* [PATCH 1/2] DT: Add documentation for spi-rt2880
@ 2013-08-09 18:51 John Crispin
2013-08-09 18:51 ` [PATCH 2/2] SPI: ralink: add Ralink SoC spi driver John Crispin
` (2 more replies)
0 siblings, 3 replies; 11+ messages in thread
From: John Crispin @ 2013-08-09 18:51 UTC (permalink / raw)
To: Mark Brown; +Cc: John Crispin, devicetree, linux-spi, linux-mips
Describe the SPI master found on the MIPS based Ralink SoC.
Signed-off-by: John Crispin <blogic@openwrt.org>
Cc: devicetree@vger.kernel.org
Cc: linux-spi@vger.kernel.org
Cc: linux-mips@linux-mips.org
---
.../devicetree/bindings/spi/spi-rt2880.txt | 26 ++++++++++++++++++++
1 file changed, 26 insertions(+)
create mode 100644 Documentation/devicetree/bindings/spi/spi-rt2880.txt
diff --git a/Documentation/devicetree/bindings/spi/spi-rt2880.txt b/Documentation/devicetree/bindings/spi/spi-rt2880.txt
new file mode 100644
index 0000000..d946626
--- /dev/null
+++ b/Documentation/devicetree/bindings/spi/spi-rt2880.txt
@@ -0,0 +1,26 @@
+Ralink SoC RT2880 and famile SPI master controller.
+
+Required properties:
+- compatible : "ralink,rt2880-spi"
+- reg : The register base for the controller.
+- #address-cells : <1>, as required by generic SPI binding.
+- #size-cells : <0>, also as required by generic SPI binding.
+
+Child nodes as per the generic SPI binding.
+
+Example:
+
+ spi@b00 {
+ compatible = "ralink,rt2880-spi";
+ reg = <0xb00 0x100>;
+
+ #address-cells = <1>;
+ #size-cells = <0>;
+
+ m25p80@0 {
+ compatible = "m25p80";
+ reg = <0>;
+ spi-max-frequency = <10000000>;
+ };
+ };
+
--
1.7.10.4
^ permalink raw reply related [flat|nested] 11+ messages in thread
* [PATCH 2/2] SPI: ralink: add Ralink SoC spi driver
2013-08-09 18:51 [PATCH 1/2] DT: Add documentation for spi-rt2880 John Crispin
@ 2013-08-09 18:51 ` John Crispin
2013-08-11 13:26 ` Mark Brown
2013-08-12 16:10 ` James Hogan
2013-08-09 20:44 ` [PATCH 1/2] DT: Add documentation for spi-rt2880 Sergei Shtylyov
2013-08-09 23:35 ` Kumar Gala
2 siblings, 2 replies; 11+ messages in thread
From: John Crispin @ 2013-08-09 18:51 UTC (permalink / raw)
To: Mark Brown; +Cc: Gabor Juhos, linux-spi, linux-mips
From: Gabor Juhos <juhosg@openwrt.org>
Add the driver needed to make SPI work on Ralink SoC.
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>
Acked-by: John Crispin <blogic@openwrt.org>
Cc: linux-spi@vger.kernel.org
Cc: linux-mips@linux-mips.org
---
drivers/spi/Kconfig | 6 +
drivers/spi/Makefile | 1 +
drivers/spi/spi-rt2880.c | 457 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 464 insertions(+)
create mode 100644 drivers/spi/spi-rt2880.c
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 89cbbab..72f86f4 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -345,6 +345,12 @@ config SPI_RSPI
help
SPI driver for Renesas RSPI blocks.
+config SPI_RT2880
+ tristate "Ralink RT288x SPI Controller"
+ depends on RALINK
+ help
+ This selects a driver for the Ralink RT288x/RT305x SPI Controller.
