| // SPDX-License-Identifier: GPL-2.0-or-later |
| /* |
| * MPC52xx PSC in SPI mode driver. |
| * |
| * Maintainer: Dragos Carp |
| * |
| * Copyright (C) 2006 TOPTICA Photonics AG. |
| */ |
| |
| #include <linux/module.h> |
| #include <linux/types.h> |
| #include <linux/errno.h> |
| #include <linux/interrupt.h> |
| #include <linux/platform_device.h> |
| #include <linux/property.h> |
| #include <linux/workqueue.h> |
| #include <linux/completion.h> |
| #include <linux/io.h> |
| #include <linux/delay.h> |
| #include <linux/spi/spi.h> |
| #include <linux/slab.h> |
| |
| #include <asm/mpc52xx.h> |
| #include <asm/mpc52xx_psc.h> |
| |
| #define MCLK 20000000 /* PSC port MClk in hz */ |
| |
| struct mpc52xx_psc_spi { |
| /* driver internal data */ |
| struct mpc52xx_psc __iomem *psc; |
| struct mpc52xx_psc_fifo __iomem *fifo; |
| int irq; |
| u8 bits_per_word; |
| |
| struct completion done; |
| }; |
| |
| /* controller state */ |
| struct mpc52xx_psc_spi_cs { |
| int bits_per_word; |
| int speed_hz; |
| }; |
| |
| /* set clock freq, clock ramp, bits per work |
| * if t is NULL then reset the values to the default values |
| */ |
| static int mpc52xx_psc_spi_transfer_setup(struct spi_device *spi, |
| struct spi_transfer *t) |
| { |
| struct mpc52xx_psc_spi_cs *cs = spi->controller_state; |
| |
| cs->speed_hz = (t && t->speed_hz) |
| ? t->speed_hz : spi->max_speed_hz; |
| cs->bits_per_word = (t && t->bits_per_word) |
| ? t->bits_per_word : spi->bits_per_word; |
| cs->bits_per_word = ((cs->bits_per_word + 7) / 8) * 8; |
| return 0; |
| } |
| |
| static void mpc52xx_psc_spi_activate_cs(struct spi_device *spi) |
| { |
| struct mpc52xx_psc_spi_cs *cs = spi->controller_state; |
| struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master); |
| struct mpc52xx_psc __iomem *psc = mps->psc; |
| u32 sicr; |
| u16 ccr; |
| |
| sicr = in_be32(&psc->sicr); |
| |
| /* Set clock phase and polarity */ |
| if (spi->mode & SPI_CPHA) |
| sicr |= 0x00001000; |
| else |
| sicr &= ~0x00001000; |
| if (spi->mode & SPI_CPOL) |
| sicr |= 0x00002000; |
| else |
| sicr &= ~0x00002000; |
| |
| if (spi->mode & SPI_LSB_FIRST) |
| sicr |= 0x10000000; |
| else |
| sicr &= ~0x10000000; |
| out_be32(&psc->sicr, sicr); |
| |
| /* Set clock frequency and bits per word |
| * Because psc->ccr is defined as 16bit register instead of 32bit |
| * just set the lower byte of BitClkDiv |
| */ |
| ccr = in_be16((u16 __iomem *)&psc->ccr); |
| ccr &= 0xFF00; |
| if (cs->speed_hz) |
| ccr |= (MCLK / cs->speed_hz - 1) & 0xFF; |
| else /* by default SPI Clk 1MHz */ |
| ccr |= (MCLK / 1000000 - 1) & 0xFF; |
| out_be16((u16 __iomem *)&psc->ccr, ccr); |
| mps->bits_per_word = cs->bits_per_word; |
| } |
| |
| #define MPC52xx_PSC_BUFSIZE (MPC52xx_PSC_RFNUM_MASK + 1) |
| /* wake up when 80% fifo full */ |
| #define MPC52xx_PSC_RFALARM (MPC52xx_PSC_BUFSIZE * 20 / 100) |
| |
| static int mpc52xx_psc_spi_transfer_rxtx(struct spi_device *spi, |
| struct spi_transfer *t) |
| { |
| struct mpc52xx_psc_spi *mps = spi_master_get_devdata(spi->master); |
| struct mpc52xx_psc __iomem *psc = mps->psc; |
| struct mpc52xx_psc_fifo __iomem *fifo = mps->fifo; |
| unsigned rb = 0; /* number of bytes receieved */ |
| unsigned sb = 0; /* number of bytes sent */ |
| unsigned char *rx_buf = (unsigned char *)t->rx_buf; |
| unsigned char *tx_buf = (unsigned char *)t->tx_buf; |
| unsigned rfalarm; |
| unsigned send_at_once = MPC52xx_PSC_BUFSIZE; |
| unsigned recv_at_once; |
| int last_block = 0; |
| |
| if (!t->tx_buf && !t->rx_buf && t->len) |
| return -EINVAL; |
| |
| /* enable transmiter/receiver */ |
