From patchwork Wed Oct 4 09:04:46 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Devi Priya X-Patchwork-Id: 730905 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 5E06A10784 for ; Wed, 4 Oct 2023 09:05:41 +0000 (UTC) Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 478B7102; Wed, 4 Oct 2023 02:05:36 -0700 (PDT) Received: from pps.filterd (m0279870.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 3948wlN9030701; Wed, 4 Oct 2023 09:05:17 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quicinc.com; h=from : to : subject : date : message-id : in-reply-to : references : mime-version : content-type : content-transfer-encoding; s=qcppdkim1; bh=dHVR7Wxobr7XwKaP62PJLY+CpwSiYOfg8O2DSQP/ghg=; b=JStyiju6qUC4Hh3BuBoRyhB6P7ZCvJEeFQRfb7EZZRU/oFZdMt39JO2MuLERW+R4FXwl YeN6eceQIGz84qMa6EGttyPr3CY25sPJ4j6RCeFTT9En/vs9P77hEGPK+JmtoYKHkglQ kGEWz3KO2+bS+ov2GSdqjISSDCGG5l/sgdnetIe73L8Zz9d6u3GHGEIWo2KY9Q6/68jC uoBNWltsFox/o3VZI1oLsPy2+/9uZPbg7GtZtL6Gi9WicRfMq8ftMVIdy1jXPRiGEjWu f7J/mjf+MHWmtZP7xmcjYDZioH8jbVqBfDPoUmbMCsnxsaOLhRdI7tQy4O3T9de96npD wQ== Received: from nalasppmta02.qualcomm.com (Global_NAT1.qualcomm.com [129.46.96.20]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 3th18jgetm-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 04 Oct 2023 09:05:16 +0000 Received: from nalasex01a.na.qualcomm.com (nalasex01a.na.qualcomm.com [10.47.209.196]) by NALASPPMTA02.qualcomm.com (8.17.1.5/8.17.1.5) with ESMTPS id 39495FND007032 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Wed, 4 Oct 2023 09:05:15 GMT Received: from hu-devipriy-blr.qualcomm.com (10.80.80.8) by nalasex01a.na.qualcomm.com (10.47.209.196) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1118.36; Wed, 4 Oct 2023 02:05:10 -0700 From: Devi Priya To: , , , , , , , , , , , , , , Subject: [PATCH V13 1/4] pwm: driver for qualcomm ipq6018 pwm block Date: Wed, 4 Oct 2023 14:34:46 +0530 Message-ID: <20231004090449.256229-2-quic_devipriy@quicinc.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231004090449.256229-1-quic_devipriy@quicinc.com> References: <20231004090449.256229-1-quic_devipriy@quicinc.com> Precedence: bulk X-Mailing-List: devicetree@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Originating-IP: [10.80.80.8] X-ClientProxiedBy: nasanex01b.na.qualcomm.com (10.46.141.250) To nalasex01a.na.qualcomm.com (10.47.209.196) X-QCInternal: smtphost X-Proofpoint-Virus-Version: vendor=nai engine=6200 definitions=5800 signatures=585085 X-Proofpoint-GUID: tMUHqMAoLHqHgIaNbm94wsuZerecFNpw X-Proofpoint-ORIG-GUID: tMUHqMAoLHqHgIaNbm94wsuZerecFNpw X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.267,Aquarius:18.0.980,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-10-04_01,2023-10-02_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 impostorscore=0 mlxlogscore=999 bulkscore=0 spamscore=0 priorityscore=1501 lowpriorityscore=0 mlxscore=0 adultscore=0 malwarescore=0 suspectscore=0 clxscore=1015 phishscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2309180000 definitions=main-2310040064 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_BLOCKED, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Driver for the PWM block in Qualcomm IPQ6018 line