diff options
Diffstat (limited to 'drivers/spi')
| -rw-r--r-- | drivers/spi/Kconfig | 18 | ||||
| -rw-r--r-- | drivers/spi/Makefile | 1 | ||||
| -rw-r--r-- | drivers/spi/atmel_spi.c | 131 | ||||
| -rw-r--r-- | drivers/spi/pxa2xx_spi.c | 3 | ||||
| -rw-r--r-- | drivers/spi/spi.c | 20 | ||||
| -rw-r--r-- | drivers/spi/spi_bitbang.c | 2 | ||||
| -rw-r--r-- | drivers/spi/spi_butterfly.c | 2 | ||||
| -rw-r--r-- | drivers/spi/spi_gpio.c | 360 | ||||
| -rw-r--r-- | drivers/spi/spi_lm70llp.c | 35 | ||||
| -rw-r--r-- | drivers/spi/spi_s3c24xx.c | 38 |
10 files changed, 521 insertions, 89 deletions
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig index b9d0efb6803f..4a6fe01831a8 100644 --- a/drivers/spi/Kconfig +++ b/drivers/spi/Kconfig @@ -78,7 +78,7 @@ config SPI_AU1550 will be called au1550_spi. config SPI_BITBANG - tristate "Bitbanging SPI master" + tristate "Utilities for Bitbanging SPI masters" help With a few GPIO pins, your system can bitbang the SPI protocol. Select this to get SPI support through I/O pins (GPIO, parallel @@ -100,6 +100,22 @@ config SPI_BUTTERFLY inexpensive battery powered microcontroller evaluation board. This same cable can be used to flash new firmware. +config SPI_GPIO + tristate "GPIO-based bitbanging SPI Master" + depends on GENERIC_GPIO + select SPI_BITBANG + help + This simple GPIO bitbanging SPI master uses the arch-neutral GPIO + interface to manage MOSI, MISO, SCK, and chipselect signals. SPI + slaves connected to a bus using this driver are configured as usual, + except that the spi_board_info.controller_data holds the GPIO number + for the chipselect used by this controller driver. + + Note that this driver often won't achieve even 1 Mbit/sec speeds, + making it unusually slow for SPI. If your platform can inline + GPIO operations, you should be able to leverage that for better + speed with a custom version of this driver; see the source code. + config SPI_IMX tristate "Freescale iMX SPI controller" depends on ARCH_IMX && EXPERIMENTAL diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile index ccf18de34e1e..5e9f521b8844 100644 --- a/drivers/spi/Makefile +++ b/drivers/spi/Makefile @@ -16,6 +16,7 @@ obj-$(CONFIG_SPI_BFIN) += spi_bfin5xx.o obj-$(CONFIG_SPI_BITBANG) += spi_bitbang.o obj-$(CONFIG_SPI_AU1550) += au1550_spi.o obj-$(CONFIG_SPI_BUTTERFLY) += spi_butterfly.o +obj-$(CONFIG_SPI_GPIO) += spi_gpio.o obj-$(CONFIG_SPI_IMX) += spi_imx.o obj-$(CONFIG_SPI_LM70_LLP) += spi_lm70llp.o obj-$(CONFIG_SPI_PXA2XX) += pxa2xx_spi.o diff --git a/drivers/spi/atmel_spi.c b/drivers/spi/atmel_spi.c index 8abae4ad0fa5..5e39bac9c51b 100644 --- a/drivers/spi/atmel_spi.c +++ b/drivers/spi/atmel_spi.c @@ -30,13 +30,6 @@ * The core SPI transfer engine just talks to a register bank to set up * DMA transfers; transfer queue progress is driven by IRQs. The clock * framework provides the base clock, subdivided for each spi_device. - * - * Newer controllers, marked with "new_1" flag, have: - * - CR.LASTXFER - * - SPI_MR.DIV32 may become FDIV or must-be-zero (here: always zero) - * - SPI_SR.TXEMPTY, SPI_SR.NSSR (and corresponding irqs) - * - SPI_CSRx.CSAAT - * - SPI_CSRx.SBCR allows faster clocking */ struct atmel_spi { spinlock_t lock; @@ -45,7 +38,6 @@ struct atmel_spi { int irq; struct clk *clk; struct platform_device *pdev; - unsigned new_1:1; struct spi_device *stay; u8 stopping; @@ -59,10 +51,33 @@ struct atmel_spi { dma_addr_t buffer_dma; }; +/* Controller-specific per-slave state */ +struct atmel_spi_device { + unsigned int npcs_pin; + u32 csr; +}; + #define BUFFER_SIZE PAGE_SIZE #define INVALID_DMA_ADDRESS 0xffffffff /* + * Version 2 of the SPI controller has + * - CR.LASTXFER + * - SPI_MR.DIV32 may become FDIV or