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![FUJITA Tomonori](/assets/img/avatar_default.png)
Add per-device dma_mapping_ops support for CONFIG_X86_64 as POWER architecture does: This enables us to cleanly fix the Calgary IOMMU issue that some devices are not behind the IOMMU (http://lkml.org/lkml/2008/5/8/423). I think that per-device dma_mapping_ops support would be also helpful for KVM people to support PCI passthrough but Andi thinks that this makes it difficult to support the PCI passthrough (see the above thread). So I CC'ed this to KVM camp. Comments are appreciated. A pointer to dma_mapping_ops to struct dev_archdata is added. If the pointer is non NULL, DMA operations in asm/dma-mapping.h use it. If it's NULL, the system-wide dma_ops pointer is used as before. If it's useful for KVM people, I plan to implement a mechanism to register a hook called when a new pci (or dma capable) device is created (it works with hot plugging). It enables IOMMUs to set up an appropriate dma_mapping_ops per device. The major obstacle is that dma_mapping_error doesn't take a pointer to the device unlike other DMA operations. So x86 can't have dma_mapping_ops per device. Note all the POWER IOMMUs use the same dma_mapping_error function so this is not a problem for POWER but x86 IOMMUs use different dma_mapping_error functions. The first patch adds the device argument to dma_mapping_error. The patch is trivial but large since it touches lots of drivers and dma-mapping.h in all the architecture. This patch: dma_mapping_error() doesn't take a pointer to the device unlike other DMA operations. So we can't have dma_mapping_ops per device. Note that POWER already has dma_mapping_ops per device but all the POWER IOMMUs use the same dma_mapping_error function. x86 IOMMUs use device argument. [akpm@linux-foundation.org: fix sge] [akpm@linux-foundation.org: fix svc_rdma] [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: fix bnx2x] [akpm@linux-foundation.org: fix s2io] [akpm@linux-foundation.org: fix pasemi_mac] [akpm@linux-foundation.org: fix sdhci] [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: fix sparc] [akpm@linux-foundation.org: fix ibmvscsi] Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Muli Ben-Yehuda <muli@il.ibm.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Avi Kivity <avi@qumranet.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1025 lines
26 KiB
C
1025 lines
26 KiB
C
/*
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* au1550_spi.c - au1550 psc spi controller driver
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* may work also with au1200, au1210, au1250
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* will not work on au1000, au1100 and au1500 (no full spi controller there)
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*
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* Copyright (c) 2006 ATRON electronic GmbH
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* Author: Jan Nikitenko <jan.nikitenko@gmail.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <linux/init.h>
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#include <linux/interrupt.h>
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#include <linux/errno.h>
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#include <linux/device.h>
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#include <linux/platform_device.h>
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#include <linux/resource.h>
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#include <linux/spi/spi.h>
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#include <linux/spi/spi_bitbang.h>
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#include <linux/dma-mapping.h>
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#include <linux/completion.h>
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#include <asm/mach-au1x00/au1000.h>
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#include <asm/mach-au1x00/au1xxx_psc.h>
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#include <asm/mach-au1x00/au1xxx_dbdma.h>
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#include <asm/mach-au1x00/au1550_spi.h>
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static unsigned usedma = 1;
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module_param(usedma, uint, 0644);
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/*
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#define AU1550_SPI_DEBUG_LOOPBACK
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*/
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#define AU1550_SPI_DBDMA_DESCRIPTORS 1
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#define AU1550_SPI_DMA_RXTMP_MINSIZE 2048U
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struct au1550_spi {
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struct spi_bitbang bitbang;
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volatile psc_spi_t __iomem *regs;
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int irq;
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unsigned freq_max;
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unsigned freq_min;
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unsigned len;
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unsigned tx_count;
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unsigned rx_count;
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const u8 *tx;
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u8 *rx;
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void (*rx_word)(struct au1550_spi *hw);
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void (*tx_word)(struct au1550_spi *hw);
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int (*txrx_bufs)(struct spi_device *spi, struct spi_transfer *t);
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irqreturn_t (*irq_callback)(struct au1550_spi *hw);
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struct completion master_done;
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unsigned usedma;
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u32 dma_tx_id;
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u32 dma_rx_id;
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u32 dma_tx_ch;
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u32 dma_rx_ch;
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u8 *dma_rx_tmpbuf;