of SoCs. Based on driver from downstream Codeaurora kernel tree. Removed support for older (V1) variants because I have no access to that hardware. Tested on IPQ6010 based hardware. Co-developed-by: Baruch Siach Signed-off-by: Baruch Siach Signed-off-by: Devi Priya --- V13: No change V12: Fix the below clang warning for overflow check reported by kernel test robot drivers/pwm/pwm-ipq.c:122:11: warning: result of comparison of constant 16000000000 with expression of type 'unsigned long' is always false [-Wtautological-constant-out-of-range-compare] >> if (rate > 16ULL * GIGA) v11: Address comment from Uwe Kleine-König: Drop redundant registers field comments Fix period limit check in .apply Clarify the comment explaining skip of pre_div > pwm_div values Add explicit check for clock rate within limit Add comment explaining the selection of initial pre_div Use pwm_div division with remainder instead of separate diff calculation Round up duty_cycle calculation in .get_state v10: Restore round up in pwm_div calculation; otherwise diff is always <= 0, so only bingo match works Don't overwrite min_diff on every loop iteration v9: Address comment from Uwe Kleine-König: Use period_ns*rate in dividers calculation for better accuracy Round down pre_div and pwm_div Add a comment explaining why pwm_div can't underflow Add a comment explaining why pre_div > pwm_div end the search loop Drop 'CFG_' from register macros Rename to_ipq_pwm_chip() to ipq_pwm_from_chip() Change bare 'unsigned' to 'unsigned int' Clarify the comment on separate REG1 write for enable/disable Round up the period value in .get_state Use direct readl/writel so no need to check for regmap errors v7: Change 'offset' to 'reg' for the tcsr offset (Rob) Drop clock name; there is only one clock (Bjorn) Simplify probe failure code path (Bjorn) v6: Address Uwe Kleine-König review comments: Drop IPQ_PWM_MAX_DEVICES Rely on assigned-clock-rates; drop IPQ_PWM_CLK_SRC_FREQ Simplify register offset calculation Calculate duty cycle more precisely Refuse to set inverted polarity Drop redundant IPQ_PWM_REG1_ENABLE bit clear Remove x1000 factor in pwm_div calculation, use rate directly, and round up Choose initial pre_div such that pwm_div < IPQ_PWM_MAX_DIV Ensure pre_div <= pwm_div Rename close_ to best_ Explain in comment why effective_div doesn't overflow Limit pwm_div to IPQ_PWM_MAX_DIV - 1 to allow 100% duty cycle Disable clock only after pwmchip_remove() const pwm_ops Other changes: Add missing linux/bitfield.h header include (kernel test robot) Adjust code for PWM device node under TCSR (Rob Herring) v5: Use &tcsr_q6 syscon to access registers (Bjorn Andersson) Address Uwe Kleine-König review comments: Implement .get_state() Add IPQ_PWM_ prefix to local macros Use GENMASK/BIT/FIELD_PREP for register fields access Make type of config_div_and_duty() parameters consistent Derive IPQ_PWM_MIN_PERIOD_NS from IPQ_PWM_CLK_SRC_FREQ Integrate enable/disable into config_div_and_duty() to save register read, and reduce frequency glitch on update Use min() instead of min_t() Fix comment format Use dev_err_probe() to indicate probe step failure Add missing clk_disable_unprepare() in .remove Don't set .owner