Re: [PATCH v2] spi: QUP based bus driver for Qualcomm MSM chipsets

From: Harini Jayaraman
Date: Mon Dec 12 2011 - 17:28:24 EST


On 12/07/2011 03:37 PM, Wolfram Sang wrote:
On Mon, Nov 14, 2011 at 02:58:27PM -0700, Harini Jayaraman wrote:
This bus driver supports the QUP SPI hardware controller in the Qualcomm
MSM SOCs. The Qualcomm Universal Peripheral Engine (QUP) is a general
purpose data path engine with input/output FIFOs and an embedded SPI
mini-core. The driver currently supports only FIFO mode.

Signed-off-by: Harini Jayaraman<harinij@xxxxxxxxxxxxxx>
Wow, this driver is huge. This is a rough review only, mainly to see
what can go away. This will make further reviews easier.

Thanks Wolfram for taking time to review this patch. I appreciate your comments and will incorporate them in to the next version of the patch.
---
v2: Updated copyright information (addresses comments from Bryan Huntsman).
Files renamed.
---
drivers/spi/Kconfig | 10 +
drivers/spi/Makefile | 1 +
drivers/spi/spi-qup.c | 1144 +++++++++++++++++++++++++++++++++
drivers/spi/spi-qup.h | 436 +++++++++++++
include/linux/platform_data/msm_spi.h | 19 +
5 files changed, 1610 insertions(+), 0 deletions(-)
create mode 100644 drivers/spi/spi-qup.c
create mode 100644 drivers/spi/spi-qup.h
create mode 100644 include/linux/platform_data/msm_spi.h

diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 52e2900..88ea7c5 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -280,6 +280,16 @@ config SPI_PXA2XX
config SPI_PXA2XX_PCI
def_bool SPI_PXA2XX&& X86_32&& PCI

+config SPI_QUP
+ tristate "Qualcomm MSM SPI QUPe Support"
+ depends on ARCH_MSM
+ help
+ Support for Serial Peripheral Interface for Qualcomm Universal
+ Peripheral.
+
+ This driver can also be built as a module. If so, the module
+ will be called spi-qup.
+
config SPI_S3C24XX
tristate "Samsung S3C24XX series SPI"
depends on ARCH_S3C2410&& EXPERIMENTAL
diff --git a/drivers/spi/Makefile b/drivers/spi/Makefile
index 61c3261..4d840ff 100644
--- a/drivers/spi/Makefile
+++ b/drivers/spi/Makefile
@@ -44,6 +44,7 @@ obj-$(CONFIG_SPI_PL022) += spi-pl022.o
obj-$(CONFIG_SPI_PPC4xx) += spi-ppc4xx.o
obj-$(CONFIG_SPI_PXA2XX) += spi-pxa2xx.o
obj-$(CONFIG_SPI_PXA2XX_PCI) += spi-pxa2xx-pci.o
+obj-$(CONFIG_SPI_QUP) += spi-qup.o
obj-$(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-qup.c b/drivers/spi/spi-qup.c
new file mode 100644
index 0000000..4b411d8
--- /dev/null
+++ b/drivers/spi/spi-qup.c
@@ -0,0 +1,1144 @@
+/* Copyright (c) 2008-2011, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * 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.
+ */
+
+#include<linux/version.h>
+#include<linux/kernel.h>
+#include<linux/init.h>
+#include<linux/spinlock.h>
+#include<linux/list.h>
+#include<linux/irq.h>
+#include<linux/platform_device.h>
+#include<linux/spi/spi.h>
+#include<linux/interrupt.h>
+#include<linux/err.h>
+#include<linux/clk.h>
+#include<linux/delay.h>
+#include<linux/workqueue.h>
+#include<linux/io.h>
+#include<linux/debugfs.h>
+#include<linux/sched.h>
+#include<linux/mutex.h>
+#include<linux/platform_data/msm_spi.h>
+#include "spi-qup.h"
+
+static void msm_spi_clock_set(struct msm_spi *dd, int speed)
+{
+ int rc;
+
+ rc = clk_set_rate(dd->clk, speed);
+ if (!rc)
+ dd->clock_speed = speed;
+}
+
+static int msm_spi_calculate_size(int *fifo_size,
+ int *block_size,
+ int block,
+ int mult)
+{
+ int words;
+
+ switch (block) {
+ case 0:
+ words = 1; /* 4 bytes */
+ break;
+ case 1:
+ words = 4; /* 16 bytes */
+ break;
+ case 2:
+ words = 8; /* 32 bytes */
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ switch (mult) {
+ case 0:
+ *fifo_size = words * 2;
+ break;
+ case 1:
+ *fifo_size = words * 4;
+ break;
+ case 2:
+ *fifo_size = words * 8;
+ break;
+ case 3:
+ *fifo_size = words * 16;
+ break;
+ default:
+ return -EINVAL;
+ }
I think this can be simplified. Example for this switch:

