On 11/27/2014 12:43 PM, Lee Jones wrote:
This patch adds support for the SPI portion of ST's SSC device.
Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx>
---
drivers/spi/Kconfig | 8 +
drivers/spi/Makefile | 1 +
drivers/spi/spi-st.c | 535 +++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 544 insertions(+)
create mode 100644 drivers/spi/spi-st.c
<snip>
+
+static int spi_st_probe(struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ struct device *dev = &pdev->dev;
+ struct spi_master *master;
+ struct resource *res;
+ struct spi_st *spi_st;
+ int num_cs, cs_gpio, i, ret = 0;
+ u32 var;
+
+ printk("LEE: %s: %s()[%d]: Probing\n", __FILE__, __func__, __LINE__);
+
+ master = spi_alloc_master(&pdev->dev, sizeof(*spi_st));
+ if (!master) {
+ dev_err(&pdev->dev, "failed to allocate spi master\n");
+ return -ENOMEM;
+ }
+ spi_st = spi_master_get_devdata(master);
+
+ if (!IS_ERR(dev->pins->p)) {
+ spi_st->pins_sleep =
+ pinctrl_lookup_state(dev->pins->p, PINCTRL_STATE_SLEEP);
+ if (IS_ERR(spi_st->pins_sleep))
+ dev_warn(&pdev->dev, "could not get sleep pinstate\n");
+ }
+
+ num_cs = of_gpio_named_count(np, "cs-gpios");
+
+ for (i = 0; i < num_cs; i++) {
+ cs_gpio = of_get_named_gpio(np, "cs-gpios", i);
+
+ if (!gpio_is_valid(cs_gpio)) {
+ dev_err(&pdev->dev,
+ "%d is not a valid gpio\n", cs_gpio);
+ return -EINVAL;
+ }
+
+ if (devm_gpio_request(&pdev->dev, cs_gpio, pdev->name)) {
+ dev_err(&pdev->dev,
+ "could not request %d gpio\n", cs_gpio);
+ return -EINVAL;
+ }
+ }
+
+ spi_st->clk = of_clk_get_by_name(np, "ssc");
+ if (IS_ERR(spi_st->clk)) {
+ dev_err(&pdev->dev, "Unable to request clock\n");
+ ret = PTR_ERR(spi_st->clk);
+ goto free_master;
+ }
+
+ ret = clk_prepare_enable(spi_st->clk);
+ if (ret)
+ goto free_master;
+
+ master->dev.of_node = np;
+ master->bus_num = pdev->id;
+ master->mode_bits = MODEBITS;
+ spi_st->bitbang.master = spi_master_get(master);
+ spi_st->bitbang.setup_transfer = spi_st_setup_transfer;
+ spi_st->bitbang.txrx_bufs = spi_st_txrx_bufs;
+ spi_st->bitbang.master->setup = spi_st_setup;
+ spi_st->bitbang.master->cleanup = spi_st_cleanup;
+ spi_st->bitbang.chipselect = spi_st_gpio_chipselect;
+ spi_st->dev = dev;
+
+ init_completion(&spi_st->done);
+
+ /* Get resources */
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ spi_st->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(spi_st->base)) {
+ ret = PTR_ERR(spi_st->base);
+ goto clk_disable;
+ }
+
+ spi_st->irq = irq_of_parse_and_map(np, 0);
+ if (!spi_st->irq) {
+ dev_err(&pdev->dev, "IRQ missing or invalid\n");
+ ret = -EINVAL;
+ goto clk_disable;
+ }
+
+ ret = devm_request_irq(&pdev->dev, spi_st->irq, spi_st_irq, 0,
+ pdev->name, spi_st);
+ if (ret) {
+ dev_err(&pdev->dev, "Failed to request irq %d\n", spi_st->irq);
+ goto clk_disable;
+ }
+
+ /* Disable I2C and Reset SSC */
+ writel_relaxed(0x0, spi_st->base + SSC_I2C);
+ var = readw(spi_st->base + SSC_CTL);
Why not readw_relaxed to be consistent with readl:s?
