From 2ade0172154e50c8a2bfd8634c6eff943cffea29 Mon Sep 17 00:00:00 2001 From: "SkyLake.Huang" Date: Thu, 23 Jun 2022 18:35:52 +0800 Subject: [PATCH 2/6] drivers: spi: Add support for dynamic calibration Signed-off-by: SkyLake.Huang --- drivers/spi/spi.c | 137 ++++++++++++++++++++++++++++++++++++++++ include/linux/spi/spi.h | 42 ++++++++++++ 2 files changed, 179 insertions(+) --- a/drivers/spi/spi.c +++ b/drivers/spi/spi.c @@ -1374,6 +1374,70 @@ static int spi_transfer_wait(struct spi_ return 0; } +int spi_do_calibration(struct spi_controller *ctlr, struct spi_device *spi, + int (*cal_read)(void *priv, u32 *addr, int addrlen, u8 *buf, int readlen), void *drv_priv) +{ + int datalen = ctlr->cal_rule->datalen; + int addrlen = ctlr->cal_rule->addrlen; + u8 *buf; + int ret; + int i; + struct list_head *cal_head, *listptr; + struct spi_cal_target *target; + + /* Calculate calibration result */ + int hit_val, total_hit, origin; + bool hit; + + /* Make sure we can start calibration */ + if(!ctlr->cal_target || !ctlr->cal_rule || !ctlr->append_caldata) + return 0; + + buf = kzalloc(datalen * sizeof(u8), GFP_KERNEL); + if(!buf) + return -ENOMEM; + + ret = ctlr->append_caldata(ctlr); + if (ret) + goto cal_end; + + cal_head = ctlr->cal_target; + list_for_each(listptr, cal_head) { + target = list_entry(listptr, struct spi_cal_target, list); + + hit = false; + hit_val = 0; + total_hit = 0; + origin = *target->cal_item; + + for(i=target->cal_min; i<=target->cal_max; i+=target->step) { + *target->cal_item = i; + ret = (*cal_read)(drv_priv, ctlr->cal_rule->addr, addrlen, buf, datalen); + if(ret) + break; + dev_dbg(&spi->dev, "controller cal item value: 0x%x\n", i); + if(memcmp(ctlr->cal_rule->match_data, buf, datalen * sizeof(u8)) == 0) { + hit = true; + hit_val += i; + total_hit++; + dev_dbg(&spi->dev, "golden data matches data read!\n"); + } + } + if(hit) { + *target->cal_item = DIV_ROUND_CLOSEST(hit_val, total_hit); + dev_info(&spi->dev, "calibration result: 0x%x", *target->cal_item); + } else { + *target->cal_item = origin; + dev_warn(&spi->dev, "calibration failed, fallback to default: 0x%x", origin); + } + } + +cal_end: + kfree(buf); + return ret? ret: 0; +} +EXPORT_SYMBOL_GPL(spi_do_calibration); + static void _spi_transfer_delay_ns(u32 ns) { if (!ns) @@ -2208,6 +2272,75 @@ void spi_flush_queue(struct spi_controll /*-------------------------------------------------------------------------*/ #if defined(CONFIG_OF) +static inline void alloc_cal_data(struct list_head **cal_target, + struct spi_cal_rule **cal_rule, bool enable) +{ + if(enable) { + *cal_target = kmalloc(sizeof(struct list_head), GFP_KERNEL); + INIT_LIST_HEAD(*cal_target); + *cal_rule = kmalloc(sizeof(struct spi_cal_rule), GFP_KERNEL); + } else { + kfree(*cal_target); + kfree(*cal_rule); + } +} + +static int of_spi_parse_cal_dt(struct spi_controller *ctlr, struct spi_device *spi, + struct device_node *nc) +{ + u32 value; + int rc; + const char *cal_mode; + + rc = of_property_read_bool(nc, "spi-cal-enable"); + if (rc) + alloc_cal_data(&ctlr->cal_target, &ctlr->cal_rule, true); + else + return 0; + + rc = of_property_read_string(nc, "spi-cal-mode", &cal_mode); + if(!rc) { + if(strcmp("read-data", cal_mode) == 