if (mult> 3)
return -EINVAL;

*fifo_size = (words * 2)<< mult;

Probably the whole function can be optimized away somehow?

+
+ *block_size = words * sizeof(u32); /* in bytes */
+ return 0;
+}
...


+#ifdef CONFIG_DEBUG_FS
+static int debugfs_iomem_x32_set(void *data, u64 val)
+{
+ iowrite32(val, data);
+ /* Ensure the previous write completed. */
+ wmb();
+ return 0;
+}
+
+static int debugfs_iomem_x32_get(void *data, u64 *val)
+{
+ *val = ioread32(data);
+ return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(fops_iomem_x32, debugfs_iomem_x32_get,
+ debugfs_iomem_x32_set, "0x%08llx\n");
+
+static void spi_debugfs_init(struct msm_spi *dd)
+{
+ dd->dent_spi = debugfs_create_dir(dev_name(dd->dev), NULL);
+ if (dd->dent_spi) {
+ int i;
+
+ for (i = 0; i< ARRAY_SIZE(debugfs_spi_regs); i++) {
+ dd->debugfs_spi_regs[i] =
+ debugfs_create_file(
+ debugfs_spi_regs[i].name,
+ debugfs_spi_regs[i].mode,
+ dd->dent_spi,
+ dd->base + debugfs_spi_regs[i].offset,
+ &fops_iomem_x32);
+ }
+ }
+}
+
+static void spi_debugfs_exit(struct msm_spi *dd)
+{
+ if (dd->dent_spi) {
+ int i;
+
+ debugfs_remove_recursive(dd->dent_spi);
+ dd->dent_spi = NULL;
+ for (i = 0; i< ARRAY_SIZE(debugfs_spi_regs); i++)
+ dd->debugfs_spi_regs[i] = NULL;
+ }
+}
+#else
+static void spi_debugfs_init(struct msm_spi *dd) {}
+static void spi_debugfs_exit(struct msm_spi *dd) {}
+#endif
That interface should go away. It might have been nice when developing
the driver, but we other mechanisms to read out register values.

+
+/* ===Device attributes begin=== */
+static ssize_t show_stats(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct spi_master *master = dev_get_drvdata(dev);
+ struct msm_spi *dd = spi_master_get_devdata(master);
+
+ return snprintf(buf, PAGE_SIZE,
+ "Device %s\n"
+ "rx fifo_size = %d spi words\n"
+ "tx fifo_size = %d spi words\n"
+ "rx block size = %d bytes\n"
+ "tx block size = %d bytes\n"
+ "--statistics--\n"
+ "Rx isrs = %d\n"
+ "Tx isrs = %d\n"
+ "--debug--\n"
+ "NA yet\n",
+ dev_name(dev),
+ dd->input_fifo_size,
+ dd->output_fifo_size,
+ dd->input_block_size,
+ dd->output_block_size,
+ dd->stat_rx,
+ dd->stat_tx
+ );
+}
+
+/* Reset statistics on write */
+static ssize_t set_stats(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct msm_spi *dd = dev_get_drvdata(dev);
+
+ dd->stat_rx = 0;
+ dd->stat_tx = 0;
+ return count;
+}
+
+static DEVICE_ATTR(stats, S_IRUGO | S_IWUSR, show_stats, set_stats);
+
+static struct attribute *dev_attrs[] = {
+ &dev_attr_stats.attr,
+ NULL,
+};
+
+static struct attribute_group dev_attr_grp = {
+ .attrs = dev_attrs,
+};
+/* ===Device attributes end=== */
This should go as well. Not really needed.