v4: Use div64_u64() to fix link for 32-bit targets ((kernel test robot , Uwe Kleine-König) v3: s/qcom,pwm-ipq6018/qcom,ipq6018-pwm/ (Rob Herring) Fix integer overflow on 32-bit targets (kernel test robot ) v2: Address Uwe Kleine-König review comments: Fix period calculation when out of range Don't set period larger than requested Remove PWM disable on configuration change Implement .apply instead of non-atomic .config/.enable/.disable Don't modify PWM on .request/.free Check pwm_div underflow Fix various code and comment formatting issues Other changes: Use u64 divisor safe division Remove now empty .request/.free drivers/pwm/Kconfig | 12 ++ drivers/pwm/Makefile | 1 + drivers/pwm/pwm-ipq.c | 282 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 295 insertions(+) create mode 100644 drivers/pwm/pwm-ipq.c diff --git a/drivers/pwm/Kconfig b/drivers/pwm/Kconfig index 8ebcddf91f7b..c2d51680823a 100644 --- a/drivers/pwm/Kconfig +++ b/drivers/pwm/Kconfig @@ -282,6 +282,18 @@ config PWM_INTEL_LGM To compile this driver as a module, choose M here: the module will be called pwm-intel-lgm. +config PWM_IPQ + tristate "IPQ PWM support" + depends on ARCH_QCOM || COMPILE_TEST + depends on HAVE_CLK && HAS_IOMEM + help + Generic PWM framework driver for IPQ PWM block which supports + 4 pwm channels. Each of the these channels can be configured + independent of each other. + + To compile this driver as a module, choose M here: the module + will be called pwm-ipq. + config PWM_IQS620A tristate "Azoteq IQS620A PWM support" depends on MFD_IQS62X || COMPILE_TEST diff --git a/drivers/pwm/Makefile b/drivers/pwm/Makefile index c822389c2a24..1b69e8cb2b91 100644 --- a/drivers/pwm/Makefile +++ b/drivers/pwm/Makefile @@ -24,6 +24,7 @@ obj-$(CONFIG_PWM_IMX1) += pwm-imx1.o obj-$(CONFIG_PWM_IMX27) += pwm-imx27.o obj-$(CONFIG_PWM_IMX_TPM) += pwm-imx-tpm.o obj-$(CONFIG_PWM_INTEL_LGM) += pwm-intel-lgm.o +obj-$(CONFIG_PWM_IPQ) += pwm-ipq.o obj-$(CONFIG_PWM_IQS620A) += pwm-iqs620a.o obj-$(CONFIG_PWM_JZ4740) += pwm-jz4740.o obj-$(CONFIG_PWM_KEEMBAY) += pwm-keembay.o diff --git a/drivers/pwm/pwm-ipq.c b/drivers/pwm/pwm-ipq.c new file mode 100644 index 000000000000..5dbe46bb56d6 --- /dev/null +++ b/drivers/pwm/pwm-ipq.c @@ -0,0 +1,282 @@ +// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0 +/* + * Copyright (c) 2016-2017, 2020 The Linux Foundation. All rights reserved. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* The frequency range supported is 1 Hz to clock rate */ +#define IPQ_PWM_MAX_PERIOD_NS ((u64)NSEC_PER_SEC) + +/* + * The max value specified for each field is based on the number of bits + * in the pwm control register for that field + */ +#define IPQ_PWM_MAX_DIV 0xFFFF + +/* + * Two 32-bit registers for each PWM: REG0, and REG1. + * Base offset for PWM #i is at 8 * #i. + */ +#define IPQ_PWM_REG0 0 +#define IPQ_PWM_REG0_PWM_DIV GENMASK(15, 0) +#define IPQ_PWM_REG0_HI_DURATION GENMASK(31, 16) + +#define IPQ_PWM_REG1 4 +#define IPQ_PWM_REG1_PRE_DIV GENMASK(15, 0) +/* + * Enable bit is set to enable output toggling in pwm device. + * Update bit is set to reflect the changed divider and high duration + * values in register. + */ +#define IPQ_PWM_REG1_UPDATE