+++ /dev/null
-/*
- * 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");
projects / openwrt / openwrt.git / commitdiff