// SPDX-License-Identifier: GPL-2.0+ // // Freescale i.MX7ULP LPSPI driver // // Copyright 2016 Freescale Semiconductor, Inc. // Copyright 2018 NXP Semiconductors #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define DRIVER_NAME "fsl_lpspi" #define FSL_LPSPI_RPM_TIMEOUT 50 /* 50ms */ /* i.MX7ULP LPSPI registers */ #define IMX7ULP_VERID 0x0 #define IMX7ULP_PARAM 0x4 #define IMX7ULP_CR 0x10 #define IMX7ULP_SR 0x14 #define IMX7ULP_IER 0x18 #define IMX7ULP_DER 0x1c #define IMX7ULP_CFGR0 0x20 #define IMX7ULP_CFGR1 0x24 #define IMX7ULP_DMR0 0x30 #define IMX7ULP_DMR1 0x34 #define IMX7ULP_CCR 0x40 #define IMX7ULP_FCR 0x58 #define IMX7ULP_FSR 0x5c #define IMX7ULP_TCR 0x60 #define IMX7ULP_TDR 0x64 #define IMX7ULP_RSR 0x70 #define IMX7ULP_RDR 0x74 /* General control register field define */ #define CR_RRF BIT(9) #define CR_RTF BIT(8) #define CR_RST BIT(1) #define CR_MEN BIT(0) #define SR_MBF BIT(24) #define SR_TCF BIT(10) #define SR_FCF BIT(9) #define SR_RDF BIT(1) #define SR_TDF BIT(0) #define IER_TCIE BIT(10) #define IER_FCIE BIT(9) #define IER_RDIE BIT(1) #define IER_TDIE BIT(0) #define CFGR1_PCSCFG BIT(27) #define CFGR1_PINCFG (BIT(24)|BIT(25)) #define CFGR1_PCSPOL BIT(8) #define CFGR1_NOSTALL BIT(3) #define CFGR1_MASTER BIT(0) #define FSR_RXCOUNT (BIT(16)|BIT(17)|BIT(18)) #define RSR_RXEMPTY BIT(1) #define TCR_CPOL BIT(31) #define TCR_CPHA BIT(30) #define TCR_CONT BIT(21) #define TCR_CONTC BIT(20) #define TCR_RXMSK BIT(19) #define TCR_TXMSK BIT(18) static int clkdivs[] = {1, 2, 4, 8, 16, 32, 64, 128}; struct lpspi_config { u8 bpw; u8 chip_select; u8 prescale; u16 mode; u32 speed_hz; }; struct fsl_lpspi_data { struct device *dev; void __iomem *base; struct clk *clk_ipg; struct clk *clk_per; bool is_slave; bool is_first_byte; void *rx_buf; const void *tx_buf; void (*tx)(struct fsl_lpspi_data *); void (*rx)(struct fsl_lpspi_data *); u32 remain; u8 watermark; u8 txfifosize; u8 rxfifosize; struct lpspi_config config; struct completion xfer_done; bool slave_aborted; int chipselect[0]; }; static const struct of_device_id fsl_lpspi_dt_ids[] = { { .compatible = "fsl,imx7ulp-spi", }, { /* sentinel */ } }; MODULE_DEVICE_TABLE(of, fsl_lpspi_dt_ids); #define LPSPI_BUF_RX(type) \ static void fsl_lpspi_buf_rx_##type(struct fsl_lpspi_data *fsl_lpspi) \ { \ unsigned int val = readl(fsl_lpspi->base + IMX7ULP_RDR); \ \ if (fsl_lpspi->rx_buf) { \ *(type *)fsl_lpspi->rx_buf = val; \ fsl_lpspi->rx_buf += sizeof(type); \ } \ } #define LPSPI_BUF_TX(type) \ static void fsl_lpspi_buf_tx_##type(struct fsl_lpspi_data *fsl_lpspi) \ { \ type val = 0; \ \ if (fsl_lpspi->tx_buf) { \ val = *(type *)fsl_lpspi->tx_buf; \ fsl_lpspi->tx_buf += sizeof(type); \ } \ \ fsl_lpspi->remain -= sizeof(type); \ writel(val, fsl_lpspi->base + IMX7ULP_TDR); \ } LPSPI_BUF_RX(u8) LPSPI_BUF_TX(u8) LPSPI_BUF_RX(u16) LPSPI_BUF_TX(u16) LPSPI_BUF_RX(u32) LPSPI_BUF_TX(u32) static void fsl_lpspi_intctrl(struct fsl_lpspi_data *fsl_lpspi, unsigned int enable) { writel(enable, fsl_lpspi->base + IMX7ULP_IER); } static int lpspi_prepare_xfer_hardware(struct spi_controller *controller) { struct fsl_lpspi_data *fsl_lpspi = spi_controller_get_devdata(controller); int ret; ret = pm_runtime_get_sync(fsl_lpspi->dev); if (ret < 0) { dev_err(fsl_lpspi->dev, "failed to enable clock\n"); return ret; } return 0; } static int lpspi_unprepare_xfer_hardware(struct spi_controller *controller) { struct fsl_lpspi_data *fsl_lpspi = spi_controller_get_devdata(controller); pm_runtime_mark_last_busy(fsl_lpspi->dev); pm_runtime_put_autosuspend(fsl_lpspi->dev); return 0; } static int fsl_lpspi_prepare_message(struct spi_controller *controller, struct spi_message *msg) { struct fsl_lpspi_data *fsl_lpspi = spi_controller_get_devdata(controller); struct spi_device *spi = msg->spi; int gpio = fsl_lpspi->chipselect[spi->chip_select]; if (gpio_is_valid(gpio)) gpio_direction_output(gpio, spi->mode & SPI_CS_HIGH ? 0 : 1); return 0; } static void fsl_lpspi_write_tx_fifo(struct fsl_lpspi_data *fsl_lpspi) { u8 txfifo_cnt; u32 temp; txfifo_cnt = readl(fsl_lpspi->base + IMX7ULP_FSR) & 0xff; while (txfifo_cnt < fsl_lpspi->txfifosize) { if (!fsl_lpspi->remain) break; fsl_lpspi->tx(fsl_lpspi); txfifo_cnt++; } if (txfifo_cnt < fsl_lpspi->txfifosize) { if (!fsl_lpspi->is_slave) { temp = readl(fsl_lpspi->base + IMX7ULP_TCR); temp &= ~TCR_CONTC; writel(temp, fsl_lpspi->base + IMX7ULP_TCR); } fsl_lpspi_intctrl(fsl_lpspi, IER_FCIE); } else fsl_lpspi_intctrl(fsl_lpspi, IER_TDIE); } static void fsl_lpspi_read_rx_fifo(struct fsl_lpspi_data *fsl_lpspi) { while (!(readl(fsl_lpspi->base + IMX7ULP_RSR) & RSR_RXEMPTY)) fsl_lpspi->rx(fsl_lpspi); } static void fsl_lpspi_set_cmd(struct fsl_lpspi_data *fsl_lpspi) { u32 temp = 0; temp |= fsl_lpspi->config.bpw - 1; temp |= (fsl_lpspi->config.mode & 0x3) << 30; if (!fsl_lpspi->is_slave) { temp |= fsl_lpspi->config.prescale << 27; temp |= (fsl_lpspi->config.chip_select & 0x3) << 24; /* * Set TCR_CONT will keep SS asserted after current transfer. * For the first transfer, clear TCR_CONTC to assert SS. * For subsequent transfer, set TCR_CONTC to keep SS asserted. */ temp |= TCR_CONT; if (fsl_lpspi->is_first_byte) temp &= ~TCR_CONTC; else temp |= TCR_CONTC; } writel(temp, fsl_lpspi->base + IMX7ULP_TCR); dev_dbg(fsl_lpspi->dev, "TCR=0x%x\n", temp); } static void fsl_lpspi_set_watermark(struct fsl_lpspi_data *fsl_lpspi) { u32 temp; temp = fsl_lpspi->watermark >> 1 | (fsl_lpspi->watermark >> 1) << 16; writel(temp, fsl_lpspi->base + IMX7ULP_FCR); dev_dbg(fsl_lpspi->dev, "FCR=0x%x\n", temp); } static int fsl_lpspi_set_bitrate(struct fsl_lpspi_data *fsl_lpspi) { struct lpspi_config config = fsl_lpspi->config; unsigned int perclk_rate, scldiv; u8 prescale; perclk_rate = clk_get_rate(fsl_lpspi->clk_per); if (config.speed_hz > perclk_rate / 2) { dev_err(fsl_lpspi->dev, "per-clk should be at least two times of transfer speed"); return -EINVAL; } for (prescale = 0; prescale < 8; prescale++) { scldiv = perclk_rate / (clkdivs[prescale] * config.speed_hz) - 2; if (scldiv < 256) { fsl_lpspi->config.prescale = prescale; break; } } if (prescale == 8 && scldiv >= 256) return -EINVAL; writel(scldiv | (scldiv << 8) | ((scldiv >> 1) << 16), fsl_lpspi->base + IMX7ULP_CCR); dev_dbg(fsl_lpspi->dev, "perclk=%d, speed=%d, prescale =%d, scldiv=%d\n", perclk_rate, config.speed_hz, prescale, scldiv); return 0; } static int fsl_lpspi_config(struct fsl_lpspi_data *fsl_lpspi) { u32 temp; int ret; if (!fsl_lpspi->is_slave) { ret = fsl_lpspi_set_bitrate(fsl_lpspi); if (ret) return ret; } fsl_lpspi_set_watermark(fsl_lpspi); if (!fsl_lpspi->is_slave) temp = CFGR1_MASTER; else temp = CFGR1_PINCFG; if (fsl_lpspi->config.mode & SPI_CS_HIGH) temp |= CFGR1_PCSPOL; writel(temp, fsl_lpspi->base + IMX7ULP_CFGR1); temp = readl(fsl_lpspi->base + IMX7ULP_CR); temp |= CR_RRF | CR_RTF | CR_MEN; writel(temp, fsl_lpspi->base + IMX7ULP_CR); return 0; } static int fsl_lpspi_setup_transfer(struct spi_device *spi, struct spi_transfer *t) { struct fsl_lpspi_data *fsl_lpspi = spi_controller_get_devdata(spi->controller); fsl_lpspi->config.mode = spi->mode; fsl_lpspi->config.bpw = t ? t->bits_per_word : spi->bits_per_word; fsl_lpspi->config.speed_hz = t ? t->speed_hz : spi->max_speed_hz; fsl_lpspi->config.chip_select = spi->chip_select; if (!fsl_lpspi->config.speed_hz) fsl_lpspi->config.speed_hz = spi->max_speed_hz; if (!fsl_lpspi->config.bpw) fsl_lpspi->config.bpw = spi->bits_per_word; /* Initialize the functions for transfer */ if (fsl_lpspi->config.bpw <= 8) { fsl_lpspi->rx = fsl_lpspi_buf_rx_u8; fsl_lpspi->tx = fsl_lpspi_buf_tx_u8; } else if (fsl_lpspi->config.bpw <= 16) { fsl_lpspi->rx = fsl_lpspi_buf_rx_u16; fsl_lpspi->tx = fsl_lpspi_buf_tx_u16; } else { fsl_lpspi->rx = fsl_lpspi_buf_rx_u32; fsl_lpspi->tx = fsl_lpspi_buf_tx_u32; } if (t->len <= fsl_lpspi->txfifosize) fsl_lpspi->watermark = t->len; else fsl_lpspi->watermark = fsl_lpspi->txfifosize; return fsl_lpspi_config(fsl_lpspi); } static int fsl_lpspi_slave_abort(struct spi_controller *controller) { struct fsl_lpspi_data *fsl_lpspi = spi_controller_get_devdata(controller); fsl_lpspi->slave_aborted = true; complete(&fsl_lpspi->xfer_done); return 0; } static int fsl_lpspi_wait_for_completion(struct spi_controller *controller) { struct fsl_lpspi_data *fsl_lpspi = spi_controller_get_devdata(controller); if (fsl_lpspi->is_slave) { if (wait_for_completion_interruptible(&fsl_lpspi->xfer_done) || fsl_lpspi->slave_aborted) { dev_dbg(fsl_lpspi->dev, "interrupted\n"); return -EINTR; } } else { if (!wait_for_completion_timeout(&fsl_lpspi->xfer_done, HZ)) { dev_dbg(fsl_lpspi->dev, "wait for completion timeout\n"); return -ETIMEDOUT; } } return 0; } static int fsl_lpspi_reset(struct fsl_lpspi_data *fsl_lpspi) { u32 temp; /* Disable all interrupt */ fsl_lpspi_intctrl(fsl_lpspi, 0); /* W1C for all flags in SR */ temp = 0x3F << 8; writel(temp, fsl_lpspi->base + IMX7ULP_SR); /* Clear FIFO and disable module */ temp = CR_RRF | CR_RTF; writel(temp, fsl_lpspi->base + IMX7ULP_CR); return 0; } static int fsl_lpspi_pio_transfer(struct spi_controller *controller, struct spi_transfer *t) { struct fsl_lpspi_data *fsl_lpspi = spi_controller_get_devdata(controller); int ret; fsl_lpspi->tx_buf = t->tx_buf; fsl_lpspi->rx_buf = t->rx_buf; fsl_lpspi->remain = t->len; reinit_completion(&fsl_lpspi->xfer_done); fsl_lpspi->slave_aborted = false; fsl_lpspi_write_tx_fifo(fsl_lpspi); ret = fsl_lpspi_wait_for_completion(controller); if (ret) return ret; fsl_lpspi_reset(fsl_lpspi); return 0; } static int fsl_lpspi_transfer_one(struct spi_controller *controller, struct spi_device *spi, struct