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unsigned dma_rx_tmpbuf_size;
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u32 dma_rx_tmpbuf_addr;
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struct spi_master *master;
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struct device *dev;
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struct au1550_spi_info *pdata;
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struct resource *ioarea;
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};
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/* we use an 8-bit memory device for dma transfers to/from spi fifo */
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static dbdev_tab_t au1550_spi_mem_dbdev =
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{
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.dev_id = DBDMA_MEM_CHAN,
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.dev_flags = DEV_FLAGS_ANYUSE|DEV_FLAGS_SYNC,
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.dev_tsize = 0,
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.dev_devwidth = 8,
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.dev_physaddr = 0x00000000,
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.dev_intlevel = 0,
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.dev_intpolarity = 0
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};
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static int ddma_memid; /* id to above mem dma device */
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static void au1550_spi_bits_handlers_set(struct au1550_spi *hw, int bpw);
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/*
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* compute BRG and DIV bits to setup spi clock based on main input clock rate
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* that was specified in platform data structure
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* according to au1550 datasheet:
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* psc_tempclk = psc_mainclk / (2 << DIV)
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* spiclk = psc_tempclk / (2 * (BRG + 1))
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* BRG valid range is 4..63
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* DIV valid range is 0..3
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*/
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static u32 au1550_spi_baudcfg(struct au1550_spi *hw, unsigned speed_hz)
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{
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u32 mainclk_hz = hw->pdata->mainclk_hz;
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u32 div, brg;
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for (div = 0; div < 4; div++) {
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brg = mainclk_hz / speed_hz / (4 << div);
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/* now we have BRG+1 in brg, so count with that */
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if (brg < (4 + 1)) {
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brg = (4 + 1); /* speed_hz too big */
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break; /* set lowest brg (div is == 0) */
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}
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if (brg <= (63 + 1))
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break; /* we have valid brg and div */
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}
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if (div == 4) {
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div = 3; /* speed_hz too small */
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brg = (63 + 1); /* set highest brg and div */
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}
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brg--;
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return PSC_SPICFG_SET_BAUD(brg) | PSC_SPICFG_SET_DIV(div);
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}
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static inline void au1550_spi_mask_ack_all(struct au1550_spi *hw)
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{
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hw->regs->psc_spimsk =
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PSC_SPIMSK_MM | PSC_SPIMSK_RR | PSC_SPIMSK_RO
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| PSC_SPIMSK_RU | PSC_SPIMSK_TR | PSC_SPIMSK_TO
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| PSC_SPIMSK_TU | PSC_SPIMSK_SD | PSC_SPIMSK_MD;
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au_sync();
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hw->regs->psc_spievent =
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PSC_SPIEVNT_MM | PSC_SPIEVNT_RR | PSC_SPIEVNT_RO
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| PSC_SPIEVNT_RU | PSC_SPIEVNT_TR | PSC_SPIEVNT_TO
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| PSC_SPIEVNT_TU | PSC_SPIEVNT_SD | PSC_SPIEVNT_MD;
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au_sync();
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}
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static void au1550_spi_reset_fifos(struct au1550_spi *hw)
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{
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u32 pcr;
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hw->regs->psc_spipcr = PSC_SPIPCR_RC | PSC_SPIPCR_TC;
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au_sync();
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do {
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pcr = hw->regs->psc_spipcr;
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au_sync();
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} while (pcr != 0);
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}
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/*
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* dma transfers are used for the most common spi word size of 8-bits
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* we cannot easily change already set up dma channels' width, so if we wanted
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* dma support for more than 8-bit words (up to 24 bits), we would need to
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* setup dma channels from scratch on each spi transfer, based on bits_per_word