+
config SPI_S3C24XX
tristate "Samsung S3C24XX series SPI"
depends on ARCH_S3C24XX
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 33f9c09..02b1c99 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -55,6 +55,7 @@ spi-pxa2xx-platform-$(CONFIG_SPI_PXA2XX_DMA) += spi-pxa2xx-dma.o
obj-$(CONFIG_SPI_PXA2XX) += spi-pxa2xx-platform.o
obj-$(CONFIG_SPI_PXA2XX_PCI) += spi-pxa2xx-pci.o
obj-$(CONFIG_SPI_RSPI) += spi-rspi.o
+obj-$(CONFIG_SPI_RT2880) += spi-rt2880.o
obj-$(CONFIG_SPI_S3C24XX) += spi-s3c24xx-hw.o
spi-s3c24xx-hw-y := spi-s3c24xx.o
spi-s3c24xx-hw-$(CONFIG_SPI_S3C24XX_FIQ) += spi-s3c24xx-fiq.o
diff --git a/drivers/spi/spi-rt2880.c b/drivers/spi/spi-rt2880.c
new file mode 100644
index 0000000..b3a5443
--- /dev/null
+++ b/drivers/spi/spi-rt2880.c
@@ -0,0 +1,457 @@
+/*
+ * spi-rt2880.c -- Ralink RT288x/RT305x SPI controller driver
+ *
+ * Copyright (C) 2011 Sergiy <piratfm@gmail.com>
+ * Copyright (C) 2011-2013 Gabor Juhos <juhosg@openwrt.org>
+ *
+ * Some parts are based on spi-orion.c:
+ * Author: Shadi Ammouri <shadi@marvell.com>
+ * Copyright (C) 2007-2008 Marvell Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/reset.h>
+#include <linux/spi/spi.h>
+#include <linux/platform_device.h>
+
+#define DRIVER_NAME "spi-rt2880"
+/* only one slave is supported*/
+#define RALINK_NUM_CHIPSELECTS 1
+/* in usec */
+#define RALINK_SPI_WAIT_RDY_MAX_LOOP 2000
+
+#define RAMIPS_SPI_STAT 0x00
+#define RAMIPS_SPI_CFG 0x10
+#define RAMIPS_SPI_CTL 0x14
+#define RAMIPS_SPI_DATA 0x20
+
+/* SPISTAT register bit field */
+#define SPISTAT_BUSY BIT(0)
+
+/* SPICFG register bit field */
+#define SPICFG_LSBFIRST 0
+#define SPICFG_MSBFIRST BIT(8)
+#define SPICFG_SPICLKPOL BIT(6)
+#define SPICFG_RXCLKEDGE_FALLING BIT(5)
+#define SPICFG_TXCLKEDGE_FALLING BIT(4)
+#define SPICFG_SPICLK_PRESCALE_MASK 0x7
+#define SPICFG_SPICLK_DIV2 0
+#define SPICFG_SPICLK_DIV4 1
+#define SPICFG_SPICLK_DIV8 2
+#define SPICFG_SPICLK_DIV16 3
+#define SPICFG_SPICLK_DIV32 4
+#define SPICFG_SPICLK_DIV64 5
+#define SPICFG_SPICLK_DIV128 6
+#define SPICFG_SPICLK_DISABLE 7
+
+/* SPICTL register bit field */
+#define SPICTL_HIZSDO BIT(3)
+#define SPICTL_STARTWR BIT(2)
+#define SPICTL_STARTRD BIT(1)
+#define SPICTL_SPIENA BIT(0)
+
+#ifdef DEBUG
+#define spi_debug(args...) printk(args)
+#else
+#define spi_debug(args...)
+#endif
+
+struct rt2880_spi {
+ struct spi_master *master;
+ void __iomem *base;
+ unsigned int sys_freq;
+ unsigned int speed;
+ struct clk *clk;
+};
+
+static inline struct rt2880_spi *spidev_to_rt2880_spi(struct spi_device *spi)
+{
+ return spi_master_get_devdata(spi->master);
+}
+
+static inline u32 rt2880_spi_read(struct rt2880_spi *rs, u32 reg)
+{
+ return ioread32(rs->base + reg);
+}
+
+static inline void rt2880_spi_write(struct rt2880_spi *rs, u32 reg, u32 val)
+{
+ iowrite32(val, rs->base + reg);
+}
+
+static inline void rt2880_spi_setbits(struct rt2880_spi *rs, u32 reg, u32 mask)
+{
+ void __iomem *addr = rs->base + reg;
+ u32 val;
+
+ val = ioread32(addr);
+ val |= mask;
+ iowrite32(val, addr);
+}
+
+static inline void rt2880_spi_clrbits(struct rt2880_spi *rs, u32 reg, u32 mask)
+{
+ void __iomem *addr = rs->base + reg;
+ u32 val;
+
+ val = ioread32(addr);
+ val &= ~mask;
+ iowrite32(val, addr);
+}
+
+static int rt2880_spi_baudrate_set(struct spi_device *spi, unsigned int speed)
+{
+ struct rt2880_spi *rs = spidev_to_rt2880_spi(spi);
+ u32 rate;
+ u32 prescale;
+ u32 reg;
+
+ spi_debug("%s: speed:%u\n", __func__, speed);
+
+ /*
+ * the supported rates are: 2, 4, 8, ... 128
+ * round up as we look for equal or less speed
+ */
+ rate = DIV_ROUND_UP(rs->sys_freq, speed);
+ spi_debug("%s: rate-1:%u\n", __func__, rate);
+ rate = roundup_pow_of_two(rate);
+ spi_debug("%s: rate-2:%u\n", __func__, rate);
+
+ /* check if requested speed is too small */
+ if (rate > 128)
+ return -EINVAL;
+
+ if (rate < 2)
+ rate = 2;
+
+ /* Convert the rate to SPI clock divisor value. */
+ prescale = ilog2(rate/2);
+ spi_debug("%s: prescale:%u\n", __func__, prescale);
