diff options
Diffstat (limited to 'drivers/spi/spi-imx.c')
| -rw-r--r-- | drivers/spi/spi-imx.c | 1249 |
1 files changed, 1249 insertions, 0 deletions
diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c new file mode 100644 index 000000000..f08e812b2 --- /dev/null +++ b/drivers/spi/spi-imx.c @@ -0,0 +1,1249 @@ +/* + * Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved. + * Copyright (C) 2008 Juergen Beisert + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the + * Free Software Foundation + * 51 Franklin Street, Fifth Floor + * Boston, MA 02110-1301, USA. + */ + +#include <linux/clk.h> +#include <linux/completion.h> +#include <linux/delay.h> +#include <linux/dmaengine.h> +#include <linux/dma-mapping.h> +#include <linux/err.h> +#include <linux/gpio.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/irq.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/slab.h> +#include <linux/spi/spi.h> +#include <linux/spi/spi_bitbang.h> +#include <linux/types.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/of_gpio.h> + +#include <linux/platform_data/dma-imx.h> +#include <linux/platform_data/spi-imx.h> + +#define DRIVER_NAME "spi_imx" + +#define MXC_CSPIRXDATA 0x00 +#define MXC_CSPITXDATA 0x04 +#define MXC_CSPICTRL 0x08 +#define MXC_CSPIINT 0x0c +#define MXC_RESET 0x1c + +/* generic defines to abstract from the different register layouts */ +#define MXC_INT_RR (1 << 0) /* Receive data ready interrupt */ +#define MXC_INT_TE (1 << 1) /* Transmit FIFO empty interrupt */ + +/* The maximum bytes that a sdma BD can transfer.*/ +#define MAX_SDMA_BD_BYTES (1 << 15) +#define IMX_DMA_TIMEOUT (msecs_to_jiffies(3000)) +struct spi_imx_config { + unsigned int speed_hz; + unsigned int bpw; + unsigned int mode; + u8 cs; +}; + +enum spi_imx_devtype { + IMX1_CSPI, + IMX21_CSPI, + IMX27_CSPI, + IMX31_CSPI, + IMX35_CSPI, /* CSPI on all i.mx except above */ + IMX51_ECSPI, /* ECSPI on i.mx51 and later */ +}; + +struct spi_imx_data; + +struct spi_imx_devtype_data { + void (*intctrl)(struct spi_imx_data *, int); + int (*config)(struct spi_imx_data *, struct spi_imx_config *); + void (*trigger)(struct spi_imx_data *); + int (*rx_available)(struct spi_imx_data *); + void (*reset)(struct spi_imx_data *); + enum spi_imx_devtype devtype; +}; + +struct spi_imx_data { + struct spi_bitbang bitbang; + + struct completion xfer_done; + void __iomem *base; + struct clk *clk_per; + struct clk *clk_ipg; + unsigned long spi_clk; + + unsigned int count; + void (*tx)(struct spi_imx_data *); + void (*rx)(struct spi_imx_data *); + void *rx_buf; + const void *tx_buf; + unsigned int txfifo; /* number of words pushed in tx FIFO */ + + /* DMA */ + unsigned int dma_is_inited; + unsigned int dma_finished; + bool usedma; + u32 rx_wml; + u32 tx_wml; + u32 rxt_wml; + struct completion dma_rx_completion; + struct completion dma_tx_completion; + + const struct spi_imx_devtype_data *devtype_data; + int chipselect[0]; +}; + +static inline int is_imx27_cspi(struct spi_imx_data *d) +{ + return d->devtype_data->devtype == IMX27_CSPI; +} + +static inline int is_imx35_cspi(struct spi_imx_data *d) +{ + return d->devtype_data->devtype == IMX35_CSPI; +} + +static inline unsigned spi_imx_get_fifosize(struct spi_imx_data *d) +{ + return (d->devtype_data->devtype == IMX51_ECSPI) ? 64 : 8; +} + +#define MXC_SPI_BUF_RX(type) \ +static void spi_imx_buf_rx_##type(struct spi_imx_data *spi_imx) \ +{ \ + unsigned int val = readl(spi_imx->base + MXC_CSPIRXDATA); \ + \ + if (spi_imx->rx_buf) { \ + *(type *)spi_imx->rx_buf = val; \ + spi_imx->rx_buf += sizeof(type); \ + } \ +} + +#define MXC_SPI_BUF_TX(type) \ +static void spi_imx_buf_tx_##type(struct spi_imx_data *spi_imx) \ +{ \ + type val = 0; \ + \ + if (spi_imx->tx_buf) { \ + val = *(type *)spi_imx->tx_buf; \ + spi_imx->tx_buf += sizeof(type); \ + } \ + \ + spi_imx->count -= sizeof(type); \ + \ + writel(val, spi_imx->base + MXC_CSPITXDATA); \ +} + +MXC_SPI_BUF_RX(u8) +MXC_SPI_BUF_TX(u8) +MXC_SPI_BUF_RX(u16) +MXC_SPI_BUF_TX(u16) +MXC_SPI_BUF_RX(u32) +MXC_SPI_BUF_TX(u32) + +/* First entry is reserved, second entry is valid only if SDHC_SPIEN is set + * (which is currently not the case in this driver) + */ +static int mxc_clkdivs[] = {0, 3, 4, 6, 8, 12, 16, 24, 32, 48, 64, 