diff options
Diffstat (limited to 'drivers/spi/spi-imx.c')
| -rw-r--r-- | drivers/spi/spi-imx.c | 210 |
1 files changed, 123 insertions, 87 deletions
diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c index c6e697f5e00..5daff2054ae 100644 --- a/drivers/spi/spi-imx.c +++ b/drivers/spi/spi-imx.c @@ -23,7 +23,6 @@ #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/irq.h> @@ -38,7 +37,7 @@ #include <linux/of_device.h> #include <linux/of_gpio.h> -#include <mach/spi.h> +#include <linux/platform_data/spi-imx.h> #define DRIVER_NAME "spi_imx" @@ -83,9 +82,10 @@ struct spi_imx_data { struct spi_bitbang bitbang; struct completion xfer_done; - void *base; + void __iomem *base; int irq; - struct clk *clk; + struct clk *clk_per; + struct clk *clk_ipg; unsigned long spi_clk; unsigned int count; @@ -95,7 +95,7 @@ struct spi_imx_data { const void *tx_buf; unsigned int txfifo; /* number of words pushed in tx FIFO */ - struct spi_imx_devtype_data *devtype_data; + const struct spi_imx_devtype_data *devtype_data; int chipselect[0]; }; @@ -195,6 +195,7 @@ static unsigned int spi_imx_clkdiv_2(unsigned int fin, #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) @@ -204,7 +205,8 @@ static unsigned int spi_imx_clkdiv_2(unsigned int fin, #define MX51_ECSPI_STAT_RR (1 << 3) /* MX51 eCSPI */ -static unsigned int mx51_ecspi_clkdiv(unsigned int fin, unsigned int fspi) +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 @@ -232,6 +234,10 @@ static unsigned int mx51_ecspi_clkdiv(unsigned int fin, unsigned int fspi) 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); } @@ -262,6 +268,7 @@ 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; + u32 clk = config->speed_hz, delay; /* * The hardware seems to have a race condition when changing modes. The @@ -273,7 +280,7 @@ static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx, ctrl |= MX51_ECSPI_CTRL_MODE_MASK; /* set clock speed */ - ctrl |= mx51_ecspi_clkdiv(spi_imx->spi_clk, config->speed_hz); + ctrl |= mx51_ecspi_clkdiv(spi_imx->spi_clk, config->speed_hz, &clk); /* set chip select to use */ ctrl |= MX51_ECSPI_CTRL_CS(config->cs); @@ -285,15 +292,33 @@ static int __maybe_unused mx51_ecspi_config(struct spi_imx_data *spi_imx, if (config->mode & SPI_CPHA) cfg |= MX51_ECSPI_CONFIG_SCLKPHA(config->cs); - if (config->mode & SPI_CPOL) + 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); + return 0; } @@ -616,6 +641,7 @@ static const struct of_device_id spi_imx_dt_ids[] = { { .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) { @@ -624,7 +650,7 @@ static void spi_imx_chipselect(struct spi_device *spi, int is_active) int active = is_active != BITBANG_CS_INACTIVE; int dev_is_lowactive = !(spi->mode & SPI_CS_HIGH); - if (gpio < 0) + if (!gpio_is_valid(gpio)) return; gpio_set_value(gpio, dev_is_lowactive ^ active); @@ -686,8 +712,6 @@ static int spi_imx_setupxfer(struct spi_device *spi, config.speed_hz = spi->max_speed_hz; if (!config.bpw) config.bpw = spi->bits_per_word; - if (!config.speed_hz) - config.speed_hz = spi->max_speed_hz; /* Initialize the functions for transfer */ if (config.bpw <= 8) { @@ -696,11 +720,10 @@ static int spi_imx_setupxfer(struct spi_device *spi, } else if (config.bpw <= 16) { spi_imx->rx = spi_imx_buf_rx_u16; spi_imx->tx = spi_imx_buf_tx_u16; - } else if (config.bpw <= 32) { + } else { spi_imx->rx = spi_imx_buf_rx_u32; spi_imx->tx = spi_imx_buf_tx_u32; - } else - BUG(); + } spi_imx->devtype_data->config(spi_imx, &config); @@ -717,7 +740,7 @@ static int spi_imx_transfer(struct spi_device *spi, spi_imx->count = transfer->len; spi_imx->txfifo = 0; - init_completion(&spi_imx->xfer_done); + reinit_completion(&spi_imx->xfer_done); spi_imx_push(spi_imx); @@ -736,7 +759,7 @@ static int spi_imx_setup(struct spi_device *spi) 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 >= 0) + if (gpio_is_valid(gpio)) gpio_direction_output(gpio, spi->mode & SPI_CS_HIGH ? 