Re: [PATCH][UPDATE] spi: Added spi master driver for Freescale MPC83xx SPI controller
From: David Brownell
Date: Mon Apr 10 2006 - 15:01:29 EST
On Monday 10 April 2006 10:38 am, Kumar Gala wrote:
> This driver supports the SPI controller on the MPC83xx SoC devices from
> Freescale. Note, this driver supports only the simple shift register SPI
> controller and not the descriptor based CPM or QUICCEngine SPI controller.
>
> Signed-off-by: Kumar Gala <galak@xxxxxxxxxxxxxxxxxxx>
Looks much better. It could be improved further, but this doesn't
have enough glitches that I'd object. However, I think you may need
to re-diff against the MM tree (or at least Greg's patches) since
the Makefile and Kconfig updates will conflict with pxa2xx_spi.
Signed-off-by: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
>
> ---
> commit 1e01024d79c1805e880d8863e03b6db91fc2dd25
> tree 21744404d18abbee7bc8387bd74ec018e413fab8
> parent bc33ba02f8414e91a3b2afa877be2c54d6fce564
> author Kumar Gala <galak@xxxxxxxxxxxxxxxxxxx> Mon, 10 Apr 2006 12:38:11 -0500
> committer Kumar Gala <galak@xxxxxxxxxxxxxxxxxxx> Mon, 10 Apr 2006 12:38:11 -0500
>
> drivers/spi/Kconfig | 10 +
> drivers/spi/Makefile | 1
> drivers/spi/spi_mpc83xx.c | 488 +++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 499 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
> index 7a75fae..af937bc 100644
> --- a/drivers/spi/Kconfig
> +++ b/drivers/spi/Kconfig
> @@ -75,6 +75,16 @@ config SPI_BUTTERFLY
> inexpensive battery powered microcontroller evaluation board.
> This same cable can be used to flash new firmware.
>
> +config SPI_MPC83xx
> + tristate "Freescale MPC83xx SPI controller"
> + depends on SPI_MASTER && PPC_83xx && EXPERIMENTAL
> + select SPI_BITBANG
> + help
> + This enables using the Freescale MPC83xx SPI controller in master mode.
> + Note, this driver uniquely supports the SPI controller on the MPC83xx
> + family of PowerPC processors. The MPC83xx uses a simple set of shift
> + registers for data (opposed to the CPM based descriptor model).
> +
> #
> # Add new SPI master controllers in alphabetical order above this line
> #
> diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
> index c2c87e8..502ac0b 100644
> --- a/drivers/spi/Makefile
> +++ b/drivers/spi/Makefile
> @@ -13,6 +13,7 @@ obj-$(CONFIG_SPI_MASTER) += spi.o
> # SPI master controller drivers (bus)
> obj-$(CONFIG_SPI_BITBANG) += spi_bitbang.o
> obj-$(CONFIG_SPI_BUTTERFLY) += spi_butterfly.o
> +obj-$(CONFIG_SPI_MPC83xx) += spi_mpc83xx.o
> # ... add above this line ...
>
> # SPI protocol drivers (device/link on bus)
> diff --git a/drivers/spi/spi_mpc83xx.c b/drivers/spi/spi_mpc83xx.c
> new file mode 100644
> index 0000000..a5ecdec
> --- /dev/null
> +++ b/drivers/spi/spi_mpc83xx.c
> @@ -0,0 +1,488 @@
> +/*
> + * MPC83xx SPI controller driver.
> + *
> + * Maintainer: Kumar Gala
> + *
> + * Copyright (C) 2006 Polycom, Inc.
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License as published by the
> + * Free Software Foundation; either version 2 of the License, or (at your
> + * option) any later version.
