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@@ -1,141 +0,0 @@
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-From d8bde59186dafdea5bbe8d29d3a6ae7cac98e9d0 Mon Sep 17 00:00:00 2001
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-From: Weijie Gao <[email protected]>
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-Date: Mon, 25 Jan 2021 11:19:08 +0800
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-Subject: [PATCH 11/21] serial: serial-mtk: rewrite the setbrg function
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-
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-Currently the setbrg logic of serial-mtk is messy, and should be rewritten.
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-Also an option is added to make it possible to use highspeed=3 mode for all
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-bauds.
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-
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-The new logic is:
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-1. If baud clock > 12MHz
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- a) If baud <= 115200, highspeed=0 mode will be used (ns16550 compatible)
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- b) If baud <= 576000, highspeed=2 mode will be used
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- c) any baud > 576000, highspeed=3 mode will be used
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-2. If baud clock <= 12MHz
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- Always uses highspeed=3 mode
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- a) If baud <= 115200, calculates the divisor using DIV_ROUND_CLOSEST
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- b) any baud > 115200, the same as 1. c)
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-
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-Signed-off-by: Weijie Gao <[email protected]>
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----
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- drivers/serial/serial_mtk.c | 74 +++++++++++++++++--------------------
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- 1 file changed, 33 insertions(+), 41 deletions(-)
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-
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---- a/drivers/serial/serial_mtk.c
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-+++ b/drivers/serial/serial_mtk.c
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-@@ -73,74 +73,64 @@ struct mtk_serial_regs {
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- struct mtk_serial_priv {
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- struct mtk_serial_regs __iomem *regs;
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- u32 clock;
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-+ bool force_highspeed;
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- };
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-
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- static void _mtk_serial_setbrg(struct mtk_serial_priv *priv, int baud)
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- {
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-- bool support_clk12m_baud115200;
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-- u32 quot, samplecount, realbaud;
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-+ u32 quot, realbaud, samplecount = 1;
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-
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-- if ((baud <= 115200) && (priv->clock == 12000000))
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-- support_clk12m_baud115200 = true;
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-- else
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-- support_clk12m_baud115200 = false;
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-+ /* Special case for low baud clock */
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-+ if ((baud <= 115200) && (priv->clock == 12000000)) {
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-+ writel(3, &priv->regs->highspeed);
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-+
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-+ quot = DIV_ROUND_CLOSEST(priv->clock, 256 * baud);
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-+ if (quot == 0)
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-+ quot = 1;
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-+
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-+ samplecount = DIV_ROUND_CLOSEST(priv->clock, quot * baud);
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-+
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-+ realbaud = priv->clock / samplecount / quot;
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-+ if ((realbaud > BAUD_ALLOW_MAX(baud)) ||
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-+ (realbaud < BAUD_ALLOW_MIX(baud))) {
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-+ pr_info("baud %d can't be handled\n", baud);
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-+ }
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-+
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-+ goto set_baud;
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-+ }
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-+
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-+ if (priv->force_highspeed)
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-+ goto use_hs3;
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-
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- if (baud <= 115200) {
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- writel(0, &priv->regs->highspeed);
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- quot = DIV_ROUND_CLOSEST(priv->clock, 16 * baud);
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--
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-- if (support_clk12m_baud115200) {
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-- writel(3, &priv->regs->highspeed);
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-- quot = DIV_ROUND_CLOSEST(priv->clock, 256 * baud);
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-- if (quot == 0)
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-- quot = 1;
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--
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-- samplecount = DIV_ROUND_CLOSEST(priv->clock,
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-- quot * baud);
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-- if (samplecount != 0) {
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-- realbaud = priv->clock / samplecount / quot;
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-- if ((realbaud > BAUD_ALLOW_MAX(baud)) ||
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-- (realbaud < BAUD_ALLOW_MIX(baud))) {
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-- pr_info("baud %d can't be handled\n",
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-- baud);
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-- }
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-- } else {
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-- pr_info("samplecount is 0\n");
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-- }
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-- }
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- } else if (baud <= 576000) {
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- writel(2, &priv->regs->highspeed);
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-
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- /* Set to next lower baudrate supported */
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- if ((baud == 500000) || (baud == 576000))
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- baud = 460800;
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-+
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- quot = DIV_ROUND_UP(priv->clock, 4 * baud);
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- } else {
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-+use_hs3:
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- writel(3, &priv->regs->highspeed);
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-+
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- quot = DIV_ROUND_UP(priv->clock, 256 * baud);
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-+ samplecount = DIV_ROUND_CLOSEST(priv->clock, quot * baud);
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- }
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-
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-+set_baud:
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- /* set divisor */
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- writel(UART_LCR_WLS_8 | UART_LCR_DLAB, &priv->regs->lcr);
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- writel(quot & 0xff, &priv->regs->dll);
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- writel((quot >> 8) & 0xff, &priv->regs->dlm);
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- writel(UART_LCR_WLS_8, &priv->regs->lcr);
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-
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-- if (baud > 460800) {
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-- u32 tmp;
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--
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-- tmp = DIV_ROUND_CLOSEST(priv->clock, quot * baud);
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-- writel(tmp - 1, &priv->regs->sample_count);
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-- writel((tmp - 2) >> 1, &priv->regs->sample_point);
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-- } else {
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-- writel(0, &priv->regs->sample_count);
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-- writel(0xff, &priv->regs->sample_point);
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-- }
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--
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-- if (support_clk12m_baud115200) {
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-- writel(samplecount - 1, &priv->regs->sample_count);
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-- writel((samplecount - 2) >> 1, &priv->regs->sample_point);
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-- }
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-+ /* set highspeed mode sample count & point */
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-+ writel(samplecount - 1, &priv->regs->sample_count);
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-+ writel((samplecount - 2) >> 1, &priv->regs->sample_point);
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- }
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-
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- static int _mtk_serial_putc(struct mtk_serial_priv *priv, const char ch)
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-@@ -248,6 +238,8 @@ static int mtk_serial_of_to_plat(struct
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- return -EINVAL;
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- }
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-
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-+ priv->force_highspeed = dev_read_bool(dev, "mediatek,force-highspeed");
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-+
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- return 0;
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- }
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-
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