+
+ reg = rt2880_spi_read(rs, RAMIPS_SPI_CFG);
+ reg = ((reg & ~SPICFG_SPICLK_PRESCALE_MASK) | prescale);
+ rt2880_spi_write(rs, RAMIPS_SPI_CFG, reg);
+ rs->speed = speed;
+ return 0;
+}
+
+/*
+ * called only when no transfer is active on the bus
+ */
+static int
+rt2880_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
+{
+ struct rt2880_spi *rs = spidev_to_rt2880_spi(spi);
+ unsigned int speed = spi->max_speed_hz;
+ int rc;
+ unsigned int bits_per_word = 8;
+
+ if ((t != NULL) && t->speed_hz)
+ speed = t->speed_hz;
+
+ if ((t != NULL) && t->bits_per_word)
+ bits_per_word = t->bits_per_word;
+
+ if (rs->speed != speed) {
+ spi_debug("%s: speed_hz:%u\n", __func__, speed);
+ rc = rt2880_spi_baudrate_set(spi, speed);
+ if (rc)
+ return rc;
+ }
+
+ if (bits_per_word != 8) {
+ spi_debug("%s: bad bits_per_word: %u\n", __func__,
+ bits_per_word);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static void rt2880_spi_set_cs(struct rt2880_spi *rs, int enable)
+{
+ if (enable)
+ rt2880_spi_clrbits(rs, RAMIPS_SPI_CTL, SPICTL_SPIENA);
+ else
+ rt2880_spi_setbits(rs, RAMIPS_SPI_CTL, SPICTL_SPIENA);
+}
+
+static inline int rt2880_spi_wait_till_ready(struct rt2880_spi *rs)
+{
+ int i;
+
+ for (i = 0; i < RALINK_SPI_WAIT_RDY_MAX_LOOP; i++) {
+ u32 status;
+
+ status = rt2880_spi_read(rs, RAMIPS_SPI_STAT);
+ if ((status & SPISTAT_BUSY) == 0)
+ return 0;
+
+ udelay(1);
+ }
+
+ return -ETIMEDOUT;
+}
+
+static unsigned int
+rt2880_spi_write_read(struct spi_device *spi, struct spi_transfer *xfer)
+{
+ struct rt2880_spi *rs = spidev_to_rt2880_spi(spi);
+ unsigned count = 0;
+ u8 *rx = xfer->rx_buf;
+ const u8 *tx = xfer->tx_buf;
+ int err;
+
+ spi_debug("%s(%d): %s %s\n", __func__, xfer->len,
+ (tx != NULL) ? "tx" : " ",
+ (rx != NULL) ? "rx" : " ");
+
+ if (tx) {
+ for (count = 0; count < xfer->len; count++) {
+ rt2880_spi_write(rs, RAMIPS_SPI_DATA, tx[count]);
+ rt2880_spi_setbits(rs, RAMIPS_SPI_CTL, SPICTL_STARTWR);
+ err = rt2880_spi_wait_till_ready(rs);
+ if (err) {
+ dev_err(&spi->dev, "TX failed, err=%d\n", err);
+ goto out;
+ }
+ }
+ }
+
+ if (rx) {
+ for (count = 0; count < xfer->len; count++) {
+ rt2880_spi_setbits(rs, RAMIPS_SPI_CTL, SPICTL_STARTRD);
+ err = rt2880_spi_wait_till_ready(rs);
+ if (err) {
+ dev_err(&spi->dev, "RX failed, err=%d\n", err);
+ goto out;
+ }
+ rx[count] = (u8) rt2880_spi_read(rs, RAMIPS_SPI_DATA);
+ }
+ }
+
+out:
+ return count;
+}
+
+static int rt2880_spi_transfer_one_message(struct spi_master *master,
+ struct spi_message *m)
+{
+ struct rt2880_spi *rs = spi_master_get_devdata(master);
+ struct spi_device *spi = m->spi;
+ struct spi_transfer *t = NULL;
+ int par_override = 0;
+ int status = 0;
+ int cs_active = 0;
+
+ /* Load defaults */
+ status = rt2880_spi_setup_transfer(spi, NULL);
+ if (status < 0)
+ goto msg_done;
+
+ list_for_each_entry(t, &m->transfers, transfer_list) {
+ unsigned int bits_per_word = spi->bits_per_word;
+
+ if (t->tx_buf == NULL && t->rx_buf == NULL && t->len) {
+ dev_err(&spi->dev,
+ "message rejected: invalid transfer data buffers\n");
+ status = -EIO;
+ goto msg_done;
+ }
+
+ if (t->bits_per_word)
+ bits_per_word = t->bits_per_word;
+
+ if (bits_per_word != 8) {
+ dev_err(&spi->dev,
+ "message rejected: invalid transfer bits_per_word (%d bits)\n",
+ bits_per_word);
+ status = -EIO;
+ goto msg_done;
+ }
+
+ if (t->speed_hz && t->speed_hz < (rs->sys_freq / 128)) {
+ dev_err(&spi->dev,
+ "message rejected: device min speed (%d Hz) exceeds required transfer speed (%d Hz)\n",
+ (rs->sys_freq / 128), t->speed_hz);
+ status = -EIO;
+ goto msg_done;
+ }
+
+ if (par_override || t->speed_hz || t->bits_per_word) {
+ par_override = 1;
+ status = rt2880_spi_setup_transfer(spi, t);
+ if (status < 0)
+ goto msg_done;
+ if (!t->speed_hz && !t->bits_per_word)
+ par_override = 0;
+ }
+
+ if (!cs_active) {
+ rt2880_spi_set_cs(rs, 1);
+ cs_active = 1;
+ }
+
+ if (t->len)
+ m->actual_length += rt2880_spi_write_read(spi, t);
+
+ if (t->delay_usecs)
+ udelay(t->delay_usecs);
+
