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AJvYcCVtq++lYrIOpGhx9idmhQozDqqSn9Lse7RRGXJ4FMzauUfeEOV/fDIeM17rnwUbRuVFC83/KaE4Zmy5@vger.kernel.org, AJvYcCW2ncdMnFORyr7OJZd0daP7SCBnLYurKzHanONAUQ8Sh0Ybw0x8Nz1Tgc+WhYFv3QVTD3e+deY2M7JBw1M=@vger.kernel.org, AJvYcCXr7HGtRqKZWhGH/t9xMyUw7Ch02ObfiihCstV14bLY5QCQiAHaYMjij/Fcw3QmnXnS6Dxllz65n0qU@vger.kernel.org X-Gm-Message-State: AOJu0YzrezXLvO0RbF2Oy31fI4JTyjUKaF9RHgC+cO2HT6j2OoutKF+M 4qMWVQhLT7lpEl83cCSWVOZ5zkUS4nySJmLY7BZVE5Hc6zkkvg+25j6eOOQf X-Google-Smtp-Source: AGHT+IFFn0Nk860biVolgWGFhLVE4FHknRY0i9XVI8UdRKjqK5zzvo8TW2/S/nhVsv6aS9BVgD4mgg== X-Received: by 2002:a05:6820:1501:b0:5e7:caf5:ae1f with SMTP id 006d021491bc7-5ec238a7adcmr10998214eaf.2.1730328061648; Wed, 30 Oct 2024 15:41:01 -0700 (PDT) Received: from raspberrypi ([2600:1700:90:4c80::3b]) by smtp.gmail.com with ESMTPSA id 006d021491bc7-5ec70532d1dsm39502eaf.27.2024.10.30.15.40.59 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 30 Oct 2024 15:41:01 -0700 (PDT) Date: Wed, 30 Oct 2024 17:40:58 -0500 From: Grant Peltier To: robh@kernel.org, linux@roeck-us.net, geert+renesas@glider.be, magnus.damm@gmail.com Cc: grant.peltier.jg@renesas.com, brandon.howell.jg@renesas.com, linux-hwmon@vger.kernel.org, devicetree@vger.kernel.org, linux-doc@vger.kernel.org Subject: [PATCH v6 1/2] hwmon: (pmbus/isl68137) add support for voltage divider on Vout Message-ID: <2189696bf68e64e8f8e41e71f11194c1f8a2889f.1730326916.git.grantpeltier93@gmail.com> References: Precedence: bulk X-Mailing-List: linux-hwmon@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: Some applications require Vout to be higher than the detectable voltage range of the Vsense pin for a given rail. In such applications, a voltage divider may be placed between Vout and the Vsense pin, but this results in erroneous telemetry being read back from the part. This change adds support for a voltage divider to be defined in the devicetree for a (or multiple) specific rail(s) for a supported digital multiphase device and for the applicable Vout telemetry to be scaled based on the voltage divider configuration. This change copies the implementation of the vout-voltage-divider devicetree property defined in the maxim,max20730 bindings schema since it is the best fit for the use case of scaling hwmon PMBus telemetry. The generic voltage-divider property used by many iio drivers was determined to be a poor fit because that schema is tied directly to iio and the isl68137 driver is not an iio driver. Signed-off-by: Grant Peltier --- drivers/hwmon/pmbus/isl68137.c | 209 ++++++++++++++++++++++++++++++++- 1 file changed, 204 insertions(+), 5 deletions(-) diff --git a/drivers/hwmon/pmbus/isl68137.c b/drivers/hwmon/pmbus/isl68137.c index 7e53fb1d5ea3..cd0cc82c18e7 100644 --- a/drivers/hwmon/pmbus/isl68137.c +++ b/drivers/hwmon/pmbus/isl68137.