
u8 rx_buf[DMA_CHUNKSIZ];
u8 tx_buf[DMA_CHUNKSIZ];
};
/*
* Max speed. If set, we won't go faster, promise. May be useful
* when dealing with weak hardware; misrouted signal paths or various
* debug-situations.
*/
static ulong crisv32_spi_speed_limit_Hz = 0;
/* Helper function getting the driver state from a spi_device. */
static inline struct crisv32_spi_hw_info *spidev_to_hw(struct spi_device *spi)
{
struct crisv32_spi_sser_devdata *dd = spi_master_get_devdata(spi->master);
return &dd->hw;
}
/* SPI-bitbang word transmit-function for non-DMA. */
static u32 crisv32_spi_sser_txrx_mode3(struct spi_device *spi,
unsigned nsecs, u32 word, u8 bits)
{
struct crisv32_spi_hw_info *hw = spidev_to_hw(spi);
u32 regi_sser = hw->sser.regi;
reg_sser_rw_ack_intr ack_intr = { .trdy = 1, .rdav = 1 };
reg_sser_r_intr intr = {0};
reg_sser_rw_tr_data w_data = { .data = (u8) word };
reg_sser_r_rec_data r_data;
u32 i;
/*
* The timeout reflects one iteration per 10ns (impossible at
* 200MHz clock even without the ndelay) and a wait for a full
* byte.
*/
u32 timeout = 1000000/10*8/hw->effective_speed_kHz;
BUG_ON(bits != 8);
intr = REG_RD_SSER(r_intr);
/*
* We should never get xruns when we control the transmitter
* and receiver in register mode. And if we don't have
* transmitter-ready and data-ready on entry, something's
* seriously fishy.
*/
if (!intr.trdy || !intr.rdav || intr.orun || intr.urun)
panic("sser hardware or SPI driver broken (1) 0x%x\n",
REG_TYPE_CONV(u32, reg_sser_r_intr, intr));
REG_WR_SSER(rw_ack_intr, ack_intr);
REG_WR_SSER(rw_tr_data, w_data);
for (i = 0; i < timeout; i++) {
intr = REG_RD_SSER(r_intr);
/* Wait for received data. */
if (intr.rdav)
break;
ndelay(10);
}
if (!(intr.trdy && intr.rdav) || intr.orun || intr.urun)
panic("sser hardware or SPI driver broken (2) 0x%x\n",
REG_TYPE_CONV(u32, reg_sser_r_intr, intr));
r_data = REG_RD_SSER(r_rec_data);
return r_data.data & 0xff;
}
/*
* Wait for 1/2 bit-time if the transmitter or receiver is enabled.
* We need to do this as the data-available indications may arrive
* right at the edge, with half the last cycle remaining.
*/
static void inline crisv32_spi_sser_wait_halfabit(struct crisv32_spi_hw_info
*hw)
{
if (hw->cfg.en)
ndelay(hw->half_cycle_delay_ns);
}
/*
* Assert or de-assert chip-select.
* We have two functions, with the active one assigned to the bitbang
* slot at setup, to avoid a performance penalty (1% on reads).
*/
static void crisv32_spi_sser_chip_select_active_high(struct spi_device *spi,
int value)
{
struct crisv32_spi_hw_info *hw = spidev_to_hw(spi);
u32 regi_sser = hw->sser.regi;
/*
* We may have received data at the "last producing clock
* edge". Thus we delay for another half a clock cycle.
*/
crisv32_spi_sser_wait_halfabit(hw);
hw->frm_cfg.frame_pin_use
= value == BITBANG_CS_ACTIVE ? regk_sser_gio1 : regk_sser_gio0;
REG_WR_SSER(rw_frm_cfg, hw->frm_cfg);
}
static void crisv32_spi_sser_chip_select_active_low(struct spi_device *spi,
int value)
{
struct crisv32_spi_hw_info *hw = spidev_to_hw(spi);
u32 regi_sser = hw->sser.regi;
crisv32_spi_sser_wait_halfabit(hw);
hw->frm_cfg.frame_pin_use
= value == BITBANG_CS_ACTIVE ? regk_sser_gio0 : regk_sser_gio1;
REG_WR_SSER(rw_frm_cfg, hw->frm_cfg);
}
/* Set the transmission speed in Hz. */
static int crisv32_spi_sser_set_speed_Hz(struct crisv32_spi_hw_info *hw,
u32 Hz)
{
u32 kHz;
u32 ns_delay;
u32 regi_sser = hw->sser.regi;
if (Hz > hw->max_speed_Hz)
/*
* Should we complain? Return error? Current caller
* sequences want just the max speed.
*/
Hz = hw->max_speed_Hz;
kHz = Hz/1000;
/*
* If absolutely needed, we *could* change the base frequency
* and go lower. Usually, a frequency set higher than wanted
* is a problem but lower isn't.
*/
if (Hz < 100000000 / 65536 + 1) {
printk(KERN_ERR "attempt to set invalid sser speed: %u Hz\n",
Hz);
Hz = 100000000 / 65536 + 1;
}
pr_debug("setting sser speed to %u Hz\n", Hz);
/*
* Avoid going above the requested speed if there's a
* remainder for the 100 MHz clock-divider calculation, but
* don't unnecessarily go below if it's even.
*/
hw->cfg.clk_div = 100000000/Hz - ((100000000 % Hz) == 0);
/* Make sure there's no ongoing transmission. */
crisv32_spi_sser_wait_halfabit(hw);
/*
* Wait for 3 times max of the old and the new clock before and after
* changing the frequency. Not because of documentation or empirical
* need, but because it seems sane to do so. The three-bit-times
* value is because that's the documented time it takes for a reset to
* take effect.
*/
ns_delay = 1000000*3/(kHz > hw->effective_speed_kHz
? kHz : hw->effective_speed_kHz);
ndelay(ns_delay);
REG_WR_SSER(rw_cfg, hw->cfg);
ndelay(ns_delay);
hw->effective_speed_kHz = kHz;
/*
* A timeout of twice the time for the largest chunk (not
* counting DMA overhead) plus one jiffy, should be more than
* enough for the transmission.