| out_8(&psc->command, MPC52xx_PSC_TX_ENABLE | MPC52xx_PSC_RX_ENABLE); |
| while (rb < t->len) { |
| if (t->len - rb > MPC52xx_PSC_BUFSIZE) { |
| rfalarm = MPC52xx_PSC_RFALARM; |
| last_block = 0; |
| } else { |
| send_at_once = t->len - sb; |
| rfalarm = MPC52xx_PSC_BUFSIZE - (t->len - rb); |
| last_block = 1; |
| } |
| |
| dev_dbg(&spi->dev, "send %d bytes...\n", send_at_once); |
| for (; send_at_once; sb++, send_at_once--) { |
| /* set EOF flag before the last word is sent */ |
| if (send_at_once == 1 && last_block) |
| out_8(&psc->ircr2, 0x01); |
| |
| if (tx_buf) |
| out_8(&psc->mpc52xx_psc_buffer_8, tx_buf[sb]); |
| else |
| out_8(&psc->mpc52xx_psc_buffer_8, 0); |
| } |
| |
| |
| /* enable interrupts and wait for wake up |
| * if just one byte is expected the Rx FIFO genererates no |
| * FFULL interrupt, so activate the RxRDY interrupt |
| */ |
| out_8(&psc->command, MPC52xx_PSC_SEL_MODE_REG_1); |
| if (t->len - rb == 1) { |
| out_8(&psc->mode, 0); |
| } else { |
| out_8(&psc->mode, MPC52xx_PSC_MODE_FFULL); |
| out_be16(&fifo->rfalarm, rfalarm); |
| } |
| out_be16(&psc->mpc52xx_psc_imr, MPC52xx_PSC_IMR_RXRDY); |
| wait_for_completion(&mps->done); |
| recv_at_once = in_be16(&fifo->rfnum); |
| dev_dbg(&spi->dev, "%d bytes received\n", recv_at_once); |
| |
| send_at_once = recv_at_once; |
| if (rx_buf) { |
| for (; recv_at_once; rb++, recv_at_once--) |
| rx_buf[rb] = in_8(&psc->mpc52xx_psc_buffer_8); |
| } else { |
| for (; recv_at_once; rb++, recv_at_once--) |
| in_8(&psc->mpc52xx_psc_buffer_8); |
| } |
| } |
| /* disable transmiter/receiver */ |
| out_8(&psc->command, MPC52xx_PSC_TX_DISABLE | MPC52xx_PSC_RX_DISABLE); |
| |
| return 0; |
| } |
| |
| int mpc52xx_psc_spi_transfer_one_message(struct spi_controller *ctlr, |
| struct spi_message *m) |
| { |
| struct spi_device *spi; |
| struct spi_transfer *t = NULL; |
| unsigned cs_change; |
| int status; |
| |
| spi = m->spi; |
| cs_change = 1; |
| status = 0; |
| list_for_each_entry (t, &m->transfers, transfer_list) { |
| if (t->bits_per_word || t->speed_hz) { |
| status = mpc52xx_psc_spi_transfer_setup(spi, t); |
| if (status < 0) |
| break; |
| } |
| |
| if (cs_change) |
| mpc52xx_psc_spi_activate_cs(spi); |
| cs_change = t->cs_change; |
| |
| status = mpc52xx_psc_spi_transfer_rxtx(spi, t); |
| if (status) |
| break; |
| m->actual_length += t->len; |
| |
| spi_transfer_delay_exec(t); |
| } |
| |
| m->status = status; |
| |
| mpc52xx_psc_spi_transfer_setup(spi, NULL); |
| |
| spi_finalize_current_message(ctlr); |
| |
| return 0; |
| } |
| |
| static int mpc52xx_psc_spi_setup(struct spi_device *spi) |
| { |
| struct mpc52xx_psc_spi_cs *cs = spi->controller_state; |
| |
| if (spi->bits_per_word%8) |
| return -EINVAL; |
| |
| if (!cs) { |
| cs = kzalloc(sizeof(*cs), GFP_KERNEL); |
| if (!cs) |
| return -ENOMEM; |
| spi->controller_state = cs; |
| } |
| |
| cs->bits_per_word = spi->bits_per_word; |
| cs->speed_hz = spi->max_speed_hz; |
| |
| return 0; |
| } |
| |
| static void mpc52xx_psc_spi_cleanup(struct spi_device *spi) |
| { |
| kfree(spi->controller_state); |
| } |
| |
| static int mpc52xx_psc_spi_port_config(int psc_id, struct mpc52xx_psc_spi *mps) |
| { |
| struct mpc52xx_psc __iomem *psc = mps->psc; |
| struct mpc52xx_psc_fifo __iomem *fifo = mps->fifo; |
| u32 mclken_div; |
| int ret; |
| |
| /* default sysclk is 512MHz */ |
| mclken_div = 512000000 / MCLK; |
| ret = mpc52xx_set_psc_clkdiv(psc_id, mclken_div); |
| if (ret) |
| return ret; |
| |
| /* Reset the PSC into a known state */ |
| out_8(&psc->command, MPC52xx_PSC_RST_RX); |
| out_8(&psc->command, MPC52xx_PSC_RST_TX); |
