diff options
Diffstat (limited to 'drivers/spi/spi-sh-msiof.c')
| -rw-r--r-- | drivers/spi/spi-sh-msiof.c | 749 |
1 files changed, 749 insertions, 0 deletions
diff --git a/drivers/spi/spi-sh-msiof.c b/drivers/spi/spi-sh-msiof.c new file mode 100644 index 00000000000..e00d94b2225 --- /dev/null +++ b/drivers/spi/spi-sh-msiof.c @@ -0,0 +1,749 @@ +/* + * SuperH MSIOF SPI Master Interface + * + * Copyright (c) 2009 Magnus Damm + * + * 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/err.h> +#include <linux/gpio.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> + +#include <linux/spi/sh_msiof.h> +#include <linux/spi/spi.h> +#include <linux/spi/spi_bitbang.h> + +#include <asm/unaligned.h> + +struct sh_msiof_spi_priv { + struct spi_bitbang bitbang; /* must be first for spi_bitbang.c */ + void __iomem *mapbase; + struct clk *clk; + struct platform_device *pdev; + struct sh_msiof_spi_info *info; + struct completion done; + unsigned long flags; + int tx_fifo_size; + int rx_fifo_size; +}; + +#define TMDR1 0x00 +#define TMDR2 0x04 +#define TMDR3 0x08 +#define RMDR1 0x10 +#define RMDR2 0x14 +#define RMDR3 0x18 +#define TSCR 0x20 +#define RSCR 0x22 +#define CTR 0x28 +#define FCTR 0x30 +#define STR 0x40 +#define IER 0x44 +#define TDR1 0x48 +#define TDR2 0x4c +#define TFDR 0x50 +#define RDR1 0x58 +#define RDR2 0x5c +#define RFDR 0x60 + +#define CTR_TSCKE (1 << 15) +#define CTR_TFSE (1 << 14) +#define CTR_TXE (1 << 9) +#define CTR_RXE (1 << 8) + +#define STR_TEOF (1 << 23) +#define STR_REOF (1 << 7) + +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 scr; +} const sh_msiof_spi_clk_table[] = { + { 1, 0x0007 }, + { 2, 0x0000 }, + { 4, 0x0001 }, + { 8, 0x0002 }, + { 16, 0x0003 }, + { 32, 0x0004 }, + { 64, 0x1f00 }, + { 128, 0x1f01 }, + { 256, 0x1f02 }, + { 512, 0x1f03 }, + { 1024, 0x1f04 }, +}; + +static void sh_msiof_spi_set_clk_regs(struct sh_msiof_spi_priv *p, + unsigned long parent_rate, + unsigned long spi_hz) +{ + unsigned long div = 1024; + size_t k; + + if (!WARN_ON(!spi_hz || !parent_rate)) + div = parent_rate / spi_hz; + + /* TODO: make more fine grained */ + + for (k = 0; k < ARRAY_SIZE(sh_msiof_spi_clk_table); k++) { + if (sh_msiof_spi_clk_table[k].div >= div) + break; + } + + k = min_t(int, k, ARRAY_SIZE(sh_msiof_spi_clk_table) - 1); + + sh_msiof_write(p, TSCR, sh_msiof_spi_clk_table[k].scr); + sh_msiof_write(p, RSCR, sh_msiof_spi_clk_table[k].scr); +} + +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 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 + */ + sh_msiof_write(p, FCTR, 0); + sh_msiof_write(p, TMDR1, 0xe2000005 | (lsb_first << 24)); + sh_msiof_write(p, RMDR1, 0x22000005 | (lsb_first << 24)); + + tmp = 0xa0000000; + tmp |= cpol << 30; /* TSCKIZ */ + tmp |= cpol << 28; /* RSCKIZ */ + + edge = cpol ^ !cpha; + + tmp |= edge << 27; /* TEDG */ + tmp |= edge << 26; /* REDG */ + tmp |= (tx_hi_z ? 