must-be-zero (here: always zero) + * - SPI_SR.TXEMPTY, SPI_SR.NSSR (and corresponding irqs) + * - SPI_CSRx.CSAAT + * - SPI_CSRx.SBCR allows faster clocking + * + * We can determine the controller version by reading the VERSION + * register, but I haven't checked that it exists on all chips, and + * this is cheaper anyway. + */ +static bool atmel_spi_is_v2(void) +{ + return !cpu_is_at91rm9200(); +} + +/* * Earlier SPI controllers (e.g. on at91rm9200) have a design bug whereby * they assume that spi slave device state will not change on deselect, so * that automagic deselection is OK. ("NPCSx rises if no data is to be @@ -80,39 +95,58 @@ struct atmel_spi { * Master on Chip Select 0.") No workaround exists for that ... so for * nCS0 on that chip, we (a) don't use the GPIO, (b) can't support CS_HIGH, * and (c) will trigger that first erratum in some cases. + * + * TODO: Test if the atmel_spi_is_v2() branch below works on + * AT91RM9200 if we use some other register than CSR0. However, don't + * do this unconditionally since AP7000 has an errata where the BITS + * field in CSR0 overrides all other CSRs. */ static void cs_activate(struct atmel_spi *as, struct spi_device *spi) { - unsigned gpio = (unsigned) spi->controller_data; + struct atmel_spi_device *asd = spi->controller_state; unsigned active = spi->mode & SPI_CS_HIGH; u32 mr; - int i; - u32 csr; - u32 cpol = (spi->mode & SPI_CPOL) ? SPI_BIT(CPOL) : 0; - - /* Make sure clock polarity is correct */ - for (i = 0; i < spi->master->num_chipselect; i++) { - csr = spi_readl(as, CSR0 + 4 * i); - if ((csr ^ cpol) & SPI_BIT(CPOL)) - spi_writel(as, CSR0 + 4 * i, csr ^ SPI_BIT(CPOL)); - } - mr = spi_readl(as, MR); - mr = SPI_BFINS(PCS, ~(1 << spi->chip_select), mr); + if (atmel_spi_is_v2()) { + /* + * Always use CSR0. This ensures that the clock + * switches to the correct idle polarity before we + * toggle the CS. + */ + spi_writel(as, CSR0, asd->csr); + spi_writel(as, MR, SPI_BF(PCS, 0x0e) | SPI_BIT(MODFDIS) + | SPI_BIT(MSTR)); + mr = spi_readl(as, MR); + gpio_set_value(asd->npcs_pin, active); + } else { + u32 cpol = (spi->mode & SPI_CPOL) ? SPI_BIT(CPOL) : 0; + int i; + u32 csr; + + /* Make sure clock polarity is correct */ + for (i = 0; i < spi->master->num_chipselect; i++) { + csr = spi_readl(as, CSR0 + 4 * i); + if ((csr ^ cpol) & SPI_BIT(CPOL)) + spi_writel(as, CSR0 + 4 * i, + csr ^ SPI_BIT(CPOL)); + } + + mr = spi_readl(as, MR); + mr = SPI_BFINS(PCS, ~(1 << spi->chip_select), mr); + if (spi->chip_select != 0) + gpio_set_value(asd->npcs_pin, active); + spi_writel(as, MR, mr); + } dev_dbg(&spi->dev, "activate %u%s, mr %08x\n", - gpio, active ? " (high)" : "", + asd->npcs_pin, active ? " (high)" : "", mr); - - if (!(cpu_is_at91rm9200() && spi->chip_select == 0)) - gpio_set_value(gpio, active); - spi_writel(as, MR, mr); } static void cs_deactivate(struct atmel_spi *as, struct spi_device *spi) { - unsigned gpio = (unsigned) spi->controller_data; + struct atmel_spi_device *asd = spi->controller_state; unsigned active = spi->mode & SPI_CS_HIGH; u32 mr; @@ -126,11 +160,11 @@ static void cs_deactivate(struct atmel_spi *as, struct spi_device *spi) } dev_dbg(&spi->dev, "DEactivate %u%s, mr %08x\n", - gpio, active ? " (low)" : "", + asd->npcs_pin, active ? " (low)" : "", mr); - if (!