diff options
Diffstat (limited to 'drivers/spi/spi-au1550.c')
| -rw-r--r-- | drivers/spi/spi-au1550.c | 1002 |
1 files changed, 1002 insertions, 0 deletions
diff --git a/drivers/spi/spi-au1550.c b/drivers/spi/spi-au1550.c new file mode 100644 index 000000000..f45e085c0 --- /dev/null +++ b/drivers/spi/spi-au1550.c @@ -0,0 +1,1002 @@ +/* + * au1550 psc spi controller driver + * may work also with au1200, au1210, au1250 + * will not work on au1000, au1100 and au1500 (no full spi controller there) + * + * Copyright (c) 2006 ATRON electronic GmbH + * Author: Jan Nikitenko <jan.nikitenko@gmail.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/slab.h> +#include <linux/errno.h> +#include <linux/module.h> +#include <linux/device.h> +#include <linux/platform_device.h> +#include <linux/resource.h> +#include <linux/spi/spi.h> +#include <linux/spi/spi_bitbang.h> +#include <linux/dma-mapping.h> +#include <linux/completion.h> +#include <asm/mach-au1x00/au1000.h> +#include <asm/mach-au1x00/au1xxx_psc.h> +#include <asm/mach-au1x00/au1xxx_dbdma.h> + +#include <asm/mach-au1x00/au1550_spi.h> + +static unsigned usedma = 1; +module_param(usedma, uint, 0644); + +/* +#define AU1550_SPI_DEBUG_LOOPBACK +*/ + + +#define AU1550_SPI_DBDMA_DESCRIPTORS 1 +#define AU1550_SPI_DMA_RXTMP_MINSIZE 2048U + +struct au1550_spi { + struct spi_bitbang bitbang; + + volatile psc_spi_t __iomem *regs; + int irq; + + unsigned len; + unsigned tx_count; + unsigned rx_count; + const u8 *tx; + u8 *rx; + + void (*rx_word)(struct au1550_spi *hw); + void (*tx_word)(struct au1550_spi *hw); + int (*txrx_bufs)(struct spi_device *spi, struct spi_transfer *t); + irqreturn_t (*irq_callback)(struct au1550_spi *hw); + + struct completion master_done; + + unsigned usedma; + u32 dma_tx_id; + u32 dma_rx_id; + u32 dma_tx_ch; + u32 dma_rx_ch; + + u8 *dma_rx_tmpbuf; + unsigned dma_rx_tmpbuf_size; + u32 dma_rx_tmpbuf_addr; + + struct spi_master *master; + struct device *dev; + struct au1550_spi_info *pdata; + struct resource *ioarea; +}; + + +/* we use an 8-bit memory device for dma transfers to/from spi fifo */ +static dbdev_tab_t au1550_spi_mem_dbdev = +{ + .dev_id = DBDMA_MEM_CHAN, + .dev_flags = DEV_FLAGS_ANYUSE|DEV_FLAGS_SYNC, + .dev_tsize = 0, + .dev_devwidth = 8, + .dev_physaddr = 0x00000000, + .dev_intlevel = 0, + .dev_intpolarity = 0 +}; + +static int ddma_memid; /* id to above mem dma device */ + +static void au1550_spi_bits_handlers_set(struct au1550_spi *hw, int bpw); + + +/* + * compute BRG and DIV bits to setup spi clock based on main input clock rate + * that was specified in platform data structure + * according to au1550 datasheet: + * psc_tempclk = psc_mainclk / (2 << DIV) + * spiclk = psc_tempclk / (2 * (BRG + 1)) + * BRG valid range is 4..63 + * DIV valid range is 0..3 + */ +static u32 au1550_spi_baudcfg(struct au1550_spi *hw, unsigned speed_hz) +{ + u32 mainclk_hz = hw->pdata->mainclk_hz; + u32 div, brg; + + for (div = 0; div < 4; div++) { + brg = mainclk_hz / speed_hz / (4 << div); + /* now we have BRG+1 in brg, so count with that */ + if (brg < (4 + 1)) { + brg = (4 + 1); /* speed_hz too big */ + break; /* set lowest brg (div is == 0) */ + } + if (brg <= (63 + 1)) + break; /* we have valid brg and div */ + } + if (div == 4) { + div = 3; /* speed_hz too small */ + brg = (63 + 1); /* set