96, 128, 192, + 256, 384, 512, 768, 1024}; + +/* MX21, MX27 */ +static unsigned int spi_imx_clkdiv_1(unsigned int fin, + unsigned int fspi, unsigned int max) +{ + int i; + + for (i = 2; i < max; i++) + if (fspi * mxc_clkdivs[i] >= fin) + return i; + + return max; +} + +/* MX1, MX31, MX35, MX51 CSPI */ +static unsigned int spi_imx_clkdiv_2(unsigned int fin, + unsigned int fspi) +{ + int i, div = 4; + + for (i = 0; i < 7; i++) { + if (fspi * div >= fin) + return i; + div <<= 1; + } + + return 7; +} + +static bool spi_imx_can_dma(struct spi_master *master, struct spi_device *spi, + struct spi_transfer *transfer) +{ + struct spi_imx_data *spi_imx = spi_master_get_devdata(master); + + if (spi_imx->dma_is_inited && (transfer->len > spi_imx->rx_wml) + && (transfer->len > spi_imx->tx_wml)) + return true; + return false; +} + +#define MX51_ECSPI_CTRL 0x08 +#define MX51_ECSPI_CTRL_ENABLE (1 << 0) +#define MX51_ECSPI_CTRL_XCH (1 << 2) +#define MX51_ECSPI_CTRL_SMC (1 << 3) +#define MX51_ECSPI_CTRL_MODE_MASK (0xf << 4) +#define MX51_ECSPI_CTRL_POSTDIV_OFFSET 8 +#define MX51_ECSPI_CTRL_PREDIV_OFFSET 12 +#define MX51_ECSPI_CTRL_CS(cs) ((cs) << 18) +#define MX51_ECSPI_CTRL_BL_OFFSET 20 + +#define MX51_ECSPI_CONFIG 0x0c +#define MX51_ECSPI_CONFIG_SCLKPHA(cs) (1 << ((cs) + 0)) +#define MX51_ECSPI_CONFIG_SCLKPOL(cs) (1 << ((cs) + 4)) +#define MX51_ECSPI_CONFIG_SBBCTRL(cs) (1 << ((cs) + 8)) +#define MX51_ECSPI_CONFIG_SSBPOL(cs) (1 << ((cs) + 12)) +#define MX51_ECSPI_CONFIG_SCLKCTL(cs) (1 << ((cs) + 20)) + +#define MX51_ECSPI_INT 0x10 +#define MX51_ECSPI_INT_TEEN (1 << 0) +#define MX51_ECSPI_INT_RREN (1 << 3) + +#define MX51_ECSPI_DMA 0x14 +#define MX51_ECSPI_DMA_TX_WML_OFFSET 0 +#define MX51_ECSPI_DMA_TX_WML_MASK 0x3F +#define MX51_ECSPI_DMA_RX_WML_OFFSET 16 +#define MX51_ECSPI_DMA_RX_WML_MASK (0x3F << 16) +#define MX51_ECSPI_DMA_RXT_WML_OFFSET 24 +#define MX51_ECSPI_DMA_RXT_WML_MASK (0x3F << 24) + +#define MX51_ECSPI_DMA_TEDEN_OFFSET 7 +#define MX51_ECSPI_DMA_RXDEN_OFFSET 23 +#define MX51_ECSPI_DMA_RXTDEN_OFFSET 31 + +#define MX51_ECSPI_STAT 0x18 +#define MX51_ECSPI_STAT_RR (1 << 3) + +/* MX51 eCSPI */ +static unsigned int mx51_ecspi_clkdiv(unsigned int fin, unsigned int fspi, + unsigned int *fres) +{ + /* + * there are two 4-bit dividers, the pre-divider divides by + * $pre, the post-divider by 2^$post + */ + unsigned int pre, post; + + if (unlikely(fspi > fin)) + return 0; + + post = fls(fin) - fls(fspi); + if (fin > fspi << post) + post++; + + /* now we have: (fin <= fspi << post) with post being minimal */ + + post = max(4U, post) - 4; + if (unlikely(post > 0xf)) { + pr_err("%s: cannot set clock freq: %u (base freq: %u)\n", + __func__, fspi, fin); + return 0xff; + } + + pre = DIV_ROUND_UP(fin, fspi << post) - 1; + + pr_debug("%s: fin: %u, fspi: %u, post: %u, pre: %u\n", + __func__, fin, fspi, post, pre); + + /* Resulting frequency for the SCLK line. */ + *fres = (fin / (pre + 1)) >> post; + + return (pre << MX51_ECSPI_CTRL_PREDIV_OFFSET) | + (post << MX51_ECSPI_CTRL_POSTDIV_OFFSET); +} + +static void __maybe_unused mx51_ecspi_intctrl(struct spi_imx_data *spi_imx, int enable) +{ + unsigned val = 0; + + if (enable & MXC_INT_TE) + val |= MX51_ECSPI_INT_TEEN; + + if (enable & MXC_INT_RR) + val |= MX51_ECSPI_INT_RREN; + + writel(val, spi_imx->base + MX51_ECSPI_INT); +} + +static void __maybe_unused mx51_ecspi_trigger(struct spi_imx_data *spi_imx) +{ + u32 reg = readl(spi_imx->base + MX51_ECSPI_CTRL); + + if (!spi_imx->usedma) + reg |= MX51_ECSPI_CTRL_XCH; + else if (!spi_imx->dma_finished) + reg |= MX51_ECSPI_CTRL_SMC; + else + reg &= ~MX51_ECSPI_CTRL_SMC; + writel(reg, spi_imx->base + MX51_ECSPI_CTRL); +} + +static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx, + struct spi_imx_config *config) +{ + u32 ctrl = MX51_ECSPI_CTRL_ENABLE, cfg = 0, dma = 0; + u32 tx_wml_cfg, rx_wml_cfg, rxt_wml_cfg; + u32 clk = config->speed_hz, delay; + + /* + * The hardware seems to have a race condition when changing modes. The + * current assumption is that the selection of the channel arrives + * earlier in the hardware than the mode bits when they are written at + * the same time. + * So set master mode for all channels as we do not support slave mode. + */ + ctrl |= MX51_ECSPI_CTRL_MODE_MASK; + + /* set clock speed */ + ctrl |= mx51_ecspi_clkdiv(spi_imx->spi_clk, config->speed_hz, &clk); + + /* set chip select to use */ + ctrl |= MX51_ECSPI_CTRL_CS(config->cs); + + ctrl |= (config->bpw - 1) << MX51_ECSPI_CTRL_BL_OFFSET; + + cfg |= MX51_ECSPI_CONFIG_SBBCTRL(config->cs); + + if (config->mode & SPI_CPHA) + cfg |= MX51_ECSPI_CONFIG_SCLKPHA(config->cs); + + if (config->mode & SPI_CPOL) { + cfg |= MX51_ECSPI_CONFIG_SCLKPOL(config->cs); + cfg |= MX51_ECSPI_CONFIG_SCLKCTL(config->cs); + } + if (config->mode & SPI_CS_HIGH) + cfg |= MX51_ECSPI_CONFIG_SSBPOL(config->cs); + + writel(ctrl, spi_imx->base + MX51_ECSPI_CTRL); + writel(cfg, spi_imx->base + MX51_ECSPI_CONFIG); + + /* + * Wait until the changes in the configuration register CONFIGREG + * propagate into the hardware. It takes exactly one tick of the + * SCLK clock, but we will wait two SCLK clock just to be sure. The + * effect of the delay it takes for the hardware to apply changes + * is noticable if the SCLK clock run very slow. In such a case, if + * the polarity of SCLK should be inverted, the GPIO ChipSelect might + * be asserted before the SCLK polarity changes, which would disrupt + * the SPI communication as the device on the other end would consider + * the change of SCLK polarity as a clock tick already. + */ + delay = (2 * 1000000) / clk; + if (likely(delay < 10)) /* SCLK is faster than 100 kHz */ + udelay(delay); + else /* SCLK is _very_ slow */ + usleep_range(delay, delay + 10); + + /* + * Configure the DMA register: setup the watermark + * and enable DMA request. + */ + if (spi_imx->dma_is_inited) { + dma = readl(spi_imx->base + MX51_ECSPI_DMA); + + spi_imx->rxt_wml = spi_imx_get_fifosize(spi_imx) / 2; + rx_wml_cfg = spi_imx->rx_wml << MX51_ECSPI_DMA_RX_WML_OFFSET; + tx_wml_cfg = spi_imx->tx_wml << MX51_ECSPI_DMA_TX_WML_OFFSET; + rxt_wml_cfg = spi_imx->rxt_wml << MX51_ECSPI_DMA_RXT_WML_OFFSET; + dma = (dma & ~MX51_ECSPI_DMA_TX_WML_MASK + & ~MX51_ECSPI_DMA_RX_WML_MASK + & ~MX51_ECSPI_DMA_RXT_WML_MASK) + | rx_wml_cfg | tx_wml_cfg | rxt_wml_cfg + |(1 << MX51_ECSPI_DMA_TEDEN_OFFSET) + |(1 << MX51_ECSPI_DMA_RXDEN_OFFSET) + |(1 << MX51_ECSPI_DMA_RXTDEN_OFFSET); + + writel(dma, spi_imx->base + MX51_ECSPI_DMA); + } + + return 0; +} + +static int __maybe_unused mx51_ecspi_rx_available(struct spi_imx_data *spi_imx) +{ + return readl(spi_imx->base + MX51_ECSPI_STAT) & MX51_ECSPI_STAT_RR; +} + +static void __maybe_unused mx51_ecspi_reset(struct spi_imx_data *spi_imx) +{ + /* drain receive buffer */ + while (mx51_ecspi_rx_available(spi_imx)) + readl(spi_imx->base + MXC_CSPIRXDATA); +} + +#define MX31_INTREG_TEEN (1 << 0) +#define MX31_INTREG_RREN (1 << 3) + +#define MX31_CSPICTRL_ENABLE (1 << 0) +#define MX31_CSPICTRL_MASTER (1 << 1) +#define MX31_CSPICTRL_XCH (1 << 2) +#define MX31_CSPICTRL_POL (1 << 4) +#define MX31_CSPICTRL_PHA (1 << 5) +#define MX31_CSPICTRL_SSCTL (1 << 6) +#define MX31_CSPICTRL_SSPOL (1 << 7) +#define MX31_CSPICTRL_BC_SHIFT 8 +#define MX35_CSPICTRL_BL_SHIFT 20 +#define MX31_CSPICTRL_CS_SHIFT 24 +#define MX35_CSPICTRL_CS_SHIFT 12 +#define MX31_CSPICTRL_DR_SHIFT 16 + +#define MX31_CSPISTATUS 0x14 +#define MX31_STATUS_RR (1 << 3) + +/* These functions also work for the i.MX35, but be aware that + * the i.MX35 has a slightly different register layout for bits + * we do not use here. + */ +static void __maybe_unused mx31_intctrl(struct spi_imx_data *spi_imx, int enable) +{ + unsigned int val = 0; + + if (enable & MXC_INT_TE) + val |= MX31_INTREG_TEEN; + if (enable & MXC_INT_RR) + val |= MX31_INTREG_RREN; + + writel(val, spi_imx->base + MXC_CSPIINT); +} + +static void __maybe_unused mx31_trigger(struct spi_imx_data *spi_imx) +{ + unsigned int reg; + + reg = readl(spi_imx->base + MXC_CSPICTRL); + reg |= MX31_CSPICTRL_XCH; + writel(reg, spi_imx->base + MXC_CSPICTRL); +} + +static int __maybe_unused mx31_config(struct spi_imx_data *spi_imx, + struct spi_imx_config *config) +{ + unsigned int reg = MX31_CSPICTRL_ENABLE | MX31_CSPICTRL_MASTER; + int cs = spi_imx->chipselect[config->cs]; + + reg |= spi_imx_clkdiv_2(spi_imx->spi_clk, config->speed_hz) << + MX31_CSPICTRL_DR_SHIFT; + + if (is_imx35_cspi(spi_imx)) { + reg |= (config->bpw - 1) << MX35_CSPICTRL_BL_SHIFT; + reg |= MX31_CSPICTRL_SSCTL; + } else { + reg |= (config->bpw - 1) << MX31_CSPICTRL_BC_SHIFT; + } + + if (config->mode & SPI_CPHA) + reg |= MX31_CSPICTRL_PHA; + if (config->mode & SPI_CPOL) + reg |= MX31_CSPICTRL_POL; + if (config->mode & SPI_CS_HIGH) + reg |= MX31_CSPICTRL_SSPOL; + if (cs < 0) + reg |= (cs + 32) << + (is_imx35_cspi(spi_imx) ? MX35_CSPICTRL_CS_SHIFT : + MX31_CSPICTRL_CS_SHIFT); + + writel(reg, spi_imx->base + MXC_CSPICTRL); + + return 0; +} + +static int __maybe_unused mx31_rx_available(struct spi_imx_data *spi_imx) +{ + return readl(spi_imx->base + MX31_CSPISTATUS) & MX31_STATUS_RR; +} + +static void __maybe_unused mx31_reset(struct spi_imx_data *spi_imx) +{ + /* drain receive buffer */ + while (readl(spi_imx->base + MX31_CSPISTATUS) & MX31_STATUS_RR) + readl(spi_imx->base + MXC_CSPIRXDATA); +} + +#define MX21_INTREG_RR (1 << 4) +#define MX21_INTREG_TEEN (1 << 9) +#define MX21_INTREG_RREN (1 << 13) + +#define MX21_CSPICTRL_POL (1 << 5) +#define MX21_CSPICTRL_PHA (1 << 6) +#define MX21_CSPICTRL_SSPOL (1 << 8) +#define MX21_CSPICTRL_XCH (1 << 9) +#define MX21_CSPICTRL_ENABLE (1 << 10) +#define MX21_CSPICTRL_MASTER (1 << 11) +#define MX21_CSPICTRL_DR_SHIFT 14 +#define MX21_CSPICTRL_CS_SHIFT 19 + +static void __maybe_unused mx21_intctrl(struct spi_imx_data *spi_imx, int enable) +{ + unsigned int val = 0; + + if (enable & MXC_INT_TE) + val |= MX21_INTREG_TEEN; + if (enable & MXC_INT_RR) + val |= MX21_INTREG_RREN; + + writel(val, spi_imx->base + MXC_CSPIINT); +} + +static void __maybe_unused mx21_trigger(struct spi_imx_data *spi_imx) +{ + unsigned int reg; + + reg = readl(spi_imx->base + MXC_CSPICTRL); + reg |= MX21_CSPICTRL_XCH; + writel(reg, spi_imx->base + MXC_CSPICTRL); +} + +static int __maybe_unused mx21_config(struct spi_imx_data *spi_imx, + struct spi_imx_config *config) +{ + unsigned int reg = MX21_CSPICTRL_ENABLE | MX21_CSPICTRL_MASTER; + int cs = spi_imx->chipselect[config->cs]; + unsigned int max = is_imx27_cspi(spi_imx) ? 16 : 18; + + reg |= spi_imx_clkdiv_1(spi_imx->spi_clk, config->speed_hz, max) << + MX21_CSPICTRL_DR_SHIFT; + reg |= config->bpw - 1; + + if (config->mode & SPI_CPHA) + reg |= MX21_CSPICTRL_PHA; + if (config->mode & SPI_CPOL) + reg |= MX21_CSPICTRL_POL; + if (config->mode & SPI_CS_HIGH) + reg |= MX21_CSPICTRL_SSPOL; + if (cs < 0) + reg |= (cs + 32) << MX21_CSPICTRL_CS_SHIFT; + + writel(reg, spi_imx->base + MXC_CSPICTRL); + + return 0; +} + +static int __maybe_unused mx21_rx_available(struct spi_imx_data *spi_imx) +{ + return readl(spi_imx->base + MXC_CSPIINT) & MX21_INTREG_RR; +} + +static void __maybe_unused mx21_reset(struct spi_imx_data *spi_imx) +{ + writel(1, spi_imx->base + MXC_RESET); +} + +#define MX1_INTREG_RR (1 << 3) +#define MX1_INTREG_TEEN (1 << 8) +#define MX1_INTREG_RREN (1 << 11) + +#define MX1_CSPICTRL_POL (1 << 4) +#define MX1_CSPICTRL_PHA (1 << 5) +#define MX1_CSPICTRL_XCH (1 << 8) +#define MX1_CSPICTRL_ENABLE (1 << 9) +#define MX1_CSPICTRL_MASTER (1 << 10) +#define MX1_CSPICTRL_DR_SHIFT 13 + +static void __maybe_unused mx1_intctrl(struct spi_imx_data *spi_imx, int enable) +{ + unsigned int val = 0; + + if (enable & MXC_INT_TE) + val |= MX1_INTREG_TEEN; + if (enable & MXC_INT_RR) + val |= MX1_INTREG_RREN; + + writel(val, spi_imx->base + MXC_CSPIINT); +} + +static void __maybe_unused mx1_trigger(struct spi_imx_data *spi_imx) +{ + unsigned int reg; + + reg = readl(spi_imx->base + MXC_CSPICTRL); + reg |= MX1_CSPICTRL_XCH; + writel(reg, spi_imx->base + MXC_CSPICTRL); +} + +static int __maybe_unused mx1_config(struct spi_imx_data *spi_imx, + struct spi_imx_config *config) +{ + unsigned int reg = MX1_CSPICTRL_ENABLE | MX1_CSPICTRL_MASTER; + + reg |= spi_imx_clkdiv_2(spi_imx->spi_clk, config->speed_hz) << + MX1_CSPICTRL_DR_SHIFT; + reg |= config->bpw - 1; + + if (config->mode & SPI_CPHA) + reg |= MX1_CSPICTRL_PHA; + if (config->mode & SPI_CPOL) + reg |= MX1_CSPICTRL_POL; + + writel(reg, spi_imx->base + MXC_CSPICTRL); + + return 0; +} + +static int __maybe_unused mx1_rx_available(struct spi_imx_data *spi_imx) +{ + return readl(spi_imx->base + MXC_CSPIINT) & MX1_INTREG_RR; +} + +static void __maybe_unused mx1_reset(struct spi_imx_data *spi_imx) +{ + writel(1, spi_imx->base + MXC_RESET); +} + +static struct spi_imx_devtype_data