X-Git-Url: http://git.rohieb.name/openwrt.git/blobdiff_plain/b75584fa76e7f77be5fde7c8888ef71ad2040ca0..98746e548ec1fab2dcaba8f224a599447bd239ee:/target/linux/etrax/files/drivers/spi/spi_crisv32_sser.c diff --git a/target/linux/etrax/files/drivers/spi/spi_crisv32_sser.c b/target/linux/etrax/files/drivers/spi/spi_crisv32_sser.c deleted file mode 100644 index e8d0e4973..000000000 --- a/target/linux/etrax/files/drivers/spi/spi_crisv32_sser.c +++ /dev/null @@ -1,1566 +0,0 @@ -/* - * 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 -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include -#include - -/* 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, "); -MODULE_LICENSE("GPL");