diff options
Diffstat (limited to 'kernel/drivers/spi/spi-sh-msiof.c')
| -rw-r--r-- | kernel/drivers/spi/spi-sh-msiof.c | 1291 |
1 files changed, 1291 insertions, 0 deletions
diff --git a/kernel/drivers/spi/spi-sh-msiof.c b/kernel/drivers/spi/spi-sh-msiof.c new file mode 100644 index 000000000..bcc7c635d --- /dev/null +++ b/kernel/drivers/spi/spi-sh-msiof.c @@ -0,0 +1,1291 @@ +/* + * SuperH MSIOF SPI Master Interface + * + * Copyright (c) 2009 Magnus Damm + * Copyright (C) 2014 Glider bvba + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +#include <linux/bitmap.h> +#include <linux/clk.h> +#include <linux/completion.h> +#include <linux/delay.h> +#include <linux/dma-mapping.h> +#include <linux/dmaengine.h> +#include <linux/err.h> +#include <linux/gpio.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> +#include <linux/sh_dma.h> + +#include <linux/spi/sh_msiof.h> +#include <linux/spi/spi.h> + +#include <asm/unaligned.h> + + +struct sh_msiof_chipdata { + u16 tx_fifo_size; + u16 rx_fifo_size; + u16 master_flags; +}; + +struct sh_msiof_spi_priv { + struct spi_master *master; + void __iomem *mapbase; + struct clk *clk; + struct platform_device *pdev; + const struct sh_msiof_chipdata *chipdata; + struct sh_msiof_spi_info *info; + struct completion done; + int tx_fifo_size; + int rx_fifo_size; + void *tx_dma_page; + void *rx_dma_page; + dma_addr_t tx_dma_addr; + dma_addr_t rx_dma_addr; +}; + +#define TMDR1 0x00 /* Transmit Mode Register 1 */ +#define TMDR2 0x04 /* Transmit Mode Register 2 */ +#define TMDR3 0x08 /* Transmit Mode Register 3 */ +#define RMDR1 0x10 /* Receive Mode Register 1 */ +#define RMDR2 0x14 /* Receive Mode Register 2 */ +#define RMDR3 0x18 /* Receive Mode Register 3 */ +#define TSCR 0x20 /* Transmit Clock Select Register */ +#define RSCR 0x22 /* Receive Clock Select Register (SH, A1, APE6) */ +#define CTR 0x28 /* Control Register */ +#define FCTR 0x30 /* FIFO Control Register */ +#define STR 0x40 /* Status Register */ +#define IER 0x44 /* Interrupt Enable Register */ +#define TDR1 0x48 /* Transmit Control Data Register 1 (SH, A1) */ +#define TDR2 0x4c /* Transmit Control Data Register 2 (SH, A1) */ +#define TFDR 0x50 /* Transmit FIFO Data Register */ +#define RDR1 0x58 /* Receive Control Data Register 1 (SH, A1) */ +#define RDR2 0x5c /* Receive Control Data Register 2 (SH, A1) */ +#define RFDR 0x60 /* Receive FIFO Data Register */ + +/* TMDR1 and RMDR1 */ +#define MDR1_TRMD 0x80000000 /* Transfer Mode (1 = Master mode) */ +#define MDR1_SYNCMD_MASK 0x30000000 /* SYNC Mode */ +#define MDR1_SYNCMD_SPI 0x20000000 /* Level mode/SPI */ +#define MDR1_SYNCMD_LR 0x30000000 /* L/R mode */ +#define MDR1_SYNCAC_SHIFT 25 /* Sync Polarity (1 = Active-low) */ +#define MDR1_BITLSB_SHIFT 24 /* MSB/LSB First (1 = LSB first) */ +#define MDR1_DTDL_SHIFT 20 /* Data Pin Bit Delay for MSIOF_SYNC */ +#define MDR1_SYNCDL_SHIFT 16 /* Frame Sync Signal Timing Delay */ +#define MDR1_FLD_MASK 0x0000000c /* Frame Sync Signal Interval (0-3) */ +#define MDR1_FLD_SHIFT 2 +#define MDR1_XXSTP 0x00000001 /* Transmission/Reception Stop on FIFO */ +/* TMDR1 */ +#define TMDR1_PCON 0x40000000 /* Transfer Signal Connection */ + +/* TMDR2 and RMDR2 */ +#define MDR2_BITLEN1(i) (((i) - 1) << 24) /* Data Size (8-32 bits) */ +#define MDR2_WDLEN1(i) (((i) - 1) << 16) /* Word Count (1-64/256 (SH, A1))) */ +#define MDR2_GRPMASK1 0x00000001 /* Group Output Mask 1 (SH, A1) */ + +#define MAX_WDLEN 256U + +/* TSCR and RSCR */ +#define SCR_BRPS_MASK 0x1f00 /* Prescaler Setting (1-32) */ +#define SCR_BRPS(i) (((i) - 1) << 8) +#define SCR_BRDV_MASK 0x0007 /* Baud Rate Generator's Division Ratio */ +#define SCR_BRDV_DIV_2 0x0000 +#define SCR_BRDV_DIV_4 0x0001 +#define SCR_BRDV_DIV_8 0x0002 +#define SCR_BRDV_DIV_16 0x0003 +#define SCR_BRDV_DIV_32 0x0004 +#define SCR_BRDV_DIV_1 0x0007 + +/* CTR */ +#define CTR_TSCKIZ_MASK 0xc0000000 /* Transmit Clock I/O Polarity Select */ +#define CTR_TSCKIZ_SCK 0x80000000 /* Disable SCK when TX disabled */ +#define CTR_TSCKIZ_POL_SHIFT 30 /* Transmit Clock Polarity */ +#define CTR_RSCKIZ_MASK 0x30000000 /* Receive Clock Polarity Select */ +#define CTR_RSCKIZ_SCK 0x20000000 /* Must match CTR_TSCKIZ_SCK */ +#define CTR_RSCKIZ_POL_SHIFT 28 /* Receive Clock Polarity */ +#define CTR_TEDG_SHIFT 27 /* Transmit Timing (1 = falling edge) */ +#define CTR_REDG_SHIFT 26 /* Receive Timing (1 = falling edge) */ +#define CTR_TXDIZ_MASK 0x00c00000 /* Pin Output When TX is Disabled */ +#define CTR_TXDIZ_LOW 0x00000000 /* 0 */ +#define CTR_TXDIZ_HIGH 0x00400000 /* 1 */ +#define CTR_TXDIZ_HIZ 0x00800000 /* High-impedance */ +#define CTR_TSCKE 0x00008000 /* Transmit Serial Clock Output Enable */ +#define CTR_TFSE 0x00004000 /* Transmit Frame Sync Signal Output Enable */ +#define CTR_TXE 0x00000200 /* Transmit Enable */ +#define CTR_RXE 0x00000100 /* Receive Enable */ + +/* FCTR */ +#define FCTR_TFWM_MASK 0xe0000000 /* Transmit FIFO Watermark */ +#define FCTR_TFWM_64 0x00000000 /* Transfer Request when 64 empty stages */ +#define FCTR_TFWM_32 0x20000000 /* Transfer Request when 32 empty stages */ +#define FCTR_TFWM_24 0x40000000 /* Transfer Request when 24 empty stages */ +#define FCTR_TFWM_16 0x60000000 /* Transfer Request when 16 empty stages */ +#define FCTR_TFWM_12 0x80000000 /* Transfer Request when 12 empty stages */ +#define FCTR_TFWM_8 0xa0000000 /* Transfer Request when 8 empty stages */ +#define FCTR_TFWM_4 0xc0000000 /* Transfer Request when 4 empty stages */ +#define FCTR_TFWM_1 0xe0000000 /* Transfer Request when 1 empty stage */ +#define FCTR_TFUA_MASK 0x07f00000 /* Transmit FIFO Usable Area */ +#define FCTR_TFUA_SHIFT 20 +#define FCTR_TFUA(i) ((i) << FCTR_TFUA_SHIFT) +#define FCTR_RFWM_MASK 0x0000e000 /* Receive FIFO Watermark */ +#define FCTR_RFWM_1 0x00000000 /* Transfer Request when 1 valid stages */ +#define FCTR_RFWM_4 0x00002000 /* Transfer Request when 4 valid stages */ +#define FCTR_RFWM_8 0x00004000 /* Transfer Request when 8 valid stages */ +#define FCTR_RFWM_16 0x00006000 /* Transfer Request when 16 valid stages */ +#define FCTR_RFWM_32 0x00008000 /* Transfer Request when 32 valid stages */ +#define FCTR_RFWM_64 0x0000a000 /* Transfer Request when 64 valid stages */ +#define FCTR_RFWM_128 0x0000c000 /* Transfer Request when 128 valid stages */ +#define FCTR_RFWM_256 0x0000e000 /* Transfer Request when 256 valid stages */ +#define FCTR_RFUA_MASK 0x00001ff0 /* Receive FIFO Usable Area (0x40 = full) */ +#define FCTR_RFUA_SHIFT 4 +#define FCTR_RFUA(i) ((i) << FCTR_RFUA_SHIFT) + +/* STR */ +#define STR_TFEMP 0x20000000 /* Transmit FIFO Empty */ +#define STR_TDREQ 0x10000000 /* Transmit Data Transfer Request */ +#define STR_TEOF 0x00800000 /* Frame Transmission End */ +#define STR_TFSERR 0x00200000 /* Transmit Frame Synchronization Error */ +#define STR_TFOVF 0x00100000 /* Transmit FIFO Overflow */ +#define STR_TFUDF 0x00080000 /* Transmit FIFO Underflow */ +#define STR_RFFUL 0x00002000 /* Receive FIFO Full */ +#define STR_RDREQ 0x00001000 /* Receive Data Transfer Request */ +#define STR_REOF 0x00000080 /* Frame Reception End */ +#define STR_RFSERR 0x00000020 /* Receive Frame Synchronization Error */ +#define STR_RFUDF 0x00000010 /* Receive FIFO Underflow */ +#define STR_RFOVF 0x00000008 /* Receive FIFO Overflow */ + +/* IER */ +#define IER_TDMAE 0x80000000 /* Transmit Data DMA Transfer Req. Enable */ +#define IER_TFEMPE 0x20000000 /* Transmit FIFO Empty Enable */ +#define IER_TDREQE 0x10000000 /* Transmit Data Transfer Request Enable */ +#define IER_TEOFE 0x00800000 /* Frame Transmission End Enable */ +#define IER_TFSERRE 0x00200000 /* Transmit Frame Sync Error Enable */ +#define IER_TFOVFE 0x00100000 /* Transmit FIFO Overflow Enable */ +#define IER_TFUDFE 0x00080000 /* Transmit FIFO Underflow Enable */ +#define IER_RDMAE 0x00008000 /* Receive Data DMA Transfer Req. Enable */ +#define IER_RFFULE 0x00002000 /* Receive FIFO Full Enable */ +#define IER_RDREQE 0x00001000 /* Receive Data Transfer Request Enable */ +#define IER_REOFE 0x00000080 /* Frame Reception End Enable */ +#define IER_RFSERRE 0x00000020 /* Receive Frame Sync Error Enable */ +#define IER_RFUDFE 0x00000010 /* Receive FIFO Underflow Enable */ +#define IER_RFOVFE 0x00000008 /* Receive FIFO Overflow Enable */ + + +static u32 sh_msiof_read(struct sh_msiof_spi_priv *p, int reg_offs) +{ + switch (reg_offs) { + case TSCR: + case RSCR: + return ioread16(p->mapbase + reg_offs); + default: + return ioread32(p->mapbase + reg_offs); + } +} + +static void sh_msiof_write(struct sh_msiof_spi_priv *p, int reg_offs, + u32 value) +{ + switch (reg_offs) { + case TSCR: + case RSCR: + iowrite16(value, p->mapbase + reg_offs); + break; + default: + iowrite32(value, p->mapbase + reg_offs); + break; + } +} + +static int sh_msiof_modify_ctr_wait(struct sh_msiof_spi_priv *p, + u32 clr, u32 set) +{ + u32 mask = clr | set; + u32 data; + int k; + + data = sh_msiof_read(p, CTR); + data &= ~clr; + data |= set; + sh_msiof_write(p, CTR, data); + + for (k = 100; k > 0; k--) { + if ((sh_msiof_read(p, CTR) & mask) == set) + break; + + udelay(10); + } + + return k > 0 ? 