From 6de1b143a45d3c4b8ad277b484e0d14df0d30d63 Mon Sep 17 00:00:00 2001 From: Sakari Ailus Date: Mon, 22 Oct 2012 16:27:27 -0300 Subject: [PATCH] [media] smiapp-pll: Try other pre-pll divisors The smiapp pll calculator assumed that the minimum pre-pll divisor was perfect. That may not always be the case, so let's try the others, too. Typically there are just a few alternatives. Signed-off-by: Sakari Ailus Acked-by: Laurent Pinchart Signed-off-by: Mauro Carvalho Chehab --- drivers/media/i2c/smiapp-pll.c | 131 ++++++++++++++++++--------------- 1 file changed, 73 insertions(+), 58 deletions(-) diff --git a/drivers/media/i2c/smiapp-pll.c b/drivers/media/i2c/smiapp-pll.c index e92dc46e6221..d7e347594e19 100644 --- a/drivers/media/i2c/smiapp-pll.c +++ b/drivers/media/i2c/smiapp-pll.c @@ -58,7 +58,7 @@ static int bounds_check(struct device *dev, uint32_t val, if (val >= min && val <= max) return 0; - dev_warn(dev, "%s out of bounds: %d (%d--%d)\n", str, val, min, max); + dev_dbg(dev, "%s out of bounds: %d (%d--%d)\n", str, val, min, max); return -EINVAL; } @@ -87,14 +87,14 @@ static void print_pll(struct device *dev, struct smiapp_pll *pll) dev_dbg(dev, "vt_pix_clk_freq_hz \t%d\n", pll->vt_pix_clk_freq_hz); } -int smiapp_pll_calculate(struct device *dev, struct smiapp_pll_limits *limits, - struct smiapp_pll *pll) +static int __smiapp_pll_calculate(struct device *dev, + struct smiapp_pll_limits *limits, + struct smiapp_pll *pll, uint32_t mul, + uint32_t div, uint32_t lane_op_clock_ratio) { uint32_t sys_div; uint32_t best_pix_div = INT_MAX >> 1; uint32_t vt_op_binning_div; - uint32_t lane_op_clock_ratio; - uint32_t mul, div; uint32_t more_mul_min, more_mul_max; uint32_t more_mul_factor; uint32_t min_vt_div, max_vt_div, vt_div; @@ -102,54 +102,6 @@ int smiapp_pll_calculate(struct device *dev, struct smiapp_pll_limits *limits, unsigned int i; int rval; - if (pll->flags & SMIAPP_PLL_FLAG_OP_PIX_CLOCK_PER_LANE) - lane_op_clock_ratio = pll->lanes; - else - lane_op_clock_ratio = 1; - dev_dbg(dev, "lane_op_clock_ratio: %d\n", lane_op_clock_ratio); - - dev_dbg(dev, "binning: %dx%d\n", pll->binning_horizontal, - pll->binning_vertical); - - /* CSI transfers 2 bits per clock per lane; thus times 2 */ - pll->pll_op_clk_freq_hz = pll->link_freq * 2 - * (pll->lanes / lane_op_clock_ratio); - - /* Figure out limits for pre-pll divider based on extclk */ - dev_dbg(dev, "min / max pre_pll_clk_div: %d / %d\n", - limits->min_pre_pll_clk_div, limits->max_pre_pll_clk_div); - limits->max_pre_pll_clk_div = - min_t(uint16_t, limits->max_pre_pll_clk_div, - clk_div_even(pll->ext_clk_freq_hz / - limits->min_pll_ip_freq_hz)); - limits->min_pre_pll_clk_div = - max_t(uint16_t, limits->min_pre_pll_clk_div, - clk_div_even_up( - DIV_ROUND_UP(pll->ext_clk_freq_hz, - limits->max_pll_ip_freq_hz))); - dev_dbg(dev, "pre-pll check: min / max pre_pll_clk_div: %d / %d\n", - limits->min_pre_pll_clk_div, limits->max_pre_pll_clk_div); - - i = gcd(pll->pll_op_clk_freq_hz, pll->ext_clk_freq_hz); - mul = div_u64(pll->pll_op_clk_freq_hz, i); - div = pll->ext_clk_freq_hz / i; - dev_dbg(dev, "mul %d / div %d\n", mul, div); - - limits->min_pre_pll_clk_div = - max_t(uint16_t, limits->min_pre_pll_clk_div, - clk_div_even_up( - DIV_ROUND_UP(mul * pll->ext_clk_freq_hz, - limits->max_pll_op_freq_hz))); - dev_dbg(dev, "pll_op check: min / max pre_pll_clk_div: %d / %d\n", - limits->min_pre_pll_clk_div, limits->max_pre_pll_clk_div); - - if (limits->min_pre_pll_clk_div > limits->max_pre_pll_clk_div) { - dev_err(dev, "unable