highest brg and div */ + } + brg--; + return PSC_SPICFG_SET_BAUD(brg) | PSC_SPICFG_SET_DIV(div); +} + +static inline void au1550_spi_mask_ack_all(struct au1550_spi *hw) +{ + hw->regs->psc_spimsk = + PSC_SPIMSK_MM | PSC_SPIMSK_RR | PSC_SPIMSK_RO + | PSC_SPIMSK_RU | PSC_SPIMSK_TR | PSC_SPIMSK_TO + | PSC_SPIMSK_TU | PSC_SPIMSK_SD | PSC_SPIMSK_MD; + wmb(); /* drain writebuffer */ + + hw->regs->psc_spievent = + PSC_SPIEVNT_MM | PSC_SPIEVNT_RR | PSC_SPIEVNT_RO + | PSC_SPIEVNT_RU | PSC_SPIEVNT_TR | PSC_SPIEVNT_TO + | PSC_SPIEVNT_TU | PSC_SPIEVNT_SD | PSC_SPIEVNT_MD; + wmb(); /* drain writebuffer */ +} + +static void au1550_spi_reset_fifos(struct au1550_spi *hw) +{ + u32 pcr; + + hw->regs->psc_spipcr = PSC_SPIPCR_RC | PSC_SPIPCR_TC; + wmb(); /* drain writebuffer */ + do { + pcr = hw->regs->psc_spipcr; + wmb(); /* drain writebuffer */ + } while (pcr != 0); +} + +/* + * dma transfers are used for the most common spi word size of 8-bits + * we cannot easily change already set up dma channels' width, so if we wanted + * dma support for more than 8-bit words (up to 24 bits), we would need to + * setup dma channels from scratch on each spi transfer, based on bits_per_word + * instead we have pre set up 8 bit dma channels supporting spi 4 to 8 bits + * transfers, and 9 to 24 bits spi transfers will be done in pio irq based mode + * callbacks to handle dma or pio are set up in au1550_spi_bits_handlers_set() + */ +static void au1550_spi_chipsel(struct spi_device *spi, int value) +{ + struct au1550_spi *hw = spi_master_get_devdata(spi->master); + unsigned cspol = spi->mode & SPI_CS_HIGH ? 1 : 0; + u32 cfg, stat; + + switch (value) { + case BITBANG_CS_INACTIVE: + if (hw->pdata->deactivate_cs) + hw->pdata->deactivate_cs(hw->pdata, spi->chip_select, + cspol); + break; + + case BITBANG_CS_ACTIVE: + au1550_spi_bits_handlers_set(hw, spi->bits_per_word); + + cfg = hw->regs->psc_spicfg; + wmb(); /* drain writebuffer */ + hw->regs->psc_spicfg = cfg & ~PSC_SPICFG_DE_ENABLE; + wmb(); /* drain writebuffer */ + + if (spi->mode & SPI_CPOL) + cfg |= PSC_SPICFG_BI; + else + cfg &= ~PSC_SPICFG_BI; + if (spi->mode & SPI_CPHA) + cfg &= ~PSC_SPICFG_CDE; + else + cfg |= PSC_SPICFG_CDE; + + if (spi->mode & SPI_LSB_FIRST) + cfg |= PSC_SPICFG_MLF; + else + cfg &= ~PSC_SPICFG_MLF; + + if (hw->usedma && spi->bits_per_word <= 8) + cfg &= ~PSC_SPICFG_DD_DISABLE; + else + cfg |= PSC_SPICFG_DD_DISABLE; + cfg = PSC_SPICFG_CLR_LEN(cfg); + cfg |= PSC_SPICFG_SET_LEN(spi->bits_per_word); + + cfg = PSC_SPICFG_CLR_BAUD(cfg); + cfg &= ~PSC_SPICFG_SET_DIV(3); + cfg |= au1550_spi_baudcfg(hw, spi->max_speed_hz); + + hw->regs->psc_spicfg = cfg | PSC_SPICFG_DE_ENABLE; + wmb(); /* drain writebuffer */ + do { + stat = hw->regs->psc_spistat; + wmb(); /* drain writebuffer */ + } while ((stat & PSC_SPISTAT_DR) == 0); + + if (hw->pdata->activate_cs) + hw->pdata->activate_cs(hw->pdata, spi->chip_select, + cspol); + break; + } +} + +static int au1550_spi_setupxfer(struct spi_device *spi, struct spi_transfer *t) +{ + struct au1550_spi *hw = spi_master_get_devdata(spi->master); + unsigned bpw, hz; + u32 cfg, stat; + + bpw = spi->bits_per_word; + hz = spi->max_speed_hz; + if (t) { + if (t->bits_per_word) + bpw = t->bits_per_word; + if (t->speed_hz) + hz = t->speed_hz; + } + + if (!hz) + return -EINVAL; + + au1550_spi_bits_handlers_set(hw, spi->bits_per_word); + + cfg = hw->regs->psc_spicfg; + wmb(); /* drain writebuffer */ + hw->regs->psc_spicfg = cfg & ~PSC_SPICFG_DE_ENABLE; + wmb(); /* drain writebuffer */ + + if (hw->usedma && bpw <= 8) + cfg &= ~PSC_SPICFG_DD_DISABLE; + else + cfg |= PSC_SPICFG_DD_DISABLE; + cfg = PSC_SPICFG_CLR_LEN(cfg); + cfg |= PSC_SPICFG_SET_LEN(bpw); + + cfg = PSC_SPICFG_CLR_BAUD(cfg); + cfg &= ~PSC_SPICFG_SET_DIV(3); + cfg |= au1550_spi_baudcfg(hw, hz); + + hw->regs->psc_spicfg = cfg; + wmb(); /* drain writebuffer */ + + if (cfg & PSC_SPICFG_DE_ENABLE) { + do { + stat = hw->regs->psc_spistat; + wmb(); /* drain writebuffer */ + } while ((stat & PSC_SPISTAT_DR) == 0); + } + + au1550_spi_reset_fifos(hw); + au1550_spi_mask_ack_all(hw); + return 0; +} + +/* + * for dma spi transfers, we have to setup rx channel, otherwise there is + * no reliable way how to recognize that spi transfer is done + * dma complete callbacks are called before real spi transfer is finished + * and if only tx dma channel is set up (and rx fifo overflow event masked) + * spi master done event irq is not generated unless rx fifo is empty (emptied) + * so we need rx tmp buffer to use for rx dma if user does not provide one + */ +static int au1550_spi_dma_rxtmp_alloc(struct au1550_spi *hw, unsigned size) +{ + hw->dma_rx_tmpbuf = kmalloc(size, GFP_KERNEL); + if (!hw->dma_rx_tmpbuf) + return -ENOMEM; + hw->dma_rx_tmpbuf_size = size; + hw->dma_rx_tmpbuf_addr = dma_map_single(hw->dev, hw->dma_rx_tmpbuf, + size, DMA_FROM_DEVICE); + if (dma_mapping_error(hw->dev, hw->dma_rx_tmpbuf_addr)) { + kfree(hw->dma_rx_tmpbuf); + hw->dma_rx_tmpbuf = 0; + hw->dma_rx_tmpbuf_size = 0; + return -EFAULT; + } + return 0; +} + +static void au1550_spi_dma_rxtmp_free(struct au1550_spi *hw) +{ + dma_unmap_single(hw->dev, hw->dma_rx_tmpbuf_addr, + hw->dma_rx_tmpbuf_size, DMA_FROM_DEVICE); + kfree(hw->dma_rx_tmpbuf); + hw->dma_rx_tmpbuf = 0; + hw->dma_rx_tmpbuf_size = 0; +} + +static int au1550_spi_dma_txrxb(struct spi_device *spi, struct spi_transfer *t) +{ + struct au1550_spi *hw = spi_master_get_devdata(spi->master); + dma_addr_t dma_tx_addr; + dma_addr_t dma_rx_addr; + u32 res; + + hw->len = t->len; + hw->tx_count = 0; + hw->rx_count = 0; + + hw->tx = t->tx_buf; + hw->rx = t->rx_buf; + dma_tx_addr = t->tx_dma; + dma_rx_addr = t->rx_dma; + + /* + * check if buffers are already dma mapped, map them otherwise: + * - first map the TX buffer, so cache data gets written to memory + * - then map the RX buffer, so that cache entries (with + * soon-to-be-stale data) get removed + * use rx buffer in place of tx if tx buffer was not provided + * use temp rx buffer (preallocated or realloc to fit) for rx dma + */ + if (t->tx_buf) { + if (t->tx_dma == 0) { /* if DMA_ADDR_INVALID, map it */ + dma_tx_addr = dma_map_single(hw->dev, + (void *)t->tx_buf, + t->len, DMA_TO_DEVICE); + if (dma_mapping_error(hw->dev, dma_tx_addr)) + dev_err(hw->dev, "tx dma map error\n"); + } + } + + if (t->rx_buf) { + if (t->rx_dma == 0) { /* if DMA_ADDR_INVALID, map it */ + dma_rx_addr = dma_map_single(hw->dev, + (void *)t->rx_buf, + t->len, DMA_FROM_DEVICE); + if (dma_mapping_error(hw->dev, dma_rx_addr)) + dev_err(hw->dev, "rx dma map error\n"); + } + } else { + if (t->len > hw->dma_rx_tmpbuf_size) { + int