// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) 2011-2015 Daniel Schwierzeck * Copyright (C) 2016 Hauke Mehrtens */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef CONFIG_LANTIQ #include #endif #define LTQ_SPI_RX_IRQ_NAME "spi_rx" #define LTQ_SPI_TX_IRQ_NAME "spi_tx" #define LTQ_SPI_ERR_IRQ_NAME "spi_err" #define LTQ_SPI_FRM_IRQ_NAME "spi_frm" #define LTQ_SPI_CLC 0x00 #define LTQ_SPI_PISEL 0x04 #define LTQ_SPI_ID 0x08 #define LTQ_SPI_CON 0x10 #define LTQ_SPI_STAT 0x14 #define LTQ_SPI_WHBSTATE 0x18 #define LTQ_SPI_TB 0x20 #define LTQ_SPI_RB 0x24 #define LTQ_SPI_RXFCON 0x30 #define LTQ_SPI_TXFCON 0x34 #define LTQ_SPI_FSTAT 0x38 #define LTQ_SPI_BRT 0x40 #define LTQ_SPI_BRSTAT 0x44 #define LTQ_SPI_SFCON 0x60 #define LTQ_SPI_SFSTAT 0x64 #define LTQ_SPI_GPOCON 0x70 #define LTQ_SPI_GPOSTAT 0x74 #define LTQ_SPI_FPGO 0x78 #define LTQ_SPI_RXREQ 0x80 #define LTQ_SPI_RXCNT 0x84 #define LTQ_SPI_DMACON 0xec #define LTQ_SPI_IRNEN 0xf4 #define LTQ_SPI_CLC_SMC_S 16 /* Clock divider for sleep mode */ #define LTQ_SPI_CLC_SMC_M (0xFF << LTQ_SPI_CLC_SMC_S) #define LTQ_SPI_CLC_RMC_S 8 /* Clock divider for normal run mode */ #define LTQ_SPI_CLC_RMC_M (0xFF << LTQ_SPI_CLC_RMC_S) #define LTQ_SPI_CLC_DISS BIT(1) /* Disable status bit */ #define LTQ_SPI_CLC_DISR BIT(0) /* Disable request bit */ #define LTQ_SPI_ID_TXFS_S 24 /* Implemented TX FIFO size */ #define LTQ_SPI_ID_RXFS_S 16 /* Implemented RX FIFO size */ #define LTQ_SPI_ID_MOD_S 8 /* Module ID */ #define LTQ_SPI_ID_MOD_M (0xff << LTQ_SPI_ID_MOD_S) #define LTQ_SPI_ID_CFG_S 5 /* DMA interface support */ #define LTQ_SPI_ID_CFG_M (1 << LTQ_SPI_ID_CFG_S) #define LTQ_SPI_ID_REV_M 0x1F /* Hardware revision number */ #define LTQ_SPI_CON_BM_S 16 /* Data width selection */ #define LTQ_SPI_CON_BM_M (0x1F << LTQ_SPI_CON_BM_S) #define LTQ_SPI_CON_EM BIT(24) /* Echo mode */ #define LTQ_SPI_CON_IDLE BIT(23) /* Idle bit value */ #define LTQ_SPI_CON_ENBV BIT(22) /* Enable byte valid control */ #define LTQ_SPI_CON_RUEN BIT(12) /* Receive underflow error enable */ #define LTQ_SPI_CON_TUEN BIT(11) /* Transmit underflow error enable */ #define LTQ_SPI_CON_AEN BIT(10) /* Abort error enable */ #define LTQ_SPI_CON_REN BIT(9) /* Receive overflow error enable */ #define LTQ_SPI_CON_TEN BIT(8) /* Transmit overflow error enable */ #define LTQ_SPI_CON_LB BIT(7) /* Loopback control */ #define LTQ_SPI_CON_PO BIT(6) /* Clock polarity control */ #define LTQ_SPI_CON_PH BIT(5) /* Clock phase control */ #define LTQ_SPI_CON_HB BIT(4) /* Heading control */ #define LTQ_SPI_CON_RXOFF BIT(1) /* Switch receiver off */ #define LTQ_SPI_CON_TXOFF BIT(0) /* Switch transmitter off */ #define LTQ_SPI_STAT_RXBV_S 28 #define LTQ_SPI_STAT_RXBV_M (0x7 << LTQ_SPI_STAT_RXBV_S) #define LTQ_SPI_STAT_BSY BIT(13) /* Busy flag */ #define LTQ_SPI_STAT_RUE BIT(12) /* Receive underflow error flag */ #define LTQ_SPI_STAT_TUE BIT(11) /* Transmit underflow error flag */ #define LTQ_SPI_STAT_AE BIT(10) /* Abort error flag */ #define LTQ_SPI_STAT_RE BIT(9) /* Receive error flag */ #define LTQ_SPI_STAT_TE BIT(8) /* Transmit error flag */ #define LTQ_SPI_STAT_ME BIT(7) /* Mode error flag */ #define LTQ_SPI_STAT_MS BIT(1) /* Host/target select bit */ #define LTQ_SPI_STAT_EN BIT(0) /* Enable bit */ #define LTQ_SPI_STAT_ERRORS (LTQ_SPI_STAT_ME | LTQ_SPI_STAT_TE | \ LTQ_SPI_STAT_RE | LTQ_SPI_STAT_AE | \ LTQ_SPI_STAT_TUE | LTQ_SPI_STAT_RUE) #define LTQ_SPI_WHBSTATE_SETTUE BIT(15) /* Set transmit underflow error flag */ #define LTQ_SPI_WHBSTATE_SETAE BIT(14) /* Set abort error flag */ #define LTQ_SPI_WHBSTATE_SETRE BIT(13) /* Set receive error flag */ #define LTQ_SPI_WHBSTATE_SETTE BIT(12) /* Set transmit error flag */ #define LTQ_SPI_WHBSTATE_CLRTUE BIT(11) /* Clear transmit underflow error flag */ #define LTQ_SPI_WHBSTATE_CLRAE BIT(10) /* Clear abort error flag */ #define LTQ_SPI_WHBSTATE_CLRRE BIT(9) /* Clear receive error flag */ #define LTQ_SPI_WHBSTATE_CLRTE BIT(8) /* Clear transmit error flag */ #define LTQ_SPI_WHBSTATE_SETME BIT(7) /* Set mode error flag */ #define LTQ_SPI_WHBSTATE_CLRME BIT(6) /* Clear mode error flag */ #define LTQ_SPI_WHBSTATE_SETRUE BIT(5) /* Set receive underflow error flag */ #define LTQ_SPI_WHBSTATE_CLRRUE BIT(4) /* Clear receive underflow error flag */ #define LTQ_SPI_WHBSTATE_SETMS BIT(3) /* Set host select bit */ #define LTQ_SPI_WHBSTATE_CLRMS BIT(2) /* Clear host select bit */ #define LTQ_SPI_WHBSTATE_SETEN BIT(1) /* Set enable bit (operational mode) */ #define LTQ_SPI_WHBSTATE_CLREN BIT(0) /* Clear enable bit (config mode */ #define LTQ_SPI_WHBSTATE_CLR_ERRORS (LTQ_SPI_WHBSTATE_CLRRUE | \ LTQ_SPI_WHBSTATE_CLRME | \ LTQ_SPI_WHBSTATE_CLRTE | \ LTQ_SPI_WHBSTATE_CLRRE | \ LTQ_SPI_WHBSTATE_CLRAE | \ LTQ_SPI_WHBSTATE_CLRTUE) #define LTQ_SPI_RXFCON_RXFITL_S 8 /* FIFO interrupt trigger level */ #define LTQ_SPI_RXFCON_RXFLU BIT(1) /* FIFO flush */ #define LTQ_SPI_RXFCON_RXFEN BIT(0) /* FIFO enable */ #define LTQ_SPI_TXFCON_TXFITL_S 8 /* FIFO interrupt trigger level */ #define LTQ_SPI_TXFCON_TXFLU BIT(1) /* FIFO flush */ #define LTQ_SPI_TXFCON_TXFEN BIT(0) /* FIFO enable */ #define LTQ_SPI_FSTAT_RXFFL_S 0 #define LTQ_SPI_FSTAT_TXFFL_S 8 #define LTQ_SPI_GPOCON_ISCSBN_S 8 #define LTQ_SPI_GPOCON_INVOUTN_S 0 #define LTQ_SPI_FGPO_SETOUTN_S 8 #define LTQ_SPI_FGPO_CLROUTN_S 0 #define LTQ_SPI_RXREQ_RXCNT_M 0xFFFF /* Receive count value */ #define LTQ_SPI_RXCNT_TODO_M 0xFFFF /* Receive to-do value */ #define LTQ_SPI_IRNEN_TFI BIT(4) /* TX finished interrupt */ #define LTQ_SPI_IRNEN_F BIT(3) /* Frame end interrupt request */ #define LTQ_SPI_IRNEN_E BIT(2) /* Error end interrupt request */ #define LTQ_SPI_IRNEN_T_XWAY BIT(1) /* Transmit end interrupt request */ #define LTQ_SPI_IRNEN_R_XWAY BIT(0) /* Receive end interrupt request */ #define LTQ_SPI_IRNEN_R_XRX BIT(1) /* Transmit end interrupt request */ #define LTQ_SPI_IRNEN_T_XRX BIT(0) /* Receive end interrupt request */ #define LTQ_SPI_IRNEN_ALL 0x1F struct lantiq_ssc_spi; struct lantiq_ssc_hwcfg { int (*cfg_irq)(struct platform_device *pdev, struct lantiq_ssc_spi *spi); unsigned int irnen_r; unsigned int irnen_t; unsigned int irncr; unsigned int irnicr; bool irq_ack; u32 fifo_size_mask; }; struct lantiq_ssc_spi { struct spi_controller *host; struct device *dev; void __iomem *regbase; struct clk *spi_clk; struct clk *fpi_clk; const struct lantiq_ssc_hwcfg *hwcfg; spinlock_t lock; struct workqueue_struct *wq; struct work_struct work; const u8 *tx; u8 *rx; unsigned int tx_todo; unsigned int rx_todo; unsigned int bits_per_word; unsigned int speed_hz; unsigned