(cpu_is_at91rm9200() && spi->chip_select == 0)) - gpio_set_value(gpio, !active); + if (atmel_spi_is_v2() || spi->chip_select != 0) + gpio_set_value(asd->npcs_pin, !active); } static inline int atmel_spi_xfer_is_last(struct spi_message *msg, @@ -502,6 +536,7 @@ atmel_spi_interrupt(int irq, void *dev_id) static int atmel_spi_setup(struct spi_device *spi) { struct atmel_spi *as; + struct atmel_spi_device *asd; u32 scbr, csr; unsigned int bits = spi->bits_per_word; unsigned long bus_hz; @@ -536,19 +571,16 @@ static int atmel_spi_setup(struct spi_device *spi) } /* see notes above re chipselect */ - if (cpu_is_at91rm9200() + if (!atmel_spi_is_v2() && spi->chip_select == 0 && (spi->mode & SPI_CS_HIGH)) { dev_dbg(&spi->dev, "setup: can't be active-high\n"); return -EINVAL; } - /* - * Pre-new_1 chips start out at half the peripheral - * bus speed. - */ + /* v1 chips start out at half the peripheral bus speed. */ bus_hz = clk_get_rate(as->clk); - if (!as->new_1) + if (!atmel_spi_is_v2()) bus_hz /= 2; if (spi->max_speed_hz) { @@ -589,11 +621,20 @@ static int atmel_spi_setup(struct spi_device *spi) /* chipselect must have been muxed as GPIO (e.g. in board setup) */ npcs_pin = (unsigned int)spi->controller_data; - if (!spi->controller_state) { + asd = spi->controller_state; + if (!asd) { + asd = kzalloc(sizeof(struct atmel_spi_device), GFP_KERNEL); + if (!asd) + return -ENOMEM; + ret = gpio_request(npcs_pin, spi->dev.bus_id); - if (ret) + if (ret) { + kfree(asd); return ret; - spi->controller_state = (void *)npcs_pin; + } + + asd->npcs_pin = npcs_pin; + spi->controller_state = asd; gpio_direction_output(npcs_pin, !(spi->mode & SPI_CS_HIGH)); } else { unsigned long flags; @@ -605,11 +646,14 @@ static int atmel_spi_setup(struct spi_device *spi) spin_unlock_irqrestore(&as->lock, flags); } + asd->csr = csr; + dev_dbg(&spi->dev, "setup: %lu Hz bpw %u mode 0x%x -> csr%d %08x\n", bus_hz / scbr, bits, spi->mode, spi->chip_select, csr); - spi_writel(as, CSR0 + 4 * spi->chip_select, csr); + if (!atmel_spi_is_v2()) + spi_writel(as, CSR0 + 4 * spi->chip_select, csr); return 0; } @@ -684,10 +728,11 @@ static int atmel_spi_transfer(struct spi_device *spi, struct spi_message *msg) static void atmel_spi_cleanup(struct spi_device *spi) { struct atmel_spi *as = spi_master_get_devdata(spi->master); + struct atmel_spi_device *asd = spi->controller_state; unsigned gpio = (unsigned) spi->controller_data; unsigned long flags; - if (!spi->controller_state) + if (!asd) return; spin_lock_irqsave(&as->lock, flags); @@ -697,7 +742,9 @@ static void atmel_spi_cleanup(struct spi_device *spi) } spin_unlock_irqrestore(&as->lock, flags); + spi->controller_state = NULL; gpio_free(gpio); + kfree(asd); } /*-------------------------------------------------------------------------*/ @@ -755,8 +802,6 @@ static int __init atmel_spi_probe(struct platform_device *pdev) goto out_free_buffer; as->irq = irq; as->clk = clk; - if (!cpu_is_at91rm9200()) - as->new_1 = 1; ret = request_irq(irq, atmel_spi_interrupt, 0, pdev->dev.bus_id, master); diff --git a/drivers/spi/pxa2xx_spi.c b/drivers/spi/pxa2xx_spi.c index 6104f461a3cd..d0fc4ca2f656 100644 --- a/drivers/spi/pxa2xx_spi.c +++ b/drivers/spi/pxa2xx_spi.c @@ -1561,11 +1561,12 @@ out_error_master_alloc: static int pxa2xx_spi_remove(struct platform_device *pdev) { struct driver_data *drv_data = platform_get_drvdata(pdev); - struct ssp_device *ssp = drv_data->ssp; + struct ssp_device *ssp; int status = 0; if (!drv_data) return 0; + ssp = drv_data->ssp; /* Remove the queue */ status = destroy_queue(drv_data); diff --git a/drivers/spi/spi.c b/drivers/spi/spi.c index 3734dc9708e1..643908b74bc0 100644 --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -47,7 +47,7 @@ modalias_show(struct device *dev, struct device_attribute *a, char *buf) { const struct spi_device *spi = to_spi_device(dev); - return snprintf(buf, BUS_ID_SIZE + 1, "%s\n", spi->modalias); + return sprintf(buf, "%s\n", spi->modalias); } static struct device_attribute spi_dev_attrs[] = { @@ -63,7 +63,7 @@ static int spi_match_device(struct device *dev, struct device_driver *drv) { const struct spi_device *spi = to_spi_device(dev); - return strncmp(spi->modalias, drv->name, BUS_ID_SIZE) == 0; + return strcmp(spi->modalias, drv->name) == 0; } static int spi_uevent(struct device *dev, struct kobj_uevent_env *env) @@ -243,8 +243,7 @@ int spi_add_device(struct spi_device *spi) } /* Set the bus ID string */ - snprintf(spi->dev.bus_id, sizeof spi->dev.bus_id, - "%s.