> + */
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/types.h>
> +#include <linux/kernel.h>
> +#include <linux/completion.h>
> +#include <linux/interrupt.h>
> +#include <linux/delay.h>
> +#include <linux/irq.h>
> +#include <linux/device.h>
> +#include <linux/spi/spi.h>
> +#include <linux/spi/spi_bitbang.h>
> +#include <linux/platform_device.h>
> +#include <linux/fsl_devices.h>
> +
> +#include <asm/irq.h>
> +#include <asm/io.h>
> +
> +/* SPI Controller registers */
> +struct mpc83xx_spi_reg {
> + u8 res1[0x20];
> + __be32 mode;
> + __be32 event;
> + __be32 mask;
> + __be32 command;
> + __be32 transmit;
> + __be32 receive;
> +};
> +
> +/* SPI Controller mode register definitions */
> +#define SPMODE_CI_INACTIVEHIGH (1 << 29)
> +#define SPMODE_CP_BEGIN_EDGECLK (1 << 28)
> +#define SPMODE_DIV16 (1 << 27)
> +#define SPMODE_REV (1 << 26)
> +#define SPMODE_MS (1 << 25)
> +#define SPMODE_ENABLE (1 << 24)
> +#define SPMODE_LEN(x) ((x) << 20)
> +#define SPMODE_PM(x) ((x) << 16)
> +
> +/*
> + * Default for SPI Mode:
> + * SPI MODE 0 (inactive low, phase middle, MSB, 8-bit length, slow clk
> + */
> +#define SPMODE_INIT_VAL (SPMODE_CI_INACTIVEHIGH | SPMODE_DIV16 | SPMODE_REV | \
> + SPMODE_MS | SPMODE_LEN(7) | SPMODE_PM(0xf))
> +
> +/* SPIE register values */
> +#define SPIE_NE 0x00000200 /* Not empty */
> +#define SPIE_NF 0x00000100 /* Not full */
> +
> +/* SPIM register values */
> +#define SPIM_NE 0x00000200 /* Not empty */
> +#define SPIM_NF 0x00000100 /* Not full */
> +
> +/* SPI Controller driver's private data. */
> +struct mpc83xx_spi {
> + /* bitbang has to be first */
> + struct spi_bitbang bitbang;
> + struct completion done;
> +
> + struct mpc83xx_spi_reg __iomem *base;
> +
> + /* rx & tx bufs from the spi_transfer */
> + const void *tx;
> + void *rx;
> +
> + /* functions to deal with different sized buffers */
> + void (*get_rx) (u32 rx_data, struct mpc83xx_spi *);
> + u32(*get_tx) (struct mpc83xx_spi *);
> +
> + unsigned int count;
> + u32 irq;
> +
> + unsigned nsecs; /* (clock cycle time)/2 */
> +
> + u32 sysclk;
> + void (*activate_cs) (u8 cs, u8 polarity);
> + void (*deactivate_cs) (u8 cs, u8 polarity);
> +};
> +
> +static inline void mpc83xx_spi_write_reg(__be32 __iomem * reg, u32 val)
> +{
> + out_be32(reg, val);
> +}
> +
> +static inline u32 mpc83xx_spi_read_reg(__be32 __iomem * reg)
> +{
> + return in_be32(reg);
> +}
> +
> +#define MPC83XX_SPI_RX_BUF(type) \
> +void mpc83xx_spi_rx_buf_##type(u32 data, struct mpc83xx_spi *mpc83xx_spi) \
> +{ \
> + type * rx = mpc83xx_spi->rx; \
> + *rx++ = (type)data; \
> + mpc83xx_spi->rx = rx; \
> +}
> +
> +#define MPC83XX_SPI_TX_BUF(type) \
> +u32 mpc83xx_spi_tx_buf_##type(struct mpc83xx_spi *mpc83xx_spi) \
> +{ \
> + u32 data; \
> + const type * tx = mpc83xx_spi->tx; \
> + data = *tx++; \
> + mpc83xx_spi->tx = tx; \
> + return data; \
> +}
> +
> +MPC83XX_SPI_RX_BUF(u8)
> +MPC83XX_SPI_RX_BUF(u16)
> +MPC83XX_SPI_RX_BUF(u32)
> +MPC83XX_SPI_TX_BUF(u8)
> +MPC83XX_SPI_TX_BUF(u16)
> +MPC83XX_SPI_TX_BUF(u32)
> +
> +static void mpc83xx_spi_chipselect(struct spi_device *spi, int value)
> +{
> + struct mpc83xx_spi *mpc83xx_spi;
> + u8 pol = spi->mode & SPI_CS_HIGH ? 1 : 0;
> +
> + mpc83xx_spi = spi_master_get_devdata(spi->master);
> +
> + if (value == BITBANG_CS_INACTIVE) {
> + if (mpc83xx_spi->deactivate_cs)
> + mpc83xx_spi->deactivate_cs(spi->chip_select, pol);
> + }
> +
> + if (value == BITBANG_CS_ACTIVE) {
