Messages in this thread | | | Date | Thu, 27 Nov 2014 14:24:08 +0100 | From | Maxime Coquelin <> | Subject | Re: [PATCH 1/4] spi: Add new driver for STMicroelectronics' SPI Controller |
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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@linaro.org> > --- > 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@st.com>"); > +MODULE_DESCRIPTION("STM SSC SPI driver"); > +MODULE_LICENSE("GPL v2");
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