+ if (t->cs_change) {
+ rt2880_spi_set_cs(rs, 0);
+ cs_active = 0;
+ }
+ }
+
+msg_done:
+ if (cs_active)
+ rt2880_spi_set_cs(rs, 0);
+
+ m->status = status;
+ spi_finalize_current_message(master);
+
+ return 0;
+}
+
+static int rt2880_spi_setup(struct spi_device *spi)
+{
+ struct rt2880_spi *rs = spidev_to_rt2880_spi(spi);
+
+ if ((spi->max_speed_hz == 0) ||
+ (spi->max_speed_hz > (rs->sys_freq / 2)))
+ spi->max_speed_hz = (rs->sys_freq / 2);
+
+ if (spi->max_speed_hz < (rs->sys_freq / 128)) {
+ dev_err(&spi->dev, "setup: requested speed is too low %d Hz\n",
+ spi->max_speed_hz);
+ return -EINVAL;
+ }
+
+ if (spi->bits_per_word != 0 && spi->bits_per_word != 8) {
+ dev_err(&spi->dev,
+ "setup: requested bits per words - os wrong %d bpw\n",
+ spi->bits_per_word);
+ return -EINVAL;
+ }
+
+ if (spi->bits_per_word == 0)
+ spi->bits_per_word = 8;
+
+ /*
+ * baudrate & width will be set rt2880_spi_setup_transfer
+ */
+ return 0;
+}
+
+static void rt2880_spi_reset(struct rt2880_spi *rs)
+{
+ rt2880_spi_write(rs, RAMIPS_SPI_CFG,
+ SPICFG_MSBFIRST | SPICFG_TXCLKEDGE_FALLING |
+ SPICFG_SPICLK_DIV16 | SPICFG_SPICLKPOL);
+ rt2880_spi_write(rs, RAMIPS_SPI_CTL, SPICTL_HIZSDO | SPICTL_SPIENA);
+}
+
+static int rt2880_spi_probe(struct platform_device *pdev)
+{
+ struct spi_master *master;
+ struct rt2880_spi *rs;
+ struct resource *r;
+ int status = 0;
+ void __iomem *base;
+ struct clk *clk;
+
+ r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ base = devm_request_and_ioremap(&pdev->dev, r);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(clk)) {
+ dev_err(&pdev->dev, "unable to get SYS clock, err=%d\n",
+ status);
+ return PTR_ERR(clk);
+ }
+
+ status = clk_enable(clk);
+ if (status)
+ return status;
+
+ master = spi_alloc_master(&pdev->dev, sizeof(*rs));
+ if (master == NULL) {
+ dev_dbg(&pdev->dev, "master allocation failed\n");
+ return -ENOMEM;
+ }
+
+ /* we support only mode 0, and no options */
+ master->mode_bits = 0;
+
+ master->setup = rt2880_spi_setup;
+ master->transfer_one_message = rt2880_spi_transfer_one_message;
+ master->num_chipselect = RALINK_NUM_CHIPSELECTS;
+ master->dev.of_node = pdev->dev.of_node;
+
+ dev_set_drvdata(&pdev->dev, master);
+
+ rs = spi_master_get_devdata(master);
+ rs->base = base;
+ rs->clk = clk;
+ rs->master = master;
+ rs->sys_freq = clk_get_rate(rs->clk);
+ spi_debug("%s: sys_freq: %u\n", __func__, rs->sys_freq);
+
+ device_reset(&pdev->dev);
+
+ rt2880_spi_reset(rs);
+
+ return spi_register_master(master);
+}
+
+static int rt2880_spi_remove(struct platform_device *pdev)
+{
+ struct spi_master *master;
+ struct rt2880_spi *rs;
+
+ master = dev_get_drvdata(&pdev->dev);
+ rs = spi_master_get_devdata(master);
+
+ clk_disable(rs->clk);
+ clk_put(rs->clk);
+ spi_unregister_master(master);
+
+ return 0;
+}
+
+MODULE_ALIAS("platform:" DRIVER_NAME);
+
+static const struct of_device_id rt2880_spi_match[] = {
+ { .compatible = "rt2880,rt2880-spi" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, rt2880_spi_match);
+
+static struct platform_driver rt2880_spi_driver = {
+ .driver = {
+ .name = DRIVER_NAME,
+ .owner = THIS_MODULE,
+ .of_match_table = rt2880_spi_match,
+ },
+ .probe = rt2880_spi_probe,
+ .remove = rt2880_spi_remove,
+};
+
+module_platform_driver(rt2880_spi_driver);
+
+MODULE_DESCRIPTION("Ralink SPI driver");
+MODULE_AUTHOR("Sergiy <piratfm@gmail.com>");
+MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
+MODULE_LICENSE("GPL");
--
1.7.10.4
^ permalink raw reply related [flat|nested] 11+ messages in thread
* Re: [PATCH 1/2] DT: Add documentation for spi-rt2880
2013-08-09 18:51 [PATCH 1/2] DT: Add documentation for spi-rt2880 John Crispin
2013-08-09 18:51 ` [PATCH 2/2] SPI: ralink: add Ralink SoC spi driver John Crispin
@ 2013-08-09 20:44 ` Sergei Shtylyov
2013-08-09 23:35 ` Kumar Gala
2 siblings, 0 replies; 11+ messages in thread
From: Sergei Shtylyov @ 2013-08-09 20:44 UTC (permalink / raw)
To: John Crispin; +Cc: Mark Brown, devicetree, linux-spi, linux-mips
Hello.