to compute pre_pll divisor\n"); - return -EINVAL; - } - - pll->pre_pll_clk_div = limits->min_pre_pll_clk_div; - /* * Get pre_pll_clk_div so that our pll_op_clk_freq_hz won't be * too high. @@ -193,8 +145,8 @@ int smiapp_pll_calculate(struct device *dev, struct smiapp_pll_limits *limits, more_mul_min); if (more_mul_min > more_mul_max) { - dev_warn(dev, - "unable to compute more_mul_min and more_mul_max\n"); + dev_dbg(dev, + "unable to compute more_mul_min and more_mul_max\n"); return -EINVAL; } @@ -209,7 +161,7 @@ int smiapp_pll_calculate(struct device *dev, struct smiapp_pll_limits *limits, dev_dbg(dev, "final more_mul: %d\n", i); if (i > more_mul_max) { - dev_warn(dev, "final more_mul is bad, max %d\n", more_mul_max); + dev_dbg(dev, "final more_mul is bad, max %d\n", more_mul_max); return -EINVAL; } @@ -354,8 +306,6 @@ int smiapp_pll_calculate(struct device *dev, struct smiapp_pll_limits *limits, pll->pixel_rate_csi = pll->op_pix_clk_freq_hz * lane_op_clock_ratio; - print_pll(dev, pll); - rval = bounds_check(dev, pll->pre_pll_clk_div, limits->min_pre_pll_clk_div, limits->max_pre_pll_clk_div, "pre_pll_clk_div"); @@ -411,6 +361,71 @@ int smiapp_pll_calculate(struct device *dev, struct smiapp_pll_limits *limits, return rval; } + +int smiapp_pll_calculate(struct device *dev, struct smiapp_pll_limits *limits, + struct smiapp_pll *pll) +{ + uint32_t lane_op_clock_ratio; + uint32_t mul, div; + unsigned int i; + int rval = -EINVAL; + + if (pll->flags & SMIAPP_PLL_FLAG_OP_PIX_CLOCK_PER_LANE) + lane_op_clock_ratio = pll->lanes; + else + lane_op_clock_ratio = 1; + dev_dbg(dev, "lane_op_clock_ratio: %d\n", lane_op_clock_ratio); + + dev_dbg(dev, "binning: %dx%d\n", pll->binning_horizontal, + pll->binning_vertical); + + /* CSI transfers 2 bits per clock per lane; thus times 2 */ + pll->pll_op_clk_freq_hz = pll->link_freq * 2 + * (pll->lanes / lane_op_clock_ratio); + + /* Figure out limits for pre-pll divider based on extclk */ + dev_dbg(dev, "min / max pre_pll_clk_div: %d / %d\n", + limits->min_pre_pll_clk_div, limits->max_pre_pll_clk_div); + limits->max_pre_pll_clk_div = + min_t(uint16_t, limits->max_pre_pll_clk_div, + clk_div_even(pll->ext_clk_freq_hz / + limits->min_pll_ip_freq_hz)); + limits->min_pre_pll_clk_div = + max_t(uint16_t, limits->min_pre_pll_clk_div, + clk_div_even_up( + DIV_ROUND_UP(pll->ext_clk_freq_hz, + limits->max_pll_ip_freq_hz))); + dev_dbg(dev, "pre-pll check: min / max pre_pll_clk_div: %d / %d\n", + limits->min_pre_pll_clk_div, limits->max_pre_pll_clk_div); + + i = gcd(pll->pll_op_clk_freq_hz, pll->ext_clk_freq_hz); + mul = div_u64(pll->pll_op_clk_freq_hz, i); + div = pll->ext_clk_freq_hz / i; + dev_dbg(dev, "mul %d / div %d\n", mul, div); + + limits->min_pre_pll_clk_div = + max_t(uint16_t, limits->min_pre_pll_clk_div, + clk_div_even_up( + DIV_ROUND_UP(mul * pll->ext_clk_freq_hz, + limits->max_pll_op_freq_hz))); + dev_dbg(dev, "pll_op check: min / max pre_pll_clk_div: %d / %d\n", + limits->min_pre_pll_clk_div, limits->max_pre_pll_clk_div); + + for (pll->pre_pll_clk_div = limits->min_pre_pll_clk_div; + pll->pre_pll_clk_div <= limits->max_pre_pll_clk_div; + pll->pre_pll_clk_div += 2 - (pll->pre_pll_clk_div & 1)) { + rval = __smiapp_pll_calculate(dev, limits, pll, mul, div, + lane_op_clock_ratio); + if (rval) + continue; + + print_pll(dev, pll); + return 0; + } + + dev_info(dev, "unable to compute pre_pll divisor\n"); + return rval; +} EXPORT_SYMBOL_GPL(smiapp_pll_calculate); MODULE_AUTHOR("Sakari Ailus "); -- 2.30.2