BIT(30) +#define IPQ_PWM_REG1_ENABLE BIT(31) + +struct ipq_pwm_chip { + struct pwm_chip chip; + struct clk *clk; + void __iomem *mem; +}; + +static struct ipq_pwm_chip *ipq_pwm_from_chip(struct pwm_chip *chip) +{ + return container_of(chip, struct ipq_pwm_chip, chip); +} + +static unsigned int ipq_pwm_reg_read(struct pwm_device *pwm, unsigned int reg) +{ + struct ipq_pwm_chip *ipq_chip = ipq_pwm_from_chip(pwm->chip); + unsigned int off = 8 * pwm->hwpwm + reg; + + return readl(ipq_chip->mem + off); +} + +static void ipq_pwm_reg_write(struct pwm_device *pwm, unsigned int reg, + unsigned int val) +{ + struct ipq_pwm_chip *ipq_chip = ipq_pwm_from_chip(pwm->chip); + unsigned int off = 8 * pwm->hwpwm + reg; + + writel(val, ipq_chip->mem + off); +} + +static void config_div_and_duty(struct pwm_device *pwm, unsigned int pre_div, + unsigned int pwm_div, unsigned long rate, u64 duty_ns, + bool enable) +{ + unsigned long hi_dur; + unsigned long val = 0; + + /* + * high duration = pwm duty * (pwm div + 1) + * pwm duty = duty_ns / period_ns + */ + hi_dur = div64_u64(duty_ns * rate, (pre_div + 1) * NSEC_PER_SEC); + + val = FIELD_PREP(IPQ_PWM_REG0_HI_DURATION, hi_dur) | + FIELD_PREP(IPQ_PWM_REG0_PWM_DIV, pwm_div); + ipq_pwm_reg_write(pwm, IPQ_PWM_REG0, val); + + val = FIELD_PREP(IPQ_PWM_REG1_PRE_DIV, pre_div); + ipq_pwm_reg_write(pwm, IPQ_PWM_REG1, val); + + /* PWM enable toggle needs a separate write to REG1 */ + val |= IPQ_PWM_REG1_UPDATE; + if (enable) + val |= IPQ_PWM_REG1_ENABLE; + ipq_pwm_reg_write(pwm, IPQ_PWM_REG1, val); +} + +static int ipq_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, + const struct pwm_state *state) +{ + struct ipq_pwm_chip *ipq_chip = ipq_pwm_from_chip(chip); + unsigned int pre_div, pwm_div, best_pre_div, best_pwm_div; + unsigned long rate = clk_get_rate(ipq_chip->clk); + u64 period_ns, duty_ns, period_rate; + u64 min_diff; + + if (state->polarity != PWM_POLARITY_NORMAL) + return -EINVAL; + + if (state->period < DIV64_U64_ROUND_UP(NSEC_PER_SEC, rate)) + return -ERANGE; + + period_ns = min(state->period, IPQ_PWM_MAX_PERIOD_NS); + duty_ns = min(state->duty_cycle, period_ns); + + /* + * period_ns is 1G or less. As long as rate is less than 16 GHz, + * period_rate does not overflow. Make that explicit. + */ + if ((unsigned long long)rate > 16ULL * GIGA) + return -EINVAL; + period_rate = period_ns * rate; + best_pre_div = IPQ_PWM_MAX_DIV; + best_pwm_div = IPQ_PWM_MAX_DIV; + /* + * We don't need to consider pre_div values smaller than + * + * period_rate + * pre_div_min := ------------------------------------ + * NSEC_PER_SEC * (IPQ_PWM_MAX_DIV + 1) + * + * because pre_div = pre_div_min results in a better + * approximation. + */ + pre_div = div64_u64(period_rate, + (u64)NSEC_PER_SEC * (IPQ_PWM_MAX_DIV + 1)); + min_diff = period_rate; + + for (; pre_div <= IPQ_PWM_MAX_DIV; pre_div++) { + u64 remainder; + + pwm_div = div64_u64_rem(period_rate, + (u64)NSEC_PER_SEC * (pre_div + 1), &remainder); + /* pwm_div is unsigned; the check below catches underflow */ + pwm_div--; + + /* + * Swapping values for pre_div and pwm_div produces the same + * period length. So we can skip all settings with pre_div > + * pwm_div which results in