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181 lines
5.3 KiB
Diff
181 lines
5.3 KiB
Diff
From 62b6a295d39417293adcc81dc36b7edc56546814 Mon Sep 17 00:00:00 2001
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From: Lars-Peter Clausen <lars@metafoo.de>
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Date: Sat, 24 Apr 2010 12:23:01 +0200
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Subject: [PATCH] gpio spi 3wire
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---
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drivers/spi/spi_bitbang.c | 2 +
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drivers/spi/spi_gpio.c | 60 ++++++++++++++++++++++++++------------
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include/linux/spi/spi_bitbang.h | 2 +
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3 files changed, 45 insertions(+), 19 deletions(-)
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--- a/drivers/spi/spi_bitbang.c
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+++ b/drivers/spi/spi_bitbang.c
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@@ -335,6 +335,8 @@ static void bitbang_work(struct work_str
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*/
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if (!m->is_dma_mapped)
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t->rx_dma = t->tx_dma = 0;
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+ if ((spi->mode & SPI_3WIRE) && bitbang->set_direction)
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+ bitbang->set_direction(spi, t->tx_buf != NULL);
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status = bitbang->txrx_bufs(spi, t);
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}
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if (status > 0)
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--- a/drivers/spi/spi_gpio.c
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+++ b/drivers/spi/spi_gpio.c
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@@ -46,6 +46,8 @@ struct spi_gpio {
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struct spi_bitbang bitbang;
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struct spi_gpio_platform_data pdata;
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struct platform_device *pdev;
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+
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+ int miso_pin;
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};
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/*----------------------------------------------------------------------*/
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@@ -91,19 +93,16 @@ struct spi_gpio {
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/*----------------------------------------------------------------------*/
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-static inline const struct spi_gpio_platform_data * __pure
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-spi_to_pdata(const struct spi_device *spi)
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+static inline const struct spi_gpio * __pure
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+spi_to_spi_gpio(const struct spi_device *spi)
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{
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const struct spi_bitbang *bang;
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- const struct spi_gpio *spi_gpio;
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bang = spi_master_get_devdata(spi->master);
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- spi_gpio = container_of(bang, struct spi_gpio, bitbang);
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- return &spi_gpio->pdata;
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+ return container_of(bang, struct spi_gpio, bitbang);
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}
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-/* this is #defined to avoid unused-variable warnings when inlining */
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-#define pdata spi_to_pdata(spi)
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+#define pdata &(spi_to_spi_gpio(spi)->pdata)
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static inline void setsck(const struct spi_device *spi, int is_on)
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{
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@@ -117,10 +116,9 @@ static inline void setmosi(const struct
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static inline int getmiso(const struct spi_device *spi)
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{
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- return !!gpio_get_value(SPI_MISO_GPIO);
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+ return !!gpio_get_value(spi_to_spi_gpio(spi)->miso_pin);
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}
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-#undef pdata
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/*
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* NOTE: to clock "as fast as we can", set spi_device.max_speed_hz
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@@ -183,10 +181,16 @@ static u32 spi_gpio_txrx_word_mode3(stru
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static void spi_gpio_chipselect(struct spi_device *spi, int is_active)
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{
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unsigned long cs = (unsigned long) spi->controller_data;
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+ struct spi_gpio *spi_gpio = spi_to_spi_gpio(spi);
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/* set initial clock polarity */
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- if (is_active)
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+ if (is_active) {
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setsck(spi, spi->mode & SPI_CPOL);
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+ if (spi->mode & SPI_3WIRE)
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+ spi_gpio->miso_pin = SPI_MOSI_GPIO;
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+ else
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+ spi_gpio->miso_pin = SPI_MISO_GPIO;
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+ }
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if (cs != SPI_GPIO_NO_CHIPSELECT) {
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/* SPI is normally active-low */
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@@ -202,6 +206,9 @@ static int spi_gpio_setup(struct spi_dev
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if (spi->bits_per_word > 32)