0 : 1); spi_imx_chipselect(spi, BITBANG_CS_INACTIVE); @@ -748,7 +771,36 @@ static void spi_imx_cleanup(struct spi_device *spi) { } -static int __devinit spi_imx_probe(struct platform_device *pdev) +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 = @@ -766,8 +818,12 @@ static int __devinit spi_imx_probe(struct platform_device *pdev) } ret = of_property_read_u32(np, "fsl,spi-num-chipselects", &num_cs); - if (ret < 0) - num_cs = mxc_platform_info->num_chipselect; + 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); @@ -776,28 +832,25 @@ static int __devinit spi_imx_probe(struct platform_device *pdev) 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 = spi_master_get(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 (cs_gpio < 0) + if (!gpio_is_valid(cs_gpio) && mxc_platform_info) cs_gpio = mxc_platform_info->chipselect[i]; spi_imx->chipselect[i] = cs_gpio; - if (cs_gpio < 0) + if (!gpio_is_valid(cs_gpio)) continue; - ret = gpio_request(spi_imx->chipselect[i], DRIVER_NAME); + ret = devm_gpio_request(&pdev->dev, spi_imx->chipselect[i], + DRIVER_NAME); if (ret) { - while (i > 0) { - i--; - if (spi_imx->chipselect[i] >= 0) - gpio_free(spi_imx->chipselect[i]); - } dev_err(&pdev->dev, "can't get cs gpios\n"); goto out_master_put; } @@ -808,6 +861,8 @@ static int __devinit spi_imx_probe(struct platform_device *pdev) 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); @@ -816,45 +871,46 @@ static int __devinit spi_imx_probe(struct platform_device *pdev) (struct spi_imx_devtype_data *) pdev->id_entry->driver_data; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - if (!res) { - dev_err(&pdev->dev, "can't get platform resource\n"); - ret = -ENOMEM; - goto out_gpio_free; - } - - if (!request_mem_region(res->start, resource_size(res), pdev->name)) { - dev_err(&pdev->dev, "request_mem_region failed\n"); - ret = -EBUSY; - goto out_gpio_free; - } - - spi_imx->base = ioremap(res->start, resource_size(res)); - if (!spi_imx->base) { - ret = -EINVAL; - goto out_release_mem; + 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; } spi_imx->irq = platform_get_irq(pdev, 0); if (spi_imx->irq < 0) { - ret = -EINVAL; - goto out_iounmap; + ret = spi_imx->irq; + goto out_master_put; } - ret = request_irq(spi_imx->irq, spi_imx_isr, 0, DRIVER_NAME, spi_imx); + ret = devm_request_irq(&pdev->dev, spi_imx->irq, spi_imx_isr, 0, + dev_name(&pdev->dev), spi_imx); if (ret) { dev_err(&pdev->dev, "can't get irq%d: %d\n", spi_imx->irq, ret); - goto out_iounmap; + 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 = clk_get(&pdev->dev, NULL); - if (IS_ERR(spi_imx->clk)) { - dev_err(&pdev->dev, "unable to get clock\n"); - ret = PTR_ERR(spi_imx->clk); - goto out_free_irq; + 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; } - clk_enable(spi_imx->clk); - spi_imx->spi_clk = clk_get_rate(spi_imx->clk); + 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); spi_imx->devtype_data->reset(spi_imx); @@ -869,53 +925,32 @@ static int __devinit spi_imx_probe(struct platform_device *pdev) 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(spi_imx->clk); - clk_put(spi_imx->clk); -out_free_irq: - free_irq(spi_imx->irq, spi_imx); -out_iounmap: - iounmap(spi_imx->base); -out_release_mem: - release_mem_region(res->start, resource_size(res)); -out_gpio_free: - for (i = 0; i < master->num_chipselect; i++) - if (spi_imx->chipselect[i] >= 0) - gpio_free(spi_imx->chipselect[i]); + clk_disable_unprepare(spi_imx->clk_ipg); +out_put_per: + clk_disable_unprepare(spi_imx->clk_per); out_master_put: spi_master_put(master); - kfree(master); - platform_set_drvdata(pdev, NULL); + return ret; } -static int __devexit spi_imx_remove(struct platform_device *pdev) +static int spi_imx_remove(struct platform_device *pdev) { struct spi_master *master = platform_get_drvdata(pdev); - struct resource *res = platform_get_resource(pdev, IORESOURCE_MEM, 0); struct spi_imx_data *spi_imx = spi_master_get_devdata(master); - int i; spi_bitbang_stop(&spi_imx->bitbang); writel(0, spi_imx->base + MXC_CSPICTRL); - clk_disable(spi_imx->clk); - clk_put(spi_imx->clk); - free_irq(spi_imx->irq, spi_imx); - iounmap(spi_imx->base); - - for (i = 0; i < master->num_chipselect; i++) - if (spi_imx->chipselect[i] >= 0) - gpio_free(spi_imx->chipselect[i]); - + clk_unprepare(spi_imx->clk_ipg); + clk_unprepare(spi_imx->clk_per); spi_master_put(master); - release_mem_region(res->start, resource_size(res)); - - platform_set_drvdata(pdev, NULL); - return 0; } @@ -927,10 +962,11 @@ static struct platform_driver spi_imx_driver = { }, .id_table = spi_imx_devtype, .probe = spi_imx_probe, - .remove = __devexit_p(spi_imx_remove), + .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); |
