diff options
Diffstat (limited to 'drivers/spi/spi-mpc52xx-psc.c')
| -rw-r--r-- | drivers/spi/spi-mpc52xx-psc.c | 368 |
1 files changed, 368 insertions, 0 deletions
diff --git a/drivers/spi/spi-mpc52xx-psc.c b/drivers/spi/spi-mpc52xx-psc.c new file mode 100644 index 0000000000..795c08594a --- /dev/null +++ b/drivers/spi/spi-mpc52xx-psc.c @@ -0,0 +1,368 @@ +// 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"); |