+
+static int __init msm_spi_probe(struct platform_device *pdev)
+{
+ struct spi_master *master;
+ struct msm_spi *dd;
+ struct resource *resource;
+ int rc = -ENXIO;
+ int locked = 0;
+ int clk_enabled = 0;
+ int pclk_enabled = 0;
+ struct msm_spi_platform_data *pdata = pdev->dev.platform_data;
+
+ master = spi_alloc_master(&pdev->dev, sizeof(struct msm_spi));
+ if (!master) {
+ rc = -ENOMEM;
+ dev_err(&pdev->dev, "master allocation failed\n");
+ goto err_probe_exit;
+ }
+
+ master->bus_num = pdev->id;
+ master->mode_bits = SPI_SUPPORTED_MODES;
+ master->num_chipselect = SPI_NUM_CHIPSELECTS;
+ master->setup = msm_spi_setup;
+ master->transfer = msm_spi_transfer;
+ platform_set_drvdata(pdev, master);
+ dd = spi_master_get_devdata(master);
+
+ dd->pdata = pdata;
+ rc = msm_spi_get_irq_data(dd, pdev);
+ if (rc)
+ goto err_probe_res;
+
+ resource = platform_get_resource_byname(pdev,
+ IORESOURCE_MEM, "spi_base");
+ if (!resource) {
+ rc = -ENXIO;
+ goto err_probe_res;
+ }
+
+ dd->mem_phys_addr = resource->start;
+ dd->mem_size = resource_size(resource);
+
+ spin_lock_init(&dd->queue_lock);
+ mutex_init(&dd->core_lock);
+ INIT_LIST_HEAD(&dd->queue);
+ INIT_WORK(&dd->work_data, msm_spi_workq);
+ init_waitqueue_head(&dd->continue_suspend);
+ dd->workqueue = create_singlethread_workqueue(
+ dev_name(master->dev.parent));
+ if (!dd->workqueue)
+ goto err_probe_res;
+
+ if (!devm_request_mem_region(&pdev->dev, dd->mem_phys_addr,
+ dd->mem_size, SPI_DRV_NAME)) {
+ rc = -ENXIO;
+ goto err_probe_reqmem;
+ }
+
+ dd->base = devm_ioremap(&pdev->dev, dd->mem_phys_addr, dd->mem_size);
+ if (!dd->base) {
+ rc = -ENOMEM;
+ goto err_probe_reqmem;
+ }
+
+
+ mutex_lock(&dd->core_lock);
+ locked = 1;
+ dd->dev =&pdev->dev;
+ dd->clk = clk_get(&pdev->dev, "spi_clk");
+ if (IS_ERR(dd->clk)) {
+ dev_err(&pdev->dev, "%s: unable to get spi_clk\n", __func__);
+ rc = PTR_ERR(dd->clk);
+ goto err_probe_clk_get;
+ }
+
+ dd->pclk = clk_get(&pdev->dev, "spi_pclk");
+ if (IS_ERR(dd->pclk)) {
+ dev_err(&pdev->dev, "%s: unable to get spi_pclk\n", __func__);
+ rc = PTR_ERR(dd->pclk);
+ goto err_probe_pclk_get;
+ }
+
+ if (pdata&& pdata->max_clock_speed)
+ msm_spi_clock_set(dd, dd->pdata->max_clock_speed);
+
+ rc = clk_enable(dd->clk);
+ if (rc) {
+ dev_err(&pdev->dev, "%s: unable to enable spi_clk\n",
+ __func__);
+ goto err_probe_clk_enable;
+ }
+
+ clk_enabled = 1;
+ rc = clk_enable(dd->pclk);
+ if (rc) {
+ dev_err(&pdev->dev, "%s: unable to enable spi_pclk\n",
+ __func__);
+ goto err_probe_pclk_enable;
+ }
+
+ pclk_enabled = 1;
+ rc = msm_spi_configure_gsbi(dd, pdev);
+ if (rc)
+ goto err_probe_gsbi;
+
+ msm_spi_calculate_fifo_size(dd);
+
+ /* Initialize registers */
+ writel(0x00000001, dd->base + SPI_SW_RESET);
+ msm_spi_set_state(dd, SPI_OP_STATE_RESET);
+ writel(0x00000000, dd->base + SPI_OPERATIONAL);
+ writel(0x00000000, dd->base + SPI_CONFIG);
+ writel(0x00000000, dd->base + SPI_IO_MODES);
0x0, or 0x1 will do. Save the leading 0s.