ret; + + au1550_spi_dma_rxtmp_free(hw); + ret = au1550_spi_dma_rxtmp_alloc(hw, max(t->len, + AU1550_SPI_DMA_RXTMP_MINSIZE)); + if (ret < 0) + return ret; + } + hw->rx = hw->dma_rx_tmpbuf; + dma_rx_addr = hw->dma_rx_tmpbuf_addr; + dma_sync_single_for_device(hw->dev, dma_rx_addr, + t->len, DMA_FROM_DEVICE); + } + + if (!t->tx_buf) { + dma_sync_single_for_device(hw->dev, dma_rx_addr, + t->len, DMA_BIDIRECTIONAL); + hw->tx = hw->rx; + } + + /* put buffers on the ring */ + res = au1xxx_dbdma_put_dest(hw->dma_rx_ch, virt_to_phys(hw->rx), + t->len, DDMA_FLAGS_IE); + if (!res) + dev_err(hw->dev, "rx dma put dest error\n"); + + res = au1xxx_dbdma_put_source(hw->dma_tx_ch, virt_to_phys(hw->tx), + t->len, DDMA_FLAGS_IE); + if (!res) + dev_err(hw->dev, "tx dma put source error\n"); + + au1xxx_dbdma_start(hw->dma_rx_ch); + au1xxx_dbdma_start(hw->dma_tx_ch); + + /* by default enable nearly all events interrupt */ + hw->regs->psc_spimsk = PSC_SPIMSK_SD; + wmb(); /* drain writebuffer */ + + /* start the transfer */ + hw->regs->psc_spipcr = PSC_SPIPCR_MS; + wmb(); /* drain writebuffer */ + + wait_for_completion(&hw->master_done); + + au1xxx_dbdma_stop(hw->dma_tx_ch); + au1xxx_dbdma_stop(hw->dma_rx_ch); + + if (!t->rx_buf) { + /* using the temporal preallocated and premapped buffer */ + dma_sync_single_for_cpu(hw->dev, dma_rx_addr, t->len, + DMA_FROM_DEVICE); + } + /* unmap buffers if mapped above */ + if (t->rx_buf && t->rx_dma == 0 ) + dma_unmap_single(hw->dev, dma_rx_addr, t->len, + DMA_FROM_DEVICE); + if (t->tx_buf && t->tx_dma == 0 ) + dma_unmap_single(hw->dev, dma_tx_addr, t->len, + DMA_TO_DEVICE); + + return hw->rx_count < hw->tx_count ? hw->rx_count : hw->tx_count; +} + +static irqreturn_t au1550_spi_dma_irq_callback(struct au1550_spi *hw) +{ + u32 stat, evnt; + + stat = hw->regs->psc_spistat; + evnt = hw->regs->psc_spievent; + wmb(); /* drain writebuffer */ + if ((stat & PSC_SPISTAT_DI) == 0) { + dev_err(hw->dev, "Unexpected IRQ!\n"); + return IRQ_NONE; + } + + if ((evnt & (PSC_SPIEVNT_MM | PSC_SPIEVNT_RO + | PSC_SPIEVNT_RU | PSC_SPIEVNT_TO + | PSC_SPIEVNT_TU | PSC_SPIEVNT_SD)) + != 0) { + /* + * due to an spi error we consider transfer as done, + * so mask all events until before next transfer start + * and stop the possibly running dma immediately + */ + au1550_spi_mask_ack_all(hw); + au1xxx_dbdma_stop(hw->dma_rx_ch); + au1xxx_dbdma_stop(hw->dma_tx_ch); + + /* get number of transferred bytes */ + hw->rx_count = hw->len - au1xxx_get_dma_residue(hw->dma_rx_ch); + hw->tx_count = hw->len - au1xxx_get_dma_residue(hw->dma_tx_ch); + + au1xxx_dbdma_reset(hw->dma_rx_ch); + au1xxx_dbdma_reset(hw->dma_tx_ch); + au1550_spi_reset_fifos(hw); + + if (evnt == PSC_SPIEVNT_RO) + dev_err(hw->dev, + "dma transfer: receive FIFO overflow!\n"); + else + dev_err(hw->dev, + "dma transfer: unexpected SPI error " + "(event=0x%x stat=0x%x)!