From eb798c641a34ae9cee9fcacfbe5dd40bd7777607 Mon Sep 17 00:00:00 2001 From: Vinit Shenoy Date: Tue, 17 Apr 2012 12:40:13 +0530 Subject: spi/pl022: Fix range checking for bits per word pl022 ssp controller supports word lengths from 4 to 16 (or 32) bits. Currently implemented checks were incorrect. It has following check if (pl022->vendor->max_bpw >= 32) which must be checking for <=. Also error print message is incorrect, that prints "range is from 1 to 16". Fix both these issues. Signed-off-by: Vinit Shenoy Acked-by: Linus Walleij Signed-off-by: Grant Likely --- drivers/spi/spi-pl022.c | 25 +++++++++---------------- 1 file changed, 9 insertions(+), 16 deletions(-) (limited to 'drivers/spi/spi-pl022.c') diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c index 09c925aaf320..1ead49dbebce 100644 --- a/drivers/spi/spi-pl022.c +++ b/drivers/spi/spi-pl022.c @@ -1823,9 +1823,12 @@ static int pl022_setup(struct spi_device *spi) } else chip->cs_control = chip_info->cs_control; - if (bits <= 3) { - /* PL022 doesn't support less than 4-bits */ + /* Check bits per word with vendor specific range */ + if ((bits <= 3) || (bits > pl022->vendor->max_bpw)) { status = -ENOTSUPP; + dev_err(&spi->dev, "illegal data size for this controller!\n"); + dev_err(&spi->dev, "This controller can only handle 4 <= n <= %d bit words\n", + pl022->vendor->max_bpw); goto err_config_params; } else if (bits <= 8) { dev_dbg(&spi->dev, "4 <= n <=8 bits per word\n"); @@ -1838,20 +1841,10 @@ static int pl022_setup(struct spi_device *spi) chip->read = READING_U16; chip->write = WRITING_U16; } else { - if (pl022->vendor->max_bpw >= 32) { - dev_dbg(&spi->dev, "17 <= n <= 32 bits per word\n"); - chip->n_bytes = 4; - chip->read = READING_U32; - chip->write = WRITING_U32; - } else { - dev_err(&spi->dev, - "illegal data size for this controller!\n"); - dev_err(&spi->dev, - "a standard pl022 can only handle " - "1 <= n <= 16 bit words\n"); - status = -ENOTSUPP; - goto err_config_params; - } + dev_dbg(&spi->dev, "17 <= n <= 32 bits per word\n"); + chip->n_bytes = 4; + chip->read = READING_U32; + chip->write = WRITING_U32; } /* Now Initialize all register settings required for this chip */ -- cgit v1.2.1 From 5eb806a3a68920a9f373f18b03fa14852047e62b Mon Sep 17 00:00:00 2001 From: Viresh Kumar Date: Thu, 19 Apr 2012 14:44:21 +0530 Subject: spi/pl022: Fix calculate_effective_freq() calculate_effective_freq() was still not optimized and there were cases when it returned without error and with values of cpsr and scr as zero. Also, the variable named found is not used well. This patch targets to optimize and correct this routine. Tested for SPEAr. Signed-off-by: Viresh Kumar Tested-by: Vinit Kamalaksha Shenoy Acked-by: Linus Walleij Signed-off-by: Grant Likely --- drivers/spi/spi-pl022.c | 23 +++++++++++++++++------ 1 file changed, 17 insertions(+), 6 deletions(-) (limited to 'drivers/spi/spi-pl022.c') diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c index 1ead49dbebce..8aa44e7adaef 100644 --- a/drivers/spi/spi-pl022.c +++ b/drivers/spi/spi-pl022.c @@ -1681,26 +1681,37 @@ static int calculate_effective_freq(struct pl022 *pl022, int freq, struct while (scr <= SCR_MAX) { tmp = spi_rate(rate, cpsdvsr, scr); - if (tmp > freq) + if (tmp > freq) { + /* we need lower freq */ scr++; + continue; + } + /* - * If found exact value, update and break. - * If found more closer value, update and continue. + * If found exact value, mark found and break. + * If found more closer value, update and break. */ - else if ((tmp == freq) || (tmp > best_freq)) { + if (tmp > best_freq) { best_freq = tmp; best_cpsdvsr = cpsdvsr; best_scr = scr; if (tmp == freq) - break; + found = 1; } - scr++; + /* + * increased scr will give lower rates, which are not + * required + */ + break; } cpsdvsr += 2; scr = SCR_MIN; } + WARN(!best_freq, "pl022: Matching cpsdvsr and scr not found for %d Hz rate \n", + freq); + clk_freq->cpsdvsr = (u8) (best_cpsdvsr & 0xFF); clk_freq->scr = (u8) (best_scr & 0xFF); dev_dbg(&pl022->adev->dev, -- cgit v1.2.1 From ea505bc99f77f3f9db02bb965bd59ac5db063f60 Mon Sep 17 00:00:00 2001 From: Viresh Kumar Date: Thu, 19 Apr 2012 11:48:15 +0530 Subject: spi/pl022: Allow request for higher frequency than maximum possible Currently, if we request for frequency greater than maximum possible, spi driver returns error. For example, if the spi block src frequency is 333/4 MHz, i.e. 83.33.. MHz, maximum frequency programmable would be src/2. Which would come around 41.6... It is difficult to pass frequency in these figures. We normally try to program in round figures, like 42 MHz and it should get programmed to <= requested_frequency, i.e. 41.6... For this to happen, we must not return error even if requested freq is higher than max possible. But should program it to max possible. Reported-by: Vinit Kamalaksha Shenoy Signed-off-by: Viresh Kumar Acked-by: Linus Walleij Signed-off-by: Grant Likely --- drivers/spi/spi-pl022.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) (limited to 'drivers/spi/spi-pl022.c') diff --git a/drivers/spi/spi-pl022.c b/drivers/spi/spi-pl022.c index 8aa44e7adaef..400ae2121a2a 100644 --- a/drivers/spi/spi-pl022.c +++ b/drivers/spi/spi-pl022.c @@ -1667,9 +1667,15 @@ static int calculate_effective_freq(struct pl022 *pl022, int freq, struct /* cpsdvsr = 254 & scr = 255 */ min_tclk = spi_rate(rate, CPSDVR_MAX, SCR_MAX); - if (!((freq <= max_tclk) && (freq >= min_tclk))) { + if (freq > max_tclk) + dev_warn(&pl022->adev->dev, + "Max speed that can be programmed is %d Hz, you requested %d\n", + max_tclk, freq); + + if (freq < min_tclk) { dev_err(&pl022->adev->dev, - "controller data is incorrect: out of range frequency"); + "Requested frequency: %d Hz is less than minimum possible %d Hz\n", + freq, min_tclk); return -EINVAL; } -- cgit v1.2.1