> + u32 regval = mpc83xx_spi_read_reg(&mpc83xx_spi->base->mode);
> + u32 len = spi->bits_per_word;
> + if (len == 32)
> + len = 0;
> + else
> + len = len - 1;
> +
> + /* mask out bits we are going to set */
> + regval &= ~0x38ff0000;
> +
> + if (spi->mode & SPI_CPHA)
> + regval |= SPMODE_CP_BEGIN_EDGECLK;
> + if (spi->mode & SPI_CPOL)
> + regval |= SPMODE_CI_INACTIVEHIGH;
> +
> + regval |= SPMODE_LEN(len);
> +
> + if ((mpc83xx_spi->sysclk / spi->max_speed_hz) >= 64) {
> + u8 pm = mpc83xx_spi->sysclk / (spi->max_speed_hz * 64);
> + regval |= SPMODE_PM(pm) | SPMODE_DIV16;
> + } else {
> + u8 pm = mpc83xx_spi->sysclk / (spi->max_speed_hz * 4);
> + regval |= SPMODE_PM(pm);
> + }
> +
> + mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, regval);
> + if (mpc83xx_spi->activate_cs)
> + mpc83xx_spi->activate_cs(spi->chip_select, pol);
> + }
> +}
> +
> +static
> +int mpc83xx_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
> +{
> + struct mpc83xx_spi *mpc83xx_spi;
> + u32 regval;
> + u8 bits_per_word;
> + u32 hz;
> +
> + mpc83xx_spi = spi_master_get_devdata(spi->master);
> +
> + if (t) {
> + bits_per_word = t->bits_per_word;
> + hz = t->speed_hz;
> + } else {
> + bits_per_word = 0;
> + hz = 0;
> + }
> +
> + /* spi_transfer level calls that work per-word */
> + if (!bits_per_word)
> + bits_per_word = spi->bits_per_word;
> +
> + /* Make sure its a bit width we support [4..16, 32] */
> + if ((bits_per_word < 4)
> + || ((bits_per_word > 16) && (bits_per_word != 32)))
> + return -EINVAL;
> +
> + if (bits_per_word <= 8) {
> + mpc83xx_spi->get_rx = mpc83xx_spi_rx_buf_u8;
> + mpc83xx_spi->get_tx = mpc83xx_spi_tx_buf_u8;
> + } else {
> + if (bits_per_word <= 16) {
> + mpc83xx_spi->get_rx = mpc83xx_spi_rx_buf_u16;
> + mpc83xx_spi->get_tx = mpc83xx_spi_tx_buf_u16;
> + } else {
> + if (bits_per_word <= 32) {
> + mpc83xx_spi->get_rx = mpc83xx_spi_rx_buf_u32;
> + mpc83xx_spi->get_tx = mpc83xx_spi_tx_buf_u32;
> + } else {
> + return -EINVAL;
> + }
> + }
> + }
> +
> + /* nsecs = (clock period)/2 */
> + if (!hz)
> + hz = spi->max_speed_hz;
> + mpc83xx_spi->nsecs = (1000000000 / 2) / hz;
> + if (mpc83xx_spi->nsecs > MAX_UDELAY_MS * 1000)
> + return -EINVAL;
> +
> + if (bits_per_word == 32)
> + bits_per_word = 0;
> + else
> + bits_per_word = bits_per_word - 1;
> +
> + regval = mpc83xx_spi_read_reg(&mpc83xx_spi->base->mode);
> +
> + /* Mask out bits_per_wordgth */
> + regval &= 0xff0fffff;
> + regval |= SPMODE_LEN(bits_per_word);
> +
> + mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, regval);
> +
> + return 0;
> +}
> +
> +static int mpc83xx_spi_setup(struct spi_device *spi)
> +{
> + struct spi_bitbang *bitbang;
> + struct mpc83xx_spi *mpc83xx_spi;
> + int retval;
> +
> + if (!spi->max_speed_hz)
> + return -EINVAL;
> +
> + bitbang = spi_master_get_devdata(spi->master);
> + mpc83xx_spi = spi_master_get_devdata(spi->master);
> +
> + if (!spi->bits_per_word)
> + spi->bits_per_word = 8;
> +
> + retval = mpc83xx_spi_setup_transfer(spi, NULL);
> + if (retval < 0)
> + return retval;
> +
> + dev_dbg(&spi->dev, "%s, mode %d, %u bits/w, %u nsec\n",
> + __FUNCTION__, spi->mode & (SPI_CPOL | SPI_CPHA),
> + spi->bits_per_word, 2 * mpc83xx_spi->nsecs);
> +
> + /* NOTE we _need_ to call chipselect() early, ideally with adapter
> + * setup, unless the hardware defaults cooperate to avoid confusion
> + * between normal (active low) and inverted chipselects.