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* instead we have pre set up 8 bit dma channels supporting spi 4 to 8 bits
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* transfers, and 9 to 24 bits spi transfers will be done in pio irq based mode
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* callbacks to handle dma or pio are set up in au1550_spi_bits_handlers_set()
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*/
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static void au1550_spi_chipsel(struct spi_device *spi, int value)
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{
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struct au1550_spi *hw = spi_master_get_devdata(spi->master);
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unsigned cspol = spi->mode & SPI_CS_HIGH ? 1 : 0;
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u32 cfg, stat;
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switch (value) {
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case BITBANG_CS_INACTIVE:
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if (hw->pdata->deactivate_cs)
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hw->pdata->deactivate_cs(hw->pdata, spi->chip_select,
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cspol);
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break;
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case BITBANG_CS_ACTIVE:
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au1550_spi_bits_handlers_set(hw, spi->bits_per_word);
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cfg = hw->regs->psc_spicfg;
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au_sync();
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hw->regs->psc_spicfg = cfg & ~PSC_SPICFG_DE_ENABLE;
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au_sync();
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if (spi->mode & SPI_CPOL)
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cfg |= PSC_SPICFG_BI;
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else
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cfg &= ~PSC_SPICFG_BI;
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if (spi->mode & SPI_CPHA)
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cfg &= ~PSC_SPICFG_CDE;
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else
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cfg |= PSC_SPICFG_CDE;
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if (spi->mode & SPI_LSB_FIRST)
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cfg |= PSC_SPICFG_MLF;
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else
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cfg &= ~PSC_SPICFG_MLF;
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if (hw->usedma && spi->bits_per_word <= 8)
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cfg &= ~PSC_SPICFG_DD_DISABLE;
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else
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cfg |= PSC_SPICFG_DD_DISABLE;
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cfg = PSC_SPICFG_CLR_LEN(cfg);
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cfg |= PSC_SPICFG_SET_LEN(spi->bits_per_word);
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cfg = PSC_SPICFG_CLR_BAUD(cfg);
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cfg &= ~PSC_SPICFG_SET_DIV(3);
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cfg |= au1550_spi_baudcfg(hw, spi->max_speed_hz);
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hw->regs->psc_spicfg = cfg | PSC_SPICFG_DE_ENABLE;
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au_sync();
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do {
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stat = hw->regs->psc_spistat;
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au_sync();
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} while ((stat & PSC_SPISTAT_DR) == 0);
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if (hw->pdata->activate_cs)
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hw->pdata->activate_cs(hw->pdata, spi->chip_select,
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cspol);
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break;
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}
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}
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static int au1550_spi_setupxfer(struct spi_device *spi, struct spi_transfer *t)
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{
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struct au1550_spi *hw = spi_master_get_devdata(spi->master);
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unsigned bpw, hz;
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u32 cfg, stat;
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bpw = t ? t->bits_per_word : spi->bits_per_word;
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hz = t ? t->speed_hz : spi->max_speed_hz;
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if (bpw < 4 || bpw > 24) {
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dev_err(&spi->dev, "setupxfer: invalid bits_per_word=%d\n",
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bpw);
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return -EINVAL;
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}
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if (hz > spi->max_speed_hz || hz > hw->freq_max || hz < hw->freq_min) {
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dev_err(&spi->dev, "setupxfer: clock rate=%d out of range\n",
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hz);
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return -EINVAL;
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}
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au1550_spi_bits_handlers_set(hw, spi->bits_per_word);
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cfg = hw->regs->psc_spicfg;
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au_sync();
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hw->regs->psc_spicfg = cfg & ~PSC_SPICFG_DE_ENABLE;
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au_sync();
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if (hw->usedma && bpw <= 8)
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cfg &= ~PSC_SPICFG_DD_DISABLE;
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else
