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[95.49.145.20]) by smtp.gmail.com with ESMTPSA id j15sm10502832wrp.85.2020.03.06.12.20.03 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 06 Mar 2020 12:20:04 -0800 (PST) Subject: Re: [PATCH v3 3/3] drivers: leds: add support for apa102c leds To: Nicolas Belin , linux-kernel@vger.kernel.org, linux-leds@vger.kernel.org, pavel@ucw.cz, dmurphy@ti.com, devicetree@vger.kernel.org Cc: baylibre-upstreaming@groups.io References: <1583502010-16210-1-git-send-email-nbelin@baylibre.com> <1583502010-16210-4-git-send-email-nbelin@baylibre.com> From: Jacek Anaszewski Autocrypt: addr=jacek.anaszewski@gmail.com; prefer-encrypt=mutual; keydata= xsFNBFWjfaEBEADd66EQbd6yd8YjG0kbEDT2QIkx8C7BqMXR8AdmA1OMApbfSvEZFT1D/ECR eWFBS8XtApKQx1xAs1j5z70k3zebk2eeNs5ahxi6vM4Qh89vBM46biSKeeX5fLcv7asmGb/a FnHPAfQaKFyG/Bj9V+//ef67hpjJWR3s74C6LZCFLcbZM0z/wTH+baA5Jwcnqr4h/ygosvhP X3gkRzJLSFYekmEv+WHieeKXLrJdsUPUvPJTZtvi3ELUxHNOZwX2oRJStWpmL2QGMwPokRNQ 29GvnueQdQrIl2ylhul6TSrClMrKZqOajDFng7TLgvNfyVZE8WQwmrkTrdzBLfu3kScjE14Q Volq8OtQpTsw5570D4plVKh2ahlhrwXdneSot0STk9Dh1grEB/Jfw8dknvqkdjALUrrM45eF FM4FSMxIlNV8WxueHDss9vXRbCUxzGw37Ck9JWYo0EpcpcvwPf33yntYCbnt+RQRjv7vy3w5 osVwRR4hpbL/fWt1AnZ+RvbP4kYSptOCPQ+Pp1tCw16BOaPjtlqSTcrlD2fo2IbaB5D21SUa IsdZ/XkD+V2S9jCrN1yyK2iKgxtDoUkWiqlfRgH2Ep1tZtb4NLF/S0oCr7rNLO7WbqLZQh1q ShfZR16h7YW//1/NFwnyCVaG1CP/L/io719dPWgEd/sVSKT2TwARAQABzS1KYWNlayBBbmFz emV3c2tpIDxqYWNlay5hbmFzemV3c2tpQGdtYWlsLmNvbT7Cwa8EEwEIAEICGwMHCwkIBwMC AQYVCAIJCgsDFgIBAh4BAheAAhkBFiEEvx38ClaPBfeVdXCQvWpQHLeLfCYFAl5O5twFCRIR arsAIQkQvWpQHLeLfCYWIQS/HfwKVo8F95V1cJC9alAct4t8JhIgEACtWz3zR5uxaU/GozHh iZfiyUTomQpGNvAtjjZE6UKO/cKusCcvOv0FZbfGDajcMIU8f3FUxJdybrY86KJ9a3tOddal KtB2of3/Ot/EIQjpQb28iLoY8AWnf9G4LQZtoXHiUcOAVPkKgCFnz1IENK3uvyCB9c9//KhE cRZkeAIE2sTmcI4k7/dNHpRI4nha/ZytPwTdM3BjAfxxQI5nMLptm1ksEBI7W1SDOnY3dG2J QWmqpxIefjgyiy0aU+jAw1x3RdZrokVD8OCJiJM8+Z36imarEzqIRQLh+sDNLfV3wEaBn/HU 0Vj6VrRyW2K0jAYToRFD3Ay/eGSfOOAEr/LoMr3NBTDkRLEWdOozllOwADEY9wH0BLHMp2WI hXGOStNiroIEhW2/E0udFJo9b3VoOWKWl+zcUP/keLxVUCXhpmeS7VpSkqsrCVqTVkEc8AXq xhJXeIQJC/XRpCYFc3pFUlVCFViF1ZU2OzE8TndRzzD8e/9ETrJ1GAYa78tNopYhY6AbGlv4 U01nIC93bK07O4IhtBAKsiUz3JPX/KA/dXJOC86qP373cVWVYPvZW+KOya9/7rz0MGR1az9G HqJB7q7DVcCQKt9Egae/goznnXbET6ivCNKbqkH3n/JpiPIxkaXVrbn3QlVtzYpROsS/pCOp 5Evig7kql5L0aYJIZs4zBFsKioYWCSsGAQQB2kcPAQEHQFCKEG5pCgebryz66pTa9eAo+r8y TkMEEnG8UR5oWFt3wsIbBBgBCAAgFiEEvx38ClaPBfeVdXCQvWpQHLeLfCYFAlsKioYCGwIA rwkQvWpQHLeLfCaNIAQZFggAHRYhBBTDHErITmX+em3wBGIQbFEb9KXbBQJbCoqGACEJEGIQ bFEb9KXbFiEEFMMcSshOZf56bfAEYhBsURv0pdvELgD/U+y3/hsz0bIjMQJY0LLxM/rFY9Vz 1L43+lQHXjL3MPsA/1lNm5sailsY7aFBVJxAzTa8ZAGWBdVaGo6KCvimDB8GFiEEvx38ClaP BfeVdXCQvWpQHLeLfCbuOg/+PH6gY6Z1GiCzuYb/8f7D0NOcF8+md+R6KKiQZij/6G5Y7lXQ Bz21Opl4Vz/+39i5gmfBa9LRHH4ovR9Pd6H0FCjju4XjIOJkiJYs2HgCCm6nUxRJWzPgyMPS VbqCG2ctwaUiChUdbS+09bWb2MBNjIlI4b8wLWIOtxhyn25Vifm0p+QR5A2ym4bqJJ9LSre1 qM8qdPWcnExPFU4PZFYQgZ9pX1Jyui73ZUP94L7/wg1GyJZL3ePeE4ogBXldE0g0Wq3ORqA9 gA/yvrCSyNKOHTV9JMGnnPGN+wjBYMPMOuqDPC/zcK+stdFXc6UbUM1QNgDnaomvjuloflAx aYdblM26gFfypvpFb8czcPM+BP6X6vWk+Mw9+8vW3tyK9lSg+43OjIWlBGPpO9aLZsYYxAqv J5iSxcbbOLb5q8wWct6U7EZ1RnuOfVInoBttrlYvdWtcI/5NQTptkuB/DyRhrxBJc/fKzJ4w jS2ikcWe0FnxrQpcE2yqoUIFaZMdd/Cx9bRWAGZG087t5dUHJuMnVVcpHZFnHBKr8ag1eH/K tFdDFtyln5A/f9O22xsV0pyJni7e2z7lTBitrQFG69vnVGJlHbBE2dR4GddZqAlVOUbtEcE7 /aMk4TrCtx0IyOzQiLA81aaJWhkD3fRO8cDlR4YQ3F0aqjYy8x1EnnhhohHOwU0EVaN9oQEQ AMPNymBNoCWc13U6qOztXrIKBVsLGZXq/yOaR2n7gFbFACD0TU7XuH2UcnwvNR+uQFwSrRqa EczX2V6iIy2CITXKg5Yvg12yn09gTmafuoIyKoU16XvC3aZQQ2Bn3LO2sRP0j/NuMD9GlO37 pHCVRpI2DPxFE39TMm1PLbHnDG8+lZql+dpNwWw8dDaRgyXx2Le542CcTBT52VCeeWDtqd2M wOr4LioYlfGfAqmwcwucBdTEBUxklQaOR3VbJQx6ntI2oDOBlNGvjnVDzZe+iREd5l40l+Oj TaiWvBGXkv6OI+wx5TFPp+BM6ATU+6UzFRTUWbj+LqVA/JMqYHQp04Y4H5GtjbHCa8abRvBw IKEvpwTyWZlfXPtp8gRlNmxYn6gQlTyEZAWodXwE7CE+KxNnq7bPHeLvrSn8bLNK682PoTGr 0Y00bguYLfyvEwuDYek1/h9YSXtHaCR3CEj4LU1B561G1j7FVaeYbX9bKBAoy/GxAW8J5O1n mmw7FnkSHuwO/QDe0COoO0QZ620Cf9IBWYHW4m2M2yh5981lUaiMcNM2kPgsJFYloFo2XGn6 lWU9BrWjEoNDhHZtF+yaPEuwjZo6x/3E2Tu3E5Jj0VpVcE9U1Zq/fquDY79l2RJn5ENogOs5 +Pi0GjVpEYQVWfm0PTCxNPOzOzGR4QB3BNFvABEBAAHCwZMEGAEIACYCGwwWIQS/HfwKVo8F 95V1cJC9alAct4t8JgUCXk7nGAUJEhFq9wAhCRC9alAct4t8JhYhBL8d/ApWjwX3lXVwkL1q UBy3i3wmVBwP/RNNux3dC513quZ0hFyU6ZDTxbiafprLN2PXhmLslxPktJgW/xO5xp16OXkW YgNI/TKxj3+oSu+MhEAhAFA2urFWHyqedfqdndQTzbv4yqNuyhGupzPBWNSqqJ2NwKJc9f2R wqYTXVYIO+6KLa32rpl7xvJISkx06s70lItFJjyOf6Hn1y5RBMwQN9hP2YxLhYNO3rmlNSVy 7Z/r95lZTDnnUCuxBZxnjx/pMHJ8LZtKY0t7D0esA+zYGUrmoAGUpNWEBP+uSL+f8rhjSAL0 HgoRL39ixg5Bm0MzJn9z3or++Pl5bRnSvHy6OKh7rzTjCwaGoZD+6LHBwPFPlmInX1H+yHrX lu1uPAdqG5xcsZAZFTxBRMEnYu1yYebDSA9x+iulggMZQcWC2GvHCaKIpKcFY8XCxk7Hbl5c 8hcPKWOy16NLO6Y66Ws4kMedXuNUHe4zBLVlRbcYUdgT9Brw8nxmxu3KhEVsJkwOpXLUDuzo hQNfg9em95lpAK+VOTocke8PSESy3GbEtmoMueW3caSeDHb5dRP6WrndaYhEOzAA/KjuPU7J LMXOABOMIq+R38y7e2B3TnVDCrccdZDseFPUWmH0cGCGihH/j2UZG+PImrSDCh3h5MedVHGo sI62tmWm0q6lrljwSZmMZ30w1QaGmdFpI3Q6V+nZ7TZldI3x Message-ID: Date: Fri, 6 Mar 2020 21:20:02 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: <1583502010-16210-4-git-send-email-nbelin@baylibre.