+ /*
+ * The SPI core generates a bogus input overrun error on some targets,
+ * when a transition from run to reset state occurs and if the FIFO has
+ * an odd number of entries. Hence we disable the INPUT_OVER_RUN_ERR_EN
+ * bit.
+ */
+ msm_spi_enable_error_flags(dd);
+
+ writel(SPI_IO_C_NO_TRI_STATE, dd->base + SPI_IO_CONTROL);
+ rc = msm_spi_set_state(dd, SPI_OP_STATE_RESET);
+ if (rc)
+ goto err_probe_state;
+
+ clk_disable(dd->clk);
+ clk_disable(dd->pclk);
+ clk_enabled = 0;
+ pclk_enabled = 0;
+
+ dd->suspended = 0;
+ dd->transfer_pending = 0;
+ dd->multi_xfr = 0;
+ dd->mode = SPI_MODE_NONE;
+
+ rc = msm_spi_request_irq(dd, pdev->name, master);
There is also devm_request_irq

+ if (rc)
+ goto err_probe_irq;
+
+ msm_spi_disable_irqs(dd);
+ mutex_unlock(&dd->core_lock);
+ locked = 0;
+
+ rc = spi_register_master(master);
+ if (rc)
+ goto err_probe_reg_master;
+
+ rc = sysfs_create_group(&(dd->dev->kobj),&dev_attr_grp);
+ if (rc) {
+ dev_err(&pdev->dev, "failed to create dev. attrs : %d\n", rc);
+ goto err_attrs;
+ }
+
+ spi_debugfs_init(dd);
+
+ return 0;
+
+err_attrs:
+ spi_unregister_master(master);
+err_probe_reg_master:
+ msm_spi_free_irq(dd, master);
+err_probe_irq:
+err_probe_state:
+err_probe_gsbi:
+ if (pclk_enabled)
+ clk_disable(dd->pclk);
+err_probe_pclk_enable:
+ if (clk_enabled)
+ clk_disable(dd->clk);
+err_probe_clk_enable:
+ clk_put(dd->pclk);
+err_probe_pclk_get:
+ clk_put(dd->clk);
+err_probe_clk_get:
+ if (locked)
+ mutex_unlock(&dd->core_lock);
+err_probe_reqmem:
+ destroy_workqueue(dd->workqueue);
+err_probe_res:
+ spi_master_put(master);
+err_probe_exit:
+ return rc;
+}
+
...

+static struct platform_driver msm_spi_driver = {
+ .driver = {
+ .name = SPI_DRV_NAME,
+ .owner = THIS_MODULE,
+ },
+ .suspend = msm_spi_suspend,
+ .resume = msm_spi_resume,
+ .remove = __exit_p(msm_spi_remove),
+};
What about using module_platform_driver?