imx1_cspi_devtype_data = { + .intctrl = mx1_intctrl, + .config = mx1_config, + .trigger = mx1_trigger, + .rx_available = mx1_rx_available, + .reset = mx1_reset, + .devtype = IMX1_CSPI, +}; + +static struct spi_imx_devtype_data imx21_cspi_devtype_data = { + .intctrl = mx21_intctrl, + .config = mx21_config, + .trigger = mx21_trigger, + .rx_available = mx21_rx_available, + .reset = mx21_reset, + .devtype = IMX21_CSPI, +}; + +static struct spi_imx_devtype_data imx27_cspi_devtype_data = { + /* i.mx27 cspi shares the functions with i.mx21 one */ + .intctrl = mx21_intctrl, + .config = mx21_config, + .trigger = mx21_trigger, + .rx_available = mx21_rx_available, + .reset = mx21_reset, + .devtype = IMX27_CSPI, +}; + +static struct spi_imx_devtype_data imx31_cspi_devtype_data = { + .intctrl = mx31_intctrl, + .config = mx31_config, + .trigger = mx31_trigger, + .rx_available = mx31_rx_available, + .reset = mx31_reset, + .devtype = IMX31_CSPI, +}; + +static struct spi_imx_devtype_data imx35_cspi_devtype_data = { + /* i.mx35 and later cspi shares the functions with i.mx31 one */ + .intctrl = mx31_intctrl, + .config = mx31_config, + .trigger = mx31_trigger, + .rx_available = mx31_rx_available, + .reset = mx31_reset, + .devtype = IMX35_CSPI, +}; + +static struct spi_imx_devtype_data imx51_ecspi_devtype_data = { + .intctrl = mx51_ecspi_intctrl, + .config = mx51_ecspi_config, + .trigger = mx51_ecspi_trigger, + .rx_available = mx51_ecspi_rx_available, + .reset = mx51_ecspi_reset, + .devtype = IMX51_ECSPI, +}; + +static struct platform_device_id spi_imx_devtype[] = { + { + .name = "imx1-cspi", + .driver_data = (kernel_ulong_t) &imx1_cspi_devtype_data, + }, { + .name = "imx21-cspi", + .driver_data = (kernel_ulong_t) &imx21_cspi_devtype_data, + }, { + .name = "imx27-cspi", + .driver_data = (kernel_ulong_t) &imx27_cspi_devtype_data, + }, { + .name = "imx31-cspi", + .driver_data = (kernel_ulong_t) &imx31_cspi_devtype_data, + }, { + .name = "imx35-cspi", + .driver_data = (kernel_ulong_t) &imx35_cspi_devtype_data, + }, { + .name = "imx51-ecspi", + .driver_data = (kernel_ulong_t) &imx51_ecspi_devtype_data, + }, { + /* sentinel */ + } +}; + +static const struct of_device_id spi_imx_dt_ids[] = { + { .compatible = "fsl,imx1-cspi", .data = &imx1_cspi_devtype_data, }, + { .compatible = "fsl,imx21-cspi", .data = &imx21_cspi_devtype_data, }, + { .compatible = "fsl,imx27-cspi", .data = &imx27_cspi_devtype_data, }, + { .compatible = "fsl,imx31-cspi", .data = &imx31_cspi_devtype_data, }, + { .compatible = "fsl,imx35-cspi", .data = &imx35_cspi_devtype_data, }, + { .compatible = "fsl,imx51-ecspi", .data = &imx51_ecspi_devtype_data, }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, spi_imx_dt_ids); + +static void spi_imx_chipselect(struct spi_device *spi, int is_active) +{ + struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master); + int gpio = spi_imx->chipselect[spi->chip_select]; + int active = is_active != BITBANG_CS_INACTIVE; + int dev_is_lowactive = !(spi->mode & SPI_CS_HIGH); + + if (!gpio_is_valid(gpio)) + return; + + gpio_set_value(gpio, dev_is_lowactive ^ active); +} + +static void spi_imx_push(struct spi_imx_data *spi_imx) +{ + while (spi_imx->txfifo < spi_imx_get_fifosize(spi_imx)) { + if (!spi_imx->count) + break; + spi_imx->tx(spi_imx); + spi_imx->txfifo++; + } + + spi_imx->devtype_data->trigger(spi_imx); +} + +static irqreturn_t spi_imx_isr(int irq, void *dev_id) +{ + struct spi_imx_data *spi_imx = dev_id; + + while (spi_imx->devtype_data->rx_available(spi_imx)) { + spi_imx->rx(spi_imx); + spi_imx->txfifo--; + } + + if (spi_imx->count) { + spi_imx_push(spi_imx); + return IRQ_HANDLED; + } + + if (spi_imx->txfifo) { + /* No data left to push, but still waiting for rx data, + * enable receive data available interrupt. + */ + spi_imx->devtype_data->intctrl( + spi_imx, MXC_INT_RR); + return IRQ_HANDLED; + } + + spi_imx->devtype_data->intctrl(spi_imx, 0); + complete(&spi_imx->xfer_done); + + return IRQ_HANDLED; +} + +static int spi_imx_setupxfer(struct spi_device *spi, + struct spi_transfer *t) +{ + struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master); + struct spi_imx_config config; + + config.bpw = t ? t->bits_per_word : spi->bits_per_word; + config.speed_hz = t ? t->speed_hz : spi->max_speed_hz; + config.mode = spi->mode; + config.cs = spi->chip_select; + + if (!config.speed_hz) + config.speed_hz = spi->max_speed_hz; + if (!config.bpw) + config.bpw = spi->bits_per_word; + + /* Initialize the functions for transfer */ + if (config.bpw <= 8) { + spi_imx->rx = spi_imx_buf_rx_u8; + spi_imx->tx = spi_imx_buf_tx_u8; + } else if (config.bpw <= 16) { + spi_imx->rx = spi_imx_buf_rx_u16; + spi_imx->tx = spi_imx_buf_tx_u16; + } else { + spi_imx->rx = spi_imx_buf_rx_u32; + spi_imx->tx = spi_imx_buf_tx_u32; + } + + spi_imx->devtype_data->config(spi_imx, &config); + + return 0; +} + +static void spi_imx_sdma_exit(struct spi_imx_data *spi_imx) +{ + struct spi_master *master = spi_imx->bitbang.master; + + if (master->dma_rx) { + dma_release_channel(master->dma_rx); + master->dma_rx = NULL; + } + + if (master->dma_tx) { + dma_release_channel(master->dma_tx); + master->dma_tx = NULL; + } + + spi_imx->dma_is_inited = 0; +} + +static int spi_imx_sdma_init(struct device *dev, struct spi_imx_data *spi_imx, + struct spi_master *master, + const struct resource *res) +{ + struct dma_slave_config slave_config = {}; + int ret; + + /* use pio mode for i.mx6dl chip TKT238285 */ + if (of_machine_is_compatible("fsl,imx6dl")) + return 0; + + /* Prepare for TX DMA: */ + master->dma_tx = dma_request_slave_channel(dev, "tx"); + if (!master->dma_tx) { + dev_err(dev, "cannot get the TX DMA channel!\n"); + ret = -EINVAL; + goto err; + } + + slave_config.direction = DMA_MEM_TO_DEV; + slave_config.dst_addr = res->start + MXC_CSPITXDATA; + slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; + slave_config.dst_maxburst = spi_imx_get_fifosize(spi_imx) / 2; + ret = dmaengine_slave_config(master->dma_tx, &slave_config); + if (ret) { + dev_err(dev, "error in TX dma configuration.\n"); + goto err; + } + + /* Prepare for RX : */ + master->dma_rx = dma_request_slave_channel(dev, "rx"); + if (!master->dma_rx) { + dev_dbg(dev, "cannot get the DMA channel.\n"); + ret = -EINVAL; + goto err; + } + + slave_config.direction = DMA_DEV_TO_MEM; + slave_config.src_addr = res->start + MXC_CSPIRXDATA; + slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; + slave_config.src_maxburst = spi_imx_get_fifosize(spi_imx) / 2; + ret = dmaengine_slave_config(master->dma_rx, &slave_config); + if (ret) { + dev_err(dev, "error in RX dma configuration.\n"); + goto err; + } + + init_completion(&spi_imx->dma_rx_completion); + init_completion(&spi_imx->dma_tx_completion); + master->can_dma = spi_imx_can_dma; + master->max_dma_len = MAX_SDMA_BD_BYTES; + spi_imx->bitbang.master->flags = SPI_MASTER_MUST_RX | + SPI_MASTER_MUST_TX; + spi_imx->tx_wml = spi_imx_get_fifosize(spi_imx) / 2; + spi_imx->rx_wml = spi_imx_get_fifosize(spi_imx) / 2; + spi_imx->dma_is_inited = 1; + + return 0; +err: + spi_imx_sdma_exit(spi_imx); + return ret; +} + +static void spi_imx_dma_rx_callback(void *cookie) +{ + struct spi_imx_data *spi_imx = (struct spi_imx_data *)cookie; + + complete(&spi_imx->dma_rx_completion); +} + +static void spi_imx_dma_tx_callback(void *cookie) +{ + struct spi_imx_data *spi_imx = (struct spi_imx_data *)cookie; + + complete(&spi_imx->dma_tx_completion); +} + +static int spi_imx_dma_transfer(struct spi_imx_data *spi_imx, + struct spi_transfer *transfer) +{ + struct dma_async_tx_descriptor *desc_tx = NULL, *desc_rx = NULL; + int ret; + unsigned long timeout; + u32 dma; + int left; + struct spi_master *master = spi_imx->bitbang.master; + struct sg_table *tx = &transfer->tx_sg, *rx = &transfer->rx_sg; + + if (tx) { + desc_tx = dmaengine_prep_slave_sg(master->dma_tx, + tx->sgl, tx->nents, DMA_MEM_TO_DEV, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc_tx) + goto no_dma; + + desc_tx->callback = spi_imx_dma_tx_callback; + desc_tx->callback_param = (void *)spi_imx; + dmaengine_submit(desc_tx); + } + + if (rx) { + desc_rx = dmaengine_prep_slave_sg(master->dma_rx, + rx->sgl, rx->nents, DMA_DEV_TO_MEM, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc_rx) + goto no_dma; + + desc_rx->callback = spi_imx_dma_rx_callback; + desc_rx->callback_param = (void *)spi_imx; + dmaengine_submit(desc_rx); + } + + reinit_completion(&spi_imx->dma_rx_completion); + reinit_completion(&spi_imx->dma_tx_completion); + + /* Trigger the cspi module. */ + spi_imx->dma_finished = 0; + + dma = readl(spi_imx->base + MX51_ECSPI_DMA); + dma = dma & (~MX51_ECSPI_DMA_RXT_WML_MASK); + /* Change RX_DMA_LENGTH trigger dma fetch tail data */ + left = transfer->len % spi_imx->rxt_wml; + if (left) + writel(dma | (left << MX51_ECSPI_DMA_RXT_WML_OFFSET), + spi_imx->base + MX51_ECSPI_DMA); + spi_imx->devtype_data->trigger(spi_imx); + + dma_async_issue_pending(master->dma_tx); + dma_async_issue_pending(master->dma_rx); + /* Wait SDMA to finish the data transfer.