--- /dev/null
+/*
+ * 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/kernel.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/completion.h>
+#include <linux/pm_runtime.h>
+#include <linux/gpio.h>
+#include <linux/bitmap.h>
+#include <linux/clk.h>
+#include <linux/io.h>
+
+#include <linux/spi/spi.h>
+#include <linux/spi/spi_bitbang.h>
+#include <linux/spi/sh_msiof.h>
+
+#include <asm/spi.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 unsigned long 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,
+ unsigned long 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,
+ unsigned long clr, unsigned long set)
+{
+ unsigned long mask = clr | set;
+ unsigned long 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,
+ int cpol, int cpha,
+ int tx_hi_z, int lsb_first)
+{
+ unsigned long tmp;
+ int edge;
+
+ /*
+ * CPOL CPHA TSCKIZ RSCKIZ TEDG REDG(!)
+ * 0 0 10 10 1 0
+ * 0 1 10 10 0 1
+ * 1 0 11 11 0 1
+ * 1 1 11 11 1 0
+ *
+ * (!) Note: REDG is inverted recommended data sheet setting
+ */
+
+ 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 : !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,
+ int bits, int words)
+{
+ unsigned long dr2;
+
+ 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 unsigned char *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 unsigned short *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 unsigned short *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 unsigned int *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 unsigned int *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_read_fifo_8(struct sh_msiof_spi_priv *p,
+ void *rx_buf, int words, int fs)
+{
+ unsigned char *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)
+{
+ unsigned short *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)
+{
+ unsigned short *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)
+{
+ unsigned int *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)
+{
+ unsigned int *buf_32 = rx_buf;
+ int k;
+
+ for (k = 0; k < words; k++)
+ put_unaligned(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;
+ bits = 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;
+ hz = 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;
+
+ bits = sh_msiof_spi_bits(spi, t);
+
+ /* 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 {
+ 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) {
+ n = sh_msiof_spi_txrx_once(p, tx_fifo, rx_fifo,
+ t->tx_buf + bytes_done,
+ t->rx_buf + bytes_done,
+ 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), sh_msiof_spi_irq);
+ 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");
projects / GitHub / LineageOS / android_kernel_motorola_exynos9610.git / commitdiff