On 08/09/2013 10:51 PM, John Crispin wrote:
> Describe the SPI master found on the MIPS based Ralink SoC.
> Signed-off-by: John Crispin <blogic@openwrt.org>
> Cc: devicetree@vger.kernel.org
> Cc: linux-spi@vger.kernel.org
> Cc: linux-mips@linux-mips.org
> ---
> .../devicetree/bindings/spi/spi-rt2880.txt | 26 ++++++++++++++++++++
> 1 file changed, 26 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/spi/spi-rt2880.txt
> diff --git a/Documentation/devicetree/bindings/spi/spi-rt2880.txt b/Documentation/devicetree/bindings/spi/spi-rt2880.txt
> new file mode 100644
> index 0000000..d946626
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/spi/spi-rt2880.txt
> @@ -0,0 +1,26 @@
> +Ralink SoC RT2880 and famile SPI master controller.
> +
> +Required properties:
> +- compatible : "ralink,rt2880-spi"
> +- reg : The register base for the controller.
> +- #address-cells : <1>, as required by generic SPI binding.
> +- #size-cells : <0>, also as required by generic SPI binding.
> +
> +Child nodes as per the generic SPI binding.
> +
> +Example:
> +
> + spi@b00 {
> + compatible = "ralink,rt2880-spi";
> + reg = <0xb00 0x100>;
> +
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + m25p80@0 {
Don't call nodes with chip names. ePAPR [1] says: "the name of a node
should be somewhat generic, reflecting the function of the device and not its
precise programming model". I suspect this is a flash device, ePAPR suggests
using "flash" as a name in this case.
> + compatible = "m25p80";
> + reg = <0>;
> + spi-max-frequency = <10000000>;
> + };
> + };
> +
WBR, Sergei
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 1/2] DT: Add documentation for spi-rt2880
2013-08-09 18:51 [PATCH 1/2] DT: Add documentation for spi-rt2880 John Crispin
2013-08-09 18:51 ` [PATCH 2/2] SPI: ralink: add Ralink SoC spi driver John Crispin
2013-08-09 20:44 ` [PATCH 1/2] DT: Add documentation for spi-rt2880 Sergei Shtylyov
@ 2013-08-09 23:35 ` Kumar Gala
2 siblings, 0 replies; 11+ messages in thread
From: Kumar Gala @ 2013-08-09 23:35 UTC (permalink / raw)
To: John Crispin; +Cc: Mark Brown, devicetree, linux-spi, linux-mips
On Aug 9, 2013, at 1:51 PM, John Crispin wrote:
> Describe the SPI master found on the MIPS based Ralink SoC.
Ralink RT2880 SoC
>
> Signed-off-by: John Crispin <blogic@openwrt.org>
> Cc: devicetree@vger.kernel.org
> Cc: linux-spi@vger.kernel.org
> Cc: linux-mips@linux-mips.org
> ---
> .../devicetree/bindings/spi/spi-rt2880.txt | 26 ++++++++++++++++++++
> 1 file changed, 26 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/spi/spi-rt2880.txt
>
> diff --git a/Documentation/devicetree/bindings/spi/spi-rt2880.txt b/Documentation/devicetree/bindings/spi/spi-rt2880.txt
> new file mode 100644
> index 0000000..d946626
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/spi/spi-rt2880.txt
> @@ -0,0 +1,26 @@
> +Ralink SoC RT2880 and famile SPI master controller.
famile? was that suppose to be family?
> +
> +Required properties:
> +- compatible : "ralink,rt2880-spi"
> +- reg : The register base for the controller.
> +- #address-cells : <1>, as required by generic SPI binding.
> +- #size-cells : <0>, also as required by generic SPI binding.
> +
> +Child nodes as per the generic SPI binding.