+
+static int __init msm_spi_init(void)
+{
+ return platform_driver_probe(&msm_spi_driver, msm_spi_probe);
+}
+module_init(msm_spi_init);
+
+static void __exit msm_spi_exit(void)
+{
+ platform_driver_unregister(&msm_spi_driver);
+}
+module_exit(msm_spi_exit);
+
+MODULE_LICENSE("GPL v2");
+MODULE_VERSION("0.3");
MODULE_VERSION is not really needed these days.

+MODULE_ALIAS("platform:"SPI_DRV_NAME);
diff --git a/drivers/spi/spi-qup.h b/drivers/spi/spi-qup.h
new file mode 100644
index 0000000..be0dc66
--- /dev/null
+++ b/drivers/spi/spi-qup.h
@@ -0,0 +1,436 @@
+/* Copyright (c) 2008-2011, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * 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.
+ */
+
...

+#ifdef CONFIG_DEBUG_FS
+static const struct {
+ const char *name;
+ mode_t mode;
+ int offset;
+} debugfs_spi_regs[] = {
+ {"config", S_IRUGO | S_IWUSR, SPI_CONFIG},
+ {"io_control", S_IRUGO | S_IWUSR, SPI_IO_CONTROL},
+ {"io_modes", S_IRUGO | S_IWUSR, SPI_IO_MODES},
+ {"sw_reset", S_IWUSR, SPI_SW_RESET},
+ {"time_out", S_IRUGO | S_IWUSR, SPI_TIME_OUT},
+ {"time_out_current", S_IRUGO, SPI_TIME_OUT_CURRENT},
+ {"mx_output_count", S_IRUGO | S_IWUSR, SPI_MX_OUTPUT_COUNT},
+ {"mx_output_cnt_current", S_IRUGO, SPI_MX_OUTPUT_CNT_CURRENT},
+ {"mx_input_count", S_IRUGO | S_IWUSR, SPI_MX_INPUT_COUNT},
+ {"mx_input_cnt_current", S_IRUGO, SPI_MX_INPUT_CNT_CURRENT},
+ {"mx_read_count", S_IRUGO | S_IWUSR, SPI_MX_READ_COUNT},
+ {"mx_read_cnt_current", S_IRUGO, SPI_MX_READ_CNT_CURRENT},
+ {"operational", S_IRUGO | S_IWUSR, SPI_OPERATIONAL},
+ {"error_flags", S_IRUGO | S_IWUSR, SPI_ERROR_FLAGS},
+ {"error_flags_en", S_IRUGO | S_IWUSR, SPI_ERROR_FLAGS_EN},
+ {"deassert_wait", S_IRUGO | S_IWUSR, SPI_DEASSERT_WAIT},
+ {"output_debug", S_IRUGO, SPI_OUTPUT_DEBUG},
+ {"input_debug", S_IRUGO, SPI_INPUT_DEBUG},
+ {"test_ctrl", S_IRUGO | S_IWUSR, SPI_TEST_CTRL},
+ {"output_fifo", S_IWUSR, SPI_OUTPUT_FIFO},
+ {"input_fifo" , S_IRUSR, SPI_INPUT_FIFO},
+ {"spi_state", S_IRUGO | S_IWUSR, SPI_STATE},
+ {"qup_config", S_IRUGO | S_IWUSR, QUP_CONFIG},
+ {"qup_error_flags", S_IRUGO | S_IWUSR, QUP_ERROR_FLAGS},
+ {"qup_error_flags_en", S_IRUGO | S_IWUSR, QUP_ERROR_FLAGS_EN},
+ {"mx_write_cnt", S_IRUGO | S_IWUSR, QUP_MX_WRITE_COUNT},
+ {"mx_write_cnt_current", S_IRUGO, QUP_MX_WRITE_CNT_CURRENT},
+ {"output_fifo_word_cnt", S_IRUGO, SPI_OUTPUT_FIFO_WORD_CNT},
+ {"input_fifo_word_cnt", S_IRUGO, SPI_INPUT_FIFO_WORD_CNT},
+};
+#endif
Again, drop it.