bigger constraints for selecting + * the duty_cycle than with the two values swapped. + */ + if (pre_div > pwm_div) + break; + + /* + * Make sure we can do 100% duty cycle where + * hi_dur == pwm_div + 1 + */ + if (pwm_div > IPQ_PWM_MAX_DIV - 1) + continue; + + if (remainder < min_diff) { + best_pre_div = pre_div; + best_pwm_div = pwm_div; + min_diff = remainder; + + if (min_diff == 0) /* bingo */ + break; + } + } + + /* config divider values for the closest possible frequency */ + config_div_and_duty(pwm, best_pre_div, best_pwm_div, + rate, duty_ns, state->enabled); + + return 0; +} + +static int ipq_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm, + struct pwm_state *state) +{ + struct ipq_pwm_chip *ipq_chip = ipq_pwm_from_chip(chip); + unsigned long rate = clk_get_rate(ipq_chip->clk); + unsigned int pre_div, pwm_div, hi_dur; + u64 effective_div, hi_div; + u32 reg0, reg1; + + reg0 = ipq_pwm_reg_read(pwm, IPQ_PWM_REG0); + reg1 = ipq_pwm_reg_read(pwm, IPQ_PWM_REG1); + + state->polarity = PWM_POLARITY_NORMAL; + state->enabled = reg1 & IPQ_PWM_REG1_ENABLE; + + pwm_div = FIELD_GET(IPQ_PWM_REG0_PWM_DIV, reg0); + hi_dur = FIELD_GET(IPQ_PWM_REG0_HI_DURATION, reg0); + pre_div = FIELD_GET(IPQ_PWM_REG1_PRE_DIV, reg1); + + /* No overflow here, both pre_div and pwm_div <= 0xffff */ + effective_div = (u64)(pre_div + 1) * (pwm_div + 1); + state->period = DIV64_U64_ROUND_UP(effective_div * NSEC_PER_SEC, rate); + + hi_div = hi_dur * (pre_div + 1); + state->duty_cycle = DIV64_U64_ROUND_UP(hi_div * NSEC_PER_SEC, rate); + + return 0; +} + +static const struct pwm_ops ipq_pwm_ops = { + .apply = ipq_pwm_apply, + .get_state = ipq_pwm_get_state, + .owner = THIS_MODULE, +}; + +static int ipq_pwm_probe(struct platform_device *pdev) +{ + struct ipq_pwm_chip *pwm; + struct device *dev = &pdev->dev; + int ret; + + pwm = devm_kzalloc(dev, sizeof(*pwm), GFP_KERNEL); + if (!pwm) + return -ENOMEM; + + platform_set_drvdata(pdev, pwm); + + pwm->mem = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(pwm->mem)) + return dev_err_probe(dev, PTR_ERR(pwm->mem), + "regs map failed"); + + pwm->clk = devm_clk_get(dev, NULL); + if (IS_ERR(pwm->clk)) + return dev_err_probe(dev, PTR_ERR(pwm->clk), + "failed to get clock"); + + ret = clk_prepare_enable(pwm->clk); + if (ret) + return dev_err_probe(dev, ret, "clock enable failed"); + + pwm->chip.dev = dev; + pwm->chip.ops = &ipq_pwm_ops; + pwm->chip.npwm = 4; + + ret = pwmchip_add(&pwm->chip); + if (ret < 0) { + dev_err_probe(dev, ret, "pwmchip_add() failed\n"); + clk_disable_unprepare(pwm->clk); + } + + return ret; +} + +static int ipq_pwm_remove(struct platform_device *pdev) +{ + struct ipq_pwm_chip *pwm = platform_get_drvdata(pdev); + + pwmchip_remove(&pwm->chip); + clk_disable_unprepare(pwm->clk); + + return 0; +} + +static const struct of_device_id pwm_ipq_dt_match[] = { + { .compatible = "qcom,ipq6018-pwm", }, + {} +}; +MODULE_DEVICE_TABLE(of, pwm_ipq_dt_match); + +static struct platform_driver ipq_pwm_driver = { + .driver = { + .name = "ipq-pwm", + .of_match_table = pwm_ipq_dt_match, + }, + .probe = ipq_pwm_probe, + .remove = ipq_pwm_remove, +}; + +module_platform_driver(ipq_pwm_driver); + +MODULE_LICENSE("Dual BSD/GPL");