0){ + ctlr->cal_rule->mode = SPI_CAL_READ_DATA; + } else if(strcmp("read-pp", cal_mode) == 0) { + ctlr->cal_rule->mode = SPI_CAL_READ_PP; + return 0; + } else if(strcmp("read-sfdp", cal_mode) == 0){ + ctlr->cal_rule->mode = SPI_CAL_READ_SFDP; + return 0; + } + } else + goto err; + + ctlr->cal_rule->datalen = 0; + rc = of_property_read_u32(nc, "spi-cal-datalen", &value); + if(!rc && value > 0) { + ctlr->cal_rule->datalen = value; + + ctlr->cal_rule->match_data = kzalloc(value * sizeof(u8), GFP_KERNEL); + rc = of_property_read_u8_array(nc, "spi-cal-data", + ctlr->cal_rule->match_data, value); + if(rc) + kfree(ctlr->cal_rule->match_data); + } + + rc = of_property_read_u32(nc, "spi-cal-addrlen", &value); + if(!rc && value > 0) { + ctlr->cal_rule->addrlen = value; + + ctlr->cal_rule->addr = kzalloc(value * sizeof(u32), GFP_KERNEL); + rc = of_property_read_u32_array(nc, "spi-cal-addr", + ctlr->cal_rule->addr, value); + if(rc) + kfree(ctlr->cal_rule->addr); + } + return 0; + +err: + alloc_cal_data(&ctlr->cal_target, &ctlr->cal_rule, false); + return 0; +} + static int of_spi_parse_dt(struct spi_controller *ctlr, struct spi_device *spi, struct device_node *nc) { @@ -2326,6 +2459,10 @@ of_register_spi_device(struct spi_contro if (rc) goto err_out; + rc = of_spi_parse_cal_dt(ctlr, spi, nc); + if (rc) + goto err_out; + /* Store a pointer to the node in the device structure */ of_node_get(nc); spi->dev.of_node = nc; --- a/include/linux/spi/spi.h +++ b/include/linux/spi/spi.h @@ -298,6 +298,40 @@ struct spi_driver { struct device_driver driver; }; +enum { + SPI_CAL_READ_DATA = 0, + SPI_CAL_READ_PP = 1, /* only for SPI-NAND */ + SPI_CAL_READ_SFDP = 2, /* only for SPI-NOR */ +}; + +struct nand_addr { + unsigned int lun; + unsigned int plane; + unsigned int eraseblock; + unsigned int page; + unsigned int dataoffs; +}; + +/** + * Read calibration rule from device dts node. + * Once calibration result matches the rule, we regard is as success. + */ +struct spi_cal_rule { + int datalen; + u8 *match_data; + int addrlen; + u32 *addr; + int mode; +}; + +struct spi_cal_target { + u32 *cal_item; + int cal_min; /* min of cal_item */ + int cal_max; /* max of cal_item */ + int step; /* Increase/decrease cal_item */ + struct list_head list; +}; + static inline struct spi_driver *to_spi_driver(struct device_driver *drv) { return drv ? container_of(drv, struct spi_driver, driver) : NULL; @@ -683,6 +717,11 @@ struct spi_controller { void *dummy_rx; void *dummy_tx; + /* For calibration */ + int (*append_caldata)(struct spi_controller *ctlr); + struct list_head *cal_target; + struct spi_cal_rule *cal_rule; + int (*fw_translate_cs)(struct spi_controller *ctlr, unsigned cs); /* @@ -1490,6 +1529,9 @@ spi_register_board_info(struct spi_board { return 0; } #endif +extern int spi_do_calibration(struct spi_controller *ctlr, + struct spi_device *spi, int (*cal_read)(void *, u32 *, int, u8 *, int), void *drv_priv); + /* If you're hotplugging an adapter with devices (parport, usb, etc) * use spi_new_device() to describe each device. You can also call * spi_unregister_device() to start making that device vanish, but