> +
> +Example:
> +
> + spi@b00 {
> + compatible = "ralink,rt2880-spi";
> + reg = <0xb00 0x100>;
> +
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + m25p80@0 {
> + compatible = "m25p80";
> + reg = <0>;
> + spi-max-frequency = <10000000>;
> + };
> + };
> +
> --
> 1.7.10.4
>
> --
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^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 2/2] SPI: ralink: add Ralink SoC spi driver
2013-08-09 18:51 ` [PATCH 2/2] SPI: ralink: add Ralink SoC spi driver John Crispin
@ 2013-08-11 13:26 ` Mark Brown
2013-08-13 18:43 ` John Crispin
2013-08-12 16:10 ` James Hogan
1 sibling, 1 reply; 11+ messages in thread
From: Mark Brown @ 2013-08-11 13:26 UTC (permalink / raw)
To: John Crispin; +Cc: Gabor Juhos, linux-spi, linux-mips
[-- Attachment #1: Type: text/plain, Size: 3703 bytes --]
On Fri, Aug 09, 2013 at 08:51:27PM +0200, John Crispin wrote:
Looks fairly good, a few things below but most of them are just using
the core to do things instead of open coding them in the driver rather
than anything substantial.
> +#ifdef DEBUG
> +#define spi_debug(args...) printk(args)
> +#else
> +#define spi_debug(args...)
> +#endif
This shouldn't be driver specific if it's useful, though really it looks
like the driver should just be using dev_dbg() and friends.
> +static inline void rt2880_spi_setbits(struct rt2880_spi *rs, u32 reg, u32 mask)
> +{
> + void __iomem *addr = rs->base + reg;
> + u32 val;
> +
> + val = ioread32(addr);
> + val |= mask;
> + iowrite32(val, addr);
> +}
Is this always called with a suitable lock held?
> + if (bits_per_word != 8) {
You should be setting bits_per_word_mask in the master structure, then
you don't need to check for this.
> +static inline int rt2880_spi_wait_till_ready(struct rt2880_spi *rs)
> +{
> + int i;
> +
> + for (i = 0; i < RALINK_SPI_WAIT_RDY_MAX_LOOP; i++) {
> + u32 status;
> +
> + status = rt2880_spi_read(rs, RAMIPS_SPI_STAT);
> + if ((status & SPISTAT_BUSY) == 0)
> + return 0;
> +
> + udelay(1);
> + }
A cpu_relax() here would be nice.
> +static unsigned int
> +rt2880_spi_write_read(struct spi_device *spi, struct spi_transfer *xfer)
> +{
> + struct rt2880_spi *rs = spidev_to_rt2880_spi(spi);
> + unsigned count = 0;
> + u8 *rx = xfer->rx_buf;
> + const u8 *tx = xfer->tx_buf;
> + int err;
> +
> + spi_debug("%s(%d): %s %s\n", __func__, xfer->len,
> + (tx != NULL) ? "tx" : " ",
> + (rx != NULL) ? "rx" : " ");
> +
> + if (tx) {
> + for (count = 0; count < xfer->len; count++) {
> + rt2880_spi_write(rs, RAMIPS_SPI_DATA, tx[count]);
> + rt2880_spi_setbits(rs, RAMIPS_SPI_CTL, SPICTL_STARTWR);
> + err = rt2880_spi_wait_till_ready(rs);
> + if (err) {
> + dev_err(&spi->dev, "TX failed, err=%d\n", err);
> + goto out;
> + }
> + }
> + }
> +
> + if (rx) {
There is presumably a maximum transfer size here from the FIFO that is
holding the data?
> + if (bits_per_word != 8) {
> + dev_err(&spi->dev,
> + "message rejected: invalid transfer bits_per_word (%d bits)\n",
> + bits_per_word);
Like I say set bits_per_word_mask...
> + if (t->speed_hz && t->speed_hz < (rs->sys_freq / 128)) {
> + dev_err(&spi->dev,
> + "message rejected: device min speed (%d Hz) exceeds required transfer speed (%d Hz)\n",
> + (rs->sys_freq / 128), t->speed_hz);
> + status = -EIO;
> + goto msg_done;
> + }
Set min_speed_hz in the spi_master and the core will check this for you.
> + if (spi->max_speed_hz < (rs->sys_freq / 128)) {
> + dev_err(&spi->dev, "setup: requested speed is too low %d Hz\n",
> + spi->max_speed_hz);
> + return -EINVAL;
> + }
> +
> + if (spi->bits_per_word != 0 && spi->bits_per_word != 8) {
> + dev_err(&spi->dev,
> + "setup: requested bits per words - os wrong %d bpw\n",
> + spi->bits_per_word);
> + return -EINVAL;
> + }
Again the core can do this for you.
> + r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + base = devm_request_and_ioremap(&pdev->dev, r);
> + if (IS_ERR(base))
> + return PTR_ERR(base);
devm_ioremap_resource().
> + status = clk_enable(clk);
> + if (status)
> + return status;
clk_prepare_enable(), and it'd be nice to use runtime PM and enable the
clock only when doing transfers though that's not essential.
> +static int rt2880_spi_remove(struct platform_device *pdev)
> +{
> + struct spi_master *master;
> + struct rt2880_spi *rs;
> +
> + master = dev_get_drvdata(&pdev->dev);
> + rs = spi_master_get_devdata(master);
> +
> + clk_disable(rs->clk);
> + clk_put(rs->clk);
No clk_put if you've used devm_clk_get().