0 : -ETIMEDOUT; +} + +static irqreturn_t sh_msiof_spi_irq(int irq, void *data) +{ + struct sh_msiof_spi_priv *p = data; + + /* just disable the interrupt and wake up */ + sh_msiof_write(p, IER, 0); + complete(&p->done); + + return IRQ_HANDLED; +} + +static struct { + unsigned short div; + unsigned short brdv; +} const sh_msiof_spi_div_table[] = { + { 1, SCR_BRDV_DIV_1 }, + { 2, SCR_BRDV_DIV_2 }, + { 4, SCR_BRDV_DIV_4 }, + { 8, SCR_BRDV_DIV_8 }, + { 16, SCR_BRDV_DIV_16 }, + { 32, SCR_BRDV_DIV_32 }, +}; + +static void sh_msiof_spi_set_clk_regs(struct sh_msiof_spi_priv *p, + unsigned long parent_rate, u32 spi_hz) +{ + unsigned long div = 1024; + u32 brps, scr; + size_t k; + + if (!WARN_ON(!spi_hz || !parent_rate)) + div = DIV_ROUND_UP(parent_rate, spi_hz); + + for (k = 0; k < ARRAY_SIZE(sh_msiof_spi_div_table); k++) { + brps = DIV_ROUND_UP(div, sh_msiof_spi_div_table[k].div); + if (brps <= 32) /* max of brdv is 32 */ + break; + } + + k = min_t(int, k, ARRAY_SIZE(sh_msiof_spi_div_table) - 1); + + scr = sh_msiof_spi_div_table[k].brdv | SCR_BRPS(brps); + sh_msiof_write(p, TSCR, scr); + if (!(p->chipdata->master_flags & SPI_MASTER_MUST_TX)) + sh_msiof_write(p, RSCR, scr); +} + +static u32 sh_msiof_get_delay_bit(u32 dtdl_or_syncdl) +{ + /* + * DTDL/SYNCDL bit : p->info->dtdl or p->info->syncdl + * b'000 : 0 + * b'001 : 100 + * b'010 : 200 + * b'011 (SYNCDL only) : 300 + * b'101 : 50 + * b'110 : 150 + */ + if (dtdl_or_syncdl % 100) + return dtdl_or_syncdl / 100 + 5; + else + return dtdl_or_syncdl / 100; +} + +static u32 sh_msiof_spi_get_dtdl_and_syncdl(struct sh_msiof_spi_priv *p) +{ + u32 val; + + if (!p->info) + return 0; + + /* check if DTDL and SYNCDL is allowed value */ + if (p->info->dtdl > 200 || p->info->syncdl > 300) { + dev_warn(&p->pdev->dev, "DTDL or SYNCDL is too large\n"); + return 0; + } + + /* check if the sum of DTDL and SYNCDL becomes an integer value */ + if ((p->info->dtdl + p->info->syncdl) % 100) { + dev_warn(&p->pdev->dev, "the sum of DTDL/SYNCDL is not good\n"); + return 0; + } + + val = sh_msiof_get_delay_bit(p->info->dtdl) << MDR1_DTDL_SHIFT; + val |= sh_msiof_get_delay_bit(p->info->syncdl) << MDR1_SYNCDL_SHIFT; + + return val; +} + +static void sh_msiof_spi_set_pin_regs(struct sh_msiof_spi_priv *p, + u32 cpol, u32 cpha, + u32 tx_hi_z, u32 lsb_first, u32 cs_high) +{ + u32 tmp; + int edge; + + /* + * CPOL CPHA TSCKIZ RSCKIZ TEDG REDG + * 0 0 10 10 1 1 + * 0 1 10 10 0 0 + * 1 0 11 11 0 0 + * 1 1 11 11 1 1 + */ + tmp = MDR1_SYNCMD_SPI | 1 << MDR1_FLD_SHIFT | MDR1_XXSTP; + tmp |= !cs_high << MDR1_SYNCAC_SHIFT; + tmp |= lsb_first << MDR1_BITLSB_SHIFT; + tmp |= sh_msiof_spi_get_dtdl_and_syncdl(p); + sh_msiof_write(p, TMDR1, tmp | MDR1_TRMD | TMDR1_PCON); + if (p->chipdata->master_flags & SPI_MASTER_MUST_TX) { + /* These bits are reserved if RX needs TX */ + tmp &= ~0x0000ffff; + } + sh_msiof_write(p, RMDR1, tmp); + + tmp = 0; + tmp |= CTR_TSCKIZ_SCK | cpol << CTR_TSCKIZ_POL_SHIFT; + tmp |= CTR_RSCKIZ_SCK | cpol << CTR_RSCKIZ_POL_SHIFT; + + edge = cpol ^ !cpha; + + tmp |= edge << CTR_TEDG_SHIFT; + tmp |= edge << CTR_REDG_SHIFT; + tmp |= tx_hi_z ? CTR_TXDIZ_HIZ : CTR_TXDIZ_LOW; + sh_msiof_write(p, CTR, tmp); +} + +static void sh_msiof_spi_set_mode_regs(struct sh_msiof_spi_priv *p, + const void *tx_buf, void *rx_buf, + u32 bits, u32 words) +{ + u32 dr2 = MDR2_BITLEN1(bits) | MDR2_WDLEN1(words); + + if (tx_buf || (p->chipdata->master_flags & SPI_MASTER_MUST_TX)) + sh_msiof_write(p, TMDR2, dr2); + else + sh_msiof_write(p, TMDR2, dr2 | MDR2_GRPMASK1); + + if (rx_buf) + sh_msiof_write(p, RMDR2, dr2); +} + +static void sh_msiof_reset_str(struct sh_msiof_spi_priv *p) +{ + sh_msiof_write(p, STR, sh_msiof_read(p, STR)); +} + +static void sh_msiof_spi_write_fifo_8(struct sh_msiof_spi_priv *p, + const void *tx_buf, int words, int fs) +{ + const u8 *buf_8 = tx_buf; + int k; + + for (k = 0; k < words; k++) + sh_msiof_write(p, TFDR, buf_8[k] << fs); +} + +static void sh_msiof_spi_write_fifo_16(struct sh_msiof_spi_priv *p, + const void *tx_buf, int words, int fs) +{ + const u16 *buf_16 = tx_buf; + int k; + + for (k = 0; k < words; k++) + sh_msiof_write(p, TFDR, buf_16[k] << fs); +} + +static void sh_msiof_spi_write_fifo_16u(struct sh_msiof_spi_priv *p, + const void *tx_buf, int words, int fs) +{ + const u16 *buf_16 = tx_buf; + int k; + + for (k = 0; k < words; k++) + sh_msiof_write(p, TFDR, get_unaligned(&buf_16[k]) << fs); +} + +static