2 : 0) << 22; /* TXDIZ */ + 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 = ((bits - 1) << 24) | ((words - 1) << 16); + + if (tx_buf) + sh_msiof_write(p, TMDR2, dr2); + else + sh_msiof_write(p, TMDR2, dr2 | 1); + + if (rx_buf) + sh_msiof_write(p, RMDR2, dr2); + + sh_msiof_write(p, IER, STR_TEOF | STR_REOF); +} + +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_bits(struct spi_device *spi, struct spi_transfer *t) +{ + int bits; + + bits = t ? t->bits_per_word : 0; + if (!bits) + bits = spi->bits_per_word; + return bits; +} + +static unsigned long sh_msiof_spi_hz(struct spi_device *spi, + struct spi_transfer *t) +{ + unsigned long hz; + + hz = t ? t->speed_hz : 0; + if (!hz) + hz = spi->max_speed_hz; + return hz; +} + +static int sh_msiof_spi_setup_transfer(struct spi_device *spi, + struct spi_transfer *t) +{ + int bits; + + /* noting to check hz values against since parent clock is disabled */ + + bits = sh_msiof_spi_bits(spi, t); + if (bits < 8) + return -EINVAL; + if (bits > 32) + return -EINVAL; + + return spi_bitbang_setup_transfer(spi, t); +} + +static void sh_msiof_spi_chipselect(struct spi_device *spi, int is_on) +{ + struct sh_msiof_spi_priv *p = spi_master_get_devdata(spi->master); + int value; + + /* chip select is active low unless SPI_CS_HIGH is set */ + if (spi->mode & SPI_CS_HIGH) + value = (is_on == BITBANG_CS_ACTIVE) ? 1 : 0; + else + value = (is_on == BITBANG_CS_ACTIVE) ? 0 : 1; + + if (is_on == BITBANG_CS_ACTIVE) { + if (!test_and_set_bit(0, &p->flags)) { + pm_runtime_get_sync(&p->pdev->dev); + clk_enable(p->clk); + } + + /* 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)); + } + + /* use spi->controller data for CS (same strategy as spi_gpio) */ + gpio_set_value((unsigned)spi->controller_data, value); + + if (is_on == BITBANG_CS_INACTIVE) { + if (test_and_clear_bit(0, &p->flags)) { + clk_disable(p->clk); + pm_runtime_put(&p->pdev->dev); + } + } +} + +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; + + /* setup msiof transfer mode registers */ + sh_msiof_spi_set_mode_regs(p, tx_buf, rx_buf, bits, words); + + /* write tx fifo */ + if (tx_buf) + tx_fifo(p, tx_buf, words, fifo_shift); + + /* setup clock and rx/tx signals */ + ret = sh_msiof_modify_ctr_wait(p, 0, CTR_TSCKE); + if (rx_buf) + ret = ret ? ret : sh_msiof_modify_ctr_wait(p, 0, CTR_RXE); + ret = ret ? ret : sh_msiof_modify_ctr_wait(p, 0, CTR_TXE); + + /* start by setting frame bit */ + INIT_COMPLETION(p->done); + ret = ret ? ret : sh_msiof_modify_ctr_wait(p, 0, CTR_TFSE); + if (ret) { + dev_err(&p->pdev->dev, "failed to start hardware\n"); + goto err; + } + + /* wait for tx fifo to be emptied / rx fifo to be filled */ + wait_for_completion(&p->done); + + /* read rx fifo */ + if (rx_buf) + rx_fifo(p, rx_buf, words, fifo_shift); + + /* clear status bits */ + sh_msiof_reset_str(p); + + /* shut down frame, tx/tx and clock signals */ + ret = sh_msiof_modify_ctr_wait(p, CTR_TFSE, 0); + ret = ret ? ret : sh_msiof_modify_ctr_wait(p, CTR_TXE, 0); + if (rx_buf) + ret = ret ? ret : sh_msiof_modify_ctr_wait(p, CTR_RXE, 0); + ret = ret ? ret : sh_msiof_modify_ctr_wait(p, CTR_TSCKE, 