clk: tegra30: Add CSI pad clock gates

Tegra30 has CSI pad bits in both PLLD and PLLD2 clocks that are required
for the correct work of the CSI block. Add CSI pad A and pad B clock gates
with PLLD/PLLD2 parents, respectively. Add a plld2 spinlock, like one plld
uses, to prevent simultaneous access since both the PLLDx and CSIx_PAD
clocks use the same registers

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
Reviewed-by: Mikko Perttunen <mperttunen@nvidia.com>
Tested-by: Luca Ceresoli <luca.ceresoli@bootlin.com> # tegra20, parallel camera
Signed-off-by: Thierry Reding <treding@nvidia.com>

Author: clamor-s

drivers/clk/tegra/clk-tegra30.c

@@ -154,6 +154,7 @@ static unsigned long input_freq;
 
 static DEFINE_SPINLOCK(cml_lock);
 static DEFINE_SPINLOCK(pll_d_lock);
+static DEFINE_SPINLOCK(pll_d2_lock);
 
 #define TEGRA_INIT_DATA_MUX(_name, _parents, _offset,	\
 			    _clk_num, _gate_flags, _clk_id)	\
@@ -859,7 +860,7 @@ static void __init tegra30_pll_init(void)
 
 	/* PLLD2 */
 	clk = tegra_clk_register_pll("pll_d2", "pll_ref", clk_base, pmc_base, 0,
-			    &pll_d2_params, NULL);
+			    &pll_d2_params, &pll_d2_lock);
 	clks[TEGRA30_CLK_PLL_D2] = clk;
 
 	/* PLLD2_OUT0 */
@@ -1008,6 +1009,16 @@ static void __init tegra30_periph_clk_init(void)
 				    0, 48, periph_clk_enb_refcnt);
 	clks[TEGRA30_CLK_DSIA] = clk;
 
+	/* csia_pad */
+	clk = clk_register_gate(NULL, "csia_pad", "pll_d", CLK_SET_RATE_PARENT,
+				clk_base + PLLD_BASE, 26, 0, &pll_d_lock);
+	clks[TEGRA30_CLK_CSIA_PAD] = clk;
+
+	/* csib_pad */
+	clk = clk_register_gate(NULL, "csib_pad", "pll_d2", CLK_SET_RATE_PARENT,
+				clk_base + PLLD2_BASE, 26, 0, &pll_d2_lock);
+	clks[TEGRA30_CLK_CSIB_PAD] = clk;
+
 	/* csus */
 	clk = tegra_clk_register_periph_gate("csus", "vi_sensor", 0,
 					     clk_base, 0, TEGRA30_CLK_CSUS,