int tx_fifo_size; unsigned int rx_fifo_size; unsigned int base_cs; unsigned int fdx_tx_level; }; static u32 lantiq_ssc_readl(const struct lantiq_ssc_spi *spi, u32 reg) { return __raw_readl(spi->regbase + reg); } static void lantiq_ssc_writel(const struct lantiq_ssc_spi *spi, u32 val, u32 reg) { __raw_writel(val, spi->regbase + reg); } static void lantiq_ssc_maskl(const struct lantiq_ssc_spi *spi, u32 clr, u32 set, u32 reg) { u32 val = __raw_readl(spi->regbase + reg); val &= ~clr; val |= set; __raw_writel(val, spi->regbase + reg); } static unsigned int tx_fifo_level(const struct lantiq_ssc_spi *spi) { const struct lantiq_ssc_hwcfg *hwcfg = spi->hwcfg; u32 fstat = lantiq_ssc_readl(spi, LTQ_SPI_FSTAT); return (fstat >> LTQ_SPI_FSTAT_TXFFL_S) & hwcfg->fifo_size_mask; } static unsigned int rx_fifo_level(const struct lantiq_ssc_spi *spi) { const struct lantiq_ssc_hwcfg *hwcfg = spi->hwcfg; u32 fstat = lantiq_ssc_readl(spi, LTQ_SPI_FSTAT); return (fstat >> LTQ_SPI_FSTAT_RXFFL_S) & hwcfg->fifo_size_mask; } static unsigned int tx_fifo_free(const struct lantiq_ssc_spi *spi) { return spi->tx_fifo_size - tx_fifo_level(spi); } static void rx_fifo_reset(const struct lantiq_ssc_spi *spi) { u32 val = spi->rx_fifo_size << LTQ_SPI_RXFCON_RXFITL_S; val |= LTQ_SPI_RXFCON_RXFEN | LTQ_SPI_RXFCON_RXFLU; lantiq_ssc_writel(spi, val, LTQ_SPI_RXFCON); } static void tx_fifo_reset(const struct lantiq_ssc_spi *spi) { u32 val = 1 << LTQ_SPI_TXFCON_TXFITL_S; val |= LTQ_SPI_TXFCON_TXFEN | LTQ_SPI_TXFCON_TXFLU; lantiq_ssc_writel(spi, val, LTQ_SPI_TXFCON); } static void rx_fifo_flush(const struct lantiq_ssc_spi *spi) { lantiq_ssc_maskl(spi, 0, LTQ_SPI_RXFCON_RXFLU, LTQ_SPI_RXFCON); } static void tx_fifo_flush(const struct lantiq_ssc_spi *spi) { lantiq_ssc_maskl(spi, 0, LTQ_SPI_TXFCON_TXFLU, LTQ_SPI_TXFCON); } static void hw_enter_config_mode(const struct lantiq_ssc_spi *spi) { lantiq_ssc_writel(spi, LTQ_SPI_WHBSTATE_CLREN, LTQ_SPI_WHBSTATE); } static void hw_enter_active_mode(const struct lantiq_ssc_spi *spi) { lantiq_ssc_writel(spi, LTQ_SPI_WHBSTATE_SETEN, LTQ_SPI_WHBSTATE); } static void hw_setup_speed_hz(const struct lantiq_ssc_spi *spi, unsigned int max_speed_hz) { u32 spi_clk, brt; /* * SPI module clock is derived from FPI bus clock dependent on * divider value in CLC.RMS which is always set to 1. * * f_SPI * baudrate = -------------- * 2 * (BR + 1) */ spi_clk = clk_get_rate(spi->fpi_clk) / 2; if (max_speed_hz > spi_clk) brt = 0; else brt = spi_clk / max_speed_hz - 1; if (brt > 0xFFFF) brt = 0xFFFF; dev_dbg(spi->dev, "spi_clk %u, max_speed_hz %u, brt %u\n", spi_clk, max_speed_hz, brt); lantiq_ssc_writel(spi, brt, LTQ_SPI_BRT); } static void hw_setup_bits_per_word(const struct lantiq_ssc_spi *spi, unsigned int bits_per_word) { u32 bm; /* CON.BM value = bits_per_word - 1 */ bm = (bits_per_word - 1) << LTQ_SPI_CON_BM_S; lantiq_ssc_maskl(spi, LTQ_SPI_CON_BM_M, bm, LTQ_SPI_CON); } static void hw_setup_clock_mode(const struct lantiq_ssc_spi *spi, unsigned int mode) { u32 con_set = 0, con_clr = 0; /* * SPI mode mapping in CON register: * Mode CPOL CPHA CON.PO CON.PH * 0 0 0 0 1 * 1 0 1 0 0 * 2 1 0 1 1 * 3 1 1 1 0 */ if (mode & SPI_CPHA) con_clr |= LTQ_SPI_CON_PH; else con_set |= LTQ_SPI_CON_PH; if (mode & SPI_CPOL) con_set |= LTQ_SPI_CON_PO | LTQ_SPI_CON_IDLE; else con_clr |= LTQ_SPI_CON_PO | LTQ_SPI_CON_IDLE; /* Set heading control */ if (mode & SPI_LSB_FIRST) con_clr |= LTQ_SPI_CON_HB; else con_set |= LTQ_SPI_CON_HB; /* Set loopback mode */ if (mode & SPI_LOOP) con_set |= LTQ_SPI_CON_LB; else con_clr |= LTQ_SPI_CON_LB; lantiq_ssc_maskl(spi, con_clr, con_set, LTQ_SPI_CON); } static void lantiq_ssc_hw_init(const struct lantiq_ssc_spi *spi) { const struct lantiq_ssc_hwcfg *hwcfg = spi->hwcfg; /* * Set clock divider for run mode to 1 to * run at same frequency as FPI bus */ lantiq_ssc_writel(spi, 1 << LTQ_SPI_CLC_RMC_S, LTQ_SPI_CLC); /* Put controller into config mode */ hw_enter_config_mode(spi); /* Clear error flags */ lantiq_ssc_maskl(spi, 0, LTQ_SPI_WHBSTATE_CLR_ERRORS, LTQ_SPI_WHBSTATE); /* Enable error checking, disable TX/RX */ lantiq_ssc_writel(spi, LTQ_SPI_CON_RUEN | LTQ_SPI_CON_AEN | LTQ_SPI_CON_TEN | LTQ_SPI_CON_REN | LTQ_SPI_CON_TXOFF | LTQ_SPI_CON_RXOFF, LTQ_SPI_CON); /* Setup default SPI mode */ hw_setup_bits_per_word(spi, spi->bits_per_word); hw_setup_clock_mode(spi, SPI_MODE_0); /* Enable host mode and clear error flags */ lantiq_ssc_writel(spi, LTQ_SPI_WHBSTATE_SETMS | LTQ_SPI_WHBSTATE_CLR_ERRORS, LTQ_SPI_WHBSTATE); /* Reset GPIO/CS registers */ lantiq_ssc_writel(spi, 0, LTQ_SPI_GPOCON); lantiq_ssc_writel(spi, 0xFF00, LTQ_SPI_FPGO); /* Enable and flush FIFOs */ rx_fifo_reset(spi); tx_fifo_reset(spi); /* Enable interrupts */ lantiq_ssc_writel(spi, hwcfg->irnen_t | hwcfg->irnen_r | LTQ_SPI_IRNEN_E, LTQ_SPI_IRNEN); } static int lantiq_ssc_setup(struct spi_device *spidev) { struct spi_controller *host = spidev->controller; struct lantiq_ssc_spi *spi = spi_controller_get_devdata(host); unsigned int cs = spi_get_chipselect(spidev, 0); u32 gpocon; /* GPIOs are used for CS */ if (spi_get_csgpiod(spidev, 0)) return 0; dev_dbg(spi->dev, "using internal chipselect %u\n", cs); if (cs < spi->base_cs) { dev_err(spi->dev, "chipselect %i too small (min %i)\n", cs, spi->base_cs); return -EINVAL; } /* set GPO pin to CS mode */ gpocon = 1 << ((cs - spi->base_cs) + LTQ_SPI_GPOCON_ISCSBN_S); /* invert GPO pin */ if (spidev->mode & SPI_CS_HIGH) gpocon |= 1 << (cs - spi->base_cs); lantiq_ssc_maskl(spi, 0, gpocon, LTQ_SPI_GPOCON); return 0; } static int lantiq_ssc_prepare_message(struct spi_controller *host, struct spi_message *message) { struct lantiq_ssc_spi *spi = spi_controller_get_devdata(host); hw_enter_config_mode(spi); hw_setup_clock_mode(spi, message->spi->mode); hw_enter_active_mode(spi); return 0; } static void hw_setup_transfer(struct lantiq_ssc_spi *spi, struct spi_device *spidev, struct spi_transfer *t) { unsigned int speed_hz = t->speed_hz; unsigned int bits_per_word = t->bits_per_word; u32 con; if (bits_per_word != spi->bits_per_word || speed_hz != spi->speed_hz) { hw_enter_config_mode(spi); hw_setup_speed_hz(spi, speed_hz); hw_setup_bits_per_word(spi, bits_per_word); hw_enter_active_mode(spi); spi->speed_hz = speed_hz; spi->bits_per_word = bits_per_word; } /* Configure transmitter and receiver */ con = lantiq_ssc_readl(spi, LTQ_SPI_CON); if (t->tx_buf) con &= ~LTQ_SPI_CON_TXOFF; else con |= LTQ_SPI_CON_TXOFF; if (t->rx_buf) con &= ~LTQ_SPI_CON_RXOFF; else con |= LTQ_SPI_CON_RXOFF; lantiq_ssc_writel(spi, con, LTQ_SPI_CON); } static