*/
hw->dma_timeout = 1 + usecs_to_jiffies(1000*2*DMA_CHUNKSIZ*8/kHz);
hw->half_cycle_delay_ns
= 1000000/2/hw->effective_speed_kHz;
pr_debug(".clk_div %d, half %d, eff %d\n",
hw->cfg.clk_div, hw->half_cycle_delay_ns,
hw->effective_speed_kHz);
return 0;
}
/*
* Set up transmitter and receiver for non-DMA access.
* Unfortunately, it doesn't seem like hispeed works for this mode
* (mea culpa), so we're stuck with lospeed-mode. A little slower,
* but that's what you get for not allocating DMA.
*/
static int crisv32_setup_spi_sser_for_reg_access(struct crisv32_spi_hw_info *hw)
{
u32 regi_sser = hw->sser.regi;
reg_sser_rw_cfg cfg = {0};
reg_sser_rw_frm_cfg frm_cfg = {0};
reg_sser_rw_tr_cfg tr_cfg = {0};
reg_sser_rw_rec_cfg rec_cfg = {0};
reg_sser_rw_intr_mask mask = {0};
reg_sser_rw_extra extra = {0};
reg_sser_rw_tr_data tr_data = {0};
reg_sser_r_intr intr;
cfg.en = 0;
tr_cfg.tr_en = 1;
rec_cfg.rec_en = 1;
REG_WR_SSER(rw_cfg, cfg);
REG_WR_SSER(rw_tr_cfg, tr_cfg);
REG_WR_SSER(rw_rec_cfg, rec_cfg);
REG_WR_SSER(rw_intr_mask, mask);
/*
* See 23.7.2 SPI in the hardware documentation.
* Except our configuration uses bulk mode; MMC/SD-SPI
* isn't isochronous in nature.
* Step 1.
*/
cfg.gate_clk = regk_sser_yes;
cfg.clkgate_in = regk_sser_no;
cfg.clkgate_ctrl = regk_sser_tr;
/* Step 2. */
cfg.out_clk_pol = regk_sser_pos;
cfg.out_clk_src = regk_sser_intern_clk;
/* Step 3. */
tr_cfg.clk_src = regk_sser_intern;
rec_cfg.clk_src = regk_sser_intern;
frm_cfg.clk_src = regk_sser_intern;
/* Step 4. */
tr_cfg.clk_pol = regk_sser_neg;
rec_cfg.clk_pol = regk_sser_pos;
frm_cfg.clk_pol = regk_sser_neg;
/*
* Step 5: frame pin (PC03 or PD03) is frame; the status pin
* (PC02, PD02) is configured as input.
*/
frm_cfg.frame_pin_dir = regk_sser_out;
/*
* Contrary to the doc example, we don't generate the frame
* signal "automatically". This setting of the frame pin as
* constant 1, reflects an inactive /CS setting, for just idle
* clocking. When we need to transmit or receive data, we
* change it.
*/
frm_cfg.frame_pin_use = regk_sser_gio1;
frm_cfg.status_pin_dir = regk_sser_in;
/*
* Step 6. This is probably not necessary, as we don't
* generate the frame signal automatically. Nevertheless,
* modified for bulk transmission.
*/
frm_cfg.out_on = regk_sser_tr;
frm_cfg.out_off = regk_sser_tr;
/* Step 7. Similarly, maybe not necessary. */
frm_cfg.type = regk_sser_level;
frm_cfg.level = regk_sser_neg_lo;
/* Step 8. These we have to set according to the bulk mode,
* which for tr_delay is the same as for iso; a value of 1
* means in sync with the frame signal. For rec_delay, we
* start it at the same time as the transmitter. See figure
* 23.7 in the hw documentation. */
frm_cfg.tr_delay = 1;
frm_cfg.rec_delay = 0;
/* Step 9. */
tr_cfg.sample_size = 7;
rec_cfg.sample_size = 7;
/* Step 10. */
frm_cfg.wordrate = 7;
/* Step 11 (but for bulk). */
tr_cfg.rate_ctrl = regk_sser_bulk;
/*
* Step 12. Similarly, maybe not necessary; still, modified
* for bulk.
*/
tr_cfg.frm_src = regk_sser_intern;
rec_cfg.frm_src = regk_sser_tx_bulk;
/* Step 13. */
tr_cfg.mode = regk_sser_lospeed;
rec_cfg.mode = regk_sser_lospeed;
/* Step 14. */
tr_cfg.sh_dir = regk_sser_msbfirst;
rec_cfg.sh_dir = regk_sser_msbfirst;
/*
* Extra step for bulk-specific settings and other general
* settings not specified in the SPI config example.
* It's uncertain whether all of these are needed.
*/
tr_cfg.bulk_wspace = 1;
tr_cfg.use_dma = 0;
tr_cfg.urun_stop = 1;
rec_cfg.orun_stop = 1;
rec_cfg.use_dma = 0;
rec_cfg.fifo_thr = regk_sser_inf;
frm_cfg.early_wend = regk_sser_yes;
cfg.clk_dir = regk_sser_out;
tr_cfg.data_pin_use = regk_sser_dout;
cfg.base_freq = regk_sser_f100;
/* Setup for the initial frequency given to us. */
hw->cfg = cfg;
crisv32_spi_sser_set_speed_Hz(hw, hw->max_speed_Hz);
cfg = hw->cfg;
/*
* Write it all, except cfg which is already written by
* crisv32_spi_sser_set_speed_Hz.
*/
REG_WR_SSER(rw_frm_cfg, frm_cfg);
REG_WR_SSER(rw_tr_cfg, tr_cfg);
REG_WR_SSER(rw_rec_cfg, rec_cfg);
REG_WR_SSER(rw_extra, extra);
/*
* The transmit-register needs to be written before the
* transmitter is enabled, and to get a valid trdy signal
* waiting for us when we want to transmit a byte. Because
* the "frame event" is that the transmitter is written, this
* will cause a dummy 0xff-byte to be transmitted, but that's
* ok, because /CS is inactive.
