From 2989b45923b96981a3f50be7f64afdf9221c3b17 Mon Sep 17 00:00:00 2001 From: Eugen Hristev Date: Wed, 11 Sep 2019 08:24:28 +0000 Subject: [PATCH] i2c: at91: add support for digital filtering Add new platform data support for digital filtering for i2c. The sama5d4, sama5d2 and sam9x60 support this feature. Signed-off-by: Eugen Hristev Acked-by: Ludovic Desroches Reviewed-by: Peter Rosin Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-at91-core.c | 9 +++++++++ drivers/i2c/busses/i2c-at91-master.c | 9 +++++++++ drivers/i2c/busses/i2c-at91.h | 5 +++++ 3 files changed, 23 insertions(+) diff --git a/drivers/i2c/busses/i2c-at91-core.c b/drivers/i2c/busses/i2c-at91-core.c index caf1846c200c..e96360f5571d 100644 --- a/drivers/i2c/busses/i2c-at91-core.c +++ b/drivers/i2c/busses/i2c-at91-core.c @@ -68,6 +68,7 @@ static struct at91_twi_pdata at91rm9200_config = { .has_unre_flag = true, .has_alt_cmd = false, .has_hold_field = false, + .has_dig_filtr = false, }; static struct at91_twi_pdata at91sam9261_config = { @@ -76,6 +77,7 @@ static struct at91_twi_pdata at91sam9261_config = { .has_unre_flag = false, .has_alt_cmd = false, .has_hold_field = false, + .has_dig_filtr = false, }; static struct at91_twi_pdata at91sam9260_config = { @@ -84,6 +86,7 @@ static struct at91_twi_pdata at91sam9260_config = { .has_unre_flag = false, .has_alt_cmd = false, .has_hold_field = false, + .has_dig_filtr = false, }; static struct at91_twi_pdata at91sam9g20_config = { @@ -92,6 +95,7 @@ static struct at91_twi_pdata at91sam9g20_config = { .has_unre_flag = false, .has_alt_cmd = false, .has_hold_field = false, + .has_dig_filtr = false, }; static struct at91_twi_pdata at91sam9g10_config = { @@ -100,6 +104,7 @@ static struct at91_twi_pdata at91sam9g10_config = { .has_unre_flag = false, .has_alt_cmd = false, .has_hold_field = false, + .has_dig_filtr = false, }; static const struct platform_device_id at91_twi_devtypes[] = { @@ -130,6 +135,7 @@ static struct at91_twi_pdata at91sam9x5_config = { .has_unre_flag = false, .has_alt_cmd = false, .has_hold_field = false, + .has_dig_filtr = false, }; static struct at91_twi_pdata sama5d4_config = { @@ -138,6 +144,7 @@ static struct at91_twi_pdata sama5d4_config = { .has_unre_flag = false, .has_alt_cmd = false, .has_hold_field = true, + .has_dig_filtr = true, }; static struct at91_twi_pdata sama5d2_config = { @@ -146,6 +153,7 @@ static struct at91_twi_pdata sama5d2_config = { .has_unre_flag = true, .has_alt_cmd = true, .has_hold_field = true, + .has_dig_filtr = true, }; static struct at91_twi_pdata sam9x60_config = { @@ -154,6 +162,7 @@ static struct at91_twi_pdata sam9x60_config = { .has_unre_flag = true, .has_alt_cmd = true, .has_hold_field = true, + .has_dig_filtr = true, }; static const struct of_device_id atmel_twi_dt_ids[] = { diff --git a/drivers/i2c/busses/i2c-at91-master.c b/drivers/i2c/busses/i2c-at91-master.c index a3fcc35ffd3b..df80557eabfe 100644 --- a/drivers/i2c/busses/i2c-at91-master.c +++ b/drivers/i2c/busses/i2c-at91-master.c @@ -31,12 +31,18 @@ void at91_init_twi_bus_master(struct at91_twi_dev *dev) { + struct at91_twi_pdata *pdata = dev->pdata; + /* FIFO should be enabled immediately after the software reset */ if (dev->fifo_size) at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_FIFOEN); at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_MSEN); at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_SVDIS); at91_twi_write(dev, AT91_TWI_CWGR, dev->twi_cwgr_reg); + + /* enable digital filter */ + if (pdata->has_dig_filtr && dev->enable_dig_filt) + at91_twi_write(dev, AT91_TWI_FILTR, AT91_TWI_FILTR_FILT); } /* @@ -793,6 +799,9 @@ int at91_twi_probe_master(struct platform_device *pdev, dev_info(dev->dev, "Using FIFO (%u data)\n", dev->fifo_size); } + dev->enable_dig_filt = of_property_read_bool(pdev->dev.of_node, + "i2c-digital-filter"); + at91_calc_twi_clock(dev); dev->adapter.algo = &at91_twi_algorithm; diff --git a/drivers/i2c/busses/i2c-at91.h b/drivers/i2c/busses/i2c-at91.h index 499b506f6128..c75447ec3acd 100644 --- a/drivers/i2c/busses/i2c-at91.h +++ b/drivers/i2c/busses/i2c-at91.h @@ -84,6 +84,9 @@ #define AT91_TWI_ACR_DATAL(len) ((len) & 0xff) #define AT91_TWI_ACR_DIR BIT(8) +#define AT91_TWI_FILTR 0x0044 +#define AT91_TWI_FILTR_FILT BIT(0) + #define AT91_TWI_FMR 0x0050 /* FIFO Mode Register */ #define AT91_TWI_FMR_TXRDYM(mode) (((mode) & 0x3) << 0) #define AT91_TWI_FMR_TXRDYM_MASK (0x3 << 0) @@ -108,6 +111,7 @@ struct at91_twi_pdata { bool has_unre_flag; bool has_alt_cmd; bool has_hold_field; + bool has_dig_filtr; struct at_dma_slave dma_slave; }; @@ -145,6 +149,7 @@ struct at91_twi_dev { unsigned smr; struct i2c_client *slave; #endif + bool enable_dig_filt; }; unsigned at91_twi_read(struct at91_twi_dev *dev, unsigned reg); -- 2.11.0