--- /dev/null
+/*
+ * au1550_spi.c - 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/errno.h>
+#include <linux/device.h>
+#include <linux/platform_device.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 freq_max;
+ unsigned freq_min;
+
+ 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;
+};
+
+
+/* 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 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;
+ au_sync();
+
+ 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;
+ au_sync();
+}
+
+static void au1550_spi_reset_fifos(struct au1550_spi *hw)
+{
+ u32 pcr;
+
+ hw->regs->psc_spipcr = PSC_SPIPCR_RC | PSC_SPIPCR_TC;
+ au_sync();
+ do {
+ pcr = hw->regs->psc_spipcr;
+ au_sync();
+ } 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;
+ au_sync();
+ hw->regs->psc_spicfg = cfg & ~PSC_SPICFG_DE_ENABLE;
+ au_sync();
+
+ 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;
+ au_sync();
+ do {
+ stat = hw->regs->psc_spistat;
+ au_sync();
+ } 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 = t ? t->bits_per_word : spi->bits_per_word;
+ hz = t ? t->speed_hz : spi->max_speed_hz;
+
+ if (bpw < 4 || bpw > 24) {
+ dev_err(&spi->dev, "setupxfer: invalid bits_per_word=%d\n",
+ bpw);
+ return -EINVAL;
+ }
+ if (hz > spi->max_speed_hz || hz > hw->freq_max || hz < hw->freq_min) {
+ dev_err(&spi->dev, "setupxfer: clock rate=%d out of range\n",
+ hz);
+ return -EINVAL;
+ }
+
+ au1550_spi_bits_handlers_set(hw, spi->bits_per_word);
+
+ cfg = hw->regs->psc_spicfg;
+ au_sync();
+ hw->regs->psc_spicfg = cfg & ~PSC_SPICFG_DE_ENABLE;
+ au_sync();
+
+ 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;
+ au_sync();
+
+ if (cfg & PSC_SPICFG_DE_ENABLE) {
+ do {
+ stat = hw->regs->psc_spistat;
+ au_sync();
+ } while ((stat & PSC_SPISTAT_DR) == 0);
+ }
+
+ au1550_spi_reset_fifos(hw);
+ au1550_spi_mask_ack_all(hw);
+ return 0;
+}
+
+static int au1550_spi_setup(struct spi_device *spi)
+{
+ struct au1550_spi *hw = spi_master_get_devdata(spi->master);
+
+ if (spi->bits_per_word == 0)
+ spi->bits_per_word = 8;
+ if (spi->bits_per_word < 4 || spi->bits_per_word > 24) {
+ dev_err(&spi->dev, "setup: invalid bits_per_word=%d\n",
+ spi->bits_per_word);
+ return -EINVAL;
+ }
+
+ if (spi->max_speed_hz == 0)
+ spi->max_speed_hz = hw->freq_max;
+ if (spi->max_speed_hz > hw->freq_max
+ || spi->max_speed_hz < hw->freq_min)
+ return -EINVAL;
+ /*
+ * NOTE: cannot change speed and other hw settings immediately,
+ * otherwise sharing of spi bus is not possible,
+ * so do not call setupxfer(spi, NULL) here
+ */
+ 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->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
+ * 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->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(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) {
+ 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(dma_tx_addr))
+ dev_err(hw->dev, "tx dma map error\n");
+ }
+ } else {
+ 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, hw->rx, t->len);
+ if (!res)
+ dev_err(hw->dev, "rx dma put dest error\n");
+
+ res = au1xxx_dbdma_put_source(hw->dma_tx_ch, (void *)hw->tx, t->len);
+ 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;
+ au_sync();
+
+ /* start the transfer */
+ hw->regs->psc_spipcr = PSC_SPIPCR_MS;
+ au_sync();
+
+ 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;
+ au_sync();
+ 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 immediatelly
+ */
+ au1550_spi_mask_ack_all(hw);
+ au1xxx_dbdma_stop(hw->dma_rx_ch);
+ au1xxx_dbdma_stop(hw->dma_tx_ch);
+
+ /* get number of transfered 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);
+
+ dev_err(hw->dev,
+ "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); \
+ au_sync(); \
+ 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; \
+ au_sync(); \
+}
+
+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;
+ au_sync();
+ if (stat & PSC_SPISTAT_TF)
+ break;
+ }
+
+ /* enable event interrupts */
+ hw->regs->psc_spimsk = mask;
+ au_sync();
+
+ /* start the transfer */
+ hw->regs->psc_spipcr = PSC_SPIPCR_MS;
+ au_sync();
+
+ 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;
+ au_sync();
+ 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) {
+ dev_err(hw->dev,
+ "Unexpected SPI error: event=0x%x stat=0x%x!\n",
+ evnt, stat);
+ /*
+ * 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);
+ 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;
+ au_sync();
+
+ if ((stat & PSC_SPISTAT_RE) == 0 && hw->rx_count < hw->len) {