*/
tr_data.data = 0xffff;
REG_WR_SSER(rw_tr_data, tr_data);
/*
* We ack everything interrupt-wise; left-over indicators don't have
* to come from *this* code.
*/
REG_WRINT_SSER(rw_ack_intr, -1);
/*
* Wait 3 cycles before enabling, after the transmit register
* has been written. (This'll be just a few microseconds for
* e.g. 400 KHz.)
*/
ndelay(3 * 2 * hw->half_cycle_delay_ns);
cfg.en = 1;
REG_WR_SSER(rw_cfg, cfg);
/*
* Now wait for 8 + 3 cycles. The 0xff byte should now have
* been transmitted and dummy data received.
*/
ndelay((8 + 3) * 2 * hw->half_cycle_delay_ns);
/*
* Sanity-check that we have data-available and the
* transmitter is ready to send new data.
*/
intr = REG_RD_SSER(r_intr);
if (!intr.rdav || !intr.trdy)
panic("sser hw or SPI driver broken (3) 0x%x",
REG_TYPE_CONV(u32, reg_sser_r_intr, intr));
hw->frm_cfg = frm_cfg;
hw->tr_cfg = tr_cfg;
hw->rec_cfg = rec_cfg;
hw->extra = extra;
hw->cfg = cfg;
return 0;
}
/* Initialization, maybe fault recovery. */
static void crisv32_reset_dma_hw(u32 regi)
{
REG_WR_INT(dma, regi, rw_intr_mask, 0);
DMA_RESET(regi);
DMA_WAIT_UNTIL_RESET(regi);
DMA_ENABLE(regi);
REG_WR_INT(dma, regi, rw_ack_intr, -1);
DMA_WR_CMD(regi, regk_dma_set_w_size1);
}
/* Interrupt from SSER, for use with DMA when only the transmitter is used. */
static irqreturn_t sser_interrupt(int irqno, void *arg)
{
struct crisv32_spi_hw_info *hw = arg;
u32 regi_sser = hw->sser.regi;
reg_sser_r_intr intr = REG_RD_SSER(r_intr);
if (intr.tidle == 0 && intr.urun == 0) {
printk(KERN_ERR
"sser @0x%x: spurious sser intr, flags: 0x%x\n",
regi_sser, REG_TYPE_CONV(u32, reg_sser_r_intr, intr));
} else if (intr.urun == 0) {
hw->dma_actually_done = 1;
complete(&hw->dma_done);
} else {
/*
* Make any reception time out and notice the error,
* which it might not otherwise do data was *received*
* successfully.
*/
u32 regi_dmain = hw->dmain.regi;
/*
* Recommended practice before acking urun is to turn
* off sser. That might not be enough to stop DMA-in
* from signalling success if the underrun was late in
* the transmission, so we disable the DMA-in
* interrupts too.
*/
REG_WRINT_SSER(rw_cfg, 0);
REG_WRINT_DI(rw_intr_mask, 0);
REG_WRINT_DI(rw_ack_intr, -1);
}
REG_WRINT_SSER(rw_intr_mask, 0);
/*
* We must at least ack urun together with tidle, but keep it
* simple and ack them all.
*/
REG_WRINT_SSER(rw_ack_intr, -1);
return IRQ_HANDLED;
}
/*
* Interrupt from receiver DMA connected to SSER, for use when the
* receiver is used, with or without the transmitter.
*/
static irqreturn_t rec_dma_interrupt(int irqno, void *arg)
{
struct crisv32_spi_hw_info *hw = arg;
u32 regi_dmain = hw->dmain.regi;
u32 regi_sser = hw->sser.regi;
reg_dma_r_intr intr = REG_RD_DI(r_intr);
if (intr.data == 0) {
printk(KERN_ERR
"sser @0x%x: spurious rec dma intr, flags: 0x%x\n",
regi_dmain, REG_TYPE_CONV(u32, reg_dma_r_intr, intr));
} else {
hw->dma_actually_done = 1;
complete(&hw->dma_done);
}
REG_WRINT_DI(rw_intr_mask, 0);
/* Avoid false underrun indications; stop all sser interrupts. */
REG_WRINT_SSER(rw_intr_mask, 0);
REG_WRINT_SSER(rw_ack_intr, -1);
REG_WRINT_DI(rw_ack_intr, -1);
return IRQ_HANDLED;
}
/*
* Set up transmitter and receiver for DMA access. We use settings
* from the "Atmel fast flash" example.
*/
static int crisv32_setup_spi_sser_for_dma_access(struct crisv32_spi_hw_info
*hw)
{
int ret;
u32 regi_sser = hw->sser.regi;
reg_sser_rw_cfg cfg = {0};
reg_sser_rw_frm_cfg frm_cfg = {0};
reg_sser_rw_tr_cfg tr_cfg = {0};
reg_sser_rw_rec_cfg rec_cfg = {0};
reg_sser_rw_intr_mask mask = {0};
reg_sser_rw_extra extra = {0};
cfg.en = 0;
tr_cfg.tr_en = 1;
rec_cfg.rec_en = 1;
REG_WR_SSER(rw_cfg, cfg);
REG_WR_SSER(rw_tr_cfg, tr_cfg);
REG_WR_SSER(rw_rec_cfg, rec_cfg);
REG_WR_SSER(rw_intr_mask, mask);
/*
* See 23.7.5.2 (Atmel fast flash) in the hardware documentation.
* Step 1.