> + */
> +
> + /* deselect chip (low or high) */
> + spin_lock(&bitbang->lock);
> + if (!bitbang->busy) {
> + bitbang->chipselect(spi, BITBANG_CS_INACTIVE);
> + ndelay(mpc83xx_spi->nsecs);
> + }
> + spin_unlock(&bitbang->lock);
> +
> + return 0;
> +}
> +
> +static int mpc83xx_spi_bufs(struct spi_device *spi, struct spi_transfer *t)
> +{
> + struct mpc83xx_spi *mpc83xx_spi;
> + u32 word;
> +
> + mpc83xx_spi = spi_master_get_devdata(spi->master);
> +
> + mpc83xx_spi->tx = t->tx_buf;
> + mpc83xx_spi->rx = t->rx_buf;
> + mpc83xx_spi->count = t->len;
> + INIT_COMPLETION(mpc83xx_spi->done);
> +
> + /* enable rx ints */
> + mpc83xx_spi_write_reg(&mpc83xx_spi->base->mask, SPIM_NE);
> +
> + /* transmit word */
> + word = mpc83xx_spi->get_tx(mpc83xx_spi);
> + mpc83xx_spi_write_reg(&mpc83xx_spi->base->transmit, word);
> +
> + wait_for_completion(&mpc83xx_spi->done);
> +
> + /* disable rx ints */
> + mpc83xx_spi_write_reg(&mpc83xx_spi->base->mask, 0);
> +
> + return t->len - mpc83xx_spi->count;
> +}
> +
> +irqreturn_t mpc83xx_spi_irq(s32 irq, void *context_data,
> + struct pt_regs * ptregs)
> +{
> + struct mpc83xx_spi *mpc83xx_spi = context_data;
> + u32 event;
> + irqreturn_t ret = IRQ_NONE;
> +
> + /* Get interrupt events(tx/rx) */
> + event = mpc83xx_spi_read_reg(&mpc83xx_spi->base->event);
> +
> + /* We need handle RX first */
> + if (event & SPIE_NE) {
> + u32 rx_data = mpc83xx_spi_read_reg(&mpc83xx_spi->base->receive);
> +
> + if (mpc83xx_spi->rx)
> + mpc83xx_spi->get_rx(rx_data, mpc83xx_spi);
> +
> + ret = IRQ_HANDLED;
> + }
> +
> + if ((event & SPIE_NF) == 0)
> + /* spin until TX is done */
> + while (((event =
> + mpc83xx_spi_read_reg(&mpc83xx_spi->base->event)) &
> + SPIE_NF) == 0)
> + ;
> +
> + mpc83xx_spi->count -= 1;
> + if (mpc83xx_spi->count) {
> + if (mpc83xx_spi->tx) {
> + u32 word = mpc83xx_spi->get_tx(mpc83xx_spi);
> + mpc83xx_spi_write_reg(&mpc83xx_spi->base->transmit,
> + word);
> + }
> + } else {
> + complete(&mpc83xx_spi->done);
> + }
> +
> + /* Clear the events */
> + mpc83xx_spi_write_reg(&mpc83xx_spi->base->event, event);
> +
> + return ret;
> +}
> +
> +static int __devinit mpc83xx_spi_probe(struct platform_device *dev)
> +{
> + struct spi_master *master;
> + struct mpc83xx_spi *mpc83xx_spi;
> + struct fsl_spi_platform_data *pdata;
> + struct resource *r;
> + u32 regval;
> + int ret = 0;
> +
> + /* Get resources(memory, IRQ) associated with the device */
> + master = spi_alloc_master(&dev->dev, sizeof(struct mpc83xx_spi));
> +
> + if (master == NULL) {
> + ret = -ENOMEM;
> + goto err;
> + }
> +
> + platform_set_drvdata(dev, master);
> + pdata = dev->dev.platform_data;
> +
> + if (pdata == NULL) {
> + ret = -ENODEV;
> + goto free_master;
> + }
> +
> + r = platform_get_resource(dev, IORESOURCE_MEM, 0);
> + if (r == NULL) {
> + ret = -ENODEV;
> + goto free_master;
> + }
> +
> + mpc83xx_spi = spi_master_get_devdata(master);
> + mpc83xx_spi->bitbang.master = spi_master_get(master);
> + mpc83xx_spi->bitbang.chipselect = mpc83xx_spi_chipselect;