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include @@ -20,6 +21,7 @@ #define ISL68137_VOUT_AVS 0x30 #define RAA_DMPVR2_READ_VMON 0xc8 +#define MAX_CHANNELS 4 enum chips { isl68137, @@ -72,6 +74,17 @@ enum variants { raa_dmpvr2_hv, }; +struct isl68137_channel { + u32 vout_voltage_divider[2]; +}; + +struct isl68137_data { + struct pmbus_driver_info info; + struct isl68137_channel channel[MAX_CHANNELS]; +}; + +#define to_isl68137_data(x) container_of(x, struct isl68137_data, info) + static const struct i2c_device_id raa_dmpvr_id[]; static ssize_t isl68137_avs_enable_show_page(struct i2c_client *client, @@ -163,13 +176,32 @@ static const struct attribute_group *isl68137_attribute_groups[] = { static int raa_dmpvr2_read_word_data(struct i2c_client *client, int page, int phase, int reg) { + const struct pmbus_driver_info *info = pmbus_get_driver_info(client); + const struct isl68137_data *data = to_isl68137_data(info); int ret; + u64 temp; switch (reg) { case PMBUS_VIRT_READ_VMON: ret = pmbus_read_word_data(client, page, phase, RAA_DMPVR2_READ_VMON); break; + case PMBUS_READ_POUT: + case PMBUS_READ_VOUT: + /* + * In cases where a voltage divider is attached to the target + * rail between Vout and the Vsense pin, both Vout and Pout + * should be scaled by the voltage divider scaling factor. + * I.e. Vout = Vsense * Rtotal / Rout + */ + ret = pmbus_read_word_data(client, page, phase, reg); + if (ret > 0) { + temp = DIV_U64_ROUND_CLOSEST((u64)ret * + data->channel[page].vout_voltage_divider[1], + data->channel[page].vout_voltage_divider[0]); + ret = clamp_val(temp, 0, 0xffff); + } + break; default: ret = -ENODATA; break; @@ -178,6 +210,40 @@ static int raa_dmpvr2_read_word_data(struct i2c_client *client, int page, return ret; } +static int raa_dmpvr2_write_word_data(struct i2c_client *client, int page, + int reg, u16 word) +{ + const struct pmbus_driver_info *info = pmbus_get_driver_info(client); + const struct isl68137_data *data = to_isl68137_data(info); + int ret; + u64 temp; + + switch (reg) { + case PMBUS_VOUT_MAX: + case PMBUS_VOUT_MARGIN_HIGH: + case PMBUS_VOUT_MARGIN_LOW: + case PMBUS_VOUT_OV_FAULT_LIMIT: + case PMBUS_VOUT_UV_FAULT_LIMIT: + case PMBUS_VOUT_COMMAND: + /* + * In cases where a voltage divider is attached to the target + * rail between Vout and the Vsense pin, Vout related PMBus + * commands should be scaled based on the expected voltage + * at the Vsense pin. + * I.e. Vsense = Vout * Rout / Rtotal + */ + temp = DIV_U64_ROUND_CLOSEST((u64)word * + data->channel[page].vout_voltage_divider[0], + data->channel[page].vout_voltage_divider[1]); + ret = clamp_val(temp, 0, 0xffff); + break; + default: + ret = -ENODATA; + break; + } + return ret; +} + static struct pmbus_driver_info raa_dmpvr_info = { .pages = 3, .format[PSC_VOLTAGE_IN] = direct, @@ -220,14 +286,91 @@ static struct pmbus_driver_info raa_dmpvr_info = { | PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_POUT, }; +static int isl68137_probe_child_from_dt(struct device *dev, + struct device_node *child, + struct isl68137_data *data) +{ + u32 channel, rout, rtotal; + int err; + + err = of_property_read_u32(child, "reg", &channel); + if (err) { + dev_err(dev, "missing reg property of %pOFn\n", child); + return err; + } + if (channel >= data->info.pages) { + dev_err(dev, "invalid reg %d of %pOFn\n", channel, child); + return -EINVAL; + } + + err = of_property_read_u32_array(child, "vout-voltage-divider", + data->channel[channel].vout_voltage_divider, + ARRAY_SIZE(data->channel[channel].vout_voltage_divider)); + if (err && err != -EINVAL) { + dev_err(dev, + "malformed vout-voltage-divider value for channel %d\n", + channel); + return err; + } + + rout = data->channel[channel].vout_voltage_divider[0]; + rtotal = data->channel[channel].vout_voltage_divider[1]; + if (rout == 0) { + dev_err(dev, + "Voltage divider output resistance must be greater than 0\n"); + return -EINVAL; + } + if (rtotal < rout) { + dev_err(dev, + "Voltage divider total resistance is less than output resistance\n"); + return -EINVAL; + } + + return 0; +} + +static int isl68137_probe_from_dt(struct device *dev, + struct isl68137_data *data) +{ + const struct device_node *np = dev->of_node; + struct device_node *child; + int err; + + for_each_child_of_node(np, child) { + if (strcmp(child->name, "channel")) + continue; + + err = isl68137_probe_child_from_dt(dev, child, data); + if (err) + return err; + } + + return 0; +} + static int isl68137_probe(struct i2c_client *client) { + struct device *dev = &client->dev; struct pmbus_driver_info *info; + struct isl68137_data *data; + int i, err; - info = devm_kzalloc(&client->dev, sizeof(*info), GFP_KERNEL); - if (!info) + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); + if (!data) return -ENOMEM; - memcpy(info, &raa_dmpvr_info, sizeof(*info)); + + /* + * Initialize all voltage dividers to Rout=1 and Rtotal=1 to simplify + * logic in PMBus word read/write functions + */ + for (i = 0; i < MAX_CHANNELS; i++) + memset(data->channel[i].vout_voltage_divider, + 1, + sizeof(data->channel[i].vout_voltage_divider)); + + + memcpy(&data->info, &raa_dmpvr_info, sizeof(data->info)); + info = &data->info; switch (i2c_match_id(raa_dmpvr_id, client)->driver_data) { case raa_dmpvr1_2rail: @@ -242,6 +385,7 @@ static int isl68137_probe(struct i2c_client *client) case raa_dmpvr2_1rail: info->pages = 1; info->read_word_data = raa_dmpvr2_read_word_data; + info->write_word_data = raa_dmpvr2_write_word_data; break; case raa_dmpvr2_2rail_nontc: info->func[0] &= ~PMBUS_HAVE_TEMP3; @@ -250,9 +394,11 @@ static int isl68137_probe(struct i2c_client *client) case raa_dmpvr2_2rail: info->pages = 2; info->read_word_data = raa_dmpvr2_read_word_data; + info->write_word_data = raa_dmpvr2_write_word_data; break; case raa_dmpvr2_3rail: info->read_word_data = raa_dmpvr2_read_word_data; + info->write_word_data = raa_dmpvr2_write_word_data; break; case raa_dmpvr2_hv: info->pages = 1; @@ -263,11 +409,16 @@ static int isl68137_probe(struct i2c_client *client) info->m[PSC_POWER] = 2; info->R[PSC_POWER] = -1; info->read_word_data = raa_dmpvr2_read_word_data; + info->write_word_data = raa_dmpvr2_write_word_data; break; default: return -ENODEV; } + err = isl68137_probe_from_dt(dev, data); + if (err) + return err; + return pmbus_do_probe(client, info); } @@ -318,11 +469,59 @@ static const struct i2c_device_id raa_dmpvr_id[] = { MODULE_DEVICE_TABLE(i2c, raa_dmpvr_id); +static const struct of_device_id isl68137_of_match[] = { + { .compatible = "renesas,isl68137", .data = (void *)raa_dmpvr1_2rail }, + { .compatible = "renesas,isl68220", .data = (void *)raa_dmpvr2_2rail }, + { .compatible = "renesas,isl68221", .data = (void *)raa_dmpvr2_3rail }, + { .compatible = "renesas,isl68222", .data = (void *)raa_dmpvr2_2rail }, + { .compatible = "renesas,isl68223", .data = (void *)raa_dmpvr2_2rail }, + { .compatible = "renesas,isl68224", .data = (void *)raa_dmpvr2_3rail }, + { .compatible = "renesas,isl68225", .data = (void *)raa_dmpvr2_2rail }, + { .compatible = "renesas,isl68226", .data = (void *)raa_dmpvr2_3rail }, + { .compatible = "renesas,isl68227", .data = (void *)raa_dmpvr2_1rail }, + { .compatible = "renesas,isl68229", .data = (void *)raa_dmpvr2_3rail }, + { .compatible = "renesas,isl68233", .data = (void *)raa_dmpvr2_2rail }, + { .compatible = "renesas,isl68239", .data = (void *)raa_dmpvr2_3rail }, + + { .compatible = "renesas,isl69222", .data = (void *)raa_dmpvr2_2rail }, + { .compatible = "renesas,isl69223", .data = (void *)raa_dmpvr2_3rail }, + { .compatible = "renesas,isl69224", .data = (void *)raa_dmpvr2_2rail }, + { .compatible = "renesas,isl69225", .data = (void *)raa_dmpvr2_2rail }, + { .compatible = "renesas,isl69227", .data = (void *)raa_dmpvr2_3rail }, + { .compatible = "renesas,isl69228", .data = (void *)raa_dmpvr2_3rail }, + { .compatible = "renesas,isl69234", .data = (void *)raa_dmpvr2_2rail }, + { .compatible = "renesas,isl69236", .data = (void *)raa_dmpvr2_2rail }, + { .compatible = "renesas,isl69239", .data = (void *)raa_dmpvr2_3rail }, + { .compatible = "renesas,isl69242", .data = (void *)raa_dmpvr2_2rail }, + { .compatible = "renesas,isl69243", .data = (void *)raa_dmpvr2_1rail }, + { .compatible = "renesas,isl69247", .data = (void *)raa_dmpvr2_2rail }, + { .compatible = "renesas,isl69248", .data = (void *)raa_dmpvr2_2rail }, + { .compatible = "renesas,isl69254", .data = (void *)raa_dmpvr2_2rail }, + { .compatible = "renesas,isl69255", .data = (void *)raa_dmpvr2_2rail }, + { .compatible = "renesas,isl69256", .data = (void *)raa_dmpvr2_2rail }, + { .compatible = "renesas,isl69259", .data = (void *)raa_dmpvr2_2rail }, + { .compatible = "renesas,isl69260", .data = (void *)raa_dmpvr2_2rail }, + { .compatible = "renesas,isl69268", .data = (void *)raa_dmpvr2_2rail }, + { .compatible = "renesas,isl69269", .data = (void *)raa_dmpvr2_3rail }, + { .compatible = "renesas,isl69298", .data = (void *)raa_dmpvr2_2rail }, + + { .compatible = "renesas,raa228000", .data = (void *)raa_dmpvr2_hv }, + { .compatible = "renesas,raa228004", .data = (void *)raa_dmpvr2_hv }, + { .compatible = "renesas,raa228006", .data = (void *)raa_dmpvr2_hv }, + { .compatible = "renesas,raa228228", .data = (void *)raa_dmpvr2_2rail_nontc }, + { .compatible = "renesas,raa229001", .data = (void *)raa_dmpvr2_2rail }, + { .compatible = "renesas,raa229004", .data = (void *)raa_dmpvr2_2rail }, + { }, +}; + +MODULE_DEVICE_TABLE(of, isl68137_of_match); + /* This is the driver that will be inserted */ static struct i2c_driver isl68137_driver = { .driver = { - .name = "isl68137", - }, + .name = "isl68137", + .of_match_table = isl68137_of_match, + }, .probe = isl68137_probe, .id_table = raa_dmpvr_id, };