*/
cfg.gate_clk = regk_sser_no;
/* Step 2. */
cfg.out_clk_pol = regk_sser_pos;
/* Step 3. */
cfg.out_clk_src = regk_sser_intern_clk;
/* Step 4. */
tr_cfg.sample_size = 1;
rec_cfg.sample_size = 1;
/* Step 5. */
frm_cfg.wordrate = 7;
/* Step 6. */
tr_cfg.clk_src = regk_sser_intern;
rec_cfg.clk_src = regk_sser_intern;
frm_cfg.clk_src = regk_sser_intern;
tr_cfg.clk_pol = regk_sser_neg;
frm_cfg.clk_pol = regk_sser_neg;
/* Step 7. */
rec_cfg.clk_pol = regk_sser_pos;
/* Step 8. */
frm_cfg.tr_delay = 1;
/* Step 9. */
frm_cfg.rec_delay = 1;
/* Step 10. */
tr_cfg.sh_dir = regk_sser_msbfirst;
rec_cfg.sh_dir = regk_sser_msbfirst;
/* Step 11. */
tr_cfg.frm_src = regk_sser_intern;
rec_cfg.frm_src = regk_sser_intern;
/* Step 12. */
tr_cfg.rate_ctrl = regk_sser_iso;
/*
* Step 13. Note that 0 != tx_null, so we're good regarding
* the descriptor .md field.
*/
tr_cfg.eop_stop = 1;
/* Step 14. */
frm_cfg.frame_pin_use = regk_sser_gio1;
frm_cfg.frame_pin_dir = regk_sser_out;
/* Step 15. */
extra.clkon_en = 1;
extra.clkoff_en = 1;
/* Step 16. We'll modify this value for each "burst". */
extra.clkoff_cycles = 7;
/* Step 17. */
cfg.prepare = 1;
/*
* Things left out from the documented startup procedure.
* It's uncertain whether all of these are needed.
*/
frm_cfg.status_pin_dir = regk_sser_in;
tr_cfg.mode = regk_sser_hispeed;
rec_cfg.mode = regk_sser_hispeed;
frm_cfg.out_on = regk_sser_intern_tb;
frm_cfg.out_off = regk_sser_rec;
frm_cfg.type = regk_sser_level;
tr_cfg.use_dma = 1;
tr_cfg.urun_stop = 1;
rec_cfg.orun_stop = 1;
rec_cfg.use_dma = 1;
rec_cfg.fifo_thr = regk_sser_inf;
frm_cfg.early_wend = regk_sser_yes;
cfg.clk_dir = regk_sser_out;
tr_cfg.data_pin_use = regk_sser_dout;
cfg.base_freq = regk_sser_f100;
REG_WR_SSER(rw_frm_cfg, frm_cfg);
REG_WR_SSER(rw_tr_cfg, tr_cfg);
REG_WR_SSER(rw_rec_cfg, rec_cfg);
REG_WR_SSER(rw_extra, extra);
REG_WR_SSER(rw_cfg, cfg);
hw->frm_cfg = frm_cfg;
hw->tr_cfg = tr_cfg;
hw->rec_cfg = rec_cfg;
hw->extra = extra;
hw->cfg = cfg;
crisv32_spi_sser_set_speed_Hz(hw, hw->max_speed_Hz);
ret = request_irq(hw->sser.irq, sser_interrupt, 0, "sser", hw);
if (ret != 0)
goto noirq;
ret = request_irq(hw->dmain.irq, rec_dma_interrupt, 0, "sser rec", hw);
if (ret != 0)
goto free_outirq;
crisv32_reset_dma_hw(hw->dmain.regi);
crisv32_reset_dma_hw(hw->dmaout.regi);
return 0;
free_outirq:
free_irq(hw->sser.irq, hw);
noirq:
return ret;
}
/* SPI-master setup function for non-DMA. */
static int crisv32_spi_sser_regs_master_setup(struct spi_device *spi)
{
struct crisv32_spi_hw_info *hw = spidev_to_hw(spi);
struct spi_bitbang *bitbang = spi_master_get_devdata(spi->master);
int ret = 0;
/* Just do a little initial constraining checks. */
if (spi->bits_per_word == 0)
spi->bits_per_word = 8;
if (spi->bits_per_word != 8)
return -EINVAL;
bitbang->chipselect = (spi->mode & SPI_CS_HIGH) != 0
? crisv32_spi_sser_chip_select_active_high
: crisv32_spi_sser_chip_select_active_low;
if (hw->max_speed_Hz == 0) {
u32 max_speed_Hz;
/*
* At this time; at the first call to the SPI master
* setup function, spi->max_speed_hz reflects the
* board-init value. It will be changed later on by
* the protocol master, but at the master setup call
* is the only time we actually get to see the hw max
* and thus a reasonable time to init the hw field.
*/
/* The module parameter overrides everything. */
if (crisv32_spi_speed_limit_Hz != 0)
max_speed_Hz = crisv32_spi_speed_limit_Hz;
/*
* I never could get hispeed mode to work for non-DMA.
* We adjust the max speed here (where we could
* presumably fix it), not in the board info file.
*/
else if (spi->max_speed_hz > 16667000)
max_speed_Hz = 16667000;
else
max_speed_Hz = spi->max_speed_hz;
hw->max_speed_Hz = max_speed_Hz;
spi->max_speed_hz = max_speed_Hz;
/*
* We also do one-time initialization of the hardware at this
* point. We could defer to the return to the probe-function
* from spi_bitbang_start, but other hardware setup (like
* subsequent calls to this function before that) would have
* to be deferred until then too.
*/
ret = crisv32_setup_spi_sser_for_reg_access(hw);
if (ret != 0)
return ret;
ret = spi_bitbang_setup(spi);
if (ret != 0)
return ret;
dev_info(&spi->dev,
"CRIS v32 SPI driver for sser%d\n",
spi->master->bus_num);
}
return 0;
}
/*
* SPI-master setup_transfer-function used for both DMA and non-DMA
* (single function for DMA, together with spi_bitbang_setup_transfer
* for non-DMA).
