Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756643Ab2HTOWx (ORCPT ); Mon, 20 Aug 2012 10:22:53 -0400 Received: from mail-ob0-f174.google.com ([209.85.214.174]:42005 "EHLO mail-ob0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751820Ab2HTOWt (ORCPT ); Mon, 20 Aug 2012 10:22:49 -0400 Message-ID: <50324835.6030806@gmail.com> Date: Mon, 20 Aug 2012 09:22:45 -0500 From: Rob Herring User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:14.0) Gecko/20120714 Thunderbird/14.0 MIME-Version: 1.0 To: Alexandre Pereira da Silva CC: Roland Stigge , Grant Likely , Rob Landley , devicetree-discuss@lists.ozlabs.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, spi-devel-general@lists.sourceforge.net, "Mark Brown (broonie@opensource.wolfsonmicro.com)" , Linus Walleij Subject: Re: [PATCH RESEND v4] spi/pl022: add devicetree support References: <1345462769-17386-1-git-send-email-aletes.xgr@gmail.com> In-Reply-To: <1345462769-17386-1-git-send-email-aletes.xgr@gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 13031 Lines: 353 On 08/20/2012 06:39 AM, Alexandre Pereira da Silva wrote: > Add the chipselect array and cur_cs properties to pl022 main structure > > Add a wrapper function to decide if the cs should be controlled by the > cs_control callback or the chipselect gpio > > Populate chipselect property from cs-gpios > > Populate master->dev.of_node, so the spi bus can find child spi > devices and register them > > At pl022 setup, fill chip_data structure from dt nodes, if not provided > by platform. > > Signed-off-by: Alexandre Pereira da Silva > Acked-by: Roland Stigge > --- > Applies to v3.6-rc1 > > Changes since v3: > * Proper use of IS_ENABLED > > Changes since v2: > * Use IS_ENABLED instead of #ifdef > * Remove bogus const change > > Changes since v1: > * return EPROBE_DEFFER if gpios are not initialized yet > > Thanks Thierry Reding for reviewing and improvements suggestions > > .../devicetree/bindings/spi/spi_pl022.txt | 15 +++ > drivers/spi/spi-pl022.c | 114 ++++++++++++++++---- > 2 files changed, 110 insertions(+), 19 deletions(-) > > diff --git a/Documentation/devicetree/bindings/spi/spi_pl022.txt b/Documentation/devicetree/bindings/spi/spi_pl022.txt > index 306ec3f..b089ec7 100644 > --- a/Documentation/devicetree/bindings/spi/spi_pl022.txt > +++ b/Documentation/devicetree/bindings/spi/spi_pl022.txt > @@ -6,7 +6,22 @@ Required properties: > - interrupts : Should contain SPI controller interrupt > > Optional properties: > +- pl022,num-chipselects : total number of chipselects We have this for other spi controllers too. Define a generic property. > - cs-gpios : should specify GPIOs used for chipselects. > The gpios will be referred to as reg = in the SPI child nodes. > If unspecified, a single SPI device without a chip select can be used. > > +SPI slave nodes must be children of the SPI master node and can > +contain the following properties. > +See include/linux/amba/pl022.h for more details DT binding is independent of Linux, so you should not refer to Linux docs. > + > +- pl022,hierarchy : master or slave interface Is attaching a master and using the pl022 as a slave really a supported use case? The DT spi bindings are really designed for a master node with N slave nodes. So there is more general question of how to describe a spi controller as a slave. It's not really one I care to answer as the Linux spi framework isn't designed to act as a slave. > +- pl022,interface : interface type And valid values are? > +- pl022,slave-tx-disable : disconnect tx line in slave mode > +- pl022,com-mode : polling, interrupt or dma > +- pl022,rx-level-trig : Rx FIFO watermark level > +- pl022,tx-level-trig : Tx FIFO watermark level > +- pl022,ctrl-len : Microwire interface: Control length > +- pl022,wait-state : Microwire interface: Wait state > +- pl022,duplex : Microwire interface: Full/Half duplex Most of these properties aren't used anywhere in the kernel other than u300 and I'm not sure what to purpose of dummy_chip_info is. Perhaps Linus has some input? I think either they can be decided by the spi controller (com-mode, fifo watermark) or should be standard properties (microwire settings). I would argue they should be removed if the spi framework doesn't have support in a standard way. > + > diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c > index 400ae21..d8d7d21 100644 > --- a/drivers/spi/spi-pl022.c > +++ b/drivers/spi/spi-pl022.c > @@ -40,6 +40,8 @@ > #include > #include > #include > +#include > +#include > > /* > * This macro is used to define some register default values. > @@ -389,6 +391,8 @@ struct pl022 { > char *dummypage; > bool dma_running; > #endif > + int cur_cs; > + int chipselect[0]; > }; > > /** > @@ -433,6 +437,14 @@ static void null_cs_control(u32 command) > pr_debug("pl022: dummy chip select control, CS=0x%x\n", command); > } > > +static void pl022_cs_control(struct pl022 *pl022, u32 command) > +{ > + if (gpio_is_valid(pl022->cur_cs)) > + gpio_set_value(pl022->cur_cs, command); > + else > + pl022->cur_chip->cs_control(command); > +} > + > /** > * giveback - current spi_message is over, schedule next message and call > * callback of this message. Assumes that caller already > @@ -479,7 +491,7 @@ static void giveback(struct pl022 *pl022) > if (next_msg && next_msg->spi != pl022->cur_msg->spi) > next_msg = NULL; > if (!next_msg || pl022->cur_msg->state == STATE_ERROR) > - pl022->cur_chip->cs_control(SSP_CHIP_DESELECT); > + pl022_cs_control(pl022, SSP_CHIP_DESELECT); > else > pl022->next_msg_cs_active = true; > > @@ -813,8 +825,7 @@ static void dma_callback(void *data) > /* Update total bytes transferred */ > msg->actual_length += pl022->cur_transfer->len; > if (pl022->cur_transfer->cs_change) > - pl022->cur_chip-> > - cs_control(SSP_CHIP_DESELECT); > + pl022_cs_control(pl022, SSP_CHIP_DESELECT); > > /* Move to next transfer */ > msg->state = next_transfer(pl022); > @@ -1247,8 +1258,7 @@ static irqreturn_t pl022_interrupt_handler(int irq, void *dev_id) > /* Update total bytes transferred */ > msg->actual_length += pl022->cur_transfer->len; > if (pl022->cur_transfer->cs_change) > - pl022->cur_chip-> > - cs_control(SSP_CHIP_DESELECT); > + pl022_cs_control(pl022, SSP_CHIP_DESELECT); > /* Move to next transfer */ > msg->state = next_transfer(pl022); > tasklet_schedule(&pl022->pump_transfers); > @@ -1333,7 +1343,7 @@ static void pump_transfers(unsigned long data) > > /* Reselect chip select only if cs_change was requested */ > if (previous->cs_change) > - pl022->cur_chip->cs_control(SSP_CHIP_SELECT); > + pl022_cs_control(pl022, SSP_CHIP_SELECT); > } else { > /* STATE_START */ > message->state = STATE_RUNNING; > @@ -1372,7 +1382,7 @@ static void do_interrupt_dma_transfer(struct pl022 *pl022) > > /* Enable target chip, if not already active */ > if (!pl022->next_msg_cs_active) > - pl022->cur_chip->cs_control(SSP_CHIP_SELECT); > + pl022_cs_control(pl022, SSP_CHIP_SELECT); > > if (set_up_next_transfer(pl022, pl022->cur_transfer)) { > /* Error path */ > @@ -1424,12 +1434,12 @@ static void do_polling_transfer(struct pl022 *pl022) > if (previous->delay_usecs) > udelay(previous->delay_usecs); > if (previous->cs_change) > - pl022->cur_chip->cs_control(SSP_CHIP_SELECT); > + pl022_cs_control(pl022, SSP_CHIP_SELECT); > } else { > /* STATE_START */ > message->state = STATE_RUNNING; > if (!pl022->next_msg_cs_active) > - pl022->cur_chip->cs_control(SSP_CHIP_SELECT); > + pl022_cs_control(pl022, SSP_CHIP_SELECT); > } > > /* Configuration Changing Per Transfer */ > @@ -1461,7 +1471,7 @@ static void do_polling_transfer(struct pl022 *pl022) > /* Update total byte transferred */ > message->actual_length += pl022->cur_transfer->len; > if (pl022->cur_transfer->cs_change) > - pl022->cur_chip->cs_control(SSP_CHIP_DESELECT); > + pl022_cs_control(pl022, SSP_CHIP_DESELECT); > /* Move to next transfer */ > message->state = next_transfer(pl022); > } > @@ -1490,6 +1500,7 @@ static int pl022_transfer_one_message(struct spi_master *master, > > /* Setup the SPI using the per chip configuration */ > pl022->cur_chip = spi_get_ctldata(msg->spi); > + pl022->cur_cs = pl022->chipselect[msg->spi->chip_select]; > > restore_state(pl022); > flush(pl022); > @@ -1761,12 +1772,14 @@ static const struct pl022_config_chip pl022_default_chip_info = { > static int pl022_setup(struct spi_device *spi) > { > struct pl022_config_chip const *chip_info; > + struct pl022_config_chip chip_info_dt; > struct chip_data *chip; > struct ssp_clock_params clk_freq = { .cpsdvsr = 0, .scr = 0}; > int status = 0; > struct pl022 *pl022 = spi_master_get_devdata(spi->master); > unsigned int bits = spi->bits_per_word; > u32 tmp; > + struct device_node *np = spi->dev.of_node; > > if (!spi->max_speed_hz) > return -EINVAL; > @@ -1789,10 +1802,36 @@ static int