+
+/**
+ * struct msm_spi
+ * @read_buf: rx_buf from the spi_transfer.
+ * @write_buf: tx_buf from the spi_transfer.
+ * @base: location of QUP controller I/O area in memory.
+ * @dev: parent platform device.
+ * @queue_lock: lock to protect queue.
+ * @core_lock: mutex used to protect this struct.
+ * @queue: to log SPI transfer requests.
+ * @workqueue: workqueue for the SPI transfer requests.
+ * @work_data: work.
+ * @cur_msg: the current spi_message being processed.
+ * @cur_transfer: the current spi_transfer being processed.
+ * @transfer_complete: completion function to signal the end of a spi_transfer.
+ * @clk: the SPI core clock
+ * @pclk: hardware core clock. Needs to be enabled to access the QUP register
+ * @mem_phys_addr: physical address of the QUP controller.
+ * @mem_size: size of the QUP controller block.
+ * @input_fifo_size: the input FIFO size (in bytes).
+ * @output_fifo_size: the output FIFO size (in bytes).
+ * @rx_bytes_remaining: the number of rx bytes remaining to be transferred.
+ * @tx_bytes_remaining: the number of tx bytes remaining to be transferred.
+ * @clock_speed: SPI clock speed.
+ * @irq_in: assigned interrupt line for QUP interrupts.
+ * @read_xfr_cnt: number of words read from the FIFO (per transfer).
+ * @write_xfr_cnt: number of words written to the FIFO (per transfer).
+ * @write_len: the total number of tx bytes to be transferred, per
+ * spi_message. This is valid only for WR-WR and WR-RD transfers
+ * in a single spi_message.
+ * @read_len: the total number of rx bytes to be transferred, per
+ * spi_message. This is valid only for WR-WR and WR-RD transfers
+ * in a single spi_message.
+ * @bytes_per_word: bytes per word
+ * @suspended: the suspend state.
+ * @transfer_pending: when set indicates a pending transfer.
+ * @continue_suspend: head of wait queue.
+ * @mode: mode for SPI operation.
+ * @input_block_size: the input block size (in bytes).
+ * @output_block_size: the output block size (in bytes).
+ * @stat_rx: count of input interrupts handled.
+ * @stat_tx: count of output interrupts handled.
+ * @dent_spi: used for debug purposes.
+ * @debugfs_spi_regs: used for debug purposes.
+ * @pdata: platform data
+ * @multi_xfr: when set indicates multiple spi_transfers in a single
+ * spi_message.
+ * @done: flag used to signal completion.
+ * @cur_msg_len: combined length of all the transfers in a single
+ * spi_message (in bytes).
+ * @cur_tx_transfer: the current tx transfer being processed. Used in
+ * FIFO mode only.
+ * @cur_rx_transfer: the current rx transfer being processed. Used in
+ * FIFO mode only.
+ *
+ * Early QUP controller used three separate interrupt lines for input, output,
+ * and error interrupts. Later versions share a single interrupt line.
+ */
+struct msm_spi {
+ u8 *read_buf;
+ const u8 *write_buf;
+ void __iomem *base;
+ struct device *dev;
+ spinlock_t queue_lock;
+ struct mutex core_lock;
+ struct list_head queue;
+ struct workqueue_struct *workqueue;
+ struct work_struct work_data;
+ struct spi_message *cur_msg;
+ struct spi_transfer *cur_transfer;
+ struct completion transfer_complete;
+ struct clk *clk;
+ struct clk *pclk;
+ unsigned long mem_phys_addr;
+ size_t mem_size;
+ int input_fifo_size;
+ int output_fifo_size;
+ u32 rx_bytes_remaining;
+ u32 tx_bytes_remaining;
+ u32 clock_speed;
+ int irq_in;
+ int read_xfr_cnt;
+ int write_xfr_cnt;
+ int write_len;
+ int read_len;
+ int bytes_per_word;
+ bool suspended;
+ bool transfer_pending;
+ wait_queue_head_t continue_suspend;
+ enum msm_spi_mode mode;
+ int input_block_size;
+ int output_block_size;
+ int stat_rx;
+ int stat_tx;
+#ifdef CONFIG_DEBUG_FS
+ struct dentry *dent_spi;
+ struct dentry *debugfs_spi_regs[ARRAY_SIZE(debugfs_spi_regs)];
+#endif
+ struct msm_spi_platform_data *pdata;
+ bool multi_xfr;
+ bool done;
+ u32 cur_msg_len;
+ struct spi_transfer *cur_tx_transfer;
+ struct spi_transfer *cur_rx_transfer;
+};
This looks excessive. Please check if all of this is really needed?