*/
static int crisv32_spi_sser_common_setup_transfer(struct spi_device *spi,
struct spi_transfer *t)
{
struct crisv32_spi_hw_info *hw = spidev_to_hw(spi);
u8 bits_per_word;
u32 hz;
int ret = 0;
if (t) {
bits_per_word = t->bits_per_word;
hz = t->speed_hz;
} else {
bits_per_word = 0;
hz = 0;
}
if (bits_per_word == 0)
bits_per_word = spi->bits_per_word;
if (bits_per_word != 8)
return -EINVAL;
if (hz == 0)
hz = spi->max_speed_hz;
if (hz != hw->effective_speed_kHz*1000 && hz != 0)
ret = crisv32_spi_sser_set_speed_Hz(hw, hz);
return ret;
}
/* Helper for a SPI-master setup_transfer function for non-DMA. */
static int crisv32_spi_sser_regs_setup_transfer(struct spi_device *spi,
struct spi_transfer *t)
{
int ret = crisv32_spi_sser_common_setup_transfer(spi, t);
if (ret != 0)
return ret;
/* Set up the loop-over-buffer parts. */
return spi_bitbang_setup_transfer (spi, t);
}
/* SPI-master setup function for DMA. */
static int crisv32_spi_sser_dma_master_setup(struct spi_device *spi)
{
/*
* As we don't dispatch to the spi_bitbang default function,
* we need to do whatever tests it does; keep it in sync. On
* the bright side, we can use the spi->controller_state slot;
* we use it for DMA:able memory for the descriptors and
* temporary buffers to copy non-DMA:able transfers.
*/
struct crisv32_spi_hw_info *hw = spidev_to_hw(spi);
struct spi_bitbang *bitbang = spi_master_get_devdata(spi->master);
struct crisv32_spi_dma_cs *cs;
u32 dmasize;
int ret = 0;
if (hw->max_speed_Hz == 0) {
struct crisv32_spi_dma_descrs *descrp;
u32 descrp_dma;
u32 max_speed_Hz;
/* The module parameter overrides everything. */
if (crisv32_spi_speed_limit_Hz != 0)
max_speed_Hz = crisv32_spi_speed_limit_Hz;
/*
* See comment at corresponding statement in
* crisv32_spi_sser_regs_master_setup.
*/
else
max_speed_Hz = spi->max_speed_hz;
hw->max_speed_Hz = max_speed_Hz;
spi->max_speed_hz = max_speed_Hz;
ret = crisv32_setup_spi_sser_for_dma_access(hw);
if (ret != 0)
return ret;
/* Allocate some extra for necessary alignment. */
dmasize = sizeof *cs + 31
+ sizeof(struct crisv32_spi_dma_descrs);
cs = kzalloc(dmasize, GFP_KERNEL | GFP_DMA);
if (cs == NULL)
return -ENOMEM;
/*
* Make descriptors aligned within the allocated area,
* some-place after cs.
*/
descrp = (struct crisv32_spi_dma_descrs *)
(((u32) (cs + 1) + 31) & ~31);
descrp_dma = virt_to_phys(descrp);
/* Set up the "constant" parts of the descriptors. */
descrp->out_descr.eol = 1;
descrp->out_descr.intr = 1;
descrp->out_descr.out_eop = 1;
descrp->out_ctxt.saved_data = (dma_descr_data *)
(descrp_dma
+ offsetof(struct crisv32_spi_dma_descrs, out_descr));
descrp->out_ctxt.next = 0;
descrp->in_descr.eol = 1;
descrp->in_descr.intr = 1;
descrp->in_ctxt.saved_data = (dma_descr_data *)
(descrp_dma
+ offsetof(struct crisv32_spi_dma_descrs, in_descr));
descrp->in_ctxt.next = 0;
cs->descrp = descrp;
spi->controller_state = cs;
init_completion(&hw->dma_done);
dev_info(&spi->dev,
"CRIS v32 SPI driver for sser%d/DMA\n",
spi->master->bus_num);
}
/* Do our extra constraining checks. */
if (spi->bits_per_word == 0)
spi->bits_per_word = 8;
if (spi->bits_per_word != 8)
return -EINVAL;
/* SPI_LSB_FIRST deliberately left out, and we only support mode 3. */
if ((spi->mode & ~(SPI_TX_1|SPI_CS_HIGH)) != SPI_MODE_3)
return -EINVAL;
bitbang->chipselect = (spi->mode & SPI_CS_HIGH) != 0
? crisv32_spi_sser_chip_select_active_high
: crisv32_spi_sser_chip_select_active_low;
ret = bitbang->setup_transfer(spi, NULL);
if (ret != 0)
return ret;
/* Remember to de-assert chip-select before the first transfer. */
spin_lock(&bitbang->lock);
if (!bitbang->busy) {
bitbang->chipselect(spi, BITBANG_CS_INACTIVE);
ndelay(hw->half_cycle_delay_ns);
}
spin_unlock(&bitbang->lock);
return 0;
}
/* SPI-master cleanup function for DMA. */
static void crisv32_spi_sser_dma_cleanup(struct spi_device *spi)
{
kfree(spi->controller_state);
spi->controller_state = NULL;
}
/*
* Set up DMA transmitter descriptors for a chunk of data.
* The caller is responsible for working around TR 106.
*/
static void crisv32_spi_sser_setup_dma_descr_out(u32 regi,
struct crisv32_spi_dma_cs *cs,
u32 out_phys, u32 chunk_len)
{
BUG_ON(chunk_len > DMA_CHUNKSIZ);
struct crisv32_spi_dma_descrs *descrp = cs->descrp;
u32 descrp_dma = virt_to_phys(descrp);
descrp->out_descr.buf = (u8 *) out_phys;
descrp->out_descr.after = (u8 *) out_phys + chunk_len;
descrp->out_ctxt.saved_data_buf = (u8 *) out_phys;
DMA_START_CONTEXT(regi,
descrp_dma
+ offsetof(struct crisv32_spi_dma_descrs, out_ctxt));
}
/*
* Set up DMA receiver descriptors for a chunk of data.
* Also, work around TR 106.
