Hi Fabrice, Thank you for the patch! Perhaps something to improve:
[auto build test WARNING on pwm/for-next] [also build test WARNING on v4.17-rc1 next-20180416] [cannot apply to ljones-mfd/for-mfd-next] [if your patch is applied to the wrong git tree, please drop us a note to help improve the system] url: https://github.com/0day-ci/linux/commits/Fabrice-Gasnier/Add-support-for-PWM-input-capture-on-STM32/20180417-052347 base: https://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm.git for-next smatch warnings: drivers/mfd/stm32-timers.c:165 stm32_timers_dma_burst_read() warn: warn: dma_mapping_error() doesn't return an error code # https://github.com/0day-ci/linux/commit/402362a100e6b02b807fbebdc05b7159b565ffa5 git remote add linux-review https://github.com/0day-ci/linux git remote update linux-review git checkout 402362a100e6b02b807fbebdc05b7159b565ffa5 vim +165 drivers/mfd/stm32-timers.c 402362a1 Fabrice Gasnier 2018-04-16 54 402362a1 Fabrice Gasnier 2018-04-16 55 /** 402362a1 Fabrice Gasnier 2018-04-16 56 * stm32_timers_dma_burst_read - Read from timers registers using DMA. 402362a1 Fabrice Gasnier 2018-04-16 57 * 402362a1 Fabrice Gasnier 2018-04-16 58 * Read from STM32 timers registers using DMA on a single event. 402362a1 Fabrice Gasnier 2018-04-16 59 * @dev: reference to stm32_timers MFD device 402362a1 Fabrice Gasnier 2018-04-16 60 * @buf: DMA'able destination buffer 402362a1 Fabrice Gasnier 2018-04-16 61 * @id: stm32_timers_dmas event identifier (ch[1..4], up, trig or com) 402362a1 Fabrice Gasnier 2018-04-16 62 * @reg: registers start offset for DMA to read from (like CCRx for capture) 402362a1 Fabrice Gasnier 2018-04-16 63 * @num_reg: number of registers to read upon each DMA request, starting @reg. 402362a1 Fabrice Gasnier 2018-04-16 64 * @bursts: number of bursts to read (e.g. like two for pwm period capture) 402362a1 Fabrice Gasnier 2018-04-16 65 * @tmo_ms: timeout (milliseconds) 402362a1 Fabrice Gasnier 2018-04-16 66 */ 402362a1 Fabrice Gasnier 2018-04-16 67 int stm32_timers_dma_burst_read(struct device *dev, u32 *buf, 402362a1 Fabrice Gasnier 2018-04-16 68 enum stm32_timers_dmas id, u32 reg, 402362a1 Fabrice Gasnier 2018-04-16 69 unsigned int num_reg, unsigned int bursts, 402362a1 Fabrice Gasnier 2018-04-16 70 unsigned long tmo_ms) 402362a1 Fabrice Gasnier 2018-04-16 71 { 402362a1 Fabrice Gasnier 2018-04-16 72 struct stm32_timers *ddata = dev_get_drvdata(dev); 402362a1 Fabrice Gasnier 2018-04-16 73 unsigned long timeout = msecs_to_jiffies(tmo_ms); 402362a1 Fabrice Gasnier 2018-04-16 74 struct regmap *regmap = ddata->regmap; 402362a1 Fabrice Gasnier 2018-04-16 75 struct stm32_timers_dma *dma = ddata->dma; 402362a1 Fabrice Gasnier 2018-04-16 76 size_t len = num_reg * bursts * sizeof(u32); 402362a1 Fabrice Gasnier 2018-04-16 77 struct dma_async_tx_descriptor *desc; 402362a1 Fabrice Gasnier 2018-04-16 78 struct dma_slave_config config; 402362a1 Fabrice Gasnier 2018-04-16 79 dma_cookie_t cookie; 402362a1 