0); + if (ret) { + dev_err(&p->pdev->dev, "failed to shut down hardware\n"); + goto err; + } + + return words; + + err: + sh_msiof_write(p, IER, 0); + return ret; +} + +static int sh_msiof_spi_txrx(struct spi_device *spi, struct spi_transfer *t) +{ + struct sh_msiof_spi_priv *p = spi_master_get_devdata(spi->master); + void (*tx_fifo)(struct sh_msiof_spi_priv *, const void *, int, int); + void (*rx_fifo)(struct sh_msiof_spi_priv *, void *, int, int); + int bits; + int bytes_per_word; + int bytes_done; + int words; + int n; + bool swab; + + bits = sh_msiof_spi_bits(spi, t); + + if (bits <= 8 && t->len > 15 && !(t->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)t->tx_buf & 0x01) + tx_fifo = sh_msiof_spi_write_fifo_16u; + else + tx_fifo = sh_msiof_spi_write_fifo_16; + + if ((unsigned long)t->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)t->tx_buf & 0x03) + tx_fifo = sh_msiof_spi_write_fifo_s32u; + else + tx_fifo = sh_msiof_spi_write_fifo_s32; + + if ((unsigned long)t->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)t->tx_buf & 0x03) + tx_fifo = sh_msiof_spi_write_fifo_32u; + else + tx_fifo = sh_msiof_spi_write_fifo_32; + + if ((unsigned long)t->rx_buf & 0x03) + rx_fifo = sh_msiof_spi_read_fifo_32u; + else + rx_fifo = sh_msiof_spi_read_fifo_32; + } + + /* setup clocks (clock already enabled in chipselect()) */ + sh_msiof_spi_set_clk_regs(p, clk_get_rate(p->clk), + sh_msiof_spi_hz(spi, t)); + + /* transfer in fifo sized chunks */ + words = t->len / bytes_per_word; + bytes_done = 0; + + while (bytes_done < t->len) { + void *rx_buf = t->rx_buf ? t->rx_buf + bytes_done : NULL; + const void *tx_buf = t->tx_buf ? t->tx_buf + bytes_done : NULL; + n = sh_msiof_spi_txrx_once(p, tx_fifo, rx_fifo, + tx_buf, + rx_buf, + words, bits); + if (n < 0) + break; + + bytes_done += n * bytes_per_word; + words -= n; + } + + return bytes_done; +} + +static u32 sh_msiof_spi_txrx_word(struct spi_device *spi, unsigned nsecs, + u32 word, u8 bits) +{ + BUG(); /* unused but needed by bitbang code */ + return 0; +} + +static int sh_msiof_spi_probe(struct platform_device *pdev) +{ + struct resource *r; + struct spi_master *master; + struct sh_msiof_spi_priv *p; + char clk_name[16]; + 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"); + ret = -ENOMEM; + goto err0; + } + + p = spi_master_get_devdata(master); + + platform_set_drvdata(pdev, p); + p->info = pdev->dev.platform_data; + init_completion(&p->done); + + snprintf(clk_name, sizeof(clk_name), "msiof%d", pdev->id); + p->clk = clk_get(&pdev->dev, clk_name); + if (IS_ERR(p->clk)) { + dev_err(&pdev->dev, "cannot get clock \"%s\"\n", clk_name); + ret = PTR_ERR(p->clk); + goto err1; + } + + r = platform_get_resource(pdev, IORESOURCE_MEM, 0); + i = platform_get_irq(pdev, 0); + if (!r || i < 0) { + dev_err(&pdev->dev, "cannot get platform resources\n"); + ret = -ENOENT; + goto err2; + } + p->mapbase = ioremap_nocache(r->start, resource_size(r)); + if (!p->mapbase) { + dev_err(&pdev->dev, "unable