+ var |= SSC_CTL_SR;
+ writel_relaxed(var, spi_st->base + SSC_CTL);
+
+ udelay(1);
+ var = readl_relaxed(spi_st->base + SSC_CTL);
+ var &= ~SSC_CTL_SR;
+ writel_relaxed(var, spi_st->base + SSC_CTL);
+
+ /* Set SSC into slave mode before reconfiguring PIO pins */
+ var = readl_relaxed(spi_st->base + SSC_CTL);
+ var &= ~SSC_CTL_MS;
+ writel_relaxed(var, spi_st->base + SSC_CTL);
+
+ /* Start "bitbang" worker */
+ ret = spi_bitbang_start(&spi_st->bitbang);
+ if (ret) {
+ dev_err(&pdev->dev, "bitbang start failed [%d]\n", ret);
+ goto clk_disable;
+ }
+
+ dev_info(&pdev->dev, "registered SPI Bus %d\n", master->bus_num);
+
+ platform_set_drvdata(pdev, master);
Shouldn't you call devm_spi_register_master ?
+
+ /* by default the device is on */
+ pm_runtime_set_active(&pdev->dev);
+ pm_runtime_enable(&pdev->dev);
+
+ return 0;
+
+clk_disable:
+ clk_disable_unprepare(spi_st->clk);
+free_master:
+ spi_master_put(master);
+
+ return ret;
+}
+
+static int spi_st_remove(struct platform_device *pdev)
+{
+ struct spi_master *master = platform_get_drvdata(pdev);
+ struct spi_st *spi_st = spi_master_get_devdata(master);
+
+ spi_bitbang_stop(&spi_st->bitbang);
+ clk_disable_unprepare(spi_st->clk);
+
+ if (spi_st->pins_sleep)
+ pinctrl_select_state(pdev->dev.pins->p, spi_st->pins_sleep);
You should use pinctrl_pm_select_sleep_state(dev); instead.
+
+ spi_master_put(spi_st->bitbang.master);
If you use devm_spi_register_master at probe time,
you shouldn't need to call spi_master_put IIUC.
+
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int spi_st_suspend(struct device *dev)
+{
+ struct spi_master *master = dev_get_drvdata(dev);
+ struct spi_st *spi_st = spi_master_get_devdata(master);
+
+ writel_relaxed(0, spi_st->base + SSC_IEN);
+
+ if (!IS_ERR(spi_st->pins_sleep))
+ pinctrl_select_state(dev->pins->p, spi_st->pins_sleep);
Ditto
+
+ clk_disable_unprepare(spi_st->clk);
+
+ return 0;
+}
+
+static int spi_st_resume(struct device *dev)
+{
+ struct spi_master *master = dev_get_drvdata(dev);
+ struct spi_st *spi_st = spi_master_get_devdata(master);
+ int ret;
+
+ ret = clk_prepare_enable(spi_st->clk);
+
+ if (!IS_ERR(dev->pins->default_state))
+ pinctrl_select_state(dev->pins->p, dev->pins->default_state);
pinctrl_pm_select_default_state(i2c_dev->dev);
pinctrl_pm_select_idle_state(i2c_dev->dev);
+
+ return ret;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(spi_st_pm, spi_st_suspend, spi_st_resume);
+
+static struct of_device_id stm_spi_match[] = {
+ { .compatible = "st,comms-ssc-spi", },
+ { .compatible = "st,comms-ssc4-spi", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, stm_spi_match);
+
+static struct platform_driver spi_st_driver = {
+ .driver = {
+ .name = "spi-st",
+ .pm = &spi_st_pm,
+ .of_match_table = of_match_ptr(stm_spi_match),
+ },
+ .probe = spi_st_probe,
+ .remove = spi_st_remove,
+};
+module_platform_driver(spi_st_driver);
+
+MODULE_AUTHOR("Patrice Chotard <patrice.chotard@xxxxxx>");
+MODULE_DESCRIPTION("STM SSC SPI driver");
+MODULE_LICENSE("GPL v2");
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