\n", evnt, stat); + + complete(&hw->master_done); + return IRQ_HANDLED; + } + + if ((evnt & PSC_SPIEVNT_MD) != 0) { + /* transfer completed successfully */ + au1550_spi_mask_ack_all(hw); + hw->rx_count = hw->len; + hw->tx_count = hw->len; + complete(&hw->master_done); + } + return IRQ_HANDLED; +} + + +/* routines to handle different word sizes in pio mode */ +#define AU1550_SPI_RX_WORD(size, mask) \ +static void au1550_spi_rx_word_##size(struct au1550_spi *hw) \ +{ \ + u32 fifoword = hw->regs->psc_spitxrx & (u32)(mask); \ + wmb(); /* drain writebuffer */ \ + if (hw->rx) { \ + *(u##size *)hw->rx = (u##size)fifoword; \ + hw->rx += (size) / 8; \ + } \ + hw->rx_count += (size) / 8; \ +} + +#define AU1550_SPI_TX_WORD(size, mask) \ +static void au1550_spi_tx_word_##size(struct au1550_spi *hw) \ +{ \ + u32 fifoword = 0; \ + if (hw->tx) { \ + fifoword = *(u##size *)hw->tx & (u32)(mask); \ + hw->tx += (size) / 8; \ + } \ + hw->tx_count += (size) / 8; \ + if (hw->tx_count >= hw->len) \ + fifoword |= PSC_SPITXRX_LC; \ + hw->regs->psc_spitxrx = fifoword; \ + wmb(); /* drain writebuffer */ \ +} + +AU1550_SPI_RX_WORD(8,0xff) +AU1550_SPI_RX_WORD(16,0xffff) +AU1550_SPI_RX_WORD(32,0xffffff) +AU1550_SPI_TX_WORD(8,0xff) +AU1550_SPI_TX_WORD(16,0xffff) +AU1550_SPI_TX_WORD(32,0xffffff) + +static int au1550_spi_pio_txrxb(struct spi_device *spi, struct spi_transfer *t) +{ + u32 stat, mask; + struct au1550_spi *hw = spi_master_get_devdata(spi->master); + + hw->tx = t->tx_buf; + hw->rx = t->rx_buf; + hw->len = t->len; + hw->tx_count = 0; + hw->rx_count = 0; + + /* by default enable nearly all events after filling tx fifo */ + mask = PSC_SPIMSK_SD; + + /* fill the transmit FIFO */ + while (hw->tx_count < hw->len) { + + hw->tx_word(hw); + + if (hw->tx_count >= hw->len) { + /* mask tx fifo request interrupt as we are done */ + mask |= PSC_SPIMSK_TR; + } + + stat = hw->regs->psc_spistat; + wmb(); /* drain writebuffer */ + if (stat & PSC_SPISTAT_TF) + break; + } + + /* enable event interrupts */ + hw->regs->psc_spimsk = mask; + wmb(); /* drain writebuffer */ + + /* start the transfer */ + hw->regs->psc_spipcr = PSC_SPIPCR_MS; + wmb(); /* drain writebuffer */ + + wait_for_completion(&hw->master_done); + + return hw->rx_count < hw->tx_count ? hw->rx_count : hw->tx_count; +} + +static irqreturn_t au1550_spi_pio_irq_callback(struct au1550_spi *hw) +{ + int busy; + u32 stat, evnt; + + stat = hw->regs->psc_spistat; + evnt = hw->regs->psc_spievent; + wmb(); /* drain writebuffer */ + if ((stat & PSC_SPISTAT_DI) == 0) { + dev_err(hw->dev, "Unexpected IRQ!\n"); + return IRQ_NONE; + } + + if ((evnt & (PSC_SPIEVNT_MM | PSC_SPIEVNT_RO + | PSC_SPIEVNT_RU | PSC_SPIEVNT_TO + | PSC_SPIEVNT_SD)) + != 0) { + /* + * due to an error we consider transfer as done, + * so mask all events until before next transfer start + */ + au1550_spi_mask_ack_all(hw); + au1550_spi_reset_fifos(hw); + dev_err(hw->dev, + "pio transfer: unexpected SPI error " + "(event=0x%x stat=0x%x)!\n", evnt, stat); + complete(&hw->master_done); + return IRQ_HANDLED; + } + + /* + * while there is something to read from rx fifo + * or there is a space to write to tx fifo: + */ + do { + busy = 0; + stat = hw->regs->psc_spistat; + wmb(); /* drain writebuffer */ + + /* + * Take care to not let the Rx FIFO overflow. + * + * We only write a byte if we have read one at least. Initially, + * the write fifo is full, so we should read from the read fifo + * first. + * In case we miss a word from the read fifo, we should get a + * RO event and should back out. + */ + if (!(stat & PSC_SPISTAT_RE) && hw->rx_count < hw->len) { + hw->rx_word(hw); + busy = 1; + + if (!