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return -EINVAL;
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+ if (!(spi->mode & SPI_3WIRE) && !gpio_is_valid(SPI_MISO_GPIO))
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+ return -EINVAL;
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+
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if (!spi->controller_state) {
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if (cs != SPI_GPIO_NO_CHIPSELECT) {
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status = gpio_request(cs, dev_name(&spi->dev));
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@@ -219,6 +226,16 @@ static int spi_gpio_setup(struct spi_dev
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return status;
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}
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+static void spi_gpio_set_direction(struct spi_device *spi, bool is_tx)
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+{
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+ if (is_tx)
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+ gpio_direction_output(SPI_MISO_GPIO, 0);
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+ else
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+ gpio_direction_input(SPI_MISO_GPIO);
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+}
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+
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+#undef pdata
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+
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static void spi_gpio_cleanup(struct spi_device *spi)
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{
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unsigned long cs = (unsigned long) spi->controller_data;
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@@ -253,18 +270,20 @@ spi_gpio_request(struct spi_gpio_platfor
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if (value)
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goto done;
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- value = spi_gpio_alloc(SPI_MISO_GPIO, label, true);
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+ value = spi_gpio_alloc(SPI_SCK_GPIO, label, false);
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if (value)
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goto free_mosi;
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- value = spi_gpio_alloc(SPI_SCK_GPIO, label, false);
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- if (value)
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- goto free_miso;
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+ if (gpio_is_valid(SPI_MISO_GPIO)) {
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+ value = spi_gpio_alloc(SPI_MISO_GPIO, label, true);
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+ if (value)
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+ goto free_sck;
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+ }
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goto done;
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-free_miso:
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- gpio_free(SPI_MISO_GPIO);
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+free_sck:
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+ gpio_free(SPI_SCK_GPIO);
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free_mosi:
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gpio_free(SPI_MOSI_GPIO);
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done:
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@@ -312,13 +331,15 @@ static int __devinit spi_gpio_probe(stru
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spi_gpio->bitbang.txrx_word[SPI_MODE_2] = spi_gpio_txrx_word_mode2;
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spi_gpio->bitbang.txrx_word[SPI_MODE_3] = spi_gpio_txrx_word_mode3;
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spi_gpio->bitbang.setup_transfer = spi_bitbang_setup_transfer;
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- spi_gpio->bitbang.flags = SPI_CS_HIGH;
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+ spi_gpio->bitbang.set_direction = spi_gpio_set_direction;
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+ spi_gpio->bitbang.flags = SPI_CS_HIGH | SPI_3WIRE;
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status = spi_bitbang_start(&spi_gpio->bitbang);
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if (status < 0) {
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spi_master_put(spi_gpio->bitbang.master);
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gpio_free:
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- gpio_free(SPI_MISO_GPIO);
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+ if (gpio_is_valid(SPI_MOSI_GPIO))
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+ gpio_free(SPI_MISO_GPIO);
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gpio_free(SPI_MOSI_GPIO);
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gpio_free(SPI_SCK_GPIO);
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spi_master_put(master);
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@@ -342,7 +363,8 @@ static int __devexit spi_gpio_remove(str
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platform_set_drvdata(pdev, NULL);
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- gpio_free(SPI_MISO_GPIO);
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+ if (gpio_is_valid(SPI_MISO_GPIO))
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+ gpio_free(SPI_MISO_GPIO);
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gpio_free(SPI_MOSI_GPIO);
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gpio_free(SPI_SCK_GPIO);
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--- a/include/linux/spi/spi_bitbang.h
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+++ b/include/linux/spi/spi_bitbang.h
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@@ -34,6 +34,8 @@ struct spi_bitbang {
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u32 (*txrx_word[4])(struct spi_device *spi,
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unsigned nsecs,
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u32 word, u8 bits);
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+
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+ void (*set_direction)(struct spi_device *, bool is_tx);
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};
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/* you can call these default bitbang->master methods from your custom
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