*/
static void crisv32_spi_sser_setup_dma_descr_in(u32 regi_dmain,
struct crisv32_spi_dma_cs *cs,
u32 in_phys, u32 chunk_len)
{
BUG_ON(chunk_len > DMA_CHUNKSIZ);
struct crisv32_spi_dma_descrs *descrp = cs->descrp;
u32 descrp_dma = virt_to_phys(descrp);
descrp->in_descr.buf = (u8 *) in_phys;
descrp->in_descr.after = (u8 *) in_phys + chunk_len;
descrp->in_ctxt.saved_data_buf = (u8 *) in_phys;
flush_dma_descr(&descrp->in_descr, 1);
DMA_START_CONTEXT(regi_dmain,
descrp_dma
+ offsetof(struct crisv32_spi_dma_descrs, in_ctxt));
}
/*
* SPI-bitbang txrx_bufs function for DMA.
* FIXME: We have SG DMA descriptors; use them.
* (Requires abandoning the spi_bitbang framework if done reasonably.)
*/
static int crisv32_spi_sser_dma_txrx_bufs(struct spi_device *spi,
struct spi_transfer *t)
{
struct crisv32_spi_dma_cs *cs = spi->controller_state;
struct crisv32_spi_hw_info *hw = spidev_to_hw(spi);
u32 len = t->len;
reg_sser_rw_cfg cfg = hw->cfg;
reg_sser_rw_tr_cfg tr_cfg = hw->tr_cfg;
reg_sser_rw_rec_cfg rec_cfg = hw->rec_cfg;
reg_sser_rw_extra extra = hw->extra;
u32 regi_sser = hw->sser.regi;
u32 dmain = 0;
u32 dmaout = 0;
u32 regi_dmain = hw->dmain.regi;
u8 *rx_buf = t->rx_buf;
/*
* Using IRQ+completion is measured to give an overhead of 14
* us, so let's instead busy-wait for the time that would be
* wasted anyway, and get back sooner. We're not counting in
* other overhead such as the DMA descriptor in the
* time-expression, which causes us to use busy-wait for
* data-lengths that actually take a bit longer than
* IRQ_USAGE_THRESHOLD_NS. Still, with IRQ_USAGE_THRESHOLD_NS
* = 14000, the threshold is for 20 MHz => 35 bytes, 25 => 44
* and 50 => 88 and the typical SPI transfer lengths for
* SDcard are { 1, 2, 7, 512 } bytes so a more complicated
* would likely give nothing but worse performance due to
* complexity.
*/
int use_irq = len * hw->half_cycle_delay_ns
> IRQ_USAGE_THRESHOLD_NS / 8 / 2;
if (len > DMA_CHUNKSIZ) {
/*
* It should be quite easy to adjust the code if the need
* arises for something much larger than the preallocated
* buffers (which could themselves easily just be increased)
* but still what fits in extra.clkoff_cycles: kmalloc a
* temporary dmaable buffer in this function and free it at
* the end. No need to optimize rare requests. Until then,
* we'll keep the code as simple as performance allows.
* Alternatively or if we need to send even larger data,
* consider calling self with the required number of "faked"
* shorter transfers here.
*/
dev_err(&spi->dev,
"Trying to transfer %d > max %d bytes:"
" need to adjust the SPI driver\n",
len, DMA_CHUNKSIZ);
return -EMSGSIZE;
}
/*
* Need to separately tell the hispeed machinery the number of
* bits in this transmission.
*/
extra.clkoff_cycles = len * 8 - 1;
if (t->tx_buf != NULL) {
if (t->tx_dma == 0) {
memcpy(cs->tx_buf, t->tx_buf, len);
dmaout = virt_to_phys(cs->tx_buf);
} else
dmaout = t->tx_dma;
crisv32_spi_sser_setup_dma_descr_out(hw->dmaout.regi,
cs, dmaout,
len);
/* No need to do anything for TR 106; this DMA only reads. */
tr_cfg.tr_en = 1;
tr_cfg.data_pin_use = regk_sser_dout;
} else {
tr_cfg.data_pin_use = (spi->mode & SPI_TX_1)
? regk_sser_gio1 : regk_sser_gio0;
tr_cfg.tr_en = 0;
}
if (rx_buf != 0) {
if (t->rx_dma == 0)
dmain = virt_to_phys(cs->rx_buf);
else
dmain = t->rx_dma;
crisv32_spi_sser_setup_dma_descr_in(regi_dmain, cs,
dmain, len);
rec_cfg.rec_en = 1;
REG_WRINT_SSER(rw_ack_intr, -1);
REG_WRINT_DI(rw_ack_intr, -1);
/*
* If we're receiving, use the rec data interrupt from DMA as
* a signal that the HW is done.
*/
if (use_irq) {
reg_sser_rw_intr_mask mask = { .urun = 1 };
reg_dma_rw_intr_mask dmask = { .data = 1 };
REG_WR_DI(rw_intr_mask, dmask);
/*
* Catch transmitter underruns too. We don't
* have to conditionalize that on the
* transmitter being enabled; it's off when
* the transmitter is off. Any overruns will
* be indicated by a timeout, so we don't have
* to check for that specifically.
*/
REG_WR_SSER(rw_intr_mask, mask);
}
} else {
rec_cfg.rec_en = 0;
/*
* Ack previous overrun, underrun and tidle interrupts. Or
* why not all. We'll get orun and urun "normally" due to the
* way hispeed is (documented to) work and need to clear them,
* and we'll have a tidle from a previous transmit if we used
* to both receive and transmit, but now only transmit.
*/
REG_WRINT_SSER(rw_ack_intr, -1);
if (use_irq) {
reg_sser_rw_intr_mask mask = { .urun = 1, .tidle = 1 };
REG_WR_SSER(rw_intr_mask, mask);
}
}
REG_WR_SSER(rw_rec_cfg, rec_cfg);
REG_WR_SSER(rw_tr_cfg, tr_cfg);
REG_WR_SSER(rw_extra, extra);
/*
* Barriers are needed to make sure that the completion inits don't
* migrate past the register writes due to gcc scheduling.
*/
mb();
hw->dma_actually_done = 0;
INIT_COMPLETION(hw->dma_done);
mb();
/*
* Wait until DMA tx FIFO has more than one byte (it reads one
* directly then one "very quickly") before starting sser tx.