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cfg |= PSC_SPICFG_DD_DISABLE;
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cfg = PSC_SPICFG_CLR_LEN(cfg);
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cfg |= PSC_SPICFG_SET_LEN(bpw);
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cfg = PSC_SPICFG_CLR_BAUD(cfg);
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cfg &= ~PSC_SPICFG_SET_DIV(3);
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cfg |= au1550_spi_baudcfg(hw, hz);
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hw->regs->psc_spicfg = cfg;
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au_sync();
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if (cfg & PSC_SPICFG_DE_ENABLE) {
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do {
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stat = hw->regs->psc_spistat;
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au_sync();
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} while ((stat & PSC_SPISTAT_DR) == 0);
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}
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au1550_spi_reset_fifos(hw);
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au1550_spi_mask_ack_all(hw);
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return 0;
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}
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/* the spi->mode bits understood by this driver: */
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#define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST)
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static int au1550_spi_setup(struct spi_device *spi)
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{
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struct au1550_spi *hw = spi_master_get_devdata(spi->master);
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if (spi->bits_per_word == 0)
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spi->bits_per_word = 8;
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if (spi->bits_per_word < 4 || spi->bits_per_word > 24) {
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dev_err(&spi->dev, "setup: invalid bits_per_word=%d\n",
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spi->bits_per_word);
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return -EINVAL;
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}
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if (spi->mode & ~MODEBITS) {
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dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
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spi->mode & ~MODEBITS);
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return -EINVAL;
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}
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if (spi->max_speed_hz == 0)
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spi->max_speed_hz = hw->freq_max;
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if (spi->max_speed_hz > hw->freq_max
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|| spi->max_speed_hz < hw->freq_min)
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return -EINVAL;
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/*
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* NOTE: cannot change speed and other hw settings immediately,
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* otherwise sharing of spi bus is not possible,
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* so do not call setupxfer(spi, NULL) here
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*/
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return 0;
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}
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/*
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* for dma spi transfers, we have to setup rx channel, otherwise there is
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* no reliable way how to recognize that spi transfer is done
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* dma complete callbacks are called before real spi transfer is finished
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* and if only tx dma channel is set up (and rx fifo overflow event masked)
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* spi master done event irq is not generated unless rx fifo is empty (emptied)
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* so we need rx tmp buffer to use for rx dma if user does not provide one
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*/
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static int au1550_spi_dma_rxtmp_alloc(struct au1550_spi *hw, unsigned size)
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{
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hw->dma_rx_tmpbuf = kmalloc(size, GFP_KERNEL);
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if (!hw->dma_rx_tmpbuf)
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return -ENOMEM;
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hw->dma_rx_tmpbuf_size = size;
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hw->dma_rx_tmpbuf_addr = dma_map_single(hw->dev, hw->dma_rx_tmpbuf,
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size, DMA_FROM_DEVICE);
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if (dma_mapping_error(hw->dev, hw->dma_rx_tmpbuf_addr)) {
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kfree(hw->dma_rx_tmpbuf);
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hw->dma_rx_tmpbuf = 0;
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hw->dma_rx_tmpbuf_size = 0;
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return -EFAULT;
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}
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return 0;
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}
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static void au1550_spi_dma_rxtmp_free(struct au1550_spi *hw)
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{
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dma_unmap_single(hw->dev, hw->dma_rx_tmpbuf_addr,
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hw->dma_rx_tmpbuf_size, DMA_FROM_DEVICE);
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kfree(hw->dma_rx_tmpbuf);
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hw->dma_rx_tmpbuf = 0;