spi_transfer *t) { struct fsl_lpspi_data *fsl_lpspi = spi_controller_get_devdata(controller); int ret; fsl_lpspi->is_first_byte = true; ret = fsl_lpspi_setup_transfer(spi, t); if (ret < 0) return ret; fsl_lpspi_set_cmd(fsl_lpspi); fsl_lpspi->is_first_byte = false; ret = fsl_lpspi_pio_transfer(controller, t); if (ret < 0) return ret; return 0; } static irqreturn_t fsl_lpspi_isr(int irq, void *dev_id) { u32 temp_SR, temp_IER; struct fsl_lpspi_data *fsl_lpspi = dev_id; temp_IER = readl(fsl_lpspi->base + IMX7ULP_IER); fsl_lpspi_intctrl(fsl_lpspi, 0); temp_SR = readl(fsl_lpspi->base + IMX7ULP_SR); fsl_lpspi_read_rx_fifo(fsl_lpspi); if ((temp_SR & SR_TDF) && (temp_IER & IER_TDIE)) { fsl_lpspi_write_tx_fifo(fsl_lpspi); return IRQ_HANDLED; } if (temp_SR & SR_MBF || readl(fsl_lpspi->base + IMX7ULP_FSR) & FSR_RXCOUNT) { writel(SR_FCF, fsl_lpspi->base + IMX7ULP_SR); fsl_lpspi_intctrl(fsl_lpspi, IER_FCIE); return IRQ_HANDLED; } if (temp_SR & SR_FCF && (temp_IER & IER_FCIE)) { writel(SR_FCF, fsl_lpspi->base + IMX7ULP_SR); complete(&fsl_lpspi->xfer_done); return IRQ_HANDLED; } return IRQ_NONE; } int fsl_lpspi_runtime_resume(struct device *dev) { struct fsl_lpspi_data *fsl_lpspi = dev_get_drvdata(dev); int ret; ret = clk_prepare_enable(fsl_lpspi->clk_per); if (ret) return ret; ret = clk_prepare_enable(fsl_lpspi->clk_ipg); if (ret) { clk_disable_unprepare(fsl_lpspi->clk_per); return ret; } return 0; } int fsl_lpspi_runtime_suspend(struct device *dev) { struct fsl_lpspi_data *fsl_lpspi = dev_get_drvdata(dev); clk_disable_unprepare(fsl_lpspi->clk_per); clk_disable_unprepare(fsl_lpspi->clk_ipg); return 0; } static int fsl_lpspi_init_rpm(struct fsl_lpspi_data *fsl_lpspi) { struct device *dev = fsl_lpspi->dev; pm_runtime_enable(dev); pm_runtime_set_autosuspend_delay(dev, FSL_LPSPI_RPM_TIMEOUT); pm_runtime_use_autosuspend(dev); return 0; } static int fsl_lpspi_probe(struct platform_device *pdev) { struct device_node *np = pdev->dev.of_node; struct fsl_lpspi_data *fsl_lpspi; struct spi_controller *controller; struct spi_imx_master *lpspi_platform_info = dev_get_platdata(&pdev->dev); struct resource *res; int i, ret, irq; u32 temp; if (of_property_read_bool((&pdev->dev)->of_node, "spi-slave")) controller = spi_alloc_slave(&pdev->dev, sizeof(struct fsl_lpspi_data)); else controller = spi_alloc_master(&pdev->dev, sizeof(struct fsl_lpspi_data)); if (!controller) return -ENOMEM; platform_set_drvdata(pdev, controller); controller->bits_per_word_mask = SPI_BPW_RANGE_MASK(8, 32); controller->bus_num = pdev->id; fsl_lpspi = spi_controller_get_devdata(controller); fsl_lpspi->dev = &pdev->dev; dev_set_drvdata(&pdev->dev, fsl_lpspi); fsl_lpspi->is_slave = of_property_read_bool((&pdev->dev)->of_node, "spi-slave"); if (!fsl_lpspi->is_slave) { for (i = 0; i < controller->num_chipselect; i++) { int cs_gpio = of_get_named_gpio(np, "cs-gpios", i); if (!gpio_is_valid(cs_gpio) && lpspi_platform_info) cs_gpio = lpspi_platform_info->chipselect[i]; fsl_lpspi->chipselect[i] = cs_gpio; if (!gpio_is_valid(cs_gpio)) continue; ret = devm_gpio_request(&pdev->dev, fsl_lpspi->chipselect[i], DRIVER_NAME); if (ret) { dev_err(&pdev->dev, "can't get cs gpios\n"); goto out_controller_put; } } controller->cs_gpios = fsl_lpspi->chipselect; controller->prepare_message = fsl_lpspi_prepare_message; } controller->transfer_one = fsl_lpspi_transfer_one; controller->prepare_transfer_hardware = lpspi_prepare_xfer_hardware; controller->unprepare_transfer_hardware = lpspi_unprepare_xfer_hardware; controller->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH; controller->flags = SPI_MASTER_MUST_RX | SPI_MASTER_MUST_TX; controller->dev.of_node = pdev->dev.of_node; controller->bus_num = pdev->id; controller->slave_abort = fsl_lpspi_slave_abort; init_completion(&fsl_lpspi->xfer_done); res = platform_get_resource(pdev, IORESOURCE_MEM, 0); fsl_lpspi->base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(fsl_lpspi->base)) { ret = PTR_ERR(fsl_lpspi->base); goto out_controller_put; } irq = platform_get_irq(pdev, 0); if (irq < 0) { ret = irq; goto out_controller_put; } ret = devm_request_irq(&pdev->dev, irq, fsl_lpspi_isr, 0, dev_name(&pdev->dev), fsl_lpspi); if (ret) { dev_err(&pdev->dev, "can't get irq%d: %d\n", irq, ret); goto out_controller_put; } fsl_lpspi->clk_per = devm_clk_get(&pdev->dev, "per"); if (IS_ERR(fsl_lpspi->clk_per)) { ret = PTR_ERR(fsl_lpspi->clk_per); goto out_controller_put; } fsl_lpspi->clk_ipg = devm_clk_get(&pdev->dev, "ipg"); if (IS_ERR(fsl_lpspi->clk_ipg)) { ret = PTR_ERR(fsl_lpspi->clk_ipg); goto out_controller_put; } /* enable the clock */ ret = fsl_lpspi_init_rpm(fsl_lpspi); if (ret) goto out_controller_put; ret = pm_runtime_get_sync(fsl_lpspi->dev); if (ret < 0) { dev_err(fsl_lpspi->dev, "failed to enable clock\n"); return ret; } temp = readl(fsl_lpspi->base + IMX7ULP_PARAM); fsl_lpspi->txfifosize = 1 << (temp & 0x0f); fsl_lpspi->rxfifosize = 1 << ((temp >> 8) & 0x0f); ret = devm_spi_register_controller(&pdev->dev, controller); if (ret < 0) { dev_err(&pdev->dev, "spi_register_controller error.\n"); goto out_controller_put; } return 0; out_controller_put: spi_controller_put(controller); return ret; } static int fsl_lpspi_remove(struct platform_device *pdev) { struct spi_controller *controller = platform_get_drvdata(pdev); struct fsl_lpspi_data *fsl_lpspi = spi_controller_get_devdata(controller); pm_runtime_disable(fsl_lpspi->dev); spi_master_put(controller); return 0; } #ifdef CONFIG_PM_SLEEP static int fsl_lpspi_suspend(struct device *dev) { int ret; pinctrl_pm_select_sleep_state(dev); ret = pm_runtime_force_suspend(dev); return ret; } static int fsl_lpspi_resume(struct device *dev) { int ret; ret = pm_runtime_force_resume(dev); if (ret) { dev_err(dev, "Error in resume: %d\n", ret); return ret; } pinctrl_pm_select_default_state(dev); return 0; } #endif /* CONFIG_PM_SLEEP */ static const struct dev_pm_ops fsl_lpspi_pm_ops = { SET_RUNTIME_PM_OPS(fsl_lpspi_runtime_suspend, fsl_lpspi_runtime_resume, NULL) SET_SYSTEM_SLEEP_PM_OPS(fsl_lpspi_suspend, fsl_lpspi_resume) }; static struct platform_driver fsl_lpspi_driver = { .driver = { .name = DRIVER_NAME, .of_match_table = fsl_lpspi_dt_ids, .pm = &fsl_lpspi_pm_ops, }, .probe = fsl_lpspi_probe, .remove = fsl_lpspi_remove, }; module_platform_driver(fsl_lpspi_driver); MODULE_DESCRIPTION("LPSPI Controller driver"); MODULE_AUTHOR("Gao Pan "); MODULE_LICENSE("GPL");