*/
if (tr_cfg.tr_en) {
u32 regi_dmaout = hw->dmaout.regi;
u32 minlen = len > 2 ? 2 : len;
while ((REG_RD_DO(rw_stat)).buf < minlen)
;
}
/* Wait until DMA-in is finished reading the descriptors. */
if (rec_cfg.rec_en)
while (DMA_BUSY(regi_dmain))
;
/*
* Wait 3 cycles before enabling (with .prepare = 1).
* FIXME: Can we cut this by some time already passed?
*/
ndelay(3 * 2 * hw->half_cycle_delay_ns);
cfg.en = 1;
REG_WR_SSER(rw_cfg, cfg);
/*
* Wait 3 more cycles plus 30 ns before letting go.
* FIXME: Can we do something else before but after the
* previous cfg write and cut this by the time already passed?
*/
cfg.prepare = 0;
hw->cfg = cfg;
ndelay(3 * 2 * hw->half_cycle_delay_ns + 30);
REG_WR_SSER(rw_cfg, cfg);
/*, We'll disable sser next the time we change the configuration. */
cfg.en = 0;
cfg.prepare = 1;
hw->cfg = cfg;
if (!use_irq) {
/*
* We use a timeout corresponding to one iteration per ns,
* which of course is at least five * insns / loop times as
* much as reality, but we'll avoid a need for reading hw
* timers directly.
*/
u32 countdown = IRQ_USAGE_THRESHOLD_NS;
do
if (rec_cfg.rec_en == 0) {
/* Using the transmitter only. */
reg_sser_r_intr intr = REG_RD_SSER(r_intr);
if (intr.tidle != 0) {
/*
* Almost done... Just check if we
* had a transmitter underrun too.
*/
if (!intr.urun)
goto transmission_done;
/*
* Fall over to the "time is up" case;
* no need to provide a special path
* for the error case.
*/
countdown = 1;
}
} else {
/* Using at least the receiver. */
if ((REG_RD_DI(r_intr)).data != 0) {
if ((REG_RD_SSER(r_intr)).urun == 0)
goto transmission_done;
countdown = 1;
}
}
while (--countdown != 0);
/*
* The time is up. Something might be wrong, or perhaps we've
* started using data lengths where the threshold was about a
* magnitude wrong. Fall over to IRQ. Remember not to ack
* interrupts here (but always above, before starting), else
* we'll have a race condition with the interrupt.
*/
if (!rec_cfg.rec_en) {
reg_sser_rw_intr_mask mask = { .urun = 1, .tidle = 1 };
REG_WR_SSER(rw_intr_mask, mask);
} else {
reg_dma_rw_intr_mask dmask = { .data = 1 };
reg_sser_rw_intr_mask mask = { .urun = 1 };
/*
* Never mind checking for tr being disabled; urun
* won't happen then.
*/
REG_WR_SSER(rw_intr_mask, mask);
REG_WR_DI(rw_intr_mask, dmask);
}
}
if (!wait_for_completion_timeout(&hw->dma_done, hw->dma_timeout)
/*
* Have to keep track manually too, else we'll get a timeout
* indication for being scheduled out too long, while the
* completion will still have trigged.
*/
&& !hw->dma_actually_done) {
u32 regi_dmaout = hw->dmaout.regi;
/*
* Transfer timed out. Should not happen for a
* working controller, except perhaps if the system is
* badly conditioned, causing DMA memory bandwidth
* starvation. Not much to do afterwards, but perhaps
* reset DMA and sser and hope it works the next time.
*/
REG_WRINT_SSER(rw_cfg, 0);
REG_WR_SSER(rw_cfg, cfg);
REG_WRINT_SSER(rw_intr_mask, 0);
REG_WRINT_DI(rw_intr_mask, 0);
REG_WRINT_SSER(rw_ack_intr, -1);
crisv32_reset_dma_hw(hw->dmain.regi);
crisv32_reset_dma_hw(hw->dmaout.regi);
dev_err(&spi->dev, "timeout %u bytes %u kHz\n",
len, hw->effective_speed_kHz);
dev_err(&spi->dev, "sser=(%x,%x,%x,%x,%x)\n",
REG_RDINT_SSER(rw_cfg), REG_RDINT_SSER(rw_tr_cfg),
REG_RDINT_SSER(rw_rec_cfg), REG_RDINT_SSER(rw_extra),
REG_RDINT_SSER(r_intr));
dev_err(&spi->dev, "tx=(%x,%x,%x,%x)\n",
dmaout, REG_RDINT_DO(rw_stat), REG_RDINT_DO(rw_data),
REG_RDINT_DO(r_intr));
dev_err(&spi->dev, "rx=(%x,%x,%x,%x)\n",
dmain, REG_RDINT_DI(rw_stat), REG_RDINT_DI(rw_data),
REG_RDINT_DI(r_intr));
return -EIO;
}
transmission_done:
/* Wait for the last half-cycle of the last cycle. */
crisv32_spi_sser_wait_halfabit(hw);
/* Reset for another call. */
REG_WR_SSER(rw_cfg, cfg);
/*
* If we had to use the temp DMAable rec buffer, copy it to the right
* position.
*/
if (t->rx_buf != 0 && t->rx_dma == 0)
memcpy (t->rx_buf, cs->rx_buf, len);
/*
* All clear. The interrupt function disabled the interrupt, we don't
* have to do more.
*/
return len;
}
/* Platform-device probe function. */
static int __devinit crisv32_spi_sser_probe(struct platform_device *dev)
{
struct spi_master *master;
struct crisv32_spi_sser_devdata *dd;
struct crisv32_spi_hw_info *hw;
struct resource *res;
struct crisv32_spi_sser_controller_data *gc;
int ret;
/*
* We need to get the controller data as a hardware resource,
* or else it wouldn't be available until *after* the
* spi_bitbang_start call!