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-leds-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-leds@vger.kernel.org Hi Nicolas, On 3/6/20 2:40 PM, Nicolas Belin wrote: > Initilial commit in order to support the apa102c RGB leds. The > RGB and global brightness management is done by creating 4 leds > from the Led Framework per apa102c led. > > Signed-off-by: Nicolas Belin > --- > drivers/leds/Kconfig | 11 ++ > drivers/leds/Makefile | 1 + > drivers/leds/leds-apa102c.c | 306 ++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 318 insertions(+) > create mode 100644 drivers/leds/leds-apa102c.c > > diff --git a/drivers/leds/Kconfig b/drivers/leds/Kconfig > index d82f1dea3711..28fa6c4f65cc 100644 > --- a/drivers/leds/Kconfig > +++ b/drivers/leds/Kconfig > @@ -69,6 +69,17 @@ config LEDS_AN30259A > To compile this driver as a module, choose M here: the module > will be called leds-an30259a. > > +config LEDS_APA102C > + tristate "LED Support for Shiji APA102C" > + depends on SPI > + depends on LEDS_CLASS > + help > + This option enables support for the APA102C RGB LEDs > + from Shiji Lighting. > + > + To compile this driver as a module, choose M here: the module > + will be called leds-apa102c. > + > config LEDS_APU > tristate "Front panel LED support for PC Engines APU/APU2/APU3 boards" > depends on LEDS_CLASS > diff --git a/drivers/leds/Makefile b/drivers/leds/Makefile > index d7e1107753fb..28dfe82900c5 100644 > --- a/drivers/leds/Makefile > +++ b/drivers/leds/Makefile > @@ -88,6 +88,7 @@ obj-$(CONFIG_LEDS_LM36274) += leds-lm36274.o > obj-$(CONFIG_LEDS_TPS6105X) += leds-tps6105x.o > > # LED SPI Drivers > +obj-$(CONFIG_LEDS_APA102C) += leds-apa102c.o > obj-$(CONFIG_LEDS_CR0014114) += leds-cr0014114.o > obj-$(CONFIG_LEDS_DAC124S085) += leds-dac124s085.o > obj-$(CONFIG_LEDS_EL15203000) += leds-el15203000.o > diff --git a/drivers/leds/leds-apa102c.c b/drivers/leds/leds-apa102c.c > new file mode 100644 > index 000000000000..0043e7a6235b > --- /dev/null > +++ b/drivers/leds/leds-apa102c.c > @@ -0,0 +1,306 @@ > +// SPDX-License-Identifier: GPL-2.0 > + > +#include > +#include > +#include > +#include > +#include > +#include "leds.h" > + > +/* > + * Copyright (C) 2020 BayLibre, SAS > + * Author: Nicolas Belin > + */ > + > +/* > + * APA102C SPI protocol description: > + * +------+----------------------------------------+------+ > + * |START | DATA FIELD: | END | > + * |FRAME | N LED FRAMES |FRAME | > + * +------+------+------+------+------+-----+------+------+ > + * | 0*32 | LED1 | LED2 | LED3 | LED4 | --- | LEDN | 1*32 | > + * +------+------+------+------+------+-----+------+------+ > + * > + * +-----------------------------------+ > + * |START FRAME 32bits | > + * +--------+--------+--------+--------+ > + * |00000000|00000000|00000000|00000000| > + * +--------+--------+--------+--------+ > + * > + * +------------------------------------+ > + * |LED FRAME 32bits | > + * +---+-----+--------+--------+--------+ > + * |111|LUMA | BLUE | GREEN | RED | > + * +---+-----+--------+--------+--------+ > + * |3b |5bits| 8bits | 8bits | 8bits | > + * +---+-----+--------+--------+--------+ > + * |MSB LSB|MSB LSB|MSB LSB|MSB LSB| > + * +---+-----+--------+--------+--------+ > + * > + * +-----------------------------------+ > + * |END FRAME 32bits | > + * +--------+--------+--------+--------+ > + * |11111111|11111111|11111111|11111111| > + * +--------+--------+--------+--------+ > + */ > + > +/* apa102c default settings */ > +#define GLOBAL_MAX_BRIGHTNESS GENMASK(4, 0) > +#define RGB_MAX_BRIGHTNESS GENMASK(7, 0) > +#define START_BYTE 0 > +#define END_BYTE GENMASK(7, 0) > +#define LED_FRAME_HEADER GENMASK(7, 5) > + > +struct apa102c_led { > + struct apa102c *priv; > + char name[LED_MAX_NAME_SIZE]; This is not needed, LED core takes care of parsing LED name. > + int color_id; > + struct led_classdev cdev; > +}; > + > +struct apa102c_rgbled { > + /* the 4 components of the apa102c rgb led: > + * global brightness, blue, green and red in that order > + */ > + struct apa102c_led component[4]; > +}; > + > +struct apa102c { > + size_t led_count; > + struct device *dev; > + struct mutex lock; > + struct spi_device *spi; > + u8 *spi_buf; > + struct apa102c_rgbled rgb_leds[]; > +}; > + > +static int apa102c_sync(struct apa102c *priv) > +{ > + int ret; > + size_t i; > + struct apa102c_rgbled *leds = priv->rgb_leds; > + u8 *buf = priv->spi_buf; > + > + /* creating the data that will be sent to all the leds at once */ > + for (i = 0; i < 4; i++) > + *buf++ = START_BYTE; > + > + /* looping on each RGB led component, getting the global brightness > + * then B, G and R values > + */ > + for (i = 0; i < priv->led_count; i++) { > + *buf++ = LED_FRAME_HEADER | > + leds[i].component[0].cdev.brightness; > + *buf++ = leds[i].component[1].cdev.brightness; > + *buf++ = leds[i].component[2].cdev.brightness; > + *buf++ = leds[i].component[3].cdev.brightness; > + } The problem is that in the monochrome LED approach (i.e. the only available one) you have to alter the state of only one LED - that on behalf of which the call is made. And anyway, you're doing here much too much, taking into account that this function is called from brightness_set op. Isn't it possible to update only one LED ? > + > + for (i = 0; i < 4; i++) > + *buf++ = END_BYTE; > + > + ret = spi_write(priv->spi, priv->spi_buf, > + (priv->led_count + 2) * sizeof(u32)); > + > + return ret; > +} > + > +static int apa102c_brightness_set(struct led_classdev *cdev, > + enum led_brightness brightness) > +{ > + int ret; > + struct apa102c_led *led = container_of(cdev, > + struct apa102c_led, > + cdev); > + > + mutex_lock(&led->priv->lock); > + /* updating the brightness then synching all the leds */ > + cdev->brightness = brightness; LED core handles that. Please