int lantiq_ssc_unprepare_message(struct spi_controller *host, struct spi_message *message) { struct lantiq_ssc_spi *spi = spi_controller_get_devdata(host); flush_workqueue(spi->wq); /* Disable transmitter and receiver while idle */ lantiq_ssc_maskl(spi, 0, LTQ_SPI_CON_TXOFF | LTQ_SPI_CON_RXOFF, LTQ_SPI_CON); return 0; } static void tx_fifo_write(struct lantiq_ssc_spi *spi) { const u8 *tx8; const u16 *tx16; const u32 *tx32; u32 data; unsigned int tx_free = tx_fifo_free(spi); spi->fdx_tx_level = 0; while (spi->tx_todo && tx_free) { switch (spi->bits_per_word) { case 2 ... 8: tx8 = spi->tx; data = *tx8; spi->tx_todo--; spi->tx++; break; case 16: tx16 = (u16 *) spi->tx; data = *tx16; spi->tx_todo -= 2; spi->tx += 2; break; case 32: tx32 = (u32 *) spi->tx; data = *tx32; spi->tx_todo -= 4; spi->tx += 4; break; default: WARN_ON(1); data = 0; break; } lantiq_ssc_writel(spi, data, LTQ_SPI_TB); tx_free--; spi->fdx_tx_level++; } } static void rx_fifo_read_full_duplex(struct lantiq_ssc_spi *spi) { u8 *rx8; u16 *rx16; u32 *rx32; u32 data; unsigned int rx_fill = rx_fifo_level(spi); /* * Wait until all expected data to be shifted in. * Otherwise, rx overrun may occur. */ while (rx_fill != spi->fdx_tx_level) rx_fill = rx_fifo_level(spi); while (rx_fill) { data = lantiq_ssc_readl(spi, LTQ_SPI_RB); switch (spi->bits_per_word) { case 2 ... 8: rx8 = spi->rx; *rx8 = data; spi->rx_todo--; spi->rx++; break; case 16: rx16 = (u16 *) spi->rx; *rx16 = data; spi->rx_todo -= 2; spi->rx += 2; break; case 32: rx32 = (u32 *) spi->rx; *rx32 = data; spi->rx_todo -= 4; spi->rx += 4; break; default: WARN_ON(1); break; } rx_fill--; } } static void rx_fifo_read_half_duplex(struct lantiq_ssc_spi *spi) { u32 data, *rx32; u8 *rx8; unsigned int rxbv, shift; unsigned int rx_fill = rx_fifo_level(spi); /* * In RX-only mode the bits per word value is ignored by HW. A value * of 32 is used instead. Thus all 4 bytes per FIFO must be read. * If remaining RX bytes are less than 4, the FIFO must be read * differently. The amount of received and valid bytes is indicated * by STAT.RXBV register value. */ while (rx_fill) { if (spi->rx_todo < 4) { rxbv = (lantiq_ssc_readl(spi, LTQ_SPI_STAT) & LTQ_SPI_STAT_RXBV_M) >> LTQ_SPI_STAT_RXBV_S; data = lantiq_ssc_readl(spi, LTQ_SPI_RB); shift = (rxbv - 1) * 8; rx8 = spi->rx; while (rxbv) { *rx8++ = (data >> shift) & 0xFF; rxbv--; shift -= 8; spi->rx_todo--; spi->rx++; } } else { data = lantiq_ssc_readl(spi, LTQ_SPI_RB); rx32 = (u32 *) spi->rx; *rx32++ = data; spi->rx_todo -= 4; spi->rx += 4; } rx_fill--; } } static void rx_request(struct lantiq_ssc_spi *spi) { unsigned int rxreq, rxreq_max; /* * To avoid receive overflows at high clocks it is better to request * only the amount of bytes that fits into all FIFOs. This value * depends on the FIFO size implemented in hardware. */ rxreq = spi->rx_todo; rxreq_max = spi->rx_fifo_size * 4; if (rxreq > rxreq_max) rxreq = rxreq_max; lantiq_ssc_writel(spi, rxreq, LTQ_SPI_RXREQ); } static irqreturn_t lantiq_ssc_xmit_interrupt(int irq, void *data) { struct lantiq_ssc_spi *spi = data; const struct lantiq_ssc_hwcfg *hwcfg = spi->hwcfg; u32 val = lantiq_ssc_readl(spi, hwcfg->irncr); spin_lock(&spi->lock); if (hwcfg->irq_ack) lantiq_ssc_writel(spi, val, hwcfg->irncr); if (spi->tx) { if (spi->rx && spi->rx_todo) rx_fifo_read_full_duplex(spi); if (spi->tx_todo) tx_fifo_write(spi); else if (!tx_fifo_level(spi)) goto completed; } else if (spi->rx) { if (spi->rx_todo) { rx_fifo_read_half_duplex(spi); if (spi->rx_todo) rx_request(spi); else goto completed; } else { goto completed; } } spin_unlock(&spi->lock); return IRQ_HANDLED; completed: queue_work(spi->wq, &spi->work); spin_unlock(&spi->lock); return IRQ_HANDLED; } static irqreturn_t lantiq_ssc_err_interrupt(int irq, void *data) { struct lantiq_ssc_spi *spi = data; const struct lantiq_ssc_hwcfg *hwcfg = spi->hwcfg; u32 stat = lantiq_ssc_readl(spi, LTQ_SPI_STAT); u32 val = lantiq_ssc_readl(spi, hwcfg->irncr); if (!(stat & LTQ_SPI_STAT_ERRORS)) return IRQ_NONE; spin_lock(&spi->lock); if (hwcfg->irq_ack) lantiq_ssc_writel(spi, val, hwcfg->irncr); if (stat & LTQ_SPI_STAT_RUE) dev_err(spi->dev, "receive underflow error\n"); if (stat & LTQ_SPI_STAT_TUE) dev_err(spi->dev, "transmit underflow error\n"); if (stat & LTQ_SPI_STAT_AE) dev_err(spi->dev, "abort error\n"); if (stat & LTQ_SPI_STAT_RE) dev_err(spi->dev, "receive overflow error\n"); if (stat & LTQ_SPI_STAT_TE) dev_err(spi->dev, "transmit overflow error\n"); if (stat & LTQ_SPI_STAT_ME) dev_err(spi->dev, "mode error\n"); /* Clear error flags */ lantiq_ssc_maskl(spi, 0, LTQ_SPI_WHBSTATE_CLR_ERRORS, LTQ_SPI_WHBSTATE); /* set bad status so it can be retried */ if (spi->host->cur_msg) spi->host->cur_msg->status = -EIO; queue_work(spi->wq, &spi->work); spin_unlock(&spi->lock); return IRQ_HANDLED; } static irqreturn_t intel_lgm_ssc_isr(int irq, void *data) { struct lantiq_ssc_spi *spi = data; const struct lantiq_ssc_hwcfg *hwcfg = spi->hwcfg; u32 val = lantiq_ssc_readl(spi, hwcfg->irncr); if (!(val & LTQ_SPI_IRNEN_ALL)) return IRQ_NONE; if (val & LTQ_SPI_IRNEN_E) return lantiq_ssc_err_interrupt(irq, data); if ((val & hwcfg->irnen_t) || (val & hwcfg->irnen_r)) return lantiq_ssc_xmit_interrupt(irq, data); return IRQ_HANDLED; } static int transfer_start(struct lantiq_ssc_spi *spi, struct spi_device *spidev, struct spi_transfer *t) { unsigned long flags; spin_lock_irqsave(&spi->lock, flags); spi->tx = t->tx_buf; spi->rx = t->rx_buf; if (t->tx_buf) { spi->tx_todo = t->len; /* initially fill TX FIFO */ tx_fifo_write(spi); } if (spi->rx) { spi->rx_todo = t->len; /* start shift clock in RX-only mode */ if (!spi->tx) rx_request(spi); } spin_unlock_irqrestore(&spi->lock, flags); return t->len; } /* * The driver only gets an interrupt when the FIFO is empty, but there * is an additional shift register from which the data is written to * the wire. We get the last interrupt when the controller starts to * write the last word to the wire, not when it is finished. Do busy * waiting till it finishes. */ static void lantiq_ssc_bussy_work(struct work_struct *work) { struct lantiq_ssc_spi *spi; unsigned long long timeout = 8LL * 1000LL; unsigned long end; spi = container_of(work, typeof(*spi), work); do_div(timeout, spi->speed_hz); timeout += timeout + 100; /* some tolerance */ end = jiffies + msecs_to_jiffies(timeout); do { u32 stat = lantiq_ssc_readl(spi, LTQ_SPI_STAT); if (!