> + mpc83xx_spi->bitbang.setup_transfer = mpc83xx_spi_setup_transfer;
> + mpc83xx_spi->bitbang.txrx_bufs = mpc83xx_spi_bufs;
> + mpc83xx_spi->sysclk = pdata->sysclk;
> + mpc83xx_spi->activate_cs = pdata->activate_cs;
> + mpc83xx_spi->deactivate_cs = pdata->deactivate_cs;
> + mpc83xx_spi->get_rx = mpc83xx_spi_rx_buf_u8;
> + mpc83xx_spi->get_tx = mpc83xx_spi_tx_buf_u8;
> +
> + mpc83xx_spi->bitbang.master->setup = mpc83xx_spi_setup;
> + init_completion(&mpc83xx_spi->done);
> +
> + mpc83xx_spi->base = ioremap(r->start, r->end - r->start + 1);
> + if (mpc83xx_spi->base == NULL) {
> + ret = -ENOMEM;
> + goto put_master;
> + }
> +
> + mpc83xx_spi->irq = platform_get_irq(dev, 0);
> +
> + if (mpc83xx_spi->irq < 0) {
> + ret = -ENXIO;
> + goto unmap_io;
> + }
> +
> + /* Register for SPI Interrupt */
> + ret = request_irq(mpc83xx_spi->irq, mpc83xx_spi_irq,
> + 0, "mpc83xx_spi", mpc83xx_spi);
> +
> + if (ret != 0)
> + goto unmap_io;
> +
> + master->bus_num = pdata->bus_num;
> + master->num_chipselect = pdata->max_chipselect;
> +
> + /* SPI controller initializations */
> + mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, 0);
> + mpc83xx_spi_write_reg(&mpc83xx_spi->base->mask, 0);
> + mpc83xx_spi_write_reg(&mpc83xx_spi->base->command, 0);
> + mpc83xx_spi_write_reg(&mpc83xx_spi->base->event, 0xffffffff);
> +
> + /* Enable SPI interface */
> + regval = pdata->initial_spmode | SPMODE_INIT_VAL | SPMODE_ENABLE;
> + mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, regval);
> +
> + ret = spi_bitbang_start(&mpc83xx_spi->bitbang);
> +
> + if (ret != 0)
> + goto free_irq;
> +
> + printk(KERN_INFO
> + "%s: MPC83xx SPI Controller driver at 0x%p (irq = %d)\n",
> + dev->dev.bus_id, mpc83xx_spi->base, mpc83xx_spi->irq);
> +
> + return ret;
> +
> +free_irq:
> + free_irq(mpc83xx_spi->irq, mpc83xx_spi);
> +unmap_io:
> + iounmap(mpc83xx_spi->base);
> +put_master:
> + spi_master_put(master);
> +free_master:
> + kfree(master);
> +err:
> + return ret;
> +}
> +
> +static int __devexit mpc83xx_spi_remove(struct platform_device *dev)
> +{
> + struct mpc83xx_spi *mpc83xx_spi;
> + struct spi_master *master;
> +
> + master = platform_get_drvdata(dev);
> + mpc83xx_spi = spi_master_get_devdata(master);
> +
> + spi_bitbang_stop(&mpc83xx_spi->bitbang);
> + free_irq(mpc83xx_spi->irq, mpc83xx_spi);
> + iounmap(mpc83xx_spi->base);
> + spi_master_put(mpc83xx_spi->bitbang.master);
> +
> + return 0;
> +}
> +
> +static struct platform_driver mpc83xx_spi_driver = {
> + .probe = mpc83xx_spi_probe,
> + .remove = __devexit_p(mpc83xx_spi_remove),
> + .driver = {
> + .name = "mpc83xx_spi",
> + },
> +};
> +
> +static int __init mpc83xx_spi_init(void)
> +{
> + return platform_driver_register(&mpc83xx_spi_driver);
> +}
> +
> +static void __exit mpc83xx_spi_exit(void)
> +{
> + platform_driver_unregister(&mpc83xx_spi_driver);
> +}
> +
> +module_init(mpc83xx_spi_init);
> +module_exit(mpc83xx_spi_exit);
> +
> +MODULE_AUTHOR("Kumar Gala");
> +MODULE_DESCRIPTION("Simple MPC83xx SPI Driver");
> +MODULE_LICENSE("GPL");
>
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