%u", spi->master->dev.bus_id, + dev_set_name(&spi->dev, "%s.%u", dev_name(&spi->master->dev), spi->chip_select); @@ -254,7 +253,7 @@ int spi_add_device(struct spi_device *spi) */ mutex_lock(&spi_add_lock); - if (bus_find_device_by_name(&spi_bus_type, NULL, spi->dev.bus_id) + if (bus_find_device_by_name(&spi_bus_type, NULL, dev_name(&spi->dev)) != NULL) { dev_err(dev, "chipselect %d already in use\n", spi->chip_select); @@ -269,7 +268,7 @@ int spi_add_device(struct spi_device *spi) status = spi->master->setup(spi); if (status < 0) { dev_err(dev, "can't %s %s, status %d\n", - "setup", spi->dev.bus_id, status); + "setup", dev_name(&spi->dev), status); goto done; } @@ -277,9 +276,9 @@ int spi_add_device(struct spi_device *spi) status = device_add(&spi->dev); if (status < 0) dev_err(dev, "can't %s %s, status %d\n", - "add", spi->dev.bus_id, status); + "add", dev_name(&spi->dev), status); else - dev_dbg(dev, "registered child %s\n", spi->dev.bus_id); + dev_dbg(dev, "registered child %s\n", dev_name(&spi->dev)); done: mutex_unlock(&spi_add_lock); @@ -504,12 +503,11 @@ int spi_register_master(struct spi_master *master) /* register the device, then userspace will see it. * registration fails if the bus ID is in use. */ - snprintf(master->dev.bus_id, sizeof master->dev.bus_id, - "spi%u", master->bus_num); + dev_set_name(&master->dev, "spi%u", master->bus_num); status = device_add(&master->dev); if (status < 0) goto done; - dev_dbg(dev, "registered master %s%s\n", master->dev.bus_id, + dev_dbg(dev, "registered master %s%s\n", dev_name(&master->dev), dynamic ? " (dynamic)" : ""); /* populate children from any spi device tables */ diff --git a/drivers/spi/spi_bitbang.c b/drivers/spi/spi_bitbang.c index 96cc39ecb6e2..85e61f451218 100644 --- a/drivers/spi/spi_bitbang.c +++ b/drivers/spi/spi_bitbang.c @@ -475,7 +475,7 @@ int spi_bitbang_start(struct spi_bitbang *bitbang) /* this task is the only thing to touch the SPI bits */ bitbang->busy = 0; bitbang->workqueue = create_singlethread_workqueue( - bitbang->master->dev.parent->bus_id); + dev_name(bitbang->master->dev.parent)); if (bitbang->workqueue == NULL) { status = -EBUSY; goto err1; diff --git a/drivers/spi/spi_butterfly.c b/drivers/spi/spi_butterfly.c index 0ee2b2090252..c2184866fa9c 100644 --- a/drivers/spi/spi_butterfly.c +++ b/drivers/spi/spi_butterfly.c @@ -287,7 +287,7 @@ static void butterfly_attach(struct parport *p) pp->dataflash = spi_new_device(pp->bitbang.master, &pp->info[0]); if (pp->dataflash) pr_debug("%s: dataflash at %s\n", p->name, - pp->dataflash->dev.bus_id); + dev_name(&pp->dataflash->dev)); // dev_info(_what?_, ...) pr_info("%s: AVR Butterfly\n", p->name); diff --git a/drivers/spi/spi_gpio.c b/drivers/spi/spi_gpio.c new file mode 100644 index 000000000000..49698cabc30d --- /dev/null +++ b/drivers/spi/spi_gpio.c @@ -0,0 +1,360 @@ +/* + * spi_gpio.c - SPI master driver using generic bitbanged GPIO + * + * Copyright (C) 2006,2008 David Brownell + * + * 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. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/platform_device.h> +#include <linux/gpio.h> + +#include <linux/spi/spi.h> +#include <linux/spi/spi_bitbang.h> +#include <linux/spi/spi_gpio.h> + + +/* + * This bitbanging SPI master driver should help make systems usable + * when a native hardware SPI engine is not available, perhaps because + * its driver isn't yet working or because the I/O pins it requires + * are used for other purposes. + * + * platform_device->driver_data ... points to spi_gpio + * + * spi->controller_state ... reserved for bitbang framework code + * spi->controller_data ... holds chipselect GPIO + * + * spi->master->dev.driver_data ... points to spi_gpio->bitbang + */ + +struct spi_gpio { + struct spi_bitbang bitbang; + struct spi_gpio_platform_data pdata; + struct platform_device *pdev; +}; + +/*----------------------------------------------------------------------*/ + +/* + * Because the overhead of going through four GPIO procedure calls + * per transferred bit can make performance a problem, this code + * is set up so that you can use it in either of two ways: + * + * - The slow generic way: set up platform_data to hold the GPIO + * numbers used for MISO/MOSI/SCK, and issue procedure calls for + * each of them. This driver can handle several such busses. + * + * - The quicker inlined way: only helps with platform GPIO code + * that inlines operations for constant GPIOs. This can give + * you tight (fast!) inner loops, but each such bus needs a + * new driver. You'll define a new C file, with Makefile and + * Kconfig support; the C code can be a total of six lines: + * + * #define DRIVER_NAME "myboard_spi2" + * #define SPI_MISO_GPIO 119 + * #define SPI_MOSI_GPIO 120 + * #define SPI_SCK_GPIO 121 + * #define SPI_N_CHIPSEL 4 + * #include "spi_gpio.c" + */ + +#ifndef DRIVER_NAME +#define DRIVER_NAME "spi_gpio" + +#define GENERIC_BITBANG /* vs tight inlines */ + +/* all functions referencing these symbols must define pdata */ +#define SPI_MISO_GPIO ((pdata)->miso) +#define SPI_MOSI_GPIO ((pdata)->mosi) +#define SPI_SCK_GPIO ((pdata)->sck) + +#define SPI_N_CHIPSEL ((pdata)->num_chipselect) + +#endif + +/*----------------------------------------------------------------------*/ + +static inline const struct spi_gpio_platform_data * __pure +spi_to_pdata(const struct spi_device *spi) +{ + const struct spi_bitbang *bang; + const struct spi_gpio *spi_gpio; + + bang = spi_master_get_devdata(spi->master); + spi_gpio = container_of(bang, struct spi_gpio, bitbang); + return &spi_gpio->pdata; +} + +/* this is #defined to avoid unused-variable warnings when inlining */ +#define pdata spi_to_pdata(spi) + +static inline void setsck(const struct spi_device *spi, int is_on) +{ + gpio_set_value(SPI_SCK_GPIO, is_on); +} + +static inline void setmosi(const struct spi_device *spi, int is_on) +{ + gpio_set_value(SPI_MOSI_GPIO, is_on); +} + +static inline int getmiso(const struct spi_device *spi) +{ + return gpio_get_value(SPI_MISO_GPIO); +} + +#undef pdata + +/* + * NOTE: this clocks "as fast as we can". It "should" be a function of the + * requested device clock. Software overhead means we usually have trouble + * reaching even one Mbit/sec (except when we can inline bitops), so for now + * we'll just assume we never need additional per-bit slowdowns. + */ +#define spidelay(nsecs) do {} while (0) + +#define EXPAND_BITBANG_TXRX +#include <linux/spi/spi_bitbang.h> + +/* + * These functions can leverage inline expansion of GPIO calls to shrink + * costs for a txrx bit, often by factors of around ten (by instruction + * count). That is particularly visible for larger word sizes, but helps + * even with default 8-bit words. + * + * REVISIT overheads calling these functions for each word also have + * significant performance costs. Having txrx_bufs() calls that inline + * the txrx_word() logic would help performance, e.g. on larger blocks + * used with flash storage or MMC/SD. There should also be ways to make + * GCC be less stupid about reloading registers