(stat & PSC_SPISTAT_TF) && hw->tx_count < hw->len) + hw->tx_word(hw); + } + } while (busy); + + hw->regs->psc_spievent = PSC_SPIEVNT_RR | PSC_SPIEVNT_TR; + wmb(); /* drain writebuffer */ + + /* + * Restart the SPI transmission in case of a transmit underflow. + * This seems to work despite the notes in the Au1550 data book + * of Figure 8-4 with flowchart for SPI master operation: + * + * """Note 1: An XFR Error Interrupt occurs, unless masked, + * for any of the following events: Tx FIFO Underflow, + * Rx FIFO Overflow, or Multiple-master Error + * Note 2: In case of a Tx Underflow Error, all zeroes are + * transmitted.""" + * + * By simply restarting the spi transfer on Tx Underflow Error, + * we assume that spi transfer was paused instead of zeroes + * transmittion mentioned in the Note 2 of Au1550 data book. + */ + if (evnt & PSC_SPIEVNT_TU) { + hw->regs->psc_spievent = PSC_SPIEVNT_TU | PSC_SPIEVNT_MD; + wmb(); /* drain writebuffer */ + hw->regs->psc_spipcr = PSC_SPIPCR_MS; + wmb(); /* drain writebuffer */ + } + + if (hw->rx_count >= hw->len) { + /* transfer completed successfully */ + au1550_spi_mask_ack_all(hw); + complete(&hw->master_done); + } + return IRQ_HANDLED; +} + +static int au1550_spi_txrx_bufs(struct spi_device *spi, struct spi_transfer *t) +{ + struct au1550_spi *hw = spi_master_get_devdata(spi->master); + return hw->txrx_bufs(spi, t); +} + +static irqreturn_t au1550_spi_irq(int irq, void *dev) +{ + struct au1550_spi *hw = dev; + return hw->irq_callback(hw); +} + +static void au1550_spi_bits_handlers_set(struct au1550_spi *hw, int bpw) +{ + if (bpw <= 8) { + if (hw->usedma) { + hw->txrx_bufs = &au1550_spi_dma_txrxb; + hw->irq_callback = &au1550_spi_dma_irq_callback; + } else { + hw->rx_word = &au1550_spi_rx_word_8; + hw->tx_word = &au1550_spi_tx_word_8; + hw->txrx_bufs = &au1550_spi_pio_txrxb; + hw->irq_callback = &au1550_spi_pio_irq_callback; + } + } else if (bpw <= 16) { + hw->rx_word = &au1550_spi_rx_word_16; + hw->tx_word = &au1550_spi_tx_word_16; + hw->txrx_bufs = &au1550_spi_pio_txrxb; + hw->irq_callback = &au1550_spi_pio_irq_callback; + } else { + hw->rx_word = &au1550_spi_rx_word_32; + hw->tx_word = &au1550_spi_tx_word_32; + hw->txrx_bufs = &au1550_spi_pio_txrxb; + hw->irq_callback = &au1550_spi_pio_irq_callback; + } +} + +static void au1550_spi_setup_psc_as_spi(struct au1550_spi *hw) +{ + u32 stat, cfg; + + /* set up the PSC for SPI mode */ + hw->regs->psc_ctrl = PSC_CTRL_DISABLE; + wmb(); /* drain writebuffer */ + hw->regs->psc_sel = PSC_SEL_PS_SPIMODE; + wmb(); /* drain writebuffer */ + + hw->regs->psc_spicfg = 0; + wmb(); /* drain writebuffer */ + + hw->regs->psc_ctrl = PSC_CTRL_ENABLE; + wmb(); /* drain writebuffer */ + + do { + stat = hw->regs->psc_spistat; + wmb(); /* drain writebuffer */ + } while ((stat & PSC_SPISTAT_SR) == 0); + + + cfg = hw->usedma ? 0 : PSC_SPICFG_DD_DISABLE; + cfg |= PSC_SPICFG_SET_LEN(8); + cfg |= PSC_SPICFG_RT_FIFO8 | PSC_SPICFG_TT_FIFO8; + /* use minimal allowed brg and div values as initial setting: */ + cfg |= PSC_SPICFG_SET_BAUD(4) | PSC_SPICFG_SET_DIV(0); + +#ifdef AU1550_SPI_DEBUG_LOOPBACK + cfg |= PSC_SPICFG_LB; +#endif + + hw->regs->psc_spicfg = cfg; + wmb(); /* drain writebuffer */ + + au1550_spi_mask_ack_all(hw); + + hw->regs->psc_spicfg |= PSC_SPICFG_DE_ENABLE; + wmb(); /* drain writebuffer */ + + do { + stat = hw->regs->psc_spistat; + wmb(); /* drain writebuffer */ + } while ((stat & PSC_SPISTAT_DR) == 0); + + au1550_spi_reset_fifos(hw); +} + + +static int au1550_spi_probe(struct platform_device *pdev) +{ + struct au1550_spi *hw; + struct spi_master *master; + struct resource *r; + int err = 0; + + master = spi_alloc_master(&pdev->dev, sizeof(struct au1550_spi)); + if (master == NULL) { + dev_err(&pdev->dev, "No memory for spi_master\n"); + err = -ENOMEM; + goto err_nomem; + } + + /* the spi->mode bits understood by this driver: */ + master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST; + master->bits_per_word_mask = SPI_BPW_RANGE_MASK(4, 24); + + hw = spi_master_get_devdata(master); + + hw->master = master; + hw->pdata = dev_get_platdata(&pdev->dev); + hw->dev = &pdev->dev; + + if (hw->pdata == NULL) { + dev_err(&pdev->dev, "No platform data supplied\n"); + err = -ENOENT; + goto err_no_pdata; + } + + r = platform_get_resource(pdev, IORESOURCE_IRQ, 0); + if (!r) { + dev_err(&pdev->dev, "no IRQ\n"); + err = -ENODEV; + goto err_no_iores; + } + hw->irq = r->start; + + hw->usedma = 0; + r = platform_get_resource(pdev, IORESOURCE_DMA, 0); + if (r) { + hw->dma_tx_id = r->start; + r = platform_get_resource(pdev, IORESOURCE_DMA, 1); + if (r) { + hw->dma_rx_id = r->start; + if (usedma && ddma_memid) { + if (pdev->dev.dma_mask == NULL) + dev_warn(&pdev->dev, "no dma mask\n"); + else + hw->usedma = 1; + } + } + } + + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!r) { + dev_err(&pdev->dev, "no mmio resource\n"); + err = -ENODEV; + goto err_no_iores; + } + + hw->ioarea = request_mem_region(r->start, sizeof(psc_spi_t), + pdev->name); + if (!hw->ioarea) { + dev_err(&pdev->dev, "Cannot reserve iomem region\n"); + err = -ENXIO; + goto err_no_iores; + } + + hw->regs = (psc_spi_t __iomem *)ioremap(r->start, sizeof(psc_spi_t)); + if (!hw->regs) { + dev_err(&pdev->dev, "cannot ioremap\n"); + err = -ENXIO; + goto err_ioremap; + } + + platform_set_drvdata(pdev, hw); + + init_completion(&hw->master_done); + + hw->bitbang.master = hw->master; + hw->bitbang.setup_transfer = au1550_spi_setupxfer; + hw->bitbang.chipselect = au1550_spi_chipsel; + hw->bitbang.txrx_bufs = au1550_spi_txrx_bufs; + + if (hw->usedma) { + hw->dma_tx_ch = au1xxx_dbdma_chan_alloc(ddma_memid, + hw->dma_tx_id, NULL, (void *)hw); + if (hw->dma_tx_ch == 0) { + dev_err(&pdev->dev, + "Cannot allocate tx dma channel\n"); + err = -ENXIO; + goto err_no_txdma; + } + au1xxx_dbdma_set_devwidth(hw->dma_tx_ch, 8); + if (au1xxx_dbdma_ring_alloc(hw->dma_tx_ch, + AU1550_SPI_DBDMA_DESCRIPTORS) == 0) { + dev_err(&pdev->dev, + "Cannot allocate tx dma descriptors\n"); + err = -ENXIO; + goto err_no_txdma_descr; + } + + + hw->dma_rx_ch = au1xxx_dbdma_chan_alloc(hw->dma_rx_id, + ddma_memid, NULL, (void *)hw); + if (hw->dma_rx_ch == 0) { + dev_err(&pdev->dev, + "Cannot allocate rx dma channel\n"); + err = -ENXIO; + goto err_no_rxdma; + } + au1xxx_dbdma_set_devwidth(hw->dma_rx_ch, 8); + if (au1xxx_dbdma_ring_alloc(hw->dma_rx_ch, + AU1550_SPI_DBDMA_DESCRIPTORS) == 0) { + dev_err(&pdev->dev, + "Cannot allocate rx dma descriptors\n"); + err = -ENXIO; + goto err_no_rxdma_descr; + } + + err = au1550_spi_dma_rxtmp_alloc(hw, + AU1550_SPI_DMA_RXTMP_MINSIZE); + if (err < 0) { + dev_err(&pdev->dev, + "Cannot allocate initial rx dma tmp buffer\n"); + goto err_dma_rxtmp_alloc; + } + } + + au1550_spi_bits_handlers_set(hw, 