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hw->dma_rx_tmpbuf_size = 0;
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}
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static int au1550_spi_dma_txrxb(struct spi_device *spi, struct spi_transfer *t)
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{
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struct au1550_spi *hw = spi_master_get_devdata(spi->master);
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dma_addr_t dma_tx_addr;
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dma_addr_t dma_rx_addr;
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u32 res;
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hw->len = t->len;
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hw->tx_count = 0;
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hw->rx_count = 0;
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hw->tx = t->tx_buf;
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hw->rx = t->rx_buf;
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dma_tx_addr = t->tx_dma;
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dma_rx_addr = t->rx_dma;
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/*
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* check if buffers are already dma mapped, map them otherwise
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* use rx buffer in place of tx if tx buffer was not provided
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* use temp rx buffer (preallocated or realloc to fit) for rx dma
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*/
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if (t->rx_buf) {
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if (t->rx_dma == 0) { /* if DMA_ADDR_INVALID, map it */
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dma_rx_addr = dma_map_single(hw->dev,
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(void *)t->rx_buf,
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t->len, DMA_FROM_DEVICE);
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if (dma_mapping_error(hw->dev, dma_rx_addr))
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dev_err(hw->dev, "rx dma map error\n");
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}
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} else {
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if (t->len > hw->dma_rx_tmpbuf_size) {
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int ret;
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au1550_spi_dma_rxtmp_free(hw);
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ret = au1550_spi_dma_rxtmp_alloc(hw, max(t->len,
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AU1550_SPI_DMA_RXTMP_MINSIZE));
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if (ret < 0)
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return ret;
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}
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hw->rx = hw->dma_rx_tmpbuf;
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dma_rx_addr = hw->dma_rx_tmpbuf_addr;
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dma_sync_single_for_device(hw->dev, dma_rx_addr,
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t->len, DMA_FROM_DEVICE);
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}
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if (t->tx_buf) {
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if (t->tx_dma == 0) { /* if DMA_ADDR_INVALID, map it */
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dma_tx_addr = dma_map_single(hw->dev,
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(void *)t->tx_buf,
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t->len, DMA_TO_DEVICE);
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if (dma_mapping_error(hw->dev, dma_tx_addr))
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dev_err(hw->dev, "tx dma map error\n");
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}
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} else {
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dma_sync_single_for_device(hw->dev, dma_rx_addr,
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t->len, DMA_BIDIRECTIONAL);
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hw->tx = hw->rx;
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}
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/* put buffers on the ring */
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res = au1xxx_dbdma_put_dest(hw->dma_rx_ch, hw->rx, t->len);
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|
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);
|
|
|
|
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); \
|
|
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_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;
|
|
au_sync();
|
|
|
|
/*
|
|
* 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;
|
|
au_sync();
|
|
|
|
/*
|
|
* 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;
|
|
au_sync();
|
|
hw->regs->psc_spipcr = PSC_SPIPCR_MS;
|
|
au_sync();
|
|
}
|
|
|
|
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 __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);
|
|
|
|
au1550_spi_reset_fifos(hw);
|
|
}
|
|
|
|
|
|
static int __init 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;
|
|
}
|
|
|
|
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;
|
|
}
|
|
|
|
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.master->setup = au1550_spi_setup;
|
|
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));
|
|
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:
|
|
iounmap((void __iomem *)hw->regs);
|
|
|
|
err_ioremap:
|
|
release_resource(hw->ioarea);
|
|
kfree(hw->ioarea);
|
|
|
|
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);
|
|
iounmap((void __iomem *)hw->regs);
|
|
release_resource(hw->ioarea);
|
|
kfree(hw->ioarea);
|
|
|
|
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;
|
|
}
|
|
|
|
/* work with hotplug and coldplug */
|
|
MODULE_ALIAS("platform:au1550-spi");
|
|
|
|
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)
|
|
{
|
|
/*
|
|
* create memory device with 8 bits dev_devwidth
|
|
* needed for proper byte ordering to spi fifo
|
|
*/
|
|
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_probe(&au1550_spi_drv, au1550_spi_probe);
|
|
}
|
|
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");
|