Fabrice Gasnier 2018-04-16 80 dma_addr_t dma_buf; 402362a1 Fabrice Gasnier 2018-04-16 81 u32 dbl, dba; 402362a1 Fabrice Gasnier 2018-04-16 82 long err; 402362a1 Fabrice Gasnier 2018-04-16 83 int ret; 402362a1 Fabrice Gasnier 2018-04-16 84 402362a1 Fabrice Gasnier 2018-04-16 85 /* Sanity check */ 402362a1 Fabrice Gasnier 2018-04-16 86 if (id < STM32_TIMERS_DMA_CH1 || id >= STM32_TIMERS_MAX_DMAS) 402362a1 Fabrice Gasnier 2018-04-16 87 return -EINVAL; 402362a1 Fabrice Gasnier 2018-04-16 88 402362a1 Fabrice Gasnier 2018-04-16 89 if (!num_reg || !bursts || reg > STM32_TIMERS_MAX_REGISTERS || 402362a1 Fabrice Gasnier 2018-04-16 90 (reg + num_reg * sizeof(u32)) > STM32_TIMERS_MAX_REGISTERS) 402362a1 Fabrice Gasnier 2018-04-16 91 return -EINVAL; 402362a1 Fabrice Gasnier 2018-04-16 92 402362a1 Fabrice Gasnier 2018-04-16 93 if (!dma->chans[id]) 402362a1 Fabrice Gasnier 2018-04-16 94 return -ENODEV; 402362a1 Fabrice Gasnier 2018-04-16 95 mutex_lock(&dma->lock); 402362a1 Fabrice Gasnier 2018-04-16 96 402362a1 Fabrice Gasnier 2018-04-16 97 /* Select DMA channel in use */ 402362a1 Fabrice Gasnier 2018-04-16 98 dma->chan = dma->chans[id]; 402362a1 Fabrice Gasnier 2018-04-16 99 dma_buf = dma_map_single(dev, buf, len, DMA_FROM_DEVICE); 402362a1 Fabrice Gasnier 2018-04-16 100 ret = dma_mapping_error(dev, dma_buf); ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ This should be: if (dma_mapping_error(dev, dma_buf)) { ret = -ENOMEM; goto unlock; } 402362a1 Fabrice Gasnier 2018-04-16 101 if (ret) 402362a1 Fabrice Gasnier 2018-04-16 102 goto unlock; 402362a1 Fabrice Gasnier 2018-04-16 103 402362a1 Fabrice Gasnier 2018-04-16 104 /* Prepare DMA read from timer registers, using DMA burst mode */ 402362a1 Fabrice Gasnier 2018-04-16 105 memset(&config, 0, sizeof(config)); 402362a1 Fabrice Gasnier 2018-04-16 106 config.src_addr = (dma_addr_t)dma->phys_base + TIM_DMAR; 402362a1 Fabrice Gasnier 2018-04-16 107 config.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES; 402362a1 Fabrice Gasnier 2018-04-16 108 ret = dmaengine_slave_config(dma->chan, &config); 402362a1 Fabrice Gasnier 2018-04-16 109 if (ret) 402362a1 Fabrice Gasnier 2018-04-16 110 goto unmap; 402362a1 Fabrice Gasnier 2018-04-16 111 402362a1 Fabrice Gasnier 2018-04-16 112 desc = dmaengine_prep_slave_single(dma->chan, dma_buf, len, 402362a1 Fabrice Gasnier 2018-04-16 113 DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT); 402362a1 Fabrice Gasnier 2018-04-16 114 if (!desc) { 402362a1 Fabrice Gasnier 2018-04-16 115 ret = -EBUSY; 402362a1 Fabrice Gasnier 2018-04-16 116 goto unmap; 402362a1 Fabrice Gasnier 2018-04-16 117 } 402362a1 Fabrice Gasnier 2018-04-16 118 402362a1 Fabrice Gasnier 2018-04-16 119 desc->callback = stm32_timers_dma_done; 402362a1 Fabrice Gasnier 2018-04-16 120 desc->callback_param = dma; 402362a1 Fabrice Gasnier 2018-04-16 121 cookie = dmaengine_submit(desc); 402362a1 Fabrice Gasnier 2018-04-16 122 ret = dma_submit_error(cookie); 402362a1 Fabrice Gasnier 2018-04-16 