| out_8(&psc->command, MPC52xx_PSC_TX_DISABLE | MPC52xx_PSC_RX_DISABLE); |
| |
| /* Disable interrupts, interrupts are based on alarm level */ |
| out_be16(&psc->mpc52xx_psc_imr, 0); |
| out_8(&psc->command, MPC52xx_PSC_SEL_MODE_REG_1); |
| out_8(&fifo->rfcntl, 0); |
| out_8(&psc->mode, MPC52xx_PSC_MODE_FFULL); |
| |
| /* Configure 8bit codec mode as a SPI master and use EOF flags */ |
| /* SICR_SIM_CODEC8|SICR_GENCLK|SICR_SPI|SICR_MSTR|SICR_USEEOF */ |
| out_be32(&psc->sicr, 0x0180C800); |
| out_be16((u16 __iomem *)&psc->ccr, 0x070F); /* default SPI Clk 1MHz */ |
| |
| /* Set 2ms DTL delay */ |
| out_8(&psc->ctur, 0x00); |
| out_8(&psc->ctlr, 0x84); |
| |
| mps->bits_per_word = 8; |
| |
| return 0; |
| } |
| |
| static irqreturn_t mpc52xx_psc_spi_isr(int irq, void *dev_id) |
| { |
| struct mpc52xx_psc_spi *mps = (struct mpc52xx_psc_spi *)dev_id; |
| struct mpc52xx_psc __iomem *psc = mps->psc; |
| |
| /* disable interrupt and wake up the work queue */ |
| if (in_be16(&psc->mpc52xx_psc_isr) & MPC52xx_PSC_IMR_RXRDY) { |
| out_be16(&psc->mpc52xx_psc_imr, 0); |
| complete(&mps->done); |
| return IRQ_HANDLED; |
| } |
| return IRQ_NONE; |
| } |
| |
| static int mpc52xx_psc_spi_of_probe(struct platform_device *pdev) |
| { |
| struct device *dev = &pdev->dev; |
| struct mpc52xx_psc_spi *mps; |
| struct spi_master *master; |
| u32 bus_num; |
| int ret; |
| |
| master = devm_spi_alloc_master(dev, sizeof(*mps)); |
| if (master == NULL) |
| return -ENOMEM; |
| |
| dev_set_drvdata(dev, master); |
| mps = spi_master_get_devdata(master); |
| |
| /* the spi->mode bits understood by this driver: */ |
| master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH | SPI_LSB_FIRST; |
| |
| ret = device_property_read_u32(dev, "cell-index", &bus_num); |
| if (ret || bus_num > 5) |
| return dev_err_probe(dev, ret ? : -EINVAL, "Invalid cell-index property\n"); |
| master->bus_num = bus_num + 1; |
| |
| master->num_chipselect = 255; |
| master->setup = mpc52xx_psc_spi_setup; |
| master->transfer_one_message = mpc52xx_psc_spi_transfer_one_message; |
| master->cleanup = mpc52xx_psc_spi_cleanup; |
| |
| device_set_node(&master->dev, dev_fwnode(dev)); |
| |
| mps->psc = devm_platform_get_and_ioremap_resource(pdev, 0, NULL); |
| if (IS_ERR(mps->psc)) |
| return dev_err_probe(dev, PTR_ERR(mps->psc), "could not ioremap I/O port range\n"); |
| |
| /* On the 5200, fifo regs are immediately ajacent to the psc regs */ |
| mps->fifo = ((void __iomem *)mps->psc) + sizeof(struct mpc52xx_psc); |
| |
| mps->irq = platform_get_irq(pdev, 0); |
| if (mps->irq < 0) |
| return mps->irq; |
| |
| ret = devm_request_irq(dev, mps->irq, mpc52xx_psc_spi_isr, 0, |
| "mpc52xx-psc-spi", mps); |
| if (ret) |
| return ret; |
| |
| ret = mpc52xx_psc_spi_port_config(master->bus_num, mps); |
| if (ret < 0) |
| return dev_err_probe(dev, ret, "can't configure PSC! Is it capable of SPI?\n"); |
| |
| init_completion(&mps->done); |
| |
| return devm_spi_register_master(dev, master); |
| } |
| |
| static const struct of_device_id mpc52xx_psc_spi_of_match[] = { |
| { .compatible = "fsl,mpc5200-psc-spi", }, |
| { .compatible = "mpc5200-psc-spi", }, /* old */ |
| {} |
| }; |
| |
| MODULE_DEVICE_TABLE(of, mpc52xx_psc_spi_of_match); |
| |
| static struct platform_driver mpc52xx_psc_spi_of_driver = { |
| .probe = mpc52xx_psc_spi_of_probe, |
| .driver = { |
| .name = "mpc52xx-psc-spi", |
| .of_match_table = mpc52xx_psc_spi_of_match, |
| }, |
| }; |
| module_platform_driver(mpc52xx_psc_spi_of_driver); |
| |
| MODULE_AUTHOR("Dragos Carp"); |
| MODULE_DESCRIPTION("MPC52xx PSC SPI Driver"); |
| MODULE_LICENSE("GPL"); |