inside the I/O loops, + * even without inlined GPIO calls; __attribute__((hot)) on GCC 4.3? + */ + +static u32 spi_gpio_txrx_word_mode0(struct spi_device *spi, + unsigned nsecs, u32 word, u8 bits) +{ + return bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits); +} + +static u32 spi_gpio_txrx_word_mode1(struct spi_device *spi, + unsigned nsecs, u32 word, u8 bits) +{ + return bitbang_txrx_be_cpha1(spi, nsecs, 0, word, bits); +} + +static u32 spi_gpio_txrx_word_mode2(struct spi_device *spi, + unsigned nsecs, u32 word, u8 bits) +{ + return bitbang_txrx_be_cpha0(spi, nsecs, 1, word, bits); +} + +static u32 spi_gpio_txrx_word_mode3(struct spi_device *spi, + unsigned nsecs, u32 word, u8 bits) +{ + return bitbang_txrx_be_cpha1(spi, nsecs, 1, word, bits); +} + +/*----------------------------------------------------------------------*/ + +static void spi_gpio_chipselect(struct spi_device *spi, int is_active) +{ + unsigned long cs = (unsigned long) spi->controller_data; + + /* set initial clock polarity */ + if (is_active) + setsck(spi, spi->mode & SPI_CPOL); + + /* SPI is normally active-low */ + gpio_set_value(cs, (spi->mode & SPI_CS_HIGH) ? is_active : !is_active); +} + +static int spi_gpio_setup(struct spi_device *spi) +{ + unsigned long cs = (unsigned long) spi->controller_data; + int status = 0; + + if (spi->bits_per_word > 32) + return -EINVAL; + + if (!spi->controller_state) { + status = gpio_request(cs, spi->dev.bus_id); + if (status) + return status; + status = gpio_direction_output(cs, spi->mode & SPI_CS_HIGH); + } + if (!status) + status = spi_bitbang_setup(spi); + if (status) { + if (!spi->controller_state) + gpio_free(cs); + } + return status; +} + +static void spi_gpio_cleanup(struct spi_device *spi) +{ + unsigned long cs = (unsigned long) spi->controller_data; + + gpio_free(cs); + spi_bitbang_cleanup(spi); +} + +static int __init spi_gpio_alloc(unsigned pin, const char *label, bool is_in) +{ + int value; + + value = gpio_request(pin, label); + if (value == 0) { + if (is_in) + value = gpio_direction_input(pin); + else + value = gpio_direction_output(pin, 0); + } + return value; +} + +static int __init +spi_gpio_request(struct spi_gpio_platform_data *pdata, const char *label) +{ + int value; + + /* NOTE: SPI_*_GPIO symbols may reference "pdata" */ + + value = spi_gpio_alloc(SPI_MOSI_GPIO, label, false); + if (value) + goto done; + + value = spi_gpio_alloc(SPI_MISO_GPIO, label, true); + if (value) + goto free_mosi; + + value = spi_gpio_alloc(SPI_SCK_GPIO, label, false); + if (value) + goto free_miso; + + goto done; + +free_miso: + gpio_free(SPI_MISO_GPIO); +free_mosi: + gpio_free(SPI_MOSI_GPIO); +done: + return value; +} + +static int __init spi_gpio_probe(struct platform_device *pdev) +{ + int status; + struct spi_master *master; + struct spi_gpio *spi_gpio; + struct spi_gpio_platform_data *pdata; + + pdata = pdev->dev.platform_data; +#ifdef GENERIC_BITBANG + if (!pdata || !pdata->num_chipselect) + return -ENODEV; +#endif + + status = spi_gpio_request(pdata, dev_name(&pdev->dev)); + if (status < 0) + return status; + + master = spi_alloc_master(&pdev->dev, sizeof *spi_gpio); + if (!master) { + status = -ENOMEM; + goto gpio_free; + } + spi_gpio = spi_master_get_devdata(master); + platform_set_drvdata(pdev, spi_gpio); + + spi_gpio->pdev = pdev; + if (pdata) + spi_gpio->pdata = *pdata; + + master->bus_num = pdev->id; + master->num_chipselect = SPI_N_CHIPSEL; + master->setup = spi_gpio_setup; + master->cleanup = spi_gpio_cleanup; + + spi_gpio->bitbang.master = spi_master_get(master); + spi_gpio->bitbang.chipselect = spi_gpio_chipselect; + spi_gpio->bitbang.txrx_word[SPI_MODE_0] = spi_gpio_txrx_word_mode0; + spi_gpio->bitbang.txrx_word[SPI_MODE_1] = spi_gpio_txrx_word_mode1; + spi_gpio->bitbang.txrx_word[SPI_MODE_2] = spi_gpio_txrx_word_mode2; + spi_gpio->bitbang.txrx_word[SPI_MODE_3] = spi_gpio_txrx_word_mode3; + spi_gpio->bitbang.setup_transfer = spi_bitbang_setup_transfer; + spi_gpio->bitbang.flags = SPI_CS_HIGH; + + status = spi_bitbang_start(&spi_gpio->bitbang); + if (status < 0) { + spi_master_put(spi_gpio->bitbang.master); +gpio_free: + gpio_free(SPI_MISO_GPIO); + gpio_free(SPI_MOSI_GPIO); + gpio_free(SPI_SCK_GPIO); + spi_master_put(master); + } + + return status; +} + +static int __exit spi_gpio_remove(struct platform_device *pdev) +{ + struct spi_gpio *spi_gpio; + struct spi_gpio_platform_data *pdata; + int status; + + spi_gpio = platform_get_drvdata(pdev); + pdata = pdev->dev.platform_data; + + /* stop() unregisters child devices too */ + status = spi_bitbang_stop(&spi_gpio->bitbang); + spi_master_put(spi_gpio->bitbang.master); + + platform_set_drvdata(pdev, NULL); + + gpio_free(SPI_MISO_GPIO); + gpio_free(SPI_MOSI_GPIO); + gpio_free(SPI_SCK_GPIO); + + return status; +} + +MODULE_ALIAS("platform:" DRIVER_NAME); + +static struct platform_driver spi_gpio_driver = { + .driver.name = DRIVER_NAME, + .driver.owner = THIS_MODULE, + .remove = __exit_p(spi_gpio_remove), +}; + +static int __init spi_gpio_init(void) +{ + return platform_driver_probe(&spi_gpio_driver, spi_gpio_probe); +} +module_init(spi_gpio_init); + +static void __exit spi_gpio_exit(void) +{ + platform_driver_unregister(&spi_gpio_driver); +} +module_exit(spi_gpio_exit); + + +MODULE_DESCRIPTION("SPI master driver using generic bitbanged GPIO "); +MODULE_AUTHOR("David Brownell"); +MODULE_LICENSE("GPL"); diff --git a/drivers/spi/spi_lm70llp.c b/drivers/spi/spi_lm70llp.c index 39d8d8ad65c0..568c781ad91c 100644 --- a/drivers/spi/spi_lm70llp.c +++ b/drivers/spi/spi_lm70llp.c @@ -1,5 +1,5 @@ /* - * spi_lm70llp.c - driver for lm70llp eval board for the LM70 sensor + * spi_lm70llp.c - driver for LM70EVAL-LLP board for the LM70 sensor * * Copyright (C) 2006 Kaiwan N Billimoria <kaiwan@designergraphix.com> * @@ -40,8 +40,12 @@ * master controller driver. The hwmon/lm70 driver is a "SPI protocol * driver", layered on top of this one and usable without the lm70llp. * + * Datasheet and Schematic: * The LM70 is a temperature sensor chip from National Semiconductor; its * datasheet is available at http://www.national.com/pf/LM/LM70.html + * The schematic for this particular board (the LM70EVAL-LLP) is + * available (on page 4) here: + * http://www.national.com/appinfo/tempsensors/files/LM70LLPEVALmanual.pdf * * Also see Documentation/spi/spi-lm70llp. The SPI<->parport code here is * (heavily) based on spi-butterfly by David Brownell. @@ -64,7 +68,7 @@ * * Note that parport pin 13 actually gets inverted by the transistor * arrangement which lets either the parport or the LM70 drive the - * SI/SO signal. + * SI/SO signal (see the schematic for details). */ #define DRVNAME "spi-lm70llp" @@ -106,12 +110,16 @@ static inline struct spi_lm70llp *spidev_to_pp(struct spi_device *spi) static inline void deassertCS(struct spi_lm70llp *pp) { u8 data = parport_read_data(pp->port); + + data &= ~0x80; /* pull D7/SI-out low while de-asserted */ parport_write_data(pp->port, data | nCS); } static inline void assertCS(struct spi_lm70llp *pp) { u8 data = parport_read_data(pp->port); + + data |= 0x80; /* pull D7/SI-out high so lm70 drives SO-in */ parport_write_data(pp->port, data & ~nCS); } @@ -184,22 +192,7 @@ static void lm70_chipselect(struct spi_device *spi, int value) */ static u32 lm70_txrx(struct spi_device *spi, unsigned nsecs, u32 word, u8 bits) { - static u32 sio=0; - static int first_time=1; - - /* First time: perform SPI