(stat & LTQ_SPI_STAT_BSY)) { spi_finalize_current_transfer(spi->host); return; } cond_resched(); } while (!time_after_eq(jiffies, end)); if (spi->host->cur_msg) spi->host->cur_msg->status = -EIO; spi_finalize_current_transfer(spi->host); } static void lantiq_ssc_handle_err(struct spi_controller *host, struct spi_message *message) { struct lantiq_ssc_spi *spi = spi_controller_get_devdata(host); /* flush FIFOs on timeout */ rx_fifo_flush(spi); tx_fifo_flush(spi); } static void lantiq_ssc_set_cs(struct spi_device *spidev, bool enable) { struct lantiq_ssc_spi *spi = spi_controller_get_devdata(spidev->controller); unsigned int cs = spi_get_chipselect(spidev, 0); u32 fgpo; if (!!(spidev->mode & SPI_CS_HIGH) == enable) fgpo = (1 << (cs - spi->base_cs)); else fgpo = (1 << (cs - spi->base_cs + LTQ_SPI_FGPO_SETOUTN_S)); lantiq_ssc_writel(spi, fgpo, LTQ_SPI_FPGO); } static int lantiq_ssc_transfer_one(struct spi_controller *host, struct spi_device *spidev, struct spi_transfer *t) { struct lantiq_ssc_spi *spi = spi_controller_get_devdata(host); hw_setup_transfer(spi, spidev, t); return transfer_start(spi, spidev, t); } static int intel_lgm_cfg_irq(struct platform_device *pdev, struct lantiq_ssc_spi *spi) { int irq; irq = platform_get_irq(pdev, 0); if (irq < 0) return irq; return devm_request_irq(&pdev->dev, irq, intel_lgm_ssc_isr, 0, "spi", spi); } static int lantiq_cfg_irq(struct platform_device *pdev, struct lantiq_ssc_spi *spi) { int irq, err; irq = platform_get_irq_byname(pdev, LTQ_SPI_RX_IRQ_NAME); if (irq < 0) return irq; err = devm_request_irq(&pdev->dev, irq, lantiq_ssc_xmit_interrupt, 0, LTQ_SPI_RX_IRQ_NAME, spi); if (err) return err; irq = platform_get_irq_byname(pdev, LTQ_SPI_TX_IRQ_NAME); if (irq < 0) return irq; err = devm_request_irq(&pdev->dev, irq, lantiq_ssc_xmit_interrupt, 0, LTQ_SPI_TX_IRQ_NAME, spi); if (err) return err; irq = platform_get_irq_byname(pdev, LTQ_SPI_ERR_IRQ_NAME); if (irq < 0) return irq; err = devm_request_irq(&pdev->dev, irq, lantiq_ssc_err_interrupt, 0, LTQ_SPI_ERR_IRQ_NAME, spi); return err; } static const struct lantiq_ssc_hwcfg lantiq_ssc_xway = { .cfg_irq = lantiq_cfg_irq, .irnen_r = LTQ_SPI_IRNEN_R_XWAY, .irnen_t = LTQ_SPI_IRNEN_T_XWAY, .irnicr = 0xF8, .irncr = 0xFC, .fifo_size_mask = GENMASK(5, 0), .irq_ack = false, }; static const struct lantiq_ssc_hwcfg lantiq_ssc_xrx = { .cfg_irq = lantiq_cfg_irq, .irnen_r = LTQ_SPI_IRNEN_R_XRX, .irnen_t = LTQ_SPI_IRNEN_T_XRX, .irnicr = 0xF8, .irncr = 0xFC, .fifo_size_mask = GENMASK(5, 0), .irq_ack = false, }; static const struct lantiq_ssc_hwcfg intel_ssc_lgm = { .cfg_irq = intel_lgm_cfg_irq, .irnen_r = LTQ_SPI_IRNEN_R_XRX, .irnen_t = LTQ_SPI_IRNEN_T_XRX, .irnicr = 0xFC, .irncr = 0xF8, .fifo_size_mask = GENMASK(7, 0), .irq_ack = true, }; static const struct of_device_id lantiq_ssc_match[] = { { .compatible = "lantiq,ase-spi", .data = &lantiq_ssc_xway, }, { .compatible = "lantiq,falcon-spi", .data = &lantiq_ssc_xrx, }, { .compatible = "lantiq,xrx100-spi", .data = &lantiq_ssc_xrx, }, { .compatible = "intel,lgm-spi", .data = &intel_ssc_lgm, }, {}, }; MODULE_DEVICE_TABLE(of, lantiq_ssc_match); static int lantiq_ssc_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct spi_controller *host; struct lantiq_ssc_spi *spi; const struct lantiq_ssc_hwcfg *hwcfg; u32 id, supports_dma, revision; unsigned int num_cs; int err; hwcfg = of_device_get_match_data(dev); host = spi_alloc_host(dev, sizeof(struct lantiq_ssc_spi)); if (!host) return -ENOMEM; spi = spi_controller_get_devdata(host); spi->host = host; spi->dev = dev; spi->hwcfg = hwcfg; platform_set_drvdata(pdev, spi); spi->regbase = devm_platform_ioremap_resource(pdev, 0); if (IS_ERR(spi->regbase)) { err = PTR_ERR(spi->regbase); goto err_host_put; } err = hwcfg->cfg_irq(pdev, spi); if (err) goto err_host_put; spi->spi_clk = devm_clk_get_enabled(dev, "gate"); if (IS_ERR(spi->spi_clk)) { err = PTR_ERR(spi->spi_clk); goto err_host_put; } /* * Use the old clk_get_fpi() function on Lantiq platform, till it * supports common clk. */ #if defined(CONFIG_LANTIQ) && !defined(CONFIG_COMMON_CLK) spi->fpi_clk = clk_get_fpi(); #else spi->fpi_clk = clk_get(dev, "freq"); #endif if (IS_ERR(spi->fpi_clk)) { err = PTR_ERR(spi->fpi_clk); goto err_host_put; } num_cs = 8; of_property_read_u32(pdev->dev.of_node, "num-cs", &num_cs); spi->base_cs = 1; of_property_read_u32(pdev->dev.of_node, "base-cs", &spi->base_cs); spin_lock_init(&spi->lock); spi->bits_per_word = 8; spi->speed_hz = 0; host->dev.of_node = pdev->dev.of_node; host->num_chipselect = num_cs; host->use_gpio_descriptors = true; host->setup = lantiq_ssc_setup; host->set_cs = lantiq_ssc_set_cs; host->handle_err = lantiq_ssc_handle_err; host->prepare_message = lantiq_ssc_prepare_message; host->unprepare_message = lantiq_ssc_unprepare_message; host->transfer_one = lantiq_ssc_transfer_one; host->mode_bits = SPI_CPOL | SPI_CPHA | SPI_LSB_FIRST | SPI_CS_HIGH | SPI_LOOP; host->bits_per_word_mask = SPI_BPW_RANGE_MASK(2, 8) | SPI_BPW_MASK(16) | SPI_BPW_MASK(32); spi->wq = alloc_ordered_workqueue(dev_name(dev), WQ_MEM_RECLAIM); if (!spi->wq) { err = -ENOMEM; goto err_clk_put; } INIT_WORK(&spi->work, lantiq_ssc_bussy_work); id = lantiq_ssc_readl(spi, LTQ_SPI_ID); spi->tx_fifo_size = (id >> LTQ_SPI_ID_TXFS_S) & hwcfg->fifo_size_mask; spi->rx_fifo_size = (id >> LTQ_SPI_ID_RXFS_S) & hwcfg->fifo_size_mask; supports_dma = (id & LTQ_SPI_ID_CFG_M) >> LTQ_SPI_ID_CFG_S; revision = id & LTQ_SPI_ID_REV_M; lantiq_ssc_hw_init(spi); dev_info(dev, "Lantiq SSC SPI controller (Rev %i, TXFS %u, RXFS %u, DMA %u)\n", revision, spi->tx_fifo_size, spi->rx_fifo_size, supports_dma); err = devm_spi_register_controller(dev, host); if (err) { dev_err(dev, "failed to register spi host\n"); goto err_wq_destroy; } return 0; err_wq_destroy: destroy_workqueue(spi->wq); err_clk_put: clk_put(spi->fpi_clk); err_host_put: spi_controller_put(host); return err; } static void lantiq_ssc_remove(struct platform_device *pdev) { struct lantiq_ssc_spi *spi = platform_get_drvdata(pdev); lantiq_ssc_writel(spi, 0, LTQ_SPI_IRNEN); lantiq_ssc_writel(spi, 0, LTQ_SPI_CLC); rx_fifo_flush(spi); tx_fifo_flush(spi); hw_enter_config_mode(spi); destroy_workqueue(spi->wq); clk_put(spi->fpi_clk); } static struct platform_driver lantiq_ssc_driver = { .probe = lantiq_ssc_probe, .remove = lantiq_ssc_remove, .driver = { .name = "spi-lantiq-ssc", .of_match_table = lantiq_ssc_match, }, }; module_platform_driver(lantiq_ssc_driver); MODULE_DESCRIPTION("Lantiq SSC SPI controller driver"); MODULE_AUTHOR("Daniel Schwierzeck "); MODULE_AUTHOR("Hauke Mehrtens "); MODULE_LICENSE("GPL"); MODULE_ALIAS("platform:spi-lantiq-ssc");