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^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 2/2] SPI: ralink: add Ralink SoC spi driver
@ 2013-08-12 16:10 ` James Hogan
0 siblings, 0 replies; 11+ messages in thread
From: James Hogan @ 2013-08-12 16:10 UTC (permalink / raw)
To: John Crispin; +Cc: Mark Brown, Gabor Juhos, linux-spi, linux-mips
On 09/08/13 19:51, John Crispin wrote:
> +#ifdef DEBUG
> +#define spi_debug(args...) printk(args)
> +#else
> +#define spi_debug(args...)
> +#endif
This looks a bit like pr_debug. If you have a device pointer around,
there's also a dev_dbg which takes an additional device pointer and
prepends it's name to the message.
> +static int rt2880_spi_probe(struct platform_device *pdev)
> +{
<snip>
> + clk = devm_clk_get(&pdev->dev, NULL);
> + if (IS_ERR(clk)) {
> + dev_err(&pdev->dev, "unable to get SYS clock, err=%d\n",
> + status);
> + return PTR_ERR(clk);
> + }
<snip>
> +}
> +
> +static int rt2880_spi_remove(struct platform_device *pdev)
> +{
> + struct spi_master *master;
> + struct rt2880_spi *rs;
> +
> + master = dev_get_drvdata(&pdev->dev);
> + rs = spi_master_get_devdata(master);
> +
> + clk_disable(rs->clk);
> + clk_put(rs->clk);
The devm_clk_get in your probe function means you don't need clk_put here.
Cheers
James
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 2/2] SPI: ralink: add Ralink SoC spi driver
@ 2013-08-12 16:10 ` James Hogan
0 siblings, 0 replies; 11+ messages in thread
From: James Hogan @ 2013-08-12 16:10 UTC (permalink / raw)
To: John Crispin; +Cc: Mark Brown, Gabor Juhos, linux-spi, linux-mips
On 09/08/13 19:51, John Crispin wrote:
> +#ifdef DEBUG
> +#define spi_debug(args...) printk(args)
> +#else
> +#define spi_debug(args...)
> +#endif
This looks a bit like pr_debug. If you have a device pointer around,
there's also a dev_dbg which takes an additional device pointer and
prepends it's name to the message.
> +static int rt2880_spi_probe(struct platform_device *pdev)
> +{
<snip>
> + clk = devm_clk_get(&pdev->dev, NULL);
> + if (IS_ERR(clk)) {
> + dev_err(&pdev->dev, "unable to get SYS clock, err=%d\n",
> + status);
> + return PTR_ERR(clk);
> + }
<snip>
> +}
> +
> +static int rt2880_spi_remove(struct platform_device *pdev)
> +{
> + struct spi_master *master;
> + struct rt2880_spi *rs;
> +
> + master = dev_get_drvdata(&pdev->dev);
> + rs = spi_master_get_devdata(master);
> +
> + clk_disable(rs->clk);
> + clk_put(rs->clk);
The devm_clk_get in your probe function means you don't need clk_put here.
Cheers
James
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 2/2] SPI: ralink: add Ralink SoC spi driver
@ 2013-08-12 16:11 ` James Hogan
0 siblings, 0 replies; 11+ messages in thread
From: James Hogan @ 2013-08-12 16:11 UTC (permalink / raw)
To: John Crispin; +Cc: Mark Brown, Gabor Juhos, linux-spi, linux-mips
Sorry, should have read Mark's feedback first :)
James
On 12/08/13 17:10, James Hogan wrote:
> On 09/08/13 19:51, John Crispin wrote:
>> +#ifdef DEBUG
>> +#define spi_debug(args...) printk(args)
>> +#else
>> +#define spi_debug(args...)
>> +#endif
>
> This looks a bit like pr_debug. If you have a device pointer around,
> there's also a dev_dbg which takes an additional device pointer and
> prepends it's name to the message.
>
>> +static int rt2880_spi_probe(struct platform_device *pdev)
>> +{
>
> <snip>
>
>> + clk = devm_clk_get(&pdev->dev, NULL);
>> + if (IS_ERR(clk)) {
>> + dev_err(&pdev->dev, "unable to get SYS clock, err=%d\n",
>> + status);
>> + return PTR_ERR(clk);
>> + }
>
> <snip>
>
>> +}
>> +
>> +static int rt2880_spi_remove(struct platform_device *pdev)
>> +{
>> + struct spi_master *master;
>> + struct rt2880_spi *rs;
>> +
>> + master = dev_get_drvdata(&pdev->dev);
>> + rs = spi_master_get_devdata(master);
>> +
>> + clk_disable(rs->clk);
>> + clk_put(rs->clk);
>
> The devm_clk_get in your probe function means you don't need clk_put here.