void sh_msiof_spi_write_fifo_32(struct sh_msiof_spi_priv *p, + const void *tx_buf, int words, int fs) +{ + const u32 *buf_32 = tx_buf; + int k; + + for (k = 0; k < words; k++) + sh_msiof_write(p, TFDR, buf_32[k] << fs); +} + +static void sh_msiof_spi_write_fifo_32u(struct sh_msiof_spi_priv *p, + const void *tx_buf, int words, int fs) +{ + const u32 *buf_32 = tx_buf; + int k; + + for (k = 0; k < words; k++) + sh_msiof_write(p, TFDR, get_unaligned(&buf_32[k]) << fs); +} + +static void sh_msiof_spi_write_fifo_s32(struct sh_msiof_spi_priv *p, + const void *tx_buf, int words, int fs) +{ + const u32 *buf_32 = tx_buf; + int k; + + for (k = 0; k < words; k++) + sh_msiof_write(p, TFDR, swab32(buf_32[k] << fs)); +} + +static void sh_msiof_spi_write_fifo_s32u(struct sh_msiof_spi_priv *p, + const void *tx_buf, int words, int fs) +{ + const u32 *buf_32 = tx_buf; + int k; + + for (k = 0; k < words; k++) + sh_msiof_write(p, TFDR, swab32(get_unaligned(&buf_32[k]) << fs)); +} + +static void sh_msiof_spi_read_fifo_8(struct sh_msiof_spi_priv *p, + void *rx_buf, int words, int fs) +{ + u8 *buf_8 = rx_buf; + int k; + + for (k = 0; k < words; k++) + buf_8[k] = sh_msiof_read(p, RFDR) >> fs; +} + +static void sh_msiof_spi_read_fifo_16(struct sh_msiof_spi_priv *p, + void *rx_buf, int words, int fs) +{ + u16 *buf_16 = rx_buf; + int k; + + for (k = 0; k < words; k++) + buf_16[k] = sh_msiof_read(p, RFDR) >> fs; +} + +static void sh_msiof_spi_read_fifo_16u(struct sh_msiof_spi_priv *p, + void *rx_buf, int words, int fs) +{ + u16 *buf_16 = rx_buf; + int k; + + for (k = 0; k < words; k++) + put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_16[k]); +} + +static void sh_msiof_spi_read_fifo_32(struct sh_msiof_spi_priv *p, + void *rx_buf, int words, int fs) +{ + u32 *buf_32 = rx_buf; + int k; + + for (k = 0; k < words; k++) + buf_32[k] = sh_msiof_read(p, RFDR) >> fs; +} + +static void sh_msiof_spi_read_fifo_32u(struct sh_msiof_spi_priv *p, + void *rx_buf, int words, int fs) +{ + u32 *buf_32 = rx_buf; + int k; + + for (k = 0; k < words; k++) + put_unaligned(sh_msiof_read(p, RFDR) >> fs, &buf_32[k]); +} + +static void sh_msiof_spi_read_fifo_s32(struct sh_msiof_spi_priv *p, + void *rx_buf, int words, int fs) +{ + u32 *buf_32 = rx_buf; + int k; + + for (k = 0; k < words; k++) + buf_32[k] = swab32(sh_msiof_read(p, RFDR) >> fs); +} + +static void sh_msiof_spi_read_fifo_s32u(struct sh_msiof_spi_priv *p, + void *rx_buf, int words, int fs) +{ + u32 *buf_32 = rx_buf; + int k; + + for (k = 0; k < words; k++) + put_unaligned(swab32(sh_msiof_read(p, RFDR) >> fs), &buf_32[k]); +} + +static int sh_msiof_spi_setup(struct spi_device *spi) +{ + struct device_node *np = spi->master->dev.of_node; + struct sh_msiof_spi_priv *p = spi_master_get_devdata(spi->master); + + pm_runtime_get_sync(&p->pdev->dev); + + if (!np) { + /* + * Use spi->controller_data for CS (same strategy as spi_gpio), + * if any. otherwise let HW control CS + */ + spi->cs_gpio = (uintptr_t)spi->controller_data; + } + + /* Configure pins before deasserting CS */ + sh_msiof_spi_set_pin_regs(p, !!(spi->mode & SPI_CPOL), + !!(spi->mode & SPI_CPHA), + !!(spi->mode & SPI_3WIRE), + !!(spi->mode & SPI_LSB_FIRST), + !!(spi->mode & SPI_CS_HIGH)); + + if (spi->cs_gpio >= 0) + gpio_set_value(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH)); + + + pm_runtime_put(&p->pdev->dev); + + return 0; +} + +static int sh_msiof_prepare_message(struct spi_master *master, + struct spi_message *msg) +{ + struct sh_msiof_spi_priv *p = spi_master_get_devdata(master); + const struct spi_device *spi = msg->spi; + + /* Configure pins before asserting CS */ + sh_msiof_spi_set_pin_regs(p, !!(spi->mode & SPI_CPOL), + !!(spi->mode & SPI_CPHA), + !!(spi->mode & SPI_3WIRE), + !!(spi->mode & SPI_LSB_FIRST), + !!