to ioremap\n"); + ret = -ENXIO; + goto err2; + } + + ret = request_irq(i, sh_msiof_spi_irq, IRQF_DISABLED, + dev_name(&pdev->dev), p); + if (ret) { + dev_err(&pdev->dev, "unable to request irq\n"); + goto err3; + } + + p->pdev = pdev; + pm_runtime_enable(&pdev->dev); + + /* The standard version of MSIOF use 64 word FIFOs */ + p->tx_fifo_size = 64; + p->rx_fifo_size = 64; + + /* Platform data may override FIFO sizes */ + 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 and bitbang code */ + master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH; + master->mode_bits |= SPI_LSB_FIRST | SPI_3WIRE; + master->flags = 0; + master->bus_num = pdev->id; + master->num_chipselect = p->info->num_chipselect; + master->setup = spi_bitbang_setup; + master->cleanup = spi_bitbang_cleanup; + + p->bitbang.master = master; + p->bitbang.chipselect = sh_msiof_spi_chipselect; + p->bitbang.setup_transfer = sh_msiof_spi_setup_transfer; + p->bitbang.txrx_bufs = sh_msiof_spi_txrx; + p->bitbang.txrx_word[SPI_MODE_0] = sh_msiof_spi_txrx_word; + p->bitbang.txrx_word[SPI_MODE_1] = sh_msiof_spi_txrx_word; + p->bitbang.txrx_word[SPI_MODE_2] = sh_msiof_spi_txrx_word; + p->bitbang.txrx_word[SPI_MODE_3] = sh_msiof_spi_txrx_word; + + ret = spi_bitbang_start(&p->bitbang); + if (ret == 0) + return 0; + + pm_runtime_disable(&pdev->dev); + err3: + iounmap(p->mapbase); + err2: + clk_put(p->clk); + err1: + spi_master_put(master); + err0: + return ret; +} + +static int sh_msiof_spi_remove(struct platform_device *pdev) +{ + struct sh_msiof_spi_priv *p = platform_get_drvdata(pdev); + int ret; + + ret = spi_bitbang_stop(&p->bitbang); + if (!ret) { + pm_runtime_disable(&pdev->dev); + free_irq(platform_get_irq(pdev, 0), p); + iounmap(p->mapbase); + clk_put(p->clk); + spi_master_put(p->bitbang.master); + } + return ret; +} + +static int sh_msiof_spi_runtime_nop(struct device *dev) +{ + /* Runtime PM callback shared between ->runtime_suspend() + * and ->runtime_resume(). Simply returns success. + * + * This driver re-initializes all registers after + * pm_runtime_get_sync() anyway so there is no need + * to save and restore registers here. + */ + return 0; +} + +static struct dev_pm_ops sh_msiof_spi_dev_pm_ops = { + .runtime_suspend = sh_msiof_spi_runtime_nop, + .runtime_resume = sh_msiof_spi_runtime_nop, +}; + +static struct platform_driver sh_msiof_spi_drv = { + .probe = sh_msiof_spi_probe, + .remove = sh_msiof_spi_remove, + .driver = { + .name = "spi_sh_msiof", + .owner = THIS_MODULE, + .pm = &sh_msiof_spi_dev_pm_ops, + }, +}; + +static int __init sh_msiof_spi_init(void) +{ + return platform_driver_register(&sh_msiof_spi_drv); +} +module_init(sh_msiof_spi_init); + +static void __exit sh_msiof_spi_exit(void) +{ + platform_driver_unregister(&sh_msiof_spi_drv); +} +module_exit(sh_msiof_spi_exit); + +MODULE_DESCRIPTION("SuperH MSIOF SPI Master Interface Driver"); +MODULE_AUTHOR("Magnus Damm"); +MODULE_LICENSE("GPL v2"); +MODULE_ALIAS("platform:spi_sh_msiof"); |