>
> Cheers
> James
>
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 2/2] SPI: ralink: add Ralink SoC spi driver
@ 2013-08-12 16:11 ` James Hogan
0 siblings, 0 replies; 11+ messages in thread
From: James Hogan @ 2013-08-12 16:11 UTC (permalink / raw)
To: John Crispin; +Cc: Mark Brown, Gabor Juhos, linux-spi, linux-mips
Sorry, should have read Mark's feedback first :)
James
On 12/08/13 17:10, James Hogan wrote:
> On 09/08/13 19:51, John Crispin wrote:
>> +#ifdef DEBUG
>> +#define spi_debug(args...) printk(args)
>> +#else
>> +#define spi_debug(args...)
>> +#endif
>
> This looks a bit like pr_debug. If you have a device pointer around,
> there's also a dev_dbg which takes an additional device pointer and
> prepends it's name to the message.
>
>> +static int rt2880_spi_probe(struct platform_device *pdev)
>> +{
>
> <snip>
>
>> + clk = devm_clk_get(&pdev->dev, NULL);
>> + if (IS_ERR(clk)) {
>> + dev_err(&pdev->dev, "unable to get SYS clock, err=%d\n",
>> + status);
>> + return PTR_ERR(clk);
>> + }
>
> <snip>
>
>> +}
>> +
>> +static int rt2880_spi_remove(struct platform_device *pdev)
>> +{
>> + struct spi_master *master;
>> + struct rt2880_spi *rs;
>> +
>> + master = dev_get_drvdata(&pdev->dev);
>> + rs = spi_master_get_devdata(master);
>> +
>> + clk_disable(rs->clk);
>> + clk_put(rs->clk);
>
> The devm_clk_get in your probe function means you don't need clk_put here.
>
> Cheers
> James
>
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 2/2] SPI: ralink: add Ralink SoC spi driver
2013-08-11 13:26 ` Mark Brown
@ 2013-08-13 18:43 ` John Crispin
2013-08-13 18:58 ` Mark Brown
0 siblings, 1 reply; 11+ messages in thread
From: John Crispin @ 2013-08-13 18:43 UTC (permalink / raw)
To: Mark Brown; +Cc: Gabor Juhos, linux-spi, linux-mips
Hi Mark,
Thanks for the review, I will send a V2 tomorrow, I want to verify my
changes on real HW first.
a few comments inline ...
> There is presumably a maximum transfer size here from the FIFO that is
> holding the data?
The hardware is not running in DMA/IRQ mode and hence it can only
read/write 1 byte at a time.
> Set min_speed_hz in the spi_master and the core will check this for you.
it seems that min_speed is not handled by the core yet. I saw several
drivers do minimum speed testing. I am leaving this code in the driver
until there is a generic minimum speed check
> clk_prepare_enable(), and it'd be nice to use runtime PM and enable the
> clock only when doing transfers though that's not essential.
>
The clock is free running and always running.
John
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 2/2] SPI: ralink: add Ralink SoC spi driver
2013-08-13 18:43 ` John Crispin
@ 2013-08-13 18:58 ` Mark Brown
0 siblings, 0 replies; 11+ messages in thread
From: Mark Brown @ 2013-08-13 18:58 UTC (permalink / raw)
To: John Crispin; +Cc: Gabor Juhos, linux-spi, linux-mips
[-- Attachment #1: Type: text/plain, Size: 999 bytes --]
On Tue, Aug 13, 2013 at 08:43:51PM +0200, John Crispin wrote:
> >There is presumably a maximum transfer size here from the FIFO that is
> >holding the data?
> The hardware is not running in DMA/IRQ mode and hence it can only
> read/write 1 byte at a time.
OK, then the code looks buggy since it does all the Tx then all the Rx
so a bidirectional transfer should fail. I'd expect Tx and Rx to be
part of the same loop in this case.
> >Set min_speed_hz in the spi_master and the core will check this for you.
> it seems that min_speed is not handled by the core yet. I saw
> several drivers do minimum speed testing. I am leaving this code in
> the driver until there is a generic minimum speed check
Or add the check to the core...
> >clk_prepare_enable(), and it'd be nice to use runtime PM and enable the
> >clock only when doing transfers though that's not essential.
> The clock is free running and always running.
It's still nice to turn it off for power, and very cheap to implement.
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^ permalink raw reply [flat|nested] 11+ messages in thread
end of thread, other threads:[~2013-08-13 18:58 UTC | newest]
Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2013-08-09 18:51 [PATCH 1/2] DT: Add documentation for spi-rt2880 John Crispin
2013-08-09 18:51 ` [PATCH 2/2] SPI: ralink: add Ralink SoC spi driver John Crispin
2013-08-11 13:26 ` Mark Brown
2013-08-13 18:43 ` John Crispin
2013-08-13 18:58 ` Mark Brown
2013-08-12 16:10 ` James Hogan
2013-08-12 16:10 ` James Hogan
2013-08-12 16:11 ` James Hogan
2013-08-12 16:11 ` James Hogan
2013-08-09 20:44 ` [PATCH 1/2] DT: Add documentation for spi-rt2880 Sergei Shtylyov
2013-08-09 23:35 ` Kumar Gala
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