+
+/* Forward declaration */
+static irqreturn_t msm_spi_input_irq(int irq, void *dev_id);
+static irqreturn_t msm_spi_output_irq(int irq, void *dev_id);
+static irqreturn_t msm_spi_error_irq(int irq, void *dev_id);
+static inline int msm_spi_set_state(struct msm_spi *dd,
+ enum msm_spi_state state);
+static void msm_spi_write_word_to_fifo(struct msm_spi *dd);
+static inline void msm_spi_write_rmn_to_fifo(struct msm_spi *dd);
+
+/* In QUP the same interrupt line is used for input, output and error */
+static inline int msm_spi_get_irq_data(struct msm_spi *dd,
+ struct platform_device *pdev)
+{
+ dd->irq_in = platform_get_irq_byname(pdev, "spi_irq_in");
+ if (dd->irq_in< 0)
+ return -EINVAL;
+
+ return 0;
+}
+
+static inline int msm_spi_configure_gsbi(struct msm_spi *dd,
+ struct platform_device *pdev)
+{
+ struct resource *resource;
+ unsigned long gsbi_mem_phys_addr;
+ size_t gsbi_mem_size;
+ void __iomem *gsbi_base;
+
+ resource = platform_get_resource_byname(pdev,
+ IORESOURCE_MEM, "gsbi_base");
+ if (!resource)
+ return -ENXIO;
+
+ gsbi_mem_phys_addr = resource->start;
+ gsbi_mem_size = resource_size(resource);
+ if (!devm_request_mem_region(&pdev->dev, gsbi_mem_phys_addr,
+ gsbi_mem_size, SPI_DRV_NAME))
+ return -ENXIO;
+
+ gsbi_base = devm_ioremap(&pdev->dev, gsbi_mem_phys_addr,
+ gsbi_mem_size);
+ if (!gsbi_base)
+ return -ENXIO;
+
+ /* Set GSBI to SPI mode */
+ writel(GSBI_SPI_CONFIG, gsbi_base + GSBI_CTRL_REG);
+
+ return 0;
+}
+
+/* Figure which irq occured and call the relevant functions */
+static irqreturn_t msm_spi_qup_irq(int irq, void *dev_id)
+{
+ u32 op, ret = IRQ_NONE;
+ struct msm_spi *dd = dev_id;
+
+ if (readl(dd->base + SPI_ERROR_FLAGS) ||
+ readl(dd->base + QUP_ERROR_FLAGS)) {
+ struct spi_master *master = dev_get_drvdata(dd->dev);
+ ret |= msm_spi_error_irq(irq, master);
+ }
+
+ op = readl(dd->base + SPI_OPERATIONAL);
+ if (op& SPI_OP_INPUT_SERVICE_FLAG) {
+ writel(SPI_OP_INPUT_SERVICE_FLAG, dd->base + SPI_OPERATIONAL);
+ ret |= msm_spi_input_irq(irq, dev_id);
+ }
+
+ if (op& SPI_OP_OUTPUT_SERVICE_FLAG) {
+ writel(SPI_OP_OUTPUT_SERVICE_FLAG, dd->base + SPI_OPERATIONAL);
+ ret |= msm_spi_output_irq(irq, dev_id);
+ }
+
+ if (dd->done) {
+ complete(&dd->transfer_complete);
+ dd->done = 0;
+ }
+ return ret;
+}
Too much code for a header file IMO.