+ hw->rx_word(hw);
+ /* ack the receive request event */
+ hw->regs->psc_spievent = PSC_SPIEVNT_RR;
+ au_sync();
+ busy = 1;
+ }
+
+ if ((stat & PSC_SPISTAT_TF) == 0 && hw->tx_count < hw->len) {
+ hw->tx_word(hw);
+ /* ack the transmit request event */
+ hw->regs->psc_spievent = PSC_SPIEVNT_TR;
+ au_sync();
+ busy = 1;
+ }
+ } while (busy);
+
+ evnt = hw->regs->psc_spievent;
+ au_sync();
+
+ if (hw->rx_count >= hw->len || (evnt & PSC_SPIEVNT_MD) != 0) {
+ /* 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 pt_regs *regs)
+{
+ 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 __init 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;
+ au_sync();
+ hw->regs->psc_sel = PSC_SEL_PS_SPIMODE;
+ au_sync();
+
+ hw->regs->psc_spicfg = 0;
+ au_sync();
+
+ hw->regs->psc_ctrl = PSC_CTRL_ENABLE;
+ au_sync();
+
+ do {
+ stat = hw->regs->psc_spistat;
+ au_sync();
+ } 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;
+ au_sync();
+
+ au1550_spi_mask_ack_all(hw);
+
+ hw->regs->psc_spicfg |= PSC_SPICFG_DE_ENABLE;
+ au_sync();
+
+ do {
+ stat = hw->regs->psc_spistat;
+ au_sync();
+ } while ((stat & PSC_SPISTAT_DR) == 0);
+}
+
+
+static int __init au1550_spi_probe(struct platform_device *pdev)
+{
+ struct au1550_spi *hw;
+ struct spi_master *master;
+ 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;
+ }
+
+ hw = spi_master_get_devdata(master);
+
+ hw->master = spi_master_get(master);
+ hw->pdata = pdev->dev.platform_data;
+ hw->dev = &pdev->dev;
+
+ if (hw->pdata == NULL) {
+ dev_err(&pdev->dev, "No platform data supplied\n");
+ err = -ENOENT;
+ goto err_no_pdata;
+ }
+
+ 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.master->setup = au1550_spi_setup;
+ hw->bitbang.txrx_bufs = au1550_spi_txrx_bufs;
+
+ switch (hw->pdata->bus_num) {
+ case 0:
+ hw->irq = AU1550_PSC0_INT;
+ hw->regs = (volatile psc_spi_t *)PSC0_BASE_ADDR;
+ hw->dma_rx_id = DSCR_CMD0_PSC0_RX;
+ hw->dma_tx_id = DSCR_CMD0_PSC0_TX;
+ break;
+ case 1:
+ hw->irq = AU1550_PSC1_INT;
+ hw->regs = (volatile psc_spi_t *)PSC1_BASE_ADDR;
+ hw->dma_rx_id = DSCR_CMD0_PSC1_RX;
+ hw->dma_tx_id = DSCR_CMD0_PSC1_TX;
+ break;
+ case 2:
+ hw->irq = AU1550_PSC2_INT;
+ hw->regs = (volatile psc_spi_t *)PSC2_BASE_ADDR;
+ hw->dma_rx_id = DSCR_CMD0_PSC2_RX;
+ hw->dma_tx_id = DSCR_CMD0_PSC2_TX;
+ break;
+ case 3:
+ hw->irq = AU1550_PSC3_INT;
+ hw->regs = (volatile psc_spi_t *)PSC3_BASE_ADDR;
+ hw->dma_rx_id = DSCR_CMD0_PSC3_RX;
+ hw->dma_tx_id = DSCR_CMD0_PSC3_TX;
+ break;
+ default:
+ dev_err(&pdev->dev, "Wrong bus_num of SPI\n");
+ err = -ENOENT;
+ goto err_no_pdata;
+ }
+
+ if (request_mem_region((unsigned long)hw->regs, sizeof(psc_spi_t),
+ pdev->name) == NULL) {
+ dev_err(&pdev->dev, "Cannot reserve iomem region\n");
+ err = -ENXIO;
+ goto err_no_iores;
+ }
+
+
+ if (usedma) {
+ if (pdev->dev.dma_mask == NULL)
+ dev_warn(&pdev->dev, "no dma mask\n");
+ else
+ hw->usedma = 1;
+ }
+
+ if (hw->usedma) {
+ /*
+ * create memory device with 8 bits dev_devwidth
+ * needed for proper byte ordering to spi fifo
+ */
+ int memid = au1xxx_ddma_add_device(&au1550_spi_mem_dbdev);
+ if (!memid) {
+ dev_err(&pdev->dev,
+ "Cannot create dma 8 bit mem device\n");
+ err = -ENXIO;
+ goto err_dma_add_dev;
+ }
+
+ hw->dma_tx_ch = au1xxx_dbdma_chan_alloc(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,
+ 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 = hw->pdata->bus_num;
+ 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));
+ hw->freq_max = hw->pdata->mainclk_hz / min_div;
+ hw->freq_min = 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:
+err_dma_add_dev:
+ release_mem_region((unsigned long)hw->regs, sizeof(psc_spi_t));
+
+err_no_iores:
+err_no_pdata:
+ spi_master_put(hw->master);
+
+err_nomem:
+ return err;
+}
+
+static int __exit 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);
+ release_mem_region((unsigned long)hw->regs, 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);
+ }
+
+ platform_set_drvdata(pdev, NULL);
+
+ spi_master_put(hw->master);
+ return 0;
+}
+
+static struct platform_driver au1550_spi_drv = {
+ .remove = __exit_p(au1550_spi_remove),
+ .driver = {
+ .name = "au1550-spi",
+ .owner = THIS_MODULE,
+ },
+};
+
+static int __init au1550_spi_init(void)
+{
+ return platform_driver_probe(&au1550_spi_drv, au1550_spi_probe);
+}
+module_init(au1550_spi_init);
+
+static void __exit au1550_spi_exit(void)
+{
+ 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");
projects / GitHub / LineageOS / android_kernel_motorola_exynos9610.git / commitdiff