spi: meson-spicc: support max 80MHz clock

The SPICC controller in Meson-AXG is capable of running at 80M clock.
The ASIC IP is improved and the clock is actually running higher than
previous old SoCs.
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
Signed-off-by: Sunny Luo <sunny.luo@amlogic.com>
Link: https://lore.kernel.org/r/20200312133131.26430-5-narmstrong@baylibre.comSigned-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-meson-spicc.c

@@ -35,7 +35,6 @@
  *   to have a CS go down over the full transfer
  */
 
-#define SPICC_MAX_FREQ	30000000
 #define SPICC_MAX_BURST	128
 
 /* Register Map */
@@ -132,6 +131,7 @@
 #define SPICC_FIFO_HALF 10
 
 struct meson_spicc_data {
+	unsigned int			max_speed_hz;
 	bool				has_oen;
 	bool				has_enhance_clk_div;
 };
@@ -693,11 +693,9 @@ static int meson_spicc_probe(struct platform_device *pdev)
 	master->transfer_one = meson_spicc_transfer_one;
 	master->use_gpio_descriptors = true;
 
-	/* Setup max rate according to the Meson GX datasheet */
-	if ((rate >> 2) > SPICC_MAX_FREQ)
-		master->max_speed_hz = SPICC_MAX_FREQ;
-	else
-		master->max_speed_hz = rate >> 2;
+	/* Setup max rate according to the Meson datasheet */
+	master->max_speed_hz = min_t(unsigned int, rate >> 1,
+				     spicc->data->max_speed_hz);
 
 	meson_spicc_oen_enable(spicc);
 
@@ -737,9 +735,11 @@ static int meson_spicc_remove(struct platform_device *pdev)
 }
 
 static const struct meson_spicc_data meson_spicc_gx_data = {
+	.max_speed_hz		= 30000000,
 };
 
 static const struct meson_spicc_data meson_spicc_axg_data = {
+	.max_speed_hz		= 80000000,
 	.has_oen		= true,
 	.has_enhance_clk_div	= true,
 };