drop this assignment. > + ret = apa102c_sync(led->priv); > + mutex_unlock(&led->priv->lock); > + > + return ret; > +} > + > +static int apa102c_probe_dt(struct apa102c *priv) > +{ > + int ret = 0; > + u32 i; > + struct apa102c_rgbled *rgb_led; > + struct apa102c_led *led; > + struct fwnode_handle *child; > + const char *rgb_led_name; > + const char *led_component_name; > + > + /* each node corresponds to an rgb led */ > + device_for_each_child_node(priv->dev, child) { > + > + ret = fwnode_property_read_u32(child, "reg", &i); > + if (ret) { > + dev_err(priv->dev, "coudld not read reg %d\n", ret); > + goto child_out; > + } > + > + if (i >= priv->led_count) { > + ret = -EINVAL; > + dev_err(priv->dev, "reg value too big\n"); > + goto child_out; > + } > + > + rgb_led = &priv->rgb_leds[i]; > + /* checking if this led config is already used by checking if > + * the priv member of the global_brightness led as already > + * been set > + */ > + if (rgb_led->component[0].priv) { > + ret = -EINVAL; > + dev_err(priv->dev, "using the same reg value twice\n"); > + goto child_out; > + } > + > + ret = fwnode_property_read_string(child, "label", > + &rgb_led_name); > + if (ret) { > + ret = -EINVAL; > + dev_err(priv->dev, "missing rgb led name\n"); > + goto child_out; > + } > + > + /* setting a color_id value for each of the 4 components of the > + * apa102c RGB led. The first component is the global brightness > + * of the led and thus has no color. The order of the colors > + * after the global brightness is then blue, green and red > + * in that order. It corresponds to the order in which the > + * values are sent using spi > + */ > + rgb_led->component[0].color_id = -1; //no color > + rgb_led->component[1].color_id = LED_COLOR_ID_BLUE; > + rgb_led->component[2].color_id = LED_COLOR_ID_GREEN; > + rgb_led->component[3].color_id = LED_COLOR_ID_RED; Each LED has to have separate DT node. We haven't had so far use case with global brightness but I think it would be OK to add LED_COLOR_ID_LUMA for that. But please hold on with making any changes until Pavel will express his opinion on that. > + > + /* now looping on each component and registering a corresponding > + * led > + */ > + for (i = 0; i < 4; i++) { > + led = &rgb_led->component[i]; > + if (led->color_id == -1) { > + /* the global brightness has no defined name > + * so setting it to "brightness". It also has > + * a different MAX_BRIGHTNESS value. > + * If a trigger is present, setting it on this > + * component > + */ > + led->cdev.max_brightness = > + GLOBAL_MAX_BRIGHTNESS; > + led_component_name = "brightness"; > + fwnode_property_read_string(child, > + "linux,default-trigger", > + &led->cdev.default_trigger); > + } else { > + /* using the color name defined by the framework > + * for the B, G and R components > + */ > + led->cdev.max_brightness = RGB_MAX_BRIGHTNESS; > + led_component_name = led_colors[led->color_id]; > + } > + > + /* the rest is common to all the components */ > + led->priv = priv; > + led->cdev.brightness_set_blocking = > + apa102c_brightness_set; > + /* creating our own led name to differentiate the 4 > + * components > + */ > + snprintf(led->name, sizeof(led->name), > + "%s_%s", rgb_led_name, led_component_name); > + led->cdev.name = led->name; > + LED core can do the above for you, if only you provide it with LED fwnode. > + ret = devm_led_classdev_register_ext(priv->dev, > + &led->cdev, > + NULL); There is no point in using *ext API and not passing led_init_data to it. Please pass struct led_init_data in the third argument, with initialized only its fwnode property. > + if (ret) { > + dev_err(priv->dev, "led register err: %d\n", > + ret); > + goto child_out; > + } > + } > + } > + > +child_out: > + return ret; > +} > + > +static int apa102c_probe(struct spi_device *spi) > +{ > + struct apa102c *priv; > + size_t led_count; > + int ret; > + > + led_count = device_get_child_node_count(&spi->dev); > + if (!led_count) { > + dev_err(&spi->dev, "No LEDs defined in device tree!"); > + return -ENODEV; > + } > + > + priv = devm_kzalloc(&spi->dev, > + struct_size(priv, rgb_leds, led_count), > + GFP_KERNEL); > + if (!priv) > + return -ENOMEM; > + > + priv->spi_buf = devm_kzalloc(&spi->dev, > + (led_count + 2) * sizeof(u32), > + GFP_KERNEL); > + if (!priv->spi_buf) > + return -ENOMEM; > + > + mutex_init(&priv->lock); > + priv->led_count = led_count; > + priv->dev = &spi->dev; > + priv->spi = spi; > + > + ret = apa102c_probe_dt(priv); > + if (ret) > + return ret; > + > + /* Set the LEDs with default values at start */ > + apa102c_sync(priv); > + if (ret) > + return ret; > + > + spi_set_drvdata(spi, priv); > + > + return 0; > +} > + > +static int apa102c_remove(struct spi_device *spi) > +{ > + struct apa102c *priv = spi_get_drvdata(spi); > + > + mutex_destroy(&priv->lock); > + > + return 0; > +} > + > +static const struct of_device_id apa102c_dt_ids[] = { > + { .compatible = "shiji,apa102c", }, > + {}, > +}; > + > +MODULE_DEVICE_TABLE(of, apa102c_dt_ids); > + > +static struct spi_driver apa102c_driver = { > + .probe = apa102c_probe, > + .remove = apa102c_remove, > + .driver = { > + .name = KBUILD_MODNAME, > + .of_match_table = apa102c_dt_ids, > + }, > +}; > + > +module_spi_driver(apa102c_driver); > + > +MODULE_AUTHOR("Nicolas Belin "); > +MODULE_DESCRIPTION("apa102c LED driver"); > +MODULE_LICENSE("GPL v2"); > +MODULE_ALIAS("spi:apa102c"); > -- Best regards, Jacek Anaszewski