123 if (ret) 402362a1 Fabrice Gasnier 2018-04-16 124 goto dma_term; 402362a1 Fabrice Gasnier 2018-04-16 125 402362a1 Fabrice Gasnier 2018-04-16 126 reinit_completion(&dma->completion); 402362a1 Fabrice Gasnier 2018-04-16 127 dma_async_issue_pending(dma->chan); 402362a1 Fabrice Gasnier 2018-04-16 128 402362a1 Fabrice Gasnier 2018-04-16 129 /* Setup and enable timer DMA burst mode */ 402362a1 Fabrice Gasnier 2018-04-16 130 dbl = FIELD_PREP(TIM_DCR_DBL, bursts - 1); 402362a1 Fabrice Gasnier 2018-04-16 131 dba = FIELD_PREP(TIM_DCR_DBA, reg >> 2); 402362a1 Fabrice Gasnier 2018-04-16 132 ret = regmap_write(regmap, TIM_DCR, dbl | dba); 402362a1 Fabrice Gasnier 2018-04-16 133 if (ret) 402362a1 Fabrice Gasnier 2018-04-16 134 goto dma_term; 402362a1 Fabrice Gasnier 2018-04-16 135 402362a1 Fabrice Gasnier 2018-04-16 136 /* Clear pending flags before enabling DMA request */ 402362a1 Fabrice Gasnier 2018-04-16 137 ret = regmap_write(regmap, TIM_SR, 0); 402362a1 Fabrice Gasnier 2018-04-16 138 if (ret) 402362a1 Fabrice Gasnier 2018-04-16 139 goto dcr_clr; 402362a1 Fabrice Gasnier 2018-04-16 140 402362a1 Fabrice Gasnier 2018-04-16 141 ret = regmap_update_bits(regmap, TIM_DIER, stm32_timers_dier_dmaen[id], 402362a1 Fabrice Gasnier 2018-04-16 142 stm32_timers_dier_dmaen[id]); 402362a1 Fabrice Gasnier 2018-04-16 143 if (ret) 402362a1 Fabrice Gasnier 2018-04-16 144 goto dcr_clr; 402362a1 Fabrice Gasnier 2018-04-16 145 402362a1 Fabrice Gasnier 2018-04-16 146 err = wait_for_completion_interruptible_timeout(&dma->completion, 402362a1 Fabrice Gasnier 2018-04-16 147 timeout); 402362a1 Fabrice Gasnier 2018-04-16 148 if (err == 0) 402362a1 Fabrice Gasnier 2018-04-16 149 ret = -ETIMEDOUT; 402362a1 Fabrice Gasnier 2018-04-16 150 else if (err < 0) 402362a1 Fabrice Gasnier 2018-04-16 151 ret = err; 402362a1 Fabrice Gasnier 2018-04-16 152 402362a1 Fabrice Gasnier 2018-04-16 153 regmap_update_bits(regmap, TIM_DIER, stm32_timers_dier_dmaen[id], 0); 402362a1 Fabrice Gasnier 2018-04-16 154 regmap_write(regmap, TIM_SR, 0); 402362a1 Fabrice Gasnier 2018-04-16 155 dcr_clr: 402362a1 Fabrice Gasnier 2018-04-16 156 regmap_write(regmap, TIM_DCR, 0); 402362a1 Fabrice Gasnier 2018-04-16 157 dma_term: 402362a1 Fabrice Gasnier 2018-04-16 158 dmaengine_terminate_all(dma->chan); 402362a1 Fabrice Gasnier 2018-04-16 159 unmap: 402362a1 Fabrice Gasnier 2018-04-16 160 dma_unmap_single(dev, dma_buf, len, DMA_FROM_DEVICE); 402362a1 Fabrice Gasnier 2018-04-16 161 unlock: 402362a1 Fabrice Gasnier 2018-04-16 162 dma->chan = NULL; 402362a1 Fabrice Gasnier 2018-04-16 163 mutex_unlock(&dma->lock); 402362a1 Fabrice Gasnier 2018-04-16 164 402362a1 Fabrice Gasnier 2018-04-16 @165 return ret; 402362a1 Fabrice Gasnier 2018-04-16 166 } 402362a1 Fabrice Gasnier 2018-04-16 167 EXPORT_SYMBOL_GPL(stm32_timers_dma_burst_read); 402362a1 Fabrice Gasnier 2018-04-16 168 --- 0-DAY kernel test infrastructure Open Source Technology Center https://lists.01.org/pipermail/kbuild-all Intel Corporation