8); + + err = request_irq(hw->irq, au1550_spi_irq, 0, pdev->name, hw); + if (err) { + dev_err(&pdev->dev, "Cannot claim IRQ\n"); + goto err_no_irq; + } + + master->bus_num = pdev->id; + master->num_chipselect = hw->pdata->num_chipselect; + + /* + * precompute valid range for spi freq - from au1550 datasheet: + * psc_tempclk = psc_mainclk / (2 << DIV) + * spiclk = psc_tempclk / (2 * (BRG + 1)) + * BRG valid range is 4..63 + * DIV valid range is 0..3 + * round the min and max frequencies to values that would still + * produce valid brg and div + */ + { + int min_div = (2 << 0) * (2 * (4 + 1)); + int max_div = (2 << 3) * (2 * (63 + 1)); + master->max_speed_hz = hw->pdata->mainclk_hz / min_div; + master->min_speed_hz = + hw->pdata->mainclk_hz / (max_div + 1) + 1; + } + + au1550_spi_setup_psc_as_spi(hw); + + err = spi_bitbang_start(&hw->bitbang); + if (err) { + dev_err(&pdev->dev, "Failed to register SPI master\n"); + goto err_register; + } + + dev_info(&pdev->dev, + "spi master registered: bus_num=%d num_chipselect=%d\n", + master->bus_num, master->num_chipselect); + + return 0; + +err_register: + free_irq(hw->irq, hw); + +err_no_irq: + au1550_spi_dma_rxtmp_free(hw); + +err_dma_rxtmp_alloc: +err_no_rxdma_descr: + if (hw->usedma) + au1xxx_dbdma_chan_free(hw->dma_rx_ch); + +err_no_rxdma: +err_no_txdma_descr: + if (hw->usedma) + au1xxx_dbdma_chan_free(hw->dma_tx_ch); + +err_no_txdma: + iounmap((void __iomem *)hw->regs); + +err_ioremap: + release_mem_region(r->start, sizeof(psc_spi_t)); + +err_no_iores: +err_no_pdata: + spi_master_put(hw->master); + +err_nomem: + return err; +} + +static int au1550_spi_remove(struct platform_device *pdev) +{ + struct au1550_spi *hw = platform_get_drvdata(pdev); + + dev_info(&pdev->dev, "spi master remove: bus_num=%d\n", + hw->master->bus_num); + + spi_bitbang_stop(&hw->bitbang); + free_irq(hw->irq, hw); + iounmap((void __iomem *)hw->regs); + release_mem_region(hw->ioarea->start, sizeof(psc_spi_t)); + + if (hw->usedma) { + au1550_spi_dma_rxtmp_free(hw); + au1xxx_dbdma_chan_free(hw->dma_rx_ch); + au1xxx_dbdma_chan_free(hw->dma_tx_ch); + } + + spi_master_put(hw->master); + return 0; +} + +/* work with hotplug and coldplug */ +MODULE_ALIAS("platform:au1550-spi"); + +static struct platform_driver au1550_spi_drv = { + .probe = au1550_spi_probe, + .remove = au1550_spi_remove, + .driver = { + .name = "au1550-spi", + }, +}; + +static int __init au1550_spi_init(void) +{ + /* + * create memory device with 8 bits dev_devwidth + * needed for proper byte ordering to spi fifo + */ + switch (alchemy_get_cputype()) { + case ALCHEMY_CPU_AU1550: + case ALCHEMY_CPU_AU1200: + case ALCHEMY_CPU_AU1300: + break; + default: + return -ENODEV; + } + + if (usedma) { + ddma_memid = au1xxx_ddma_add_device(&au1550_spi_mem_dbdev); + if (!ddma_memid) + printk(KERN_ERR "au1550-spi: cannot add memory" + "dbdma device\n"); + } + return platform_driver_register(&au1550_spi_drv); +} +module_init(au1550_spi_init); + +static void __exit au1550_spi_exit(void) +{ + if (usedma && ddma_memid) + au1xxx_ddma_del_device(ddma_memid); + platform_driver_unregister(&au1550_spi_drv); +} +module_exit(au1550_spi_exit); + +MODULE_DESCRIPTION("Au1550 PSC SPI Driver"); +MODULE_AUTHOR("Jan Nikitenko <jan.nikitenko@gmail.com>"); +MODULE_LICENSE("GPL"); |