bitbang and return the LSB of - * the result of the SPI call. - */ - if (first_time) { - sio = bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits); - first_time=0; - return (sio & 0x00ff); - } - /* Return the MSB of the result of the SPI call */ - else { - first_time=1; - return (sio >> 8); - } + return bitbang_txrx_be_cpha0(spi, nsecs, 0, word, bits); } static void spi_lm70llp_attach(struct parport *p) @@ -287,16 +280,15 @@ static void spi_lm70llp_attach(struct parport *p) pp->spidev_lm70 = spi_new_device(pp->bitbang.master, &pp->info); if (pp->spidev_lm70) dev_dbg(&pp->spidev_lm70->dev, "spidev_lm70 at %s\n", - pp->spidev_lm70->dev.bus_id); + dev_name(&pp->spidev_lm70->dev)); else { printk(KERN_WARNING "%s: spi_new_device failed\n", DRVNAME); status = -ENODEV; goto out_bitbang_stop; } - pp->spidev_lm70->bits_per_word = 16; + pp->spidev_lm70->bits_per_word = 8; lm70llp = pp; - return; out_bitbang_stop: @@ -326,7 +318,6 @@ static void spi_lm70llp_detach(struct parport *p) /* power down */ parport_write_data(pp->port, 0); - msleep(10); parport_release(pp->pd); parport_unregister_device(pp->pd); diff --git a/drivers/spi/spi_s3c24xx.c b/drivers/spi/spi_s3c24xx.c index 256d18395a23..b3ebc1d0f85f 100644 --- a/drivers/spi/spi_s3c24xx.c +++ b/drivers/spi/spi_s3c24xx.c @@ -19,6 +19,7 @@ #include <linux/err.h> #include <linux/clk.h> #include <linux/platform_device.h> +#include <linux/gpio.h> #include <linux/spi/spi.h> #include <linux/spi/spi_bitbang.h> @@ -27,7 +28,6 @@ #include <asm/dma.h> #include <mach/hardware.h> -#include <mach/regs-gpio.h> #include <plat/regs-spi.h> #include <mach/spi.h> @@ -66,7 +66,7 @@ static inline struct s3c24xx_spi *to_hw(struct spi_device *sdev) static void s3c24xx_spi_gpiocs(struct s3c2410_spi_info *spi, int cs, int pol) { - s3c2410_gpio_setpin(spi->pin_cs, pol); + gpio_set_value(spi->pin_cs, pol); } static void s3c24xx_spi_chipsel(struct spi_device *spi, int value) @@ -248,8 +248,13 @@ static void s3c24xx_spi_initialsetup(struct s3c24xx_spi *hw) writeb(SPPIN_DEFAULT, hw->regs + S3C2410_SPPIN); writeb(SPCON_DEFAULT, hw->regs + S3C2410_SPCON); - if (hw->pdata && hw->pdata->gpio_setup) - hw->pdata->gpio_setup(hw->pdata, 1); + if (hw->pdata) { + if (hw->set_cs == s3c24xx_spi_gpiocs) + gpio_direction_output(hw->pdata->pin_cs, 1); + + if (hw->pdata->gpio_setup) + hw->pdata->gpio_setup(hw->pdata, 1); + } } static int __init s3c24xx_spi_probe(struct platform_device *pdev) @@ -343,18 +348,27 @@ static int __init s3c24xx_spi_probe(struct platform_device *pdev) goto err_no_clk; } - s3c24xx_spi_initialsetup(hw); - /* setup any gpio we can */ if (!pdata->set_cs) { - hw->set_cs = s3c24xx_spi_gpiocs; + if (pdata->pin_cs < 0) { + dev_err(&pdev->dev, "No chipselect pin\n"); + goto err_register; + } - s3c2410_gpio_setpin(pdata->pin_cs, 1); - s3c2410_gpio_cfgpin(pdata->pin_cs, S3C2410_GPIO_OUTPUT); + err = gpio_request(pdata->pin_cs, dev_name(&pdev->dev)); + if (err) { + dev_err(&pdev->dev, "Failed to get gpio for cs\n"); + goto err_register; + } + + hw->set_cs = s3c24xx_spi_gpiocs; + gpio_direction_output(pdata->pin_cs, 1); } else hw->set_cs = pdata->set_cs; + s3c24xx_spi_initialsetup(hw); + /* register our spi controller */ err = spi_bitbang_start(&hw->bitbang); @@ -366,6 +380,9 @@ static int __init s3c24xx_spi_probe(struct platform_device *pdev) return 0; err_register: + if (hw->set_cs == s3c24xx_spi_gpiocs) + gpio_free(pdata->pin_cs); + clk_disable(hw->clk); clk_put(hw->clk); @@ -401,6 +418,9 @@ static int __exit s3c24xx_spi_remove(struct platform_device *dev) free_irq(hw->irq, hw); iounmap(hw->regs); + if (hw->set_cs == s3c24xx_spi_gpiocs) + gpio_free(hw->pdata->pin_cs); + release_resource(hw->ioarea); kfree(hw->ioarea); |