(spi->mode & SPI_CS_HIGH)); + return 0; +} + +static int sh_msiof_spi_start(struct sh_msiof_spi_priv *p, void *rx_buf) +{ + int ret; + + /* setup clock and rx/tx signals */ + ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TSCKE); + if (rx_buf && !ret) + ret = sh_msiof_modify_ctr_wait(p, 0, CTR_RXE); + if (!ret) + ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TXE); + + /* start by setting frame bit */ + if (!ret) + ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TFSE); + + return ret; +} + +static int sh_msiof_spi_stop(struct sh_msiof_spi_priv *p, void *rx_buf) +{ + int ret; + + /* shut down frame, rx/tx and clock signals */ + ret = sh_msiof_modify_ctr_wait(p, CTR_TFSE, 0); + if (!ret) + ret = sh_msiof_modify_ctr_wait(p, CTR_TXE, 0); + if (rx_buf && !ret) + ret = sh_msiof_modify_ctr_wait(p, CTR_RXE, 0); + if (!ret) + ret = sh_msiof_modify_ctr_wait(p, CTR_TSCKE, 0); + + return ret; +} + +static int sh_msiof_spi_txrx_once(struct sh_msiof_spi_priv *p, + void (*tx_fifo)(struct sh_msiof_spi_priv *, + const void *, int, int), + void (*rx_fifo)(struct sh_msiof_spi_priv *, + void *, int, int), + const void *tx_buf, void *rx_buf, + int words, int bits) +{ + int fifo_shift; + int ret; + + /* limit maximum word transfer to rx/tx fifo size */ + if (tx_buf) + words = min_t(int, words, p->tx_fifo_size); + if (rx_buf) + words = min_t(int, words, p->rx_fifo_size); + + /* the fifo contents need shifting */ + fifo_shift = 32 - bits; + + /* default FIFO watermarks for PIO */ + sh_msiof_write(p, FCTR, 0); + + /* setup msiof transfer mode registers */ + sh_msiof_spi_set_mode_regs(p, tx_buf, rx_buf, bits, words); + sh_msiof_write(p, IER, IER_TEOFE | IER_REOFE); + + /* write tx fifo */ + if (tx_buf) + tx_fifo(p, tx_buf, words, fifo_shift); + + reinit_completion(&p->done); + + ret = sh_msiof_spi_start(p, rx_buf); + if (ret) { + dev_err(&p->pdev->dev, "failed to start hardware\n"); + goto stop_ier; + } + + /* wait for tx fifo to be emptied / rx fifo to be filled */ + if (!wait_for_completion_timeout(&p->done, HZ)) { + dev_err(&p->pdev->dev, "PIO timeout\n"); + ret = -ETIMEDOUT; + goto stop_reset; + } + + /* read rx fifo */ + if (rx_buf) + rx_fifo(p, rx_buf, words, fifo_shift); + + /* clear status bits */ + sh_msiof_reset_str(p); + + ret = sh_msiof_spi_stop(p, rx_buf); + if (ret) { + dev_err(&p->pdev->dev, "failed to shut down hardware\n"); + return ret; + } + + return words; + +stop_reset: + sh_msiof_reset_str(p); + sh_msiof_spi_stop(p, rx_buf); +stop_ier: + sh_msiof_write(p, IER, 0); + return ret; +} + +static void sh_msiof_dma_complete(void *arg) +{ + struct sh_msiof_spi_priv *p = arg; + + sh_msiof_write(p, IER, 0); + complete(&p->done); +} + +static int sh_msiof_dma_once(struct sh_msiof_spi_priv *p, const void *tx, + void *rx, unsigned int len) +{ + u32 ier_bits = 0; + struct dma_async_tx_descriptor *desc_tx = NULL, *desc_rx = NULL; + dma_cookie_t cookie; + int ret; + + /* First prepare and submit the DMA request(s), as this may fail */ + if (rx) { + ier_bits |= IER_RDREQE | IER_RDMAE; + desc_rx = dmaengine_prep_slave_single(p->master->dma_rx, + p->rx_dma_addr, len, DMA_FROM_DEVICE, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc_rx) + return -EAGAIN; + + desc_rx->callback = sh_msiof_dma_complete; + desc_rx->callback_param = p; + cookie = dmaengine_submit(desc_rx); + if (dma_submit_error(cookie)) + return cookie; + } + + if (tx) { + ier_bits |= IER_TDREQE | IER_TDMAE; + dma_sync_single_for_device(p->master->dma_tx->device->dev, + p->tx_dma_addr, len, DMA_TO_DEVICE); + desc_tx = dmaengine_prep_slave_single(p->master->dma_tx, + p->tx_dma_addr, len, DMA_TO_DEVICE, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc_tx) { + ret = -EAGAIN; + goto no_dma_tx; + } + + if (rx) { + /* No callback */ + desc_tx->callback = NULL; + } else { + desc_tx->callback = sh_msiof_dma_complete; + desc_tx->callback_param = p; + } + cookie = dmaengine_submit(desc_tx); + if (dma_submit_error(cookie)) { + ret = cookie; + goto no_dma_tx; + } + } + + /* 1 stage FIFO watermarks for DMA */ + sh_msiof_write(p, FCTR, FCTR_TFWM_1 | FCTR_RFWM_1); + + /* setup msiof transfer mode registers (32-bit words) */ + sh_msiof_spi_set_mode_regs(p, tx, rx, 32, len / 4); + + sh_msiof_write(p, IER, ier_bits); + + reinit_completion(&p->done); + + /* Now start DMA */ + if (rx) + dma_async_issue_pending(p->master->dma_rx); + if (tx) + dma_async_issue_pending(p->master->dma_tx); + + ret = sh_msiof_spi_start(p, rx); + if (ret) { + dev_err(&p->pdev->dev, "failed to start hardware\n"); + goto stop_dma; + } + + /* wait for tx fifo to be emptied / rx fifo to be filled */ + if (!wait_for_completion_timeout(&p->done, HZ)) { + dev_err(&p->pdev->dev, "DMA timeout\n"); + ret = -ETIMEDOUT; + goto stop_reset; + } + + /* clear status bits */ + sh_msiof_reset_str(p); + + ret = sh_msiof_spi_stop(p, rx); + if (ret) { + dev_err(&p->pdev->dev, "failed to shut down hardware\n"); + return ret; + } + + if (rx) + dma_sync_single_for_cpu(p->master->dma_rx->device->dev, + p->rx_dma_addr, len, + DMA_FROM_DEVICE); + + return 0; + +stop_reset: + sh_msiof_reset_str(p); + sh_msiof_spi_stop(p, rx); +stop_dma: + if (tx) + dmaengine_terminate_all(p->master->dma_tx); +no_dma_tx: + if (rx) + dmaengine_terminate_all(p->master->dma_rx); + sh_msiof_write(p, IER, 0); + return ret; +} + +static void copy_bswap32(u32 *dst, const u32 *src, unsigned int words) +{ + /* src or dst can be unaligned, but not both */ + if ((unsigned long)src & 3) { + while (words--) { + *dst++ = swab32(get_unaligned(src)); + src++; + } + } else if ((unsigned long)dst & 3) { + while (words--) { + put_unaligned(swab32(*src++), dst); + dst++; + } + } else { + while (words--) + *dst++ = swab32(*src++); + } +} + +static void copy_wswap32(u32 *dst, const u32 *src, unsigned int words) +{ + /* src or dst can be unaligned, but not both */ + if ((unsigned long)src & 3) { + while (words--) { + *dst++ = swahw32(get_unaligned(src)); + src++; + } + } else if ((unsigned long)dst & 3) { + while (words--) { + put_unaligned(swahw32(*src++), dst); + dst++; + } + } else { + while (words--) + *dst++ = swahw32(*src++); + } +} + +static void copy_plain32(u32 *dst, const u32 *src, unsigned int words) +{ + memcpy(dst, src, words * 4); +} + +static int sh_msiof_transfer_one(struct spi_master *master, + struct spi_device *spi, + struct spi_transfer *t) +{ + struct sh_msiof_spi_priv *p = spi_master_get_devdata(master); + void (*copy32)(u32 *, const u32 *, unsigned int); + void (*tx_fifo)(struct sh_msiof_spi_priv *, const void *, int, int); + void (*rx_fifo)(struct sh_msiof_spi_priv *, void *, int, int); + const void *tx_buf = t->tx_buf; + void *rx_buf = t->rx_buf; + unsigned int len = t->len; + unsigned int bits = t->bits_per_word; + unsigned int bytes_per_word; + unsigned int words; + int n; + bool swab; + int ret; + + /* setup clocks (clock already enabled in chipselect()) */ + sh_msiof_spi_set_clk_regs(p, clk_get_rate(p->clk), t->speed_hz); + + while (master->dma_tx && len > 15) { + /* + * DMA supports 32-bit words only, hence pack 8-bit and 16-bit + * words, with byte resp. word swapping. + */ + unsigned int l = min(len, MAX_WDLEN * 4); + + if (bits <= 8) { + if (l & 3) + break; + copy32 = copy_bswap32; + } else if (bits <= 16) { + if (l & 1) + break; + copy32 = copy_wswap32; + } else { + copy32 = copy_plain32; + } + + if (tx_buf) + copy32(p->tx_dma_page, tx_buf, l / 4); + + ret = sh_msiof_dma_once(p, tx_buf, rx_buf, l); + if (ret == -EAGAIN) { + pr_warn_once("%s %s: DMA not available, falling back to PIO\n", + dev_driver_string(&p->pdev->dev), + dev_name(&p->pdev->dev)); + break; + } + if (ret) + return ret; + + if (rx_buf) { + copy32(rx_buf, p->rx_dma_page, l / 4); + rx_buf += l; + } + if (tx_buf) + tx_buf += l; + + len -= l; + if (!len) + return 0; + } + + if (bits <= 8 && len > 15 && !(len & 3)) { + bits = 32; + swab = true; + } else { + swab = false; + } + + /* setup bytes per word and fifo read/write functions */ + if (bits <= 8) { + bytes_per_word = 1; + tx_fifo = sh_msiof_spi_write_fifo_8; + rx_fifo = sh_msiof_spi_read_fifo_8; + } else if (bits <= 16) { + bytes_per_word = 2; + if ((unsigned long)tx_buf & 0x01) + tx_fifo = sh_msiof_spi_write_fifo_16u; + else + tx_fifo = sh_msiof_spi_write_fifo_16; + + if ((unsigned long)rx_buf & 0x01) + rx_fifo = sh_msiof_spi_read_fifo_16u; + else + rx_fifo = sh_msiof_spi_read_fifo_16; + } else if (swab) { + bytes_per_word = 4; + if ((unsigned long)tx_buf & 0x03) + tx_fifo = sh_msiof_spi_write_fifo_s32u; + else + tx_fifo = sh_msiof_spi_write_fifo_s32; + + if ((unsigned long)rx_buf & 0x03) + rx_fifo = sh_msiof_spi_read_fifo_s32u; + else + rx_fifo = sh_msiof_spi_read_fifo_s32; + } else { + bytes_per_word = 4; + if ((unsigned long)tx_buf & 0x03) + tx_fifo = sh_msiof_spi_write_fifo_32u; + else + tx_fifo = sh_msiof_spi_write_fifo_32; + + if ((unsigned long)rx_buf & 0x03) + rx_fifo = sh_msiof_spi_read_fifo_32u; + else + rx_fifo = sh_msiof_spi_read_fifo_32; + } + + /* transfer in fifo sized chunks */ + words = len / bytes_per_word; + + while (words > 0) { + n = sh_msiof_spi_txrx_once(p, tx_fifo, rx_fifo, tx_buf, rx_buf, + words, bits); + if (n < 0) + return n; + + if (tx_buf) + tx_buf += n * bytes_per_word; + if (rx_buf) + rx_buf += n * bytes_per_word; + words -= n; + } + + return 0; +} + +static const struct sh_msiof_chipdata sh_data = { + .tx_fifo_size = 64, + .rx_fifo_size = 64, + .master_flags = 0, +}; + +static const struct sh_msiof_chipdata r8a779x_data = { + .tx_fifo_size = 64, + .rx_fifo_size = 256, + .master_flags = SPI_MASTER_MUST_TX, +}; + +static const struct of_device_id sh_msiof_match[] = { + { .compatible = "renesas,sh-msiof", .data = &sh_data }, + { .compatible = "renesas,sh-mobile-msiof", .data = &sh_data }, + { .compatible = "renesas,msiof-r8a7790", .data = &r8a779x_data }, + { .compatible = "renesas,msiof-r8a7791", .data = &r8a779x_data }, + { .compatible = "renesas,msiof-r8a7792", .data = &r8a779x_data }, + { .compatible = "renesas,msiof-r8a7793", .data = &r8a779x_data }, + { .compatible = "renesas,msiof-r8a7794", .data = &r8a779x_data }, + {}, +}; +MODULE_DEVICE_TABLE(of, sh_msiof_match); + +#ifdef CONFIG_OF +static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev) +{ + struct sh_msiof_spi_info *info; + struct device_node *np = dev->of_node; + u32 num_cs = 1; + + info = devm_kzalloc(dev, sizeof(struct sh_msiof_spi_info), GFP_KERNEL); + if (!info) + return NULL; + + /* Parse the MSIOF properties */ + of_property_read_u32(np, "num-cs", &num_cs); + of_property_read_u32(np, "renesas,tx-fifo-size", + &info->tx_fifo_override); + of_property_read_u32(np, "renesas,rx-fifo-size", + &info->rx_fifo_override); + of_property_read_u32(np, "renesas,dtdl", &info->dtdl); + of_property_read_u32(np, "renesas,syncdl", &info->syncdl); + + info->num_chipselect = num_cs; + + return info; +} +#else +static struct sh_msiof_spi_info *sh_msiof_spi_parse_dt(struct device *dev) +{ + return NULL; +} +#endif + +static struct dma_chan *sh_msiof_request_dma_chan(struct device *dev, + enum dma_transfer_direction dir, unsigned int id, dma_addr_t port_addr) +{ + dma_cap_mask_t mask; + struct dma_chan *chan; + struct dma_slave_config cfg; + int ret; + + dma_cap_zero(mask); + dma_cap_set(DMA_SLAVE, mask); + + chan = dma_request_slave_channel_compat(mask, shdma_chan_filter, + (void *)(unsigned long)id, dev, + dir == DMA_MEM_TO_DEV ? "tx" : "rx"); + if (!chan) { + dev_warn(dev, "dma_request_slave_channel_compat failed\n"); + return NULL; + } + + memset(&cfg, 0, sizeof(cfg)); + cfg.direction = dir; + if (dir == DMA_MEM_TO_DEV) { + cfg.dst_addr = port_addr; + cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; + } else { + cfg.src_addr = port_addr; + cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; + } + + ret = dmaengine_slave_config(chan, &cfg); + if (ret) { + dev_warn(dev, "dmaengine_slave_config failed %d\n", ret); + dma_release_channel(chan); + return NULL; + } + + return chan; +} + +static int sh_msiof_request_dma(struct sh_msiof_spi_priv *p) +{ + struct platform_device *pdev = p->pdev; + struct device *dev = &pdev->dev; + const struct sh_msiof_spi_info *info = dev_get_platdata(dev); + unsigned int dma_tx_id, dma_rx_id; + const struct resource *res; + struct spi_master *master; + struct device *tx_dev, *rx_dev; + + if (dev->of_node) { + /* In the OF case we will get the slave IDs from the DT */ + dma_tx_id = 0; + dma_rx_id = 0; + } else if (info && info->dma_tx_id && info->dma_rx_id) { + dma_tx_id = info->dma_tx_id; + dma_rx_id = info->dma_rx_id; + } else { + /* The driver assumes no error */ + return 0; + } + + /* The DMA engine uses the second register set, if present */ + res = platform_get_resource(pdev, IORESOURCE_MEM, 1); + if (!res) + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + + master = p->master; + master->dma_tx = sh_msiof_request_dma_chan(dev, DMA_MEM_TO_DEV, + dma_tx_id, + res->start + TFDR); + if (!master->dma_tx) + return -ENODEV; + + master->dma_rx = sh_msiof_request_dma_chan(dev, DMA_DEV_TO_MEM, + dma_rx_id, + res->start + RFDR); + if (!master->dma_rx) + goto free_tx_chan; + + p->tx_dma_page = (void *)__get_free_page(GFP_KERNEL | GFP_DMA); + if (!p->tx_dma_page) + goto free_rx_chan; + + p->rx_dma_page = (void *)__get_free_page(GFP_KERNEL | GFP_DMA); + if (!p->rx_dma_page) + goto free_tx_page; + + tx_dev = master->dma_tx->device->dev; + p->tx_dma_addr = dma_map_single(tx_dev, p->tx_dma_page, PAGE_SIZE, + DMA_TO_DEVICE); + if (dma_mapping_error(tx_dev, p->tx_dma_addr)) + goto free_rx_page; + + rx_dev = master->dma_rx->device->dev; + p->rx_dma_addr = dma_map_single(rx_dev, p->rx_dma_page, PAGE_SIZE, + DMA_FROM_DEVICE); + if (dma_mapping_error(rx_dev, p->rx_dma_addr)) + goto unmap_tx_page; + + dev_info(dev, "DMA available"); + return 0; + +unmap_tx_page: + dma_unmap_single(tx_dev, p->tx_dma_addr, PAGE_SIZE, DMA_TO_DEVICE); +free_rx_page: + free_page((unsigned long)p->rx_dma_page); +free_tx_page: + free_page((unsigned long)p->tx_dma_page); +free_rx_chan: + dma_release_channel(master->dma_rx); +free_tx_chan: + dma_release_channel(master->dma_tx); + master->dma_tx = NULL; + return -ENODEV; +} + +static void