From patchwork Fri Mar 15 01:57:07 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Justin Swartz X-Patchwork-Id: 13592996 Received: from outgoing6.flk.host-h.net (outgoing6.flk.host-h.net [188.40.0.77]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 745A253A0; Fri, 15 Mar 2024 01:56:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=188.40.0.77 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710467828; cv=none; b=B6f/WOgOM2ObvGhMV+BIZ2QKLJ4wikGzGX4VfDB6FZkDGwlv7/tFDHbEihPL9clPV8LDiOmYAb6HOGPSJxyLLWJk6BoZkRnXN4zZ+LcmcS9fvpkjUn4jRgKmbfDdEKzY11MkQMe/OXNwhoFGhVPNbiZgtXSPjXrKBDhUaha3lrM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710467828; c=relaxed/simple; bh=k/4MAwR3FTpi3ezP4O+KfGOb9q/xcoTFPk2EDj74BQ4=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; 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auth=pass (login) smtp.auth=@risingedge.co.za X-SpamExperts-Outgoing-Class: ham X-SpamExperts-Outgoing-Evidence: SB/global_tokens (0.00107698202516) X-Recommended-Action: accept X-Filter-ID: Pt3MvcO5N4iKaDQ5O6lkdGlMVN6RH8bjRMzItlySaT9tEvqO5Dzlp8Hw8s4Xw7pgPUtbdvnXkggZ 3YnVId/Y5jcf0yeVQAvfjHznO7+bT5wCPRB8bAzJcv2cv+UqiTTc2+CpNcmBnO4XM3Sck4bwNogU WCl1nkLBzZX0KuJ9bXiS85Z42w/+2OBolTNFbPomXFWCX8oNdggW7HE9XDTdSejrkEpbuUvwMvHx 3T+KSG//gbuP7hnUK8NQdLwsVWKIss2oH4Yjh6Q4paNNh70vrmKlRYN8+ZW0XX0AH/7tz8lOUWMR 3Oz/N19DDfqg//ykQCB4rUl3suKct8rEwEjtlBjGf82vsPPH4Z6bBeyJ2ioKLll7c1zqbZ0Shnfk f76m6WzjgyOQ30CX3jGye0AgO43dPg2t4siixN3H6ipUQpsUOAoG0LIxLqqnLG/G17r2WmuNA8WT ybi1JN85FSnfKaZl5e9CnNR0t//S8nh6vX9JR7tTkgtGxbJXMnaWeORi/IOL8hFK8UwSRsjj826v xIvoo9siXVea4yN8+JzC4p2qtoJeAaAIM5zNlwLSz7WsotxMDYRAzuCR0I/uZN17IfdXFZsEUcDk 8TfE1VxuxGc2M4JzCc//R6Wyn0xEa4/gbKRUuwP9TxU53J++//mag2wVXO50BuTihrUiUr+Ne0YD 3ddZG295JphtZpms9X0aBNANCxNWMmHXUTEMGGbKThOghFKJuzFdJ78lk25pCKnYrhUnk1aI/tYo PYfrgLItviC2z3vIzjh1mXBwO7cA3KxDuzsITj9XSEsqBTpMNClkAdhK23InA2zzja5I1riDVsRE /qfh3BpRIL035Lwa3AR5iWi4B3c2TvD1mYFCey4YQsgkfE0ewNgNUY5lZOQ5d86hkdfWpdNtlHKD /N5YI0ii+HGJbtyrZfX5fEH4LjZJ4azDVvtI4xLpBrhpV1Z2g0cC96lvLg9F6alXVA5GCKQ8jPBS b1sSQu/sXnVb6BTD1y1EN4lWLphXo/QFY19Ko4ys4J2lj1UPbPmBHp1pEv3Fs7AeUg8cSzkuHTCW 7WeivJsOGdLHT5AmY9PDPjGy0z6bhalFEM/pjPCQA+BAlnIZxFSV0ux1niV+gnzf0coKruD/dlzX C6+t6EZu9kdJLKf1SPrgqyxNzu9tGWZKtpHq1b8bdjWfKogUQsVZaT9m4zuNRcgRKiGg7nXFaZTx I/6scxhAq/6af00PEtBNjYtqmoKr5eemJzKNdiP7m3gSrWCqyhAo0JR3rThOyxKFbWMT2xK3KT9R mx5HiKCYjt40eTXlWiUAYdLmsJdAoPIA+QBBCmRnfEQkXp5mAyXTIBVUuAX2KYddQlACXnsZ2u9C nazM3+ZE40UYhpZLE/UxL7hrJSk60SF3F6RYOYr2 X-Report-Abuse-To: spam@antispamquarantine.host-h.net Extract a magic number, from mt7621_spi_probe(), used to declare the number of chip select lines (which co-incides with the native chip select count of 2) to a macro. Use the newly defined MT7621_NATIVE_CS_COUNT macro to instead populate both the spi_controller's max_native_cs and num_chipselect members. Declare that the spi_controller should use_gpio_descriptors if present in the device properties (such as those declared in the cs-gpio property of a "ralink,mt7621-spi" compatible device-tree node) so that the SPI core will recalulcate num_chipselect to account for the GPIO descriptors that it should have populated in the cs_gpiod array member. Add the mt7621_spi_set_cs_gpio() function to control the logical state of a GPIO chip select line, agnostic of the electrical line state and activation polarity. Add the mt7621_spi_cleanup() function to ensure that every GPIO chip select will be deactivated when no longer in use. Extend mt7621_spi_setup() so that if an SPI device is associated with a GPIO chip select, its chip select line will be deactivated before use. Rename mt7621_spi_set_cs() to mt7621_spi_set_native_cs(), and redefine mt7621_spi_set_cs() to determine whether: to call mt7621_spi_set_cs_gpio(), in the case of the passed SPI device being associated with a GPIO chip select line, or to call