+
+static inline int msm_spi_request_irq(struct msm_spi *dd,
+ const char *name,
+ struct spi_master *master)
+{
+ return request_irq(dd->irq_in, msm_spi_qup_irq, IRQF_TRIGGER_HIGH,
+ name, dd);
+}
+
+static inline void msm_spi_free_irq(struct msm_spi *dd,
+ struct spi_master *master)
+{
+ free_irq(dd->irq_in, dd);
+}
+
+static inline void msm_spi_disable_irqs(struct msm_spi *dd)
+{
+ disable_irq(dd->irq_in);
+}
+
+static inline void msm_spi_enable_irqs(struct msm_spi *dd)
+{
+ enable_irq(dd->irq_in);
+}
+
+static inline void msm_spi_get_clk_err(struct msm_spi *dd, u32 *spi_err)
+{
+ *spi_err = readl(dd->base + QUP_ERROR_FLAGS);
+}
+
+static inline void msm_spi_ack_clk_err(struct msm_spi *dd)
+{
+ writel(QUP_ERR_MASK, dd->base + QUP_ERROR_FLAGS);
+}
+
+static inline void msm_spi_add_configs(struct msm_spi *dd, u32 *config, int n);
+
+/* QUP has no_input, no_output, and N bits at QUP_CONFIG */
+static inline void msm_spi_set_qup_config(struct msm_spi *dd, int bpw)
+{
+ u32 qup_config = readl(dd->base + QUP_CONFIG);
+
+ msm_spi_add_configs(dd,&qup_config, bpw-1);
+ writel(qup_config | QUP_CONFIG_SPI_MODE, dd->base + QUP_CONFIG);
+}
+
+static inline int msm_spi_prepare_for_write(struct msm_spi *dd)
+{
+ if (msm_spi_set_state(dd, SPI_OP_STATE_RUN))
+ return -EINVAL;
+
+ if (msm_spi_set_state(dd, SPI_OP_STATE_PAUSE))
+ return -EINVAL;
+
+ return 0;
+}
+
+static inline void msm_spi_start_write(struct msm_spi *dd, u32 read_count)
+{
+ if (read_count<= dd->input_fifo_size)
+ msm_spi_write_rmn_to_fifo(dd);
+ else
+ msm_spi_write_word_to_fifo(dd);
+}
+
+static inline void msm_spi_set_write_count(struct msm_spi *dd, int val)
+{
+ writel(val, dd->base + QUP_MX_WRITE_COUNT);
+}
+
+static inline void msm_spi_complete(struct msm_spi *dd)
+{
+ dd->done = 1;
+}
+
+static inline void msm_spi_enable_error_flags(struct msm_spi *dd)
+{
+ writel_relaxed(0x00000078, dd->base + SPI_ERROR_FLAGS_EN);
+}
+
+static inline void msm_spi_clear_error_flags(struct msm_spi *dd)
+{
+ writel_relaxed(0x0000007C, dd->base + SPI_ERROR_FLAGS);
+}
While most of these one liners are too few code for a header file IMO.
No need to encapsulate most of it, e.g use the *_irq-calls directly.
Also, please don't use magic values (0x7c) but combine the proper
defines, please.
We have different versions of the QUP controller and hence would like to abstract it out, so that subsequent versions of the QUP can be accommodated in future. I will surely combine the proper defines in my next patch.
Thanks,

Wolfram


Thanks,
Harini Jayaraman

--
Sent by an employee of the Qualcomm Innovation Center, Inc.
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum.

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