sh_msiof_release_dma(struct sh_msiof_spi_priv *p) +{ + struct spi_master *master = p->master; + struct device *dev; + + if (!master->dma_tx) + return; + + dev = &p->pdev->dev; + dma_unmap_single(master->dma_rx->device->dev, p->rx_dma_addr, + PAGE_SIZE, DMA_FROM_DEVICE); + dma_unmap_single(master->dma_tx->device->dev, p->tx_dma_addr, + PAGE_SIZE, DMA_TO_DEVICE); + free_page((unsigned long)p->rx_dma_page); + free_page((unsigned long)p->tx_dma_page); + dma_release_channel(master->dma_rx); + dma_release_channel(master->dma_tx); +} + +static int sh_msiof_spi_probe(struct platform_device *pdev) +{ + struct resource *r; + struct spi_master *master; + const struct of_device_id *of_id; + struct sh_msiof_spi_priv *p; + int i; + int ret; + + master = spi_alloc_master(&pdev->dev, sizeof(struct sh_msiof_spi_priv)); + if (master == NULL) { + dev_err(&pdev->dev, "failed to allocate spi master\n"); + return -ENOMEM; + } + + p = spi_master_get_devdata(master); + + platform_set_drvdata(pdev, p); + p->master = master; + + of_id = of_match_device(sh_msiof_match, &pdev->dev); + if (of_id) { + p->chipdata = of_id->data; + p->info = sh_msiof_spi_parse_dt(&pdev->dev); + } else { + p->chipdata = (const void *)pdev->id_entry->driver_data; + p->info = dev_get_platdata(&pdev->dev); + } + + if (!p->info) { + dev_err(&pdev->dev, "failed to obtain device info\n"); + ret = -ENXIO; + goto err1; + } + + init_completion(&p->done); + + p->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(p->clk)) { + dev_err(&pdev->dev, "cannot get clock\n"); + ret = PTR_ERR(p->clk); + goto err1; + } + + i = platform_get_irq(pdev, 0); + if (i < 0) { + dev_err(&pdev->dev, "cannot get platform IRQ\n"); + ret = -ENOENT; + goto err1; + } + + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + p->mapbase = devm_ioremap_resource(&pdev->dev, r); + if (IS_ERR(p->mapbase)) { + ret = PTR_ERR(p->mapbase); + goto err1; + } + + ret = devm_request_irq(&pdev->dev, i, sh_msiof_spi_irq, 0, + dev_name(&pdev->dev), p); + if (ret) { + dev_err(&pdev->dev, "unable to request irq\n"); + goto err1; + } + + p->pdev = pdev; + pm_runtime_enable(&pdev->dev); + + /* Platform data may override FIFO sizes */ + p->tx_fifo_size = p->chipdata->tx_fifo_size; + p->rx_fifo_size = p->chipdata->rx_fifo_size; + if (p->info->tx_fifo_override) + p->tx_fifo_size = p->info->tx_fifo_override; + if (p->info->rx_fifo_override) + p->rx_fifo_size = p->info->rx_fifo_override; + + /* init master code */ + master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH; + master->mode_bits |= SPI_LSB_FIRST | SPI_3WIRE; + master->flags = p->chipdata->master_flags; + master->bus_num = pdev->id; + master->dev.of_node = pdev->dev.of_node; + master->num_chipselect = p->info->num_chipselect; + master->setup = sh_msiof_spi_setup; + master->prepare_message = sh_msiof_prepare_message; + master->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 32); + master->auto_runtime_pm = true; + master->transfer_one = sh_msiof_transfer_one; + + ret = sh_msiof_request_dma(p); + if (ret < 0) + dev_warn(&pdev->dev, "DMA not available, using PIO\n"); + + ret = devm_spi_register_master(&pdev->dev, master); + if (ret < 0) { + dev_err(&pdev->dev, "spi_register_master error.\n"); + goto err2; + } + + return 0; + + err2: + sh_msiof_release_dma(p); + pm_runtime_disable(&pdev->dev); + err1: + spi_master_put(master); + return ret; +} + +static int sh_msiof_spi_remove(struct platform_device *pdev) +{ + struct sh_msiof_spi_priv *p = platform_get_drvdata(pdev); + + sh_msiof_release_dma(p); + pm_runtime_disable(&pdev->dev); + return 0; +} + +static struct platform_device_id spi_driver_ids[] = { + { "spi_sh_msiof", (kernel_ulong_t)&sh_data }, + { "spi_r8a7790_msiof", (kernel_ulong_t)&r8a779x_data }, + { "spi_r8a7791_msiof", (kernel_ulong_t)&r8a779x_data }, + { "spi_r8a7792_msiof", (kernel_ulong_t)&r8a779x_data }, + { "spi_r8a7793_msiof", (kernel_ulong_t)&r8a779x_data }, + { "spi_r8a7794_msiof", (kernel_ulong_t)&r8a779x_data }, + {}, +}; +MODULE_DEVICE_TABLE(platform, spi_driver_ids); + +static struct platform_driver sh_msiof_spi_drv = { + .probe = sh_msiof_spi_probe, + .remove = sh_msiof_spi_remove, + .id_table = spi_driver_ids, + .driver = { + .name = "spi_sh_msiof", + .of_match_table = of_match_ptr(sh_msiof_match), + }, +}; +module_platform_driver(sh_msiof_spi_drv); + +MODULE_DESCRIPTION("SuperH MSIOF SPI Master Interface Driver"); +MODULE_AUTHOR("Magnus Damm"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:spi_sh_msiof"); |