*/ + timeout = wait_for_completion_timeout(&spi_imx->dma_tx_completion, + IMX_DMA_TIMEOUT); + if (!timeout) { + pr_warn("%s %s: I/O Error in DMA TX\n", + dev_driver_string(&master->dev), + dev_name(&master->dev)); + dmaengine_terminate_all(master->dma_tx); + } else { + timeout = wait_for_completion_timeout( + &spi_imx->dma_rx_completion, IMX_DMA_TIMEOUT); + if (!timeout) { + pr_warn("%s %s: I/O Error in DMA RX\n", + dev_driver_string(&master->dev), + dev_name(&master->dev)); + spi_imx->devtype_data->reset(spi_imx); + dmaengine_terminate_all(master->dma_rx); + } + writel(dma | + spi_imx->rxt_wml << MX51_ECSPI_DMA_RXT_WML_OFFSET, + spi_imx->base + MX51_ECSPI_DMA); + } + + spi_imx->dma_finished = 1; + spi_imx->devtype_data->trigger(spi_imx); + + if (!timeout) + ret = -ETIMEDOUT; + else + ret = transfer->len; + + return ret; + +no_dma: + pr_warn_once("%s %s: DMA not available, falling back to PIO\n", + dev_driver_string(&master->dev), + dev_name(&master->dev)); + return -EAGAIN; +} + +static int spi_imx_pio_transfer(struct spi_device *spi, + struct spi_transfer *transfer) +{ + struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master); + + spi_imx->tx_buf = transfer->tx_buf; + spi_imx->rx_buf = transfer->rx_buf; + spi_imx->count = transfer->len; + spi_imx->txfifo = 0; + + reinit_completion(&spi_imx->xfer_done); + + spi_imx_push(spi_imx); + + spi_imx->devtype_data->intctrl(spi_imx, MXC_INT_TE); + + wait_for_completion(&spi_imx->xfer_done); + + return transfer->len; +} + +static int spi_imx_transfer(struct spi_device *spi, + struct spi_transfer *transfer) +{ + int ret; + struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master); + + if (spi_imx->bitbang.master->can_dma && + spi_imx_can_dma(spi_imx->bitbang.master, spi, transfer)) { + spi_imx->usedma = true; + ret = spi_imx_dma_transfer(spi_imx, transfer); + if (ret != -EAGAIN) + return ret; + } + spi_imx->usedma = false; + + return spi_imx_pio_transfer(spi, transfer); +} + +static int spi_imx_setup(struct spi_device *spi) +{ + struct spi_imx_data *spi_imx = spi_master_get_devdata(spi->master); + int gpio = spi_imx->chipselect[spi->chip_select]; + + dev_dbg(&spi->dev, "%s: mode %d, %u bpw, %d hz\n", __func__, + spi->mode, spi->bits_per_word, spi->max_speed_hz); + + if (gpio_is_valid(gpio)) + gpio_direction_output(gpio, spi->mode & SPI_CS_HIGH ? 0 : 1); + + spi_imx_chipselect(spi, BITBANG_CS_INACTIVE); + + return 0; +} + +static void spi_imx_cleanup(struct spi_device *spi) +{ +} + +static int +spi_imx_prepare_message(struct spi_master *master, struct spi_message *msg) +{ + struct spi_imx_data *spi_imx = spi_master_get_devdata(master); + int ret; + + ret = clk_enable(spi_imx->clk_per); + if (ret) + return ret; + + ret = clk_enable(spi_imx->clk_ipg); + if (ret) { + clk_disable(spi_imx->clk_per); + return ret; + } + + return 0; +} + +static int +spi_imx_unprepare_message(struct spi_master *master, struct spi_message *msg) +{ + struct spi_imx_data *spi_imx = spi_master_get_devdata(master); + + clk_disable(spi_imx->clk_ipg); + clk_disable(spi_imx->clk_per); + return 0; +} + +static int spi_imx_probe(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + const struct of_device_id *of_id = + of_match_device(spi_imx_dt_ids, &pdev->dev); + struct spi_imx_master *mxc_platform_info = + dev_get_platdata(&pdev->dev); + struct spi_master *master; + struct spi_imx_data *spi_imx; + struct resource *res; + int i, ret, num_cs, irq; + + if (!np && !mxc_platform_info) { + dev_err(&pdev->dev, "can't get the platform data\n"); + return -EINVAL; + } + + ret = of_property_read_u32(np, "fsl,spi-num-chipselects", &num_cs); + if (ret < 0) { + if (mxc_platform_info) + num_cs = mxc_platform_info->num_chipselect; + else + return ret; + } + + master = spi_alloc_master(&pdev->dev, + sizeof(struct spi_imx_data) + sizeof(int) * num_cs); + if (!master) + return -ENOMEM; + + platform_set_drvdata(pdev, master); + + master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 32); + master->bus_num = pdev->id; + master->num_chipselect = num_cs; + + spi_imx = spi_master_get_devdata(master); + spi_imx->bitbang.master = master; + + for (i = 0; i < master->num_chipselect; i++) { + int cs_gpio = of_get_named_gpio(np, "cs-gpios", i); + if (!gpio_is_valid(cs_gpio) && mxc_platform_info) + cs_gpio = mxc_platform_info->chipselect[i]; + + spi_imx->chipselect[i] = cs_gpio; + if (!gpio_is_valid(cs_gpio)) + continue; + + ret = devm_gpio_request(&pdev->dev, spi_imx->chipselect[i], + DRIVER_NAME); + if (ret) { + dev_err(&pdev->dev, "can't get cs gpios\n"); + goto out_master_put; + } + } + + spi_imx->bitbang.chipselect = spi_imx_chipselect; + spi_imx->bitbang.setup_transfer = spi_imx_setupxfer; + spi_imx->bitbang.txrx_bufs = spi_imx_transfer; + spi_imx->bitbang.master->setup = spi_imx_setup; + spi_imx->bitbang.master->cleanup = spi_imx_cleanup; + spi_imx->bitbang.master->prepare_message = spi_imx_prepare_message; + spi_imx->bitbang.master->unprepare_message = spi_imx_unprepare_message; + spi_imx->bitbang.master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH; + + init_completion(&spi_imx->xfer_done); + + spi_imx->devtype_data = of_id ? of_id->data : + (struct spi_imx_devtype_data *) pdev->id_entry->driver_data; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + spi_imx->base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(spi_imx->base)) { + ret = PTR_ERR(spi_imx->base); + goto out_master_put; + } + + irq = platform_get_irq(pdev, 0); + if (irq < 0) { + ret = irq; + goto out_master_put; + } + + ret = devm_request_irq(&pdev->dev, irq, spi_imx_isr, 0, + dev_name(&pdev->dev), spi_imx); + if (ret) { + dev_err(&pdev->dev, "can't get irq%d: %d\n", irq, ret); + goto out_master_put; + } + + spi_imx->clk_ipg = devm_clk_get(&pdev->dev, "ipg"); + if (IS_ERR(spi_imx->clk_ipg)) { + ret = PTR_ERR(spi_imx->clk_ipg); + goto out_master_put; + } + + spi_imx->clk_per = devm_clk_get(&pdev->dev, "per"); + if (IS_ERR(spi_imx->clk_per)) { + ret = PTR_ERR(spi_imx->clk_per); + goto out_master_put; + } + + ret = clk_prepare_enable(spi_imx->clk_per); + if (ret) + goto out_master_put; + + ret = clk_prepare_enable(spi_imx->clk_ipg); + if (ret) + goto out_put_per; + + spi_imx->spi_clk = clk_get_rate(spi_imx->clk_per); + /* + * Only validated on i.mx6 now, can remove the constrain if validated on + * other chips. + */ + if (spi_imx->devtype_data == &imx51_ecspi_devtype_data + && spi_imx_sdma_init(&pdev->dev, spi_imx, master, res)) + dev_err(&pdev->dev, "dma setup error,use pio instead\n"); + + spi_imx->devtype_data->reset(spi_imx); + + spi_imx->devtype_data->intctrl(spi_imx, 0); + + master->dev.of_node = pdev->dev.of_node; + ret = spi_bitbang_start(&spi_imx->bitbang); + if (ret) { + dev_err(&pdev->dev, "bitbang start failed with %d\n", ret); + goto out_clk_put; + } + + dev_info(&pdev->dev, "probed\n"); + + clk_disable(spi_imx->clk_ipg); + clk_disable(spi_imx->clk_per); + return ret; + +out_clk_put: + clk_disable_unprepare(spi_imx->clk_ipg); +out_put_per: + clk_disable_unprepare(spi_imx->clk_per); +out_master_put: + spi_master_put(master); + + return ret; +} + +static int spi_imx_remove(struct platform_device *pdev) +{ + struct spi_master *master = platform_get_drvdata(pdev); + struct spi_imx_data *spi_imx = spi_master_get_devdata(master); + + spi_bitbang_stop(&spi_imx->bitbang); + + writel(0, spi_imx->base + MXC_CSPICTRL); + clk_unprepare(spi_imx->clk_ipg); + clk_unprepare(spi_imx->clk_per); + spi_imx_sdma_exit(spi_imx); + spi_master_put(master); + + return 0; +} + +static struct platform_driver spi_imx_driver = { + .driver = { + .name = DRIVER_NAME, + .of_match_table = spi_imx_dt_ids, + }, + .id_table = spi_imx_devtype, + .probe = spi_imx_probe, + .remove = spi_imx_remove, +}; +module_platform_driver(spi_imx_driver); + +MODULE_DESCRIPTION("SPI Master Controller driver"); +MODULE_AUTHOR("Sascha Hauer, Pengutronix"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:" DRIVER_NAME); |