*/
res = platform_get_resource_byname(dev, 0, "controller_data_ptr");
if (res == NULL) {
dev_err(&dev->dev,
"can't get controller_data resource at probe\n");
return -EIO;
}
gc = (struct crisv32_spi_sser_controller_data *) res->start;
master = spi_alloc_master(&dev->dev, sizeof *dd);
if (master == NULL) {
dev_err(&dev->dev, "failed to allocate spi master\n");
ret = -ENOMEM;
goto err;
}
dd = spi_master_get_devdata(master);
platform_set_drvdata(dev, dd);
/*
* The device data asks for this driver, and holds the id
* number, which must be unique among the same-type devices.
* We use this as the number of this SPI bus.
*/
master->bus_num = dev->id;
/* Setup SPI bitbang adapter hooks. */
dd->bitbang.master = spi_master_get(master);
dd->bitbang.chipselect = crisv32_spi_sser_chip_select_active_low;
hw = &dd->hw;
hw->gc = gc;
/* Pre-spi_bitbang_start setup. */
if (gc->using_dma) {
/* Setup DMA and interrupts. */
ret = gc->iface_allocate(&hw->sser, &hw->dmain, &hw->dmaout);
if (ret != 0)
goto err_no_regs;
dd->bitbang.master->setup = crisv32_spi_sser_dma_master_setup;
dd->bitbang.setup_transfer
= crisv32_spi_sser_common_setup_transfer;
dd->bitbang.txrx_bufs = crisv32_spi_sser_dma_txrx_bufs;
dd->bitbang.master->cleanup = crisv32_spi_sser_dma_cleanup;
} else {
/* Just registers, then. */
ret = gc->iface_allocate(&hw->sser, NULL, NULL);
if (ret != 0)
goto err_no_regs;
dd->bitbang.master->setup
= crisv32_spi_sser_regs_master_setup;
dd->bitbang.setup_transfer
= crisv32_spi_sser_regs_setup_transfer;
dd->bitbang.master->cleanup = spi_bitbang_cleanup;
/*
* We can do all modes pretty simply, but I have no
* simple enough way to test them, so I won't.
*/
dd->bitbang.txrx_word[SPI_MODE_3]
= crisv32_spi_sser_txrx_mode3;
}
ret = spi_bitbang_start(&dd->bitbang);
if (ret)
goto err_no_bitbang;
/*
* We don't have a dev_info here, as initialization that may fail is
* postponed to the first master->setup call. It's called from
* spi_bitbang_start (above), where the call-chain doesn't look too
* close at error return values; we'll get here successfully anyway,
* so emitting a separate message here is at most confusing.
*/
dev_dbg(&dev->dev,
"CRIS v32 SPI driver for sser%d%s present\n",
master->bus_num,
gc->using_dma ? "/DMA" : "");
return 0;
err_no_bitbang:
gc->iface_free();
err_no_regs:
platform_set_drvdata(dev, NULL);
spi_master_put(dd->bitbang.master);
err:
return ret;
}
/* Platform-device remove-function. */
static int __devexit crisv32_spi_sser_remove(struct platform_device *dev)
{
struct crisv32_spi_sser_devdata *dd = platform_get_drvdata(dev);
struct crisv32_spi_hw_info *hw = &dd->hw;
struct crisv32_spi_sser_controller_data *gc = hw->gc;
int ret;
/* We need to stop all bitbanging activity separately. */
ret = spi_bitbang_stop(&dd->bitbang);
if (ret != 0)
return ret;
spi_master_put(dd->bitbang.master);
/*
* If we get here, the queue is empty and there's no activity;
* it's safe to flip the switch on the interfaces.
*/
if (gc->using_dma) {
u32 regi_dmain = hw->dmain.regi;
u32 regi_dmaout = hw->dmaout.regi;
u32 regi_sser = hw->sser.regi;
REG_WRINT_SSER(rw_intr_mask, 0);
REG_WRINT_DI(rw_intr_mask, 0);
REG_WRINT_DO(rw_intr_mask, 0);
hw->cfg.en = 0;
REG_WR_SSER(rw_cfg, hw->cfg);
DMA_RESET(regi_dmain);
DMA_RESET(regi_dmaout);
free_irq(hw->sser.irq, hw);
free_irq(hw->dmain.irq, hw);
}
gc->iface_free();
platform_set_drvdata(dev, NULL);
return 0;
}
/*
* For the time being, there's no suspend/resume support to care
* about, so those handlers default to NULL.
*/
static struct platform_driver crisv32_spi_sser_drv = {
.probe = crisv32_spi_sser_probe,
.remove = __devexit_p(crisv32_spi_sser_remove),
.driver = {
.name = "spi_crisv32_sser",
.owner = THIS_MODULE,
},
};
/* Module init function. */
static int __devinit crisv32_spi_sser_init(void)
{
return platform_driver_register(&crisv32_spi_sser_drv);
}
/* Module exit function. */
static void __devexit crisv32_spi_sser_exit(void)
{
platform_driver_unregister(&crisv32_spi_sser_drv);
}
/* Setter function for speed limit. */
static int crisv32_spi_speed_limit_Hz_setter(const char *val,
struct kernel_param *kp)
{
char *endp;
ulong num = simple_strtoul(val, &endp, 0);
if (endp == val
|| *endp != 0
|| num <= 0
/*
* We can't go above 100 MHz speed. Actually we can't go
* above 50 MHz using the sser support but it might make
* sense trying.
*/
|| num > 100000000)
return -EINVAL;
*(ulong *) kp->arg = num;
return 0;
}
module_param_call(crisv32_spi_max_speed_hz,
crisv32_spi_speed_limit_Hz_setter, param_get_ulong,
&crisv32_spi_speed_limit_Hz, 0644);
module_init(crisv32_spi_sser_init);
module_exit(crisv32_spi_sser_exit);
MODULE_DESCRIPTION("CRIS v32 SPI-SSER Driver");
MODULE_AUTHOR("Hans-Peter Nilsson, <hp@axis.com>");
MODULE_LICENSE("GPL");