mt7621_spi_set_set_native_cs() instead. Modify mt7621_transfer_one_message() to take into account that mt7621_spi_set_cs() now returns an int and should use the returned value for spi_message status indication if a failure related to GPIO access has occured. Signed-off-by: Justin Swartz --- See Documentation/devicetree/bindings/spi/spi-controller.yaml for information about cs-gpios semantics. Example: &spi0 { cs-gpios = <0>, <0>, <&gpio 18 GPIO_ACTIVE_LOW>, /* WDT_RST_N */ <&gpio 19 GPIO_ACTIVE_HIGH>; /* PERST_N */ status = "ok"; ... spidev@2 { compatible = "defective,by-design"; reg = <2>; spi-max-frequency = <16000000>; }; spidev@3 { compatible = "defective,by-design"; reg = <3>; spi-cs-high; spi-max-frequency = <16000000>; }; }; drivers/spi/spi-mt7621.c | 46 ++++++++++++++++++++++++++++++++++++---- 1 file changed, 42 insertions(+), 4 deletions(-) -- diff --git a/drivers/spi/spi-mt7621.c b/drivers/spi/spi-mt7621.c index 4e9053d03..87e164c86 100644 --- a/drivers/spi/spi-mt7621.c +++ b/drivers/spi/spi-mt7621.c @@ -52,6 +52,8 @@ #define MT7621_CPOL BIT(4) #define MT7621_LSB_FIRST BIT(3) +#define MT7621_NATIVE_CS_COUNT 2 + struct mt7621_spi { struct spi_controller *host; void __iomem *base; @@ -75,7 +77,19 @@ static inline void mt7621_spi_write(struct mt7621_spi *rs, u32 reg, u32 val) iowrite32(val, rs->base + reg); } -static void mt7621_spi_set_cs(struct spi_device *spi, int enable) +static int mt7621_spi_set_cs_gpio(struct spi_device *spi, int enable) +{ + struct gpio_desc *gpiod = spi_get_csgpiod(spi, 0); + int cs = spi_get_chipselect(spi, 0); + int status = gpiod_direction_output(gpiod, enable); + + if (status) + dev_err(&spi->dev, "set_gpio: failed to set CS%d", cs); + + return status; +} + +static void mt7621_spi_set_native_cs(struct spi_device *spi, int enable) { struct mt7621_spi *rs = spidev_to_mt7621_spi(spi); int cs = spi_get_chipselect(spi, 0); @@ -99,6 +113,15 @@ static void mt7621_spi_set_cs(struct spi_device *spi, int enable) mt7621_spi_write(rs, MT7621_SPI_POLAR, polar); } +static int mt7621_spi_set_cs(struct spi_device *spi, int enable) +{ + if (spi_is_csgpiod(spi)) + return mt7621_spi_set_cs_gpio(spi, enable); + + mt7621_spi_set_native_cs(spi,enable); + return 0; +} + static int mt7621_spi_prepare(struct spi_device *spi, unsigned int speed) { struct mt7621_spi *rs = spidev_to_mt7621_spi(spi); @@ -266,7 +289,9 @@ static int mt7621_spi_transfer_one_message(struct spi_controller *host, } /* Assert CS */ - mt7621_spi_set_cs(spi, 1); + status = mt7621_spi_set_cs(spi, 1); + if (status) + goto msg_done; m->actual_length = 0; list_for_each_entry(t, &m->transfers, transfer_list) { @@ -290,7 +315,7 @@ static int mt7621_spi_transfer_one_message(struct spi_controller *host, /* Flush data and deassert CS */ mt7621_spi_flush(rs); - mt7621_spi_set_cs(spi, 0); + status = mt7621_spi_set_cs(spi, 0); msg_done: m->status = status; @@ -313,9 +338,18 @@ static int mt7621_spi_setup(struct spi_device *spi) return -EINVAL; } + if (spi_is_csgpiod(spi)) + return mt7621_spi_set_cs_gpio(spi, 0); + return 0; } +static void mt7621_spi_cleanup(struct spi_device *spi) +{ + if (spi_is_csgpiod(spi)) + mt7621_spi_set_cs_gpio(spi, 0); +} + static const struct of_device_id mt7621_spi_match[] = { { .compatible = "ralink,mt7621-spi" }, {}, @@ -353,10 +387,14 @@ static int mt7621_spi_probe(struct platform_device *pdev) host->mode_bits = SPI_LSB_FIRST; host->flags = SPI_CONTROLLER_HALF_DUPLEX; host->setup = mt7621_spi_setup; + host->cleanup = mt7621_spi_cleanup; host->transfer_one_message = mt7621_spi_transfer_one_message; host->bits_per_word_mask = SPI_BPW_MASK(8); host->dev.of_node = pdev->dev.of_node; - host->num_chipselect = 2; + + host->max_native_cs = MT7621_NATIVE_CS_COUNT; + host->num_chipselect = host->max_native_cs; + host->use_gpio_descriptors = true; dev_set_drvdata(&pdev->dev, host);