pl022_setup(struct spi_device *spi) > chip_info = spi->controller_data; > > if (chip_info == NULL) { > - chip_info = &pl022_default_chip_info; > - /* spi_board_info.controller_data not is supplied */ > - dev_dbg(&spi->dev, > - "using default controller_data settings\n"); > + if (np) { > + chip_info_dt = pl022_default_chip_info; > + > + of_property_read_u32(np, "pl022,hierarchy", > + &chip_info_dt.hierarchy); > + of_property_read_u32(np, "pl022,interface", > + &chip_info_dt.iface); > + chip_info_dt.slave_tx_disable = > + of_property_read_bool(np, > + "pl022,slave-tx-disable"); > + of_property_read_u32(np, "pl022,com-mode", > + &chip_info_dt.com_mode); > + of_property_read_u32(np, "pl022,rx-level-trig", > + &chip_info_dt.rx_lev_trig); > + of_property_read_u32(np, "pl022,tx-level-trig", > + &chip_info_dt.tx_lev_trig); > + of_property_read_u32(np, "pl022,ctrl-len", > + &chip_info_dt.ctrl_len); > + of_property_read_u32(np, "pl022,wait-state", > + &chip_info_dt.wait_state); > + of_property_read_u32(np, "pl022,duplex", > + &chip_info_dt.duplex); > + > + chip_info = &chip_info_dt; > + } else { > + chip_info = &pl022_default_chip_info; > + /* spi_board_info.controller_data not is supplied */ > + dev_dbg(&spi->dev, > + "using default controller_data settings\n"); > + } > } else > dev_dbg(&spi->dev, > "using user supplied controller_data settings\n"); > @@ -1835,8 +1874,9 @@ static int pl022_setup(struct spi_device *spi) > chip->xfer_type = chip_info->com_mode; > if (!chip_info->cs_control) { > chip->cs_control = null_cs_control; > - dev_warn(&spi->dev, > - "chip select function is NULL for this chip\n"); > + if (!gpio_is_valid(pl022->chipselect[spi->chip_select])) > + dev_warn(&spi->dev, > + "chip select function is NULL for this chip\n"); > } else > chip->cs_control = chip_info->cs_control; > > @@ -1988,7 +2028,8 @@ pl022_probe(struct amba_device *adev, const struct amba_id *id) > struct pl022_ssp_controller *platform_info = adev->dev.platform_data; > struct spi_master *master; > struct pl022 *pl022 = NULL; /*Data for this driver */ > - int status = 0; > + struct device_node *np = adev->dev.of_node; > + int status = 0, i, num_cs; > > dev_info(&adev->dev, > "ARM PL022 driver, device ID: 0x%08x\n", adev->periphid); > @@ -1998,8 +2039,14 @@ pl022_probe(struct amba_device *adev, const struct amba_id *id) > goto err_no_pdata; > } > > + num_cs = platform_info->num_chipselect; > + if (IS_ENABLED(CONFIG_OF)) > + of_property_read_u32(np, "pl022,num-chipselects", &num_cs); > + > + > /* Allocate master with space for data */ > - master = spi_alloc_master(dev, sizeof(struct pl022)); > + master = spi_alloc_master(dev, > + sizeof(struct pl022) + sizeof(int) * num_cs); > if (master == NULL) { > dev_err(&adev->dev, "probe - cannot alloc SPI master\n"); > status = -ENOMEM; > @@ -2017,13 +2064,41 @@ pl022_probe(struct amba_device *adev, const struct amba_id *id) > * on this board > */ > master->bus_num = platform_info->bus_id; > - master->num_chipselect = platform_info->num_chipselect; > + master->num_chipselect = num_cs; > master->cleanup = pl022_cleanup; > master->setup = pl022_setup; > master->prepare_transfer_hardware = pl022_prepare_transfer_hardware; > master->transfer_one_message = pl022_transfer_one_message; > master->unprepare_transfer_hardware = pl022_unprepare_transfer_hardware; > master->rt = platform_info->rt; > + master->dev.of_node = dev->of_node; > + > + if (IS_ENABLED(CONFIG_OF)) { > + for (i = 0; i < num_cs; i++) { > + int cs_gpio = of_get_named_gpio(np, "cs-gpios", i); > + > + if (cs_gpio == -EPROBE_DEFER) { > + status = -EPROBE_DEFER; > + goto err_no_gpio; > + } > + > + pl022->chipselect[i] = cs_gpio; > + > + if (gpio_is_valid(cs_gpio)) { > + if (gpio_request(cs_gpio, "ssp-pl022")) > + dev_err(&adev->dev, > + "could not request %d gpio\n", > + cs_gpio); > + else if (gpio_direction_output(cs_gpio, 1)) > + dev_err(&adev->dev, > + "could set gpio %d as output\n", > + cs_gpio); > + } > + } > + } else { > + for (i = 0; i < num_cs; i++) > + pl022->chipselect[i] = -EINVAL; > + } > > /* > * Supports mode 0-3, loopback, and active low CS. Transfers are > @@ -2130,6 +2205,7 @@ pl022_probe(struct amba_device *adev, const struct amba_id *id) > err_no_ioremap: > amba_release_regions(adev